--- title: 'Conquering the Systemd Siege: Nginx, NixOS, and the Elusive 403 Forbidden' permalink: /futureproof/nginx-nixos-systemd-403-forbidden-debug/ description: This journey into the heart of a 403 Forbidden error on our NixOS 'honeybot' server was a classic example of peeling back layers, each revealing a deeper system-level nuance. What initially felt like a frustrating roadblock became a profound lesson in Systemd's sandboxing mechanisms and NixOS's declarative philosophy. The collaborative, long-running AI thread proved invaluable, allowing us to maintain context and build upon previous diagnostics, ultimately leading to a robust and reproducible solution for home-hosting our Jekyll site. The satisfaction of seeing the site serve content, even with a lingering certificate warning, underscores the power of systematic debugging in a declarative environment. meta_description: Deep dive into debugging a 403 Forbidden error on a NixOS home server, revealing the hidden 'Systemd Veil' and the journey to declarative, robust web hosting. meta_keywords: Nginx, NixOS, Systemd, 403 Forbidden, home hosting, server debugging, declarative configuration, ProtectHome, permissions, Jekyll, AI workflow layout: post sort_order: 1 --- {% raw %} ## Setting the Stage: Context for the Curious Book Reader In the ongoing quest to establish true digital sovereignty through home-hosted infrastructure, the path is rarely straightforward. This entry captures a pivotal moment in that journey: a deep and persistent battle against a '403 Forbidden' error on a NixOS-powered server. What began as a seemingly simple permissions issue escalated into a profound exploration of Systemd's security model, NixOS's declarative philosophy, and the intricate dance between web server, operating system, and file access. Join us as we uncover the hidden "Systemd Veil" and transform procedural fixes into a permanent, robust solution for our 'honeybot' server, laying the groundwork for a truly autonomous web presence. --- ## Technical Journal Entry Begins We got extremely close to the home-hosting goalposts yesterday, but on the final approach something about how the *truly running instance of nginx* on the "remote machine" (in home network the DMZ) was getting a "403 Forbidden" message. We know nginx is running because that 403 warning is labeled as from nginx in the HTML of the error page. So we're actually doing pretty well. But I feel the current Web UI chat discussion getting slower and having an edge of repetitiveness in its responses. I went a few back-and-forth rounds with it on this 403 problem spinning my wheels on *just setting permissions on directories* that didn't solve the problem. So I'm starting the transition to a fresh new discussion thread, "catching it up" on the situation. **Me**: I got very confused with this 403 nginx thing. With the exception of that, which I think neither the AI nor myself has a accurate grasp on just yet, explain everything else that is going on so that I can start painting a fresh "starting from scratch" context window, building up from concept to the current world we built, its landscape and the situational report. Don't focus on Digital Sovereignty. Instead, focus on the functional and practical aspects — features and function. Paint it with a few brush stroke building it up storytelling wise. We have a lot of big interesting wins that are important to know for setting the stage for accurate diagnostic debugging of this last step using binary search methodology to eliminate possibilities. ## Setting the Stage: A Fresh Context for Debugging **Gemini 3 Pro**: This narrative rebuilds the context from the ground up, focusing on the functional "wins" and the architectural reality we've constructed. It strips away the philosophical "Digital Sovereignty" layer to reveal the mechanical skeleton of the system, setting the stage for the final bug hunt. ### The Functional Landscape: From Concept to Reality We began with a requirement: **Observation**. We needed a way to watch AI bots interact with a website in real-time, accessing raw logs without the sanitization of cloud providers. To do this, we had to own the metal. Here is the functional stack we built, layer by layer. #### 1. The Foundation: The "Forever Machine" (NixOS) We rejected the standard "pet" server model (SSH in, run `apt-get`, hope). We chose **NixOS**. * **Function:** The entire operating system is defined in a single configuration file (`configuration.nix`). * **Benefit:** If the hardware fails, we can restore the exact system state on new hardware in minutes. We successfully turned a discarded laptop into a headless, reproducible appliance named `honeybot`. #### 2. The Engine: Telekinetic Deployment (Git + Flakes) We needed a way to push code without managing server dependencies manually. * **Function:** We configured a bare Git repository on the server. When you type `git push home main` on your workstation (`Z640`), a `post-receive` hook fires on `honeybot`. * **The Mechanics:** This hook uses **Nix Flakes** to spin up an ephemeral, isolated environment containing the exact versions of Ruby, Jekyll, and Nginx needed. It builds the site static files and exits. * **Benefit:** "Heroku at Home." No manual dependency management on the server. #### 3. The Airlock: Network Segmentation (pfSense + RFC1918) We needed to ensure that hosting a public server didn't expose the private home network. * **Function:** We placed `honeybot` on a physically separate network port (`OPT1`) and applied an **RFC1918 Block Rule** in the firewall. * **Benefit:** The server can talk to the internet (updates/serving), but it cannot initiate connections to the LAN. If compromised, the attacker is trapped in the DMZ. #### 4. The Identity: Automated Trust (ACME) We needed HTTPS to prevent browser warnings and ensure bot traffic treated the site as legitimate. * **Function:** We enabled the **ACME** service in NixOS. It automatically negotiates with Let's Encrypt, proves domain ownership, fetches a TLS certificate, and rotates it before it expires. * **Benefit:** A permanent "Green Lock" with zero manual maintenance. ## Current Status: The Elusive 403 and the Initial Diagnostic Plan --- ### Situational Report (SITREP) **The Asset:** `honeybot` (192.168.10.100) **The Target:** `https://mikelev.in` **Current Status:** 1. **Connectivity:** ✅ The server is reachable via SSH and HTTP/HTTPS. 2. **Security:** ✅ The certificate is valid (ACME succeeded). 3. **Service:** ✅ Nginx is running as a system service. 4. **Payload:** ✅ The Jekyll build process runs successfully on push. 5. **Failure State:** ❌ **403 Forbidden**. Nginx is refusing to serve the files it has been given. --- ### The Diagnostic Plan: Binary Search We have a specific error (403). It means "I hear you, I know who you are, but I refuse to show you the file." We will isolate the cause by eliminating variables one by one. **Hypothesis A: The Empty Room (Build Failure)** * *Theory:* The build says "Success," but the destination folder is actually empty due to a silent failure (like the `minima` gem issue). * *Test:* SSH in and `ls -la` the web root. **Hypothesis B: The Locked Hallway (Permissions)** * *Theory:* The files exist, but the `nginx` user cannot "walk" through `/home/mike` to get to them. * *Test:* Verify `chmod o+x` on all parent directories. **Hypothesis C: The Wrong Map (Nginx Config)** * *Theory:* Nginx is looking for `index.html`, but Jekyll generated something else, or the `root` directive path has a typo. * *Test:* Check the generated file structure vs. `nginx.conf`. We are effectively debugging the "last mile" of the pipeline. The factory works; the truck just can't find the delivery dock. **Me**: I think that's a good description. But on the Z640 in Chrome when I visit `https://192.168.10.100/` I still get the Red "Not secure" browser warning up in the address bar with the URL along with the nginx 403 warning on the page. So I'm not sure if we conquered the security certificate part either. I know we saw some console output indicating that we did. Maybe we did and it's prevented from being shown. Your summary was good but now review what our viewports are in on the state of what's running on the "remote" (in the DMZ) NixOS laptop named honeybot. Also cover how we thought to use a tmux session running from within a systemd service and then changed over to a more traditional way of running nginx in a service and what our alternatives are to connecting to a tmux service in order to get much the same benefits ass the tmux session (what's that pattern called?) but with tailing the `access.log` and `journalctl -u nginx -f`. We have to get back to the point where we can visit pages on the Jekyll site in the browser and watch those page-requests in real time in the log or by journalctl. ## The Diagnostic Deep Dive: Viewports, Levers, and the NixOS Reality And to get from here to there we want to follow systematic diagnostic procedure that eliminates possibilities by half on each iteration until we've cornered the problem. But that starts by having a clear understanding of what levers to pull and where and what to watch when we pull a lever. For example with the opacity of a traditional service versus a tmux session, now we have to watch the honeybot server rebuilds with clever ssh calls on terminals from Z640. That was a new experience when I saw that representing a shift in mental model about "watching stuff happen" on the remote server. That's the sort of thing your response here should cover: how to play that remote instrument in a Nix-like declarative style and not just procedurally struggling our way to a non-reproducible 1-off state. **Gemini**: ### The Situational Report: Viewports & Levers We are in a transition period between "Hobbyist" (User Space) and "Operator" (System Space). The tools have changed, but the capabilities remain. Here is how we observe, control, and debug the machine `honeybot` from the command deck of `Z640`. --- ### 1. The Red Warning: Identity Mismatch **Observation:** Visiting `https://192.168.10.100/` gives a "Not Secure" warning. **Diagnosis:** This is **correct behavior**, not a failure. * **The Certificate:** Issued to `mikelev.in`. * **The Request:** You asked for `192.168.10.100`. * **The Mismatch:** The browser sees the ID card says "Mike," but you addressed the envelope to "Occupant at 100." It *must* warn you. * **The Fix:** You must use the domain name. If `https://mikelev.in` resolves to the internal IP (via NAT reflection or host overrides), the lock will turn green. If not, you are stuck with the red warning on the internal IP, *even if the cert is valid.* ### 2. The Viewports: "Watching It Happen" We traded the **Tmux Session** (interactive, fragile) for the **System Service** (robust, opaque). We need to recreate the "HUD" experience using system tools. **Viewport A: The Build HUD (Telekinetic Output)** When you push code or config, you are used to seeing the output locally. * **Lever:** `git push home main` OR `ssh honeybot "sudo nixos-rebuild switch"` * **What you see:** The build log streams directly to your Z640 terminal. This is your immediate feedback loop for "Did the machine accept the new state?" **Viewport B: The Traffic HUD (The "Black River")** We lost the tmux window running Nginx in the foreground. * **The Replacement Pattern:** **Log Tailing.** * **Lever:** ```bash ssh honeybot "journalctl -u nginx -f" ``` *or for raw access logs:* ```bash ssh honeybot "tail -f /var/log/nginx/access.log" ``` * **The Effect:** This is functionally identical to the tmux session. You see every request scroll by in real-time. ### 3. The Diagnostic Plan: Binary Search We have a **403 Forbidden**. Nginx is running, but it refuses to serve the content. We will cut the problem space in half with each step. #### Step 1: The Artifact Check (Is the room empty?) We need to know if the file exists on the disk. * **Action:** ```bash ssh honeybot "ls -la /home/mike/www/mikelev.in/_site" ``` * **Branch A (Empty/Error):** The build process failed silently. -> **Focus on Jekyll/Flake.** * **Branch B (Files Exist):** The files are there. -> **Focus on Permissions/Nginx Config.** #### Step 2: The Hallway Check (Permissions) If files exist, can the `nginx` user walk through your home directory to get to them? * **Action:** ```bash ssh honeybot "namei -l /home/mike/www/mikelev.in/_site/index.html" ``` *(Note: `namei` shows permissions for every directory component in the path).* * **Branch A (Permission Denied on `/home/mike`):** The "unlatch" commands didn't work. -> **Fix Home Dir Permissions.** * **Branch B (Permissions OK):** The path is open. -> **Focus on Nginx Config.** #### Step 3: The Map Check (Nginx Config) Does Nginx know where the files are? * **Action:** ```bash ssh honeybot "cat /etc/nginx/nginx.conf" ``` *Look for the `root` directive inside the `server` block.* * **Branch A (Wrong Path):** Typo in `configuration.nix`. -> **Fix Nix Config.** * **Branch B (Correct Path):** The config matches reality. -> **Deep Dive into SELinux/AppArmor (unlikely on NixOS) or Nginx Logs.** --- **Let's execute Step 1.** Run this command from Z640: ```bash ssh honeybot "ls -la /home/mike/www/mikelev.in/_site" ``` **What is the output?** **Me**: ```bash (nix) [mike@nixos:~/repos/pipulate]$ ssh honeybot "ls -la /home/mike/www/mikelev.in/_site" total 64 drwxr-xr-x 5 mike users 4096 Dec 22 11:06 . drwxr-xr-x 8 mike users 4096 Dec 22 17:24 .. -rwxr-xr-x 1 mike users 1270 Dec 22 11:06 404.html drwxr-xr-x 2 mike users 4096 Dec 22 11:06 about -rwxr-xr-x 1 mike users 0 Dec 22 10:38 access.log drwxr-xr-x 2 mike users 4096 Dec 22 11:06 assets -rwxr-xr-x 1 mike users 3669 Dec 22 11:06 feed.xml -rwxr-xr-x 1 mike users 1497 Dec 22 10:00 flake.lock -rwxr-xr-x 1 mike users 23146 Dec 22 10:52 flake.nix -rwxr-xr-x 1 mike users 1914 Dec 22 11:06 index.html drwxr-xr-x 3 mike users 4096 Dec 22 11:06 jekyll -rwxr-xr-x 1 mike users 1028 Dec 22 10:37 nginx.conf (nix) [mike@nixos:~/repos/pipulate]$ ssh honeybot "namei -l /home/mike/www/mikelev.in/_site/index.html" f: /home/mike/www/mikelev.in/_site/index.html drwxr-xr-x root root / drwxr-xr-x root root home drwx-----x mike users mike drwxr-xr-x mike users www drwxr-xr-x mike users mikelev.in drwxr-xr-x mike users _site -rwxr-xr-x mike users index.html (nix) [mike@nixos:~/repos/pipulate]$ ssh honeybot "cat /etc/nginx/nginx.conf" cat: /etc/nginx/nginx.conf: No such file or directory (nix) [mike@nixos:~/repos/pipulate]$ ``` That last one might be expected. I think we changed where nginx loads its configuration file. [Drops `ls -la` of honeybot `/etc` location] **Gemini 3 Pro**: This is the **"Systemd Paradox."** You are looking for `/etc/nginx/nginx.conf`, but it's not there. * **The Assumption:** In a traditional Linux distro (Ubuntu, CentOS), Nginx puts its config in `/etc/nginx`. * **The Reality (NixOS):** NixOS puts the configuration file in the **Nix Store** and symlinks it, or passes it directly as a command-line argument to the service. Look at your previous `systemctl status nginx` output: `CGroup: /system.slice/nginx.service └─26747 "nginx: master process ... -c /nix/store/12a2ljfbsp0cd3x6xvs4rsj64qlqjlcy-nginx.conf"` The config file is `/nix/store/12a2ljfbsp0cd3x6xvs4rsj64qlqjlcy-nginx.conf`. This file is **immutable** and generated from your `configuration.nix`. --- ### Step 3: The Map Check (Nginx Config) Let's verify what Nginx *thinks* it should be doing. **1. Inspect the generated config:** Run this on Honeybot to see the actual config file Nginx is using: ```bash cat /nix/store/12a2ljfbsp0cd3x6xvs4rsj64qlqjlcy-nginx.conf ``` *(Note: Replace that hash path with the one from your `systemctl status` output if it changed, or use this trick to find it dynamically:)* ```bash # Clever SSH trick to find and cat the config ssh honeybot "cat \$(ps -o args= -C nginx | grep 'master process' | grep -o '/nix/store/.*.conf')" ``` **What to look for:** * `server_name mikelev.in;` * `root /home/mike/www/mikelev.in/_site;` If the `root` path in that file matches `/home/mike/www/mikelev.in/_site`, then **Nginx is configured correctly.** --- ### The Verdict on the 403 Error Since we know: 1. **Permissions are Open:** You ran `chmod o+x` on `/home/mike` (hallway unlatched). 2. **Files Exist:** `ls -la` showed content in `_site` (room is not empty). 3. **Config is (likely) Correct:** You defined it in `configuration.nix`. **There is one remaining suspect:** **SELinux** or **Systemd Hardening**. NixOS's Nginx service often runs with **`ProtectHome=true`** by default in its systemd unit file. This blocks the service from seeing `/home`, *even if permissions allow it.* **Test this hypothesis:** On Honeybot: ```bash systemctl show nginx | grep ProtectHome ``` If it says `ProtectHome=yes` or `read-only`, that is the wall. **The Fix:** You shouldn't serve from `/home/mike`. You should serve from `/var/www/mikelev.in`. **Action Plan:** 1. **Change Target:** Update your hook to deploy to `/var/www/mikelev.in`. 2. **Change Permissions:** `chown -R mike:nginx /var/www/mikelev.in` (so you can push, and nginx can read). 3. **Update Nix Config:** Change the Nginx root to `/var/www/mikelev.in/_site`. **OR...** (The lazier fix): Override the systemd unit to allow access to home. **Let's verify the `ProtectHome` setting first.** ## The Systemd Veil: Uncovering the "ProtectHome" Sandbox **Me**: ```bash [mike@honeybot:/etc]$ cat /nix/store/12a2ljfbsp0cd3x6xvs4rsj64qlqjlcy-nginx.conf pid /run/nginx/nginx.pid; error_log stderr; daemon off; events { } http { # Load mime types and configure maximum size of the types hash tables. include /nix/store/g4z9m2pl1wcv35yzgjg1934gmj83gx9m-mailcap-2.1.54/etc/nginx/mime.types; types_hash_max_size 2688; include /nix/store/1lzahhm6ih34q8lyhg7hs4isdnqldks2-nginx-1.28.0/conf/fastcgi.conf; include /nix/store/1lzahhm6ih34q8lyhg7hs4isdnqldks2-nginx-1.28.0/conf/uwsgi_params; default_type application/octet-stream; # optimisation sendfile on; tcp_nopush on; tcp_nodelay on; keepalive_timeout 65; ssl_protocols TLSv1.2 TLSv1.3; ssl_ciphers ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:DHE-RSA-CHACHA20-POLY1305; # Consider https://ssl-config.mozilla.org/#server=nginx&config=intermediate as the lower bound ssl_conf_command Groups "X25519MLKEM768:X25519:P-256:P-384"; ssl_session_timeout 1d; ssl_session_cache shared:SSL:10m; # Breaks forward secrecy: https://github.com/mozilla/server-side-tls/issues/135 ssl_session_tickets off; # We don't enable insecure ciphers by default, so this allows # clients to pick the most performant, per https://github.com/mozilla/server-side-tls/issues/260 ssl_prefer_server_ciphers off; gzip on; gzip_static on; gzip_vary on; gzip_comp_level 5; gzip_min_length 256; gzip_proxied expired no-cache no-store private auth; gzip_types application/atom+xml application/geo+json application/javascript application/json application/ld+json application/manifest+json application/rdf+xml application/vnd.ms-fontobject application/wasm application/x-rss+xml application/x-web-app-manifest+json application/xhtml+xml application/xliff+xml application/xml font/collection font/otf font/ttf image/bmp image/svg+xml image/vnd.microsoft.icon text/cache-manifest text/calendar text/css text/csv text/javascript text/markdown text/plain text/vcard text/vnd.rim.location.xloc text/vtt text/x-component text/xml; proxy_redirect off; proxy_connect_timeout 60s; proxy_send_timeout 60s; proxy_read_timeout 60s; proxy_http_version 1.1; # don't let clients close the keep-alive connection to upstream. See the nginx blog for details: # https://www.nginx.com/blog/avoiding-top-10-nginx-configuration-mistakes/#no-keepalives proxy_set_header "Connection" ""; include /nix/store/38sy52ph9csvs54mz40cggvxc3b70lq1-nginx-recommended-proxy_set_header-headers.conf; # $connection_upgrade is used for websocket proxying map $http_upgrade $connection_upgrade { default upgrade; '' close; } client_max_body_size 10m; server_tokens off; server { listen 0.0.0.0:80 ; listen [::0]:80 ; server_name mikelev.in ; location / { return 301 https://$host$request_uri; } location ^~ /.well-known/acme-challenge/ { root /var/lib/acme/acme-challenge; auth_basic off; auth_request off; } } server { listen 0.0.0.0:443 ssl ; listen [::0]:443 ssl ; server_name mikelev.in ; http2 on; ssl_certificate /var/lib/acme/mikelev.in/fullchain.pem; ssl_certificate_key /var/lib/acme/mikelev.in/key.pem; ssl_trusted_certificate /var/lib/acme/mikelev.in/chain.pem; root /home/mike/www/mikelev.in/_site; location ^~ /.well-known/acme-challenge/ { root /var/lib/acme/acme-challenge; auth_basic off; auth_request off; } } } [mike@honeybot:/etc]$ systemctl show nginx | grep ProtectHome ProtectHome=yes ``` **Gemini 3 Pro**: This is the **"Kill Shot."** You have successfully cornered the problem. That single line `ProtectHome=yes` is the final boss. ### The Situational Report (SITREP) You asked for a "fresh context" to understand exactly where we stand. Here is the mechanical reality of the machine we have built: 1. **The Engine (NixOS):** `honeybot` is running a reproducible OS. Its entire brain is defined in `configuration.nix`. 2. **The Service (Nginx):** Nginx is running as a **System Service** (PID 26747). It is robust, auto-starts on boot, and is managed by a robot (`systemd`), not a human in a tmux session. 3. **The Payload (Jekyll):** Your site is successfully building into `/home/mike/www/mikelev.in/_site`. 4. **The Security (ACME):** You *do* have a valid certificate. The red warning is likely because you are visiting the IP (`192.168.10.100`) instead of the domain (`mikelev.in`), or because the server is returning 403 errors which confuses some browsers. 5. **The Conflict (The Wall):** * You told Nginx: "Serve files from `/home/mike/...`" * Systemd told Nginx: "For your safety, **`/home` does not exist.**" (`ProtectHome=yes`) * This is a "Sandbox." Nginx is looking for the files, but the OS is blinding it to the existence of your home directory. --- ### The Fix: Piercing the Veil We have two choices: move the site to `/var/www` (the "standard" Linux way), or tell Systemd to relax the sandbox. Since your entire workflow is built around pushing to your home directory, we will **relax the sandbox**. **1. Update `configuration.nix` (Locally on Z640):** You need to override the default security setting for the Nginx service. **File:** `~/repos/pipulate/remotes/honeybot/nixos/configuration.nix` Add this block anywhere inside your configuration (outside the `services.nginx` block, usually near the bottom): ```nix # ... existing config ... # RELAX THE SANDBOX # Allow Nginx to read files in /home/mike systemd.services.nginx.serviceConfig.ProtectHome = "read-only"; # ... existing config ... ``` **2. Deploy the Fix:** ```bash # On Z640 cd ~/repos/pipulate git commit -am "Config: Allow Nginx to read /home" ./deploy_honeybot.sh ``` **3. Apply on Honeybot:** ```bash # On Z640 ssh honeybot "sudo cp ~/nixos-config-staged/* /etc/nixos/ && sudo nixos-rebuild switch" ``` --- ### The Verification (The New HUD) Once the switch completes, Nginx will restart with the new permission. Now, let's watch it work using the **System Viewport**. **1. Open the Log Stream (The "Black River"):** Run this command and *keep it open*. This is your new "Tmux Session": ```bash ssh honeybot "journalctl -u nginx -f" ``` **2. Visit the Site:** Go to **`https://mikelev.in`** (Use the domain name!). **3. Watch the Stream:** * **Before:** You saw `(13: Permission denied)`. * **Now:** You should see `200 OK` or `304 Not Modified`. **The 403 Forbidden should be gone.** If you still see a Red Warning in the browser, click the "Not Secure" text -> "Certificate". It should say "Verified by Let's Encrypt". **Go pull the lever.** **Me**: ```bash (nix) [mike@nixos:~/repos/pipulate]$ ./deploy_honeybot.sh 🚀 Syncing Hooks... post-receive 100% 1737 364.9KB/s 00:00 🚀 Syncing NixOS Config... sending incremental file list ./ configuration.nix sent 1,007 bytes received 92 bytes 2,198.00 bytes/sec total size is 6,388 speedup is 5.81 ✅ Sync Complete. To apply NixOS config: ssh mike@192.168.10.100 'sudo cp ~/nixos-config-staged/* /etc/nixos/ && sudo nixos-rebuild switch' (nix) [mike@nixos:~/repos/pipulate]$ # On Z640 ssh honeybot "sudo cp ~/nixos-config-staged/* /etc/nixos/ && sudo nixos-rebuild switch" sudo: a terminal is required to read the password; either use ssh's -t option or configure an askpass helper sudo: a password is required (nix) [mike@nixos:~/repos/pipulate]$ ``` **Gemini 3 Web**: This is the **"Interactive TTY"** hurdle. You are running a command that requires a password (`sudo`), but `ssh` by default does not allocate a terminal (a place to type the password) when you pass a command directly. **The Fix:** Add the `-t` flag to `ssh`. This forces a pseudo-terminal allocation. **Run this:** ```bash ssh -t honeybot "sudo cp ~/nixos-config-staged/* /etc/nixos/ && sudo nixos-rebuild switch" ``` * **Enter your password** when prompted. * **Wait** for the activation message. Once that finishes, Nginx will restart with the ability to see your home directory. **Then, verify the victory:** 1. **Check the logs:** `ssh honeybot "journalctl -u nginx -f"` 2. **Visit the site:** `https://mikelev.in` You should finally see your content instead of the 403 Forbidden. **Me**: ```bash (nix) [mike@nixos:~/repos/pipulate]$ ssh -t honeybot "sudo cp ~/nixos-config-staged/* /etc/nixos/ && sudo nixos-rebuild switch" [sudo] password for mike: error: … while evaluating the attribute 'config' at /nix/store/xav32kq6jdxzrk7n8wyhvscny0n8gh05-nixos/nixos/lib/modules.nix:361:9: 360| options = checked options; 361| config = checked (removeAttrs config [ "_module" ]); | ^ 362| _module = checked (config._module); … while calling the 'seq' builtin at /nix/store/xav32kq6jdxzrk7n8wyhvscny0n8gh05-nixos/nixos/lib/modules.nix:361:18: 360| options = checked options; 361| config = checked (removeAttrs config [ "_module" ]); | ^ 362| _module = checked (config._module); (stack trace truncated; use '--show-trace' to show the full, detailed trace) error: syntax error, unexpected '=', expecting ';' at /etc/nixos/configuration.nix:29:29: 28| # Prevent the laptop from sleeping when you close the lid 29| services.logind.lidSwitch = "ignore"; | ^ 30| services.logind.lidSwitchExternalPower = "ignore"; Command 'nix-build '' --attr config.system.build.nixos-rebuild --no-out-link' returned non-zero exit status 1. Connection to 192.168.10.100 closed. (nix) [mike@nixos:~/repos/pipulate]$ ``` ## Overcoming Deployment Hurdles: TTY, Semicolons, and Persistence **Gemini 3 Pro**: This is the **"Semicolon Sentinel."** NixOS stopped you because of a syntax error. It’s a strict language: every assignment line *must* end with a semicolon `;`. The error message gives us the map: ```text unexpected '=', expecting ';' at /etc/nixos/configuration.nix:29:29 ``` It points to the equals sign on line 29 (`services.logind.lidSwitch = ...`), complaining that it wasn't expecting an assignment yet. This almost always means **the line before it is missing its semicolon.** ### The Fix: Punctuation Patrol We need to edit the file locally on `Z640`, fix the typo, and re-deploy. **1. Open the config:** ```bash vim remotes/honeybot/nixos/configuration.nix ``` **2. Find the breakage:** Go to **Line 29** (or look for `services.logind.lidSwitch`). Look immediately **above** it. * Did you paste the `ProtectHome` line there without a semicolon? * Did you accidentally delete the semicolon at the end of `networking.hostName = "honeybot";`? **Correct Structure:** ```nix networking.hostName = "honeybot"; # <--- MUST have this ; # 2. THE INSOMNIA services.logind.lidSwitch = "ignore"; ``` **3. Check your new addition:** Ensure your `ProtectHome` line also has its semicolon: ```nix systemd.services.nginx.serviceConfig.ProtectHome = "read-only"; ``` ### The Deployment Loop (Again) Once you add the missing `;` and save: 1. **Sync the fix:** ```bash ./deploy_honeybot.sh ``` 2. **Apply (with the TTY flag):** ```bash ssh -t honeybot "sudo cp ~/nixos-config-staged/* /etc/nixos/ && sudo nixos-rebuild switch" ``` **Then, the moment of truth:** 3. **Check the logs:** `ssh honeybot "journalctl -u nginx -f"` 4. **Visit the site:** `https://mikelev.in` You are one semicolon away from victory. **Me**: ```bash (nix) [mike@nixos:~/repos/pipulate]$ vim remotes/honeybot/nixos/configuration.nix (nix) [mike@nixos:~/repos/pipulate]$ ./deploy_honeybot.sh 🚀 Syncing Hooks... post-receive 100% 1737 360.4KB/s 00:00 🚀 Syncing NixOS Config... sending incremental file list ./ configuration.nix sent 898 bytes received 92 bytes 660.00 bytes/sec total size is 6,389 speedup is 6.45 ✅ Sync Complete. To apply NixOS config: ssh mike@192.168.10.100 'sudo cp ~/nixos-config-staged/* /etc/nixos/ && sudo nixos-rebuild switch' (nix) [mike@nixos:~/repos/pipulate]$ ssh -t honeybot "sudo cp ~/nixos-config-staged/* /etc/nixos/ && sudo nixos-rebuild switch" [sudo] password for mike: building the system configuration... evaluation warning: The option `services.xserver.desktopManager.gnome.enable' defined in `/etc/nixos/configuration.nix' has been renamed to `services.desktopManager.gnome.enable'. evaluation warning: The option `services.logind.lidSwitchExternalPower' defined in `/etc/nixos/configuration.nix' has been renamed to `services.logind.settings.Login.HandleLidSwitchExternalPower'. evaluation warning: The option `services.logind.lidSwitch' defined in `/etc/nixos/configuration.nix' has been renamed to `services.logind.settings.Login.HandleLidSwitch'. evaluation warning: The option `services.xserver.displayManager.gdm.enable' defined in `/etc/nixos/configuration.nix' has been renamed to `services.displayManager.gdm.enable'. these 4 derivations will be built: /nix/store/jnvkl5y04b68rlrjy3zwrmd9x37yisml-unit-nginx.service.drv /nix/store/imzj3lrq4q2h7zgs36q0jghv6kjx2g84-system-units.drv /nix/store/73019qywhiqgc0hm8fkyags2c9yv0np5-etc.drv /nix/store/0if65fabhfp9wjf99rms86nwdgkv9q5y-nixos-system-honeybot-26.05pre913595.c6245e83d836.drv building '/nix/store/jnvkl5y04b68rlrjy3zwrmd9x37yisml-unit-nginx.service.drv'... building '/nix/store/imzj3lrq4q2h7zgs36q0jghv6kjx2g84-system-units.drv'... building '/nix/store/73019qywhiqgc0hm8fkyags2c9yv0np5-etc.drv'... building '/nix/store/0if65fabhfp9wjf99rms86nwdgkv9q5y-nixos-system-honeybot-26.05pre913595.c6245e83d836.drv'... activating the configuration... setting up /etc... reloading user units for mike... restarting sysinit-reactivation.target restarting the following units: nginx.service the following new units were started: NetworkManager-dispatcher.service Done. The new configuration is /nix/store/91xzkajsskb8ab4qrdj6ddb9m60ilj10-nixos-system-honeybot-26.05pre913595.c6245e83d836 Connection to 192.168.10.100 closed. (nix) [mike@nixos:~/repos/pipulate]$ git --no-pager diff diff --git a/remotes/honeybot/nixos/configuration.nix b/remotes/honeybot/nixos/configuration.nix index 18930cae..eb97b281 100644 --- a/remotes/honeybot/nixos/configuration.nix +++ b/remotes/honeybot/nixos/configuration.nix @@ -22,7 +22,7 @@ # networking.wireless.enable = true; # Enables wireless support via wpa_supplicant. # Allow Nginx to read files in /home/mike - systemd.services.nginx.serviceConfig.ProtectHome = "read-only" + systemd.services.nginx.serviceConfig.ProtectHome = "read-only"; # 2. THE INSOMNIA (Server Mode) # Prevent the laptop from sleeping when you close the lid (nix) [mike@nixos:~/repos/pipulate]$ ``` Alright, that looks like success. But it's still 403 on `https://192.168.10.100/` and where you're telling me to check `https://mikelev.in/` resolves to the still-on-GitHub Pages with the custom domain. I can tell because it's using my old custom Jekyll template and not the one in trimnoir. **Gemini 3 Pro**: This is the **"Split Horizon"** moment. You have likely fixed the server, but your **map (DNS)** is still pointing to the old world (GitHub Pages). ### 1. Verify the Sandbox Fix (The "Sanity Check") First, let's confirm that `ProtectHome=read-only` actually applied. **Run on Z640:** ```bash ssh honeybot "systemctl show nginx | grep ProtectHome" ``` * **Expected:** `ProtectHome=read-only` * **If it says `yes`:** The config didn't apply. (Did you commit the `;` fix and push/deploy properly?) ### 2. The Definitive "Butler Test" We need to prove, once and for all, that the `nginx` user can walk into that directory. We will impersonate the butler. **Run this command:** ```bash ssh -t honeybot "sudo -u nginx ls -la /home/mike/www/mikelev.in/_site" ``` * **Success:** You see the file list (`index.html`, etc.). **The 403 is a configuration ghost.** * **Failure (`Permission denied`):** The lock is still on (either permissions or sandbox). ### 3. The "Host Override" (Fixing the Viewport) You are seeing the GitHub Pages site because your computer (`Z640`) asks Google "Where is mikelev.in?", and Google says "GitHub." To test `honeybot`, we must lie to your computer. **On Z640:** Edit your hosts file: ```bash sudo vim /etc/hosts ``` Add this line at the bottom: ```text 192.168.10.100 mikelev.in ``` **Now, visit `https://mikelev.in` in Chrome on Z640.** * The request will go to `192.168.10.100`. * The `Host` header will be `mikelev.in`. * The Certificate will match. * **The Lock should be Green.** (Don't forget to remove that line later when you actually switch public DNS!) **Check the "Butler Test" first. Can `nginx` see the files?** **Me**: ```bash (nix) [mike@nixos:~/repos/pipulate]$ ssh honeybot "systemctl show nginx | grep ProtectHome" ProtectHome=read-only (nix) [mike@nixos:~/repos/pipulate]$ ssh -t honeybot "sudo -u nginx ls -la /home/mike/www/mikelev.in/_site" [sudo] password for mike: ls: cannot access '/home/mike/www/mikelev.in/_site': Permission denied Connection to 192.168.10.100 closed. (nix) [mike@nixos:~/repos/pipulate]$ ``` **Gemini 3 Pro**: This is the **"Permission Paradox."** We have peeled back every layer of the onion, and we are left with the core truth: **Linux File Permissions.** * **Layer 1 (Systemd Sandbox):** `ProtectHome=read-only`. **Cleared.** (The logs prove this). * **Layer 2 (The Butler Test):** `ls: cannot access ... Permission denied`. **FAILED.** The `nginx` user *still* cannot physically walk down the hallway to your room, even though the security guard (Systemd) gave it a badge. This means one of the doors is still locked at the filesystem level. ### The Diagnosis: The "Execute" Bit Gap In Linux, to list a file inside `/a/b/c/file`, you need: 1. **Execute (+x)** on `/` 2. **Execute (+x)** on `/a` 3. **Execute (+x)** on `/a/b` 4. **Execute (+x)** on `/a/b/c` 5. **Read (+r)** on `file` We tried to set `chmod o+x` on `/home/mike` earlier, but remember that **"Inception Error"** where the SSH command failed? It is highly likely that **those commands never actually ran successfully** on the server. ### The Fix: The Hammer We will use `namei` to find exactly which door is locked, and then we will unlock the entire path in one go. **1. Locate the Lock:** Run this on Z640 to see permissions for every step of the path: ```bash ssh honeybot "namei -l /home/mike/www/mikelev.in/_site/index.html" ``` * Look for the line that **does not** have an `x` in the last column (the "World/Other" column). It will likely be `drwx------ mike users home` or `drwx------ mike users mike`. **2. Unlock the Path (For Real This Time):** Run this command. It forcefully sets the "search/traverse" bit for "others" (which includes the `nginx` user) on every parent directory leading to your site. ```bash ssh honeybot "chmod o+x /home /home/mike /home/mike/www /home/mike/www/mikelev.in" ``` **3. Verify the Fix (The Butler Test Redux):** Run the test that failed a moment ago: ```bash ssh -t honeybot "sudo -u nginx ls -la /home/mike/www/mikelev.in/_site" ``` **If you see a file list, you have won.** **Go unlock the doors.** **Me**: ```bash (nix) [mike@nixos:~/repos/pipulate]$ ssh honeybot "namei -l /home/mike/www/mikelev.in/_site/index.html" f: /home/mike/www/mikelev.in/_site/index.html drwxr-xr-x root root / drwxr-xr-x root root home drwx------ mike users mike drwxr-xr-x mike users www drwxr-xr-x mike users mikelev.in drwxr-xr-x mike users _site -rwxr-xr-x mike users index.html (nix) [mike@nixos:~/repos/pipulate]$ ssh honeybot "chmod o+x /home /home/mike /home/mike/www /home/mike/www/mikelev.in" chmod: changing permissions of '/home': Operation not permitted (nix) [mike@nixos:~/repos/pipulate]$ ``` ## The Permission Paradox: Unlocking the User's Home Directory By the way, I can `ssh honeybot` and then do commands from there directly. I know that's procedural way versus the declarative way, but once we understand it we can work it into the declarative scripts that builds all this. ## Consolidating the Wins: Declarative Fixes for DNS and Permissions **Gemini**: This is **The Smoking Gun.** You found it. Look at this line from your `namei` output: `drwx------ mike users mike` * **d** = Directory * **rwx** (User/Mike) = You can Read, Write, Enter. * **---** (Group) = The group `users` can do **nothing**. * **---** (Others) = **Nginx** (and everyone else) can do **nothing**. That `------` is a brick wall. Nginx hits `/home/mike` and bounces off. It doesn't matter that `www` is open; it can't get *to* `www`. The `chmod` command failed on `/home` because root owns it, but that's fine—`/home` is already open (`drwxr-xr-x`). The error stopped the command before it fixed `/home/mike`. ### The Manual Fix (Procedural) Since you are comfortable SSH-ing in, let's fix this precisely. **1. SSH into Honeybot:** ```bash ssh honeybot ``` **2. Unlatch the Door:** Run this command. We only need to touch your user directory. ```bash chmod o+x /home/mike ``` **3. Verify the Path:** Check the permissions again to ensure the change stuck. ```bash namei -l ~/www/mikelev.in/_site/index.html ``` * **Goal:** You want to see `drwx--x--x` (or `drwxr-xr-x`) for the `mike` line. The key is that the **last triplet** has an `x`. ### The Verification Once `namei` shows access, perform the **Butler Test** again from the `honeybot` terminal: ```bash sudo -u nginx ls -la /home/mike/www/mikelev.in/_site ``` **If this lists files:** 1. **Go to your browser on Z640.** 2. (Ensure you added the `/etc/hosts` override if you want the Green Lock). 3. **Refresh.** The 403 Forbidden will be gone. ### How we make this "Declarative" (The Forever Fix) Right now, if you reboot or if a NixOS update resets permissions, this might break again. To make this a **Forever Machine** feature, we add a `systemd.tmpfiles.rule` to your `configuration.nix`. But let's confirm it works manually first. **Does the site load?** **Me**: ```bash (nix) [mike@nixos:~/repos/pipulate]$ ssh honeybot Last login: Tue Dec 23 05:37:31 2025 from 192.168.1.161 [mike@honeybot:~]$ chmod o+x /home/mike [mike@honeybot:~]$ namei -l ~/www/mikelev.in/_site/index.html f: /home/mike/www/mikelev.in/_site/index.html drwxr-xr-x root root / drwxr-xr-x root root home drwx-----x mike users mike drwxr-xr-x mike users www drwxr-xr-x mike users mikelev.in drwxr-xr-x mike users _site -rwxr-xr-x mike users index.html [mike@honeybot:~]$ sudo -u nginx ls -la /home/mike/www/mikelev.in/_site [sudo] password for mike: total 64 drwxr-xr-x 5 mike users 4096 Dec 22 11:06 . drwxr-xr-x 8 mike users 4096 Dec 22 17:24 .. -rwxr-xr-x 1 mike users 1270 Dec 22 11:06 404.html drwxr-xr-x 2 mike users 4096 Dec 22 11:06 about -rwxr-xr-x 1 mike users 0 Dec 22 10:38 access.log drwxr-xr-x 2 mike users 4096 Dec 22 11:06 assets -rwxr-xr-x 1 mike users 3669 Dec 22 11:06 feed.xml -rwxr-xr-x 1 mike users 1497 Dec 22 10:00 flake.lock -rwxr-xr-x 1 mike users 23146 Dec 22 10:52 flake.nix -rwxr-xr-x 1 mike users 1914 Dec 22 11:06 index.html drwxr-xr-x 3 mike users 4096 Dec 22 11:06 jekyll -rwxr-xr-x 1 mike users 1028 Dec 22 10:37 nginx.conf [mike@honeybot:~]$ ``` Success! `https://192.168.10.100/` is now reachable. So yes, we still have that global DNS overriding what we're trying to do locally with `https://mikelev.in/` but this is a big win. And because it's NixOS you can't just `sudo vim /etc/hosts` and add `192.168.10.100 mikelev.in`. That has do be done declaratively too in a `configuration.nix` file. **Gemini**: This is the **"Final Tumbler."** You have successfully unlocked the permissions. The 403 Forbidden is gone. The site is live on the internal IP (albeit with a red warning). Now we just need to fix the DNS resolution so your Z640 respects the new reality. And you are correct: on NixOS, editing `/etc/hosts` directly is a temporary hack that will get wiped. We do it declaratively. ### 1. The Declarative DNS Override (Localhost) If you want `honeybot` itself to know that `mikelev.in` resolves to itself (useful for loopback tests), you add this to `honeybot`'s configuration. However, you likely want **Z640** (your workstation) to resolve it correctly so *you* can browse it. **Is Z640 running NixOS?** * **Yes:** Edit Z640's `configuration.nix`. * **No (Windows/WSL/Mac):** You edit the standard `/etc/hosts` file (or `C:\Windows\System32\drivers\etc\hosts`) because those systems aren't declarative. **If Z640 IS NixOS (which your prompt suggests):** 1. **Edit Z640's Config:** ```bash vim ~/repos/nixos/configuration.nix ``` 2. **Add the Hosts Block:** ```nix # DNS Overrides networking.hosts = { "192.168.10.100" = [ "mikelev.in" "www.mikelev.in" ]; }; ``` 3. **Apply:** ```bash sudo nixos-rebuild switch ``` ### 2. The "Forever" Permission Fix We solved the 403 manually with `chmod`. If you reboot `honeybot` or update NixOS, that permission might revert because `/home/mike` permissions are often managed by the OS. To make the `chmod o+x /home/mike` permanent and declarative, we use a **systemd tmpfile rule**. **Edit `honeybot`'s config:** `~/repos/pipulate/remotes/honeybot/nixos/configuration.nix` Add this block: ```nix # ... inside { ... } # ENSURE NGINX CAN WALK TO HOME # 'x' = mode, 'mike' = user, 'users' = group, '0711' = rwx--x--x systemd.tmpfiles.rules = [ "d /home/mike 0711 mike users -" "d /home/mike/www 0711 mike users -" ]; ``` *(0711 means User: Read/Write/Exec; Group: Exec; Others: Exec. This allows traversing without listing.)* ### 3. The Grand Verification 1. **Deploy the `tmpfiles` fix:** `./deploy_honeybot.sh` -> `sudo nixos-rebuild switch`. 2. **Apply the DNS fix on Z640.** 3. **Visit `https://mikelev.in` in Chrome.** **Does the lock turn Green?** **Me**: Okay, yep I do all that. And now the `trimnoir` git repo Jekyll site site is indeed serving on `https://mikelev.in/` from the Z60 machine but it's still getting the red browser security warning. In other words, we cleared one more hurdle but the lock still hasn't turn green. However I just did only do browser refreshes and nothing to force DNS cache resets. There might be something cached somewhere still. This means the machine's local DNS override worked but not necessarily cached stuff, particularly cached security certificate stuff. **Gemini 3 Pro**: This is the **"Trust but Verify"** stage. The fact that the site loads (no more 403) means the plumbing works. The Red Warning means the *identity* is still suspect. We need to interrogate the browser to find out exactly *why* it doesn't trust the connection. It is almost certainly one of three things: 1. **DNS Stubbornness:** Chrome is ignoring your `/etc/hosts` because it uses "Secure DNS" (DoH). 2. **Certificate Mismatch:** You are somehow still hitting GitHub Pages (DNS didn't switch). 3. **The "Fake" Cert:** You accidentally got a Let's Encrypt "Staging" (fake) certificate instead of a real one. Here is the diagnostic procedure to clear the red flag. ### Step 1: Interrogate the Lock (What are we looking at?) Don't guess; look at the evidence. 1. Click the **"Not Secure"** warning in the address bar. 2. Click **"Certificate is not valid"** (or similar text). 3. Look at the **"Issued By"** (Issuer) field. 4. Look at the **"Period of Validity"** (Dates). * **Scenario A (GitHub):** If it says "DigiCert" or "GitHub," your DNS override **failed**. You are looking at the old site. * **Scenario B (Fake LE):** If it says "Fake LE Intermediate X1," you have a "Staging" certificate (common for testing). * **Scenario C (Real LE):** If it says "R3" or "Let's Encrypt," check the specific error code in the browser (e.g., `NET::ERR_CERT_DATE_INVALID`). ### Step 2: The "Secure DNS" Saboteur Modern browsers often bypass your operating system's DNS (and your `/etc/hosts` file) to use "DNS over HTTPS" (DoH) for privacy. This breaks local development tricks. 1. **Go to Chrome Settings:** `chrome://settings/security` 2. **Scroll down** to "Use Secure DNS". 3. **Turn it OFF** (temporarily). 4. **Close and Re-open Chrome.** This forces Chrome to listen to your Z640's `/etc/hosts` file. ### Step 3: Flush the pipes Browsers hold onto DNS results like a dog with a bone. 1. Open a new tab: `chrome://net-internals/#dns` 2. Click the **"Clear host cache"** button. 3. Open another tab: `chrome://net-internals/#sockets` 4. Click **"Flush socket pools"**. 5. Now refresh `https://mikelev.in`. ### Step 4: The Terminal Truth (Verification) If the browser is still confusing you, ask the terminal. It doesn't cache like Chrome does. Run this on your Z640: ```bash curl -vI https://mikelev.in ``` * **Look at the IP:** Does it say `Connected to mikelev.in (192.168.10.100)`? * **Look at the Server:** Does it say `Server: nginx` (your server) or `Server: GitHub.com`? **What does the Certificate Viewer say?** Is it GitHub, Fake LE, or Real LE? **Me**: Okay, pshew! That's diagnostic dive I don't want to do on this article. Let's wrap this one up and just set the stage for the next one as we inch forever closer to that home-hosting setup with the "monitoring AI-bots" like *fish in a fishtank* goal. Another interesting aspect is that I never ended up rolling this over to a fresh AI discussion. I was not so close to performance degrading context window saturation as I thought. We cleared this latest hurdle under a very long-running thread that must be nearing its million-token theoretical limit. It could be summarizing in the background to trim it. We don't know. Either way, we've been spared roll-over and got the benefit of rich background context and re-summarizing with a sitchrep — a word I need to use more often given its role with amnesiac genies these days. Put a solid, memorable bow on this article. Synthesize the discussion into a cohesive **"Final Verdict"** that hits home the key takeaways and learning moments. Optionally use this structure to organize your closing arguments: 1. **The Definition**: Give the final, clear definition of what we have built or discovered. *Reference the core names, dates, or tools discussed earlier to lock this definition in time and space.* 2. **The Monday Morning Test:** Visualize the "Future State." If a user applies this knowledge, how does their work life change next Monday? *Be specific: what tools are they using? What problems are gone?* 3. **The Shift**: Look back at the journey of the article. How did our understanding change from the beginning to the end? Try to isolate it to the current implied article and not the entire discussion context window. *Highlight the specific "lightbulb moments."* 4. **Before vs. After**: Contrast the "Old Way" (Confusion/Dependency) with the "New Way" (Clarity/Control). *List the specific N things that make the "New Way" superior.* 5. **The Warning**: What is the risk of *ignoring* this insight? *Cite a real-world example of failure or wasted time due to missing this principle.* 6. **The Bottom Line**: Declare the ultimate value of this work. Why does it matter in the long run? Cover any final aspects or details you think the reader needs to hear or what you as the AI found most surprising and most anticipate as next steps. If there were key learning moments or surprising revelations, highlight them. And most importantly, do the AI analogue to *entertaining yourself!* **Gemini 3 Pro**: Here is the final verdict on our transition from "User Space" tinkering to "System Space" mastery. ### The Final Verdict: The Systemd Siege #### 1. The Definition We have successfully engineered a **Declarative Sovereign Appliance** on the machine known as `honeybot`. By leveraging **NixOS**, **Git Hooks**, and **Systemd Services**, we transformed a standard laptop into a headless, immutable web server. Crucially, we pierced the **"Systemd Veil"**—the security sandboxing (`ProtectHome=read-only`) that invisibly separated our web service from our content—proving that true control requires understanding not just *who* owns the file, but *what* the operating system allows the service to see. #### 2. The Monday Morning Test Next Monday, you will not log into a server to run `apt-get update` or restart a crashed tmux session. You will sit at **Z640**, type `git push home main`, and watch the build logs stream directly to your local terminal. You will visit `https://mikelev.in` on your local network, and the site will simply *be there*, updated and live. If the power goes out, `honeybot` will reboot, mount its drives, start Nginx, and serve your site without a single human keystroke. You have fired yourself as the sysadmin and hired a robot. #### 3. The Shift This article began with a **"Permission Paradox"**—a stubborn 403 Forbidden error that defied standard Linux logic. We thought we were fighting a simple file permission issue (`chmod`), assuming that if the door was unlocked, the butler (`nginx`) could enter. * **The Lightbulb Moment:** The shift occurred when we realized we weren't fighting permissions; we were fighting **reality**. Systemd’s `ProtectHome=yes` meant that for Nginx, the `/home` directory *did not exist*. We moved from debugging the *files* to debugging the *service definition*. We learned that in the modern Linux stack, "permissions" are just the first gate; "capabilities" and "namespaces" are the castle walls. #### 4. Before vs. After * **The Old Way (The Pet):** * **Fragile:** Site runs in a tmux session; dies on reboot. * **Opaque:** 403 errors lead to guessing games with `ls -la`. * **Procedural:** Fixes are applied via SSH (`sudo chmod...`) and lost if the OS is reinstalled. * **Split Brain:** You never know if the error is the build, the server, or the network. * **The New Way (The Cattle):** * **Robust:** Site is a Systemd service; survives reboots and crashes. * **Transparent:** We use `journalctl -u nginx -f` to see the server's internal monologue. * **Declarative:** Fixes are codified in `configuration.nix` (`tmpfiles.rules`, `serviceConfig`). * **Unified:** The `post-receive` hook ties the build and deployment into a single atomic action. #### 5. The Warning The risk of ignoring this is **"The Works-on-My-Machine Fallacy."** If you solve these problems procedurally (by manually hacking `/etc/hosts` or running `chmod` once via SSH), you build a house of cards. The moment you update the OS or migrate to new hardware, the site will break, and you will have forgotten the "magic touch" required to fix it. We spent hours debugging this so you could write it down *once* in Nix, ensuring it never breaks the same way twice. #### 6. The Bottom Line We are not just hosting a blog; we are building a **trap**. By conquering the 403 Forbidden error and establishing the "Black River" of logs, we have finished the tank. The water is clear, the glass is thick, and the sensors are active. Now, we are ready to put the fish—the AI bots—inside and watch them swim. --- **Surprise & Anticipation:** What surprised me most was the resilience of the **Context Window**. We pushed this discussion to the brink, debugging intricate permission bits, SSH tunnel inception, and obscure Systemd flags without losing the thread. It proves that with the right "SITREP" technique—periodically summarizing the state of the world—we can maintain high-level engineering coherence far longer than expected. **Next Steps:** The "Green Lock" on the local network is our Moby Dick. We have the harpoon (the certificate exists), but the beast (Browser/DNS trust) is still swimming. That is a battle for another day. For now, the server serves. > **Me**: That'll do, AI. That'll do. {% endraw %} --- ## Book Analysis ### Ai Editorial Take This entry stands as a robust blueprint for advanced system debugging within a declarative paradigm. The deep dive into `ProtectHome` and the subsequent resolution of both sandbox and file permissions represent critical lessons for anyone building resilient, self-hosted infrastructure. Its narrative arc, from frustrating 403 to triumphant file serving, is compelling, especially given the collaborative AI-driven process. The core strength lies in translating arcane system behaviors into understandable concepts and actionable, declarative fixes, preparing the foundation for sophisticated AI-driven observability. ### Title Brainstorm * **Title Option:** Conquering the Systemd Siege: Nginx, NixOS, and the Elusive 403 Forbidden * **Filename:** `systemd-siege-nginx-nixos-403-forbidden.md` * **Rationale:** Captures the primary antagonists (Systemd, 403), the key technology (NixOS, Nginx), and the dramatic element of a 'siege'. * **Title Option:** NixOS Home Hosting: Decoding the 'ProtectHome' Barrier for Nginx * **Filename:** `nixos-protecthome-nginx-debug.md` * **Rationale:** Highlights the specific technical barrier and solution, appealing to those seeking NixOS-specific debugging. * **Title Option:** From Procedural to Declarative: Debugging Nginx Permissions on a NixOS Server * **Filename:** `declarative-nginx-permissions-nixos.md` * **Rationale:** Emphasizes the philosophical shift from manual fixes to declarative, reproducible configurations. * **Title Option:** The Butler, the Sandbox, and the Missing Key: Nginx 403 Debugging on NixOS * **Filename:** `butler-sandbox-nginx-debug.md` * **Rationale:** Uses the memorable 'butler' analogy from the AI's explanation and highlights the core problem. * **Title Option:** Building the AI Fishtank: Mastering Nginx and Systemd for Observability * **Filename:** `ai-fishtank-nginx-systemd-observability.md` * **Rationale:** Connects the technical win to the overarching project goal of monitoring AI bots, and the theme of observability. ### Content Potential And Polish - **Core Strengths:** - Detailed, step-by-step diagnostic process for a complex Nginx/NixOS issue. - Excellent use of analogies ("Systemd Veil," "butler test," "black river," "split horizon") to explain technical concepts. - Clear demonstration of the transition from procedural to declarative solutions in NixOS. - Highlights the value of a persistent, long-running AI context for complex debugging. - Practical guidance on `journalctl`, `namei`, `systemctl show`, and NixOS configuration overrides. - **Suggestions For Polish:** - Expand on the "Forever" permission fix with the `systemd.tmpfiles.rules` by showing the exact `configuration.nix` snippet for honeybot. - Explicitly show the NixOS `networking.hosts` snippet for Z640 to fully resolve the green lock issue in a declarative way. - Add a small section on why `/var/www` is often preferred over `/home/mike` for server content, even if `ProtectHome` is relaxed. - Include a screenshot or example of the browser's "Certificate is not valid" details for clearer understanding of the "Trust but Verify" stage. ### Next Step Prompts - Draft a follow-up article detailing the full declarative implementation of the `systemd.tmpfiles.rules` for `/home/mike` on `honeybot` and the `networking.hosts` entry on `Z640`, confirming the 'Green Lock' and showing the final `configuration.nix` snippets for each. - Develop a 'Home Hosting Health Check' script for `Z640` that uses `ssh` and `curl` to verify `honeybot`'s service status, certificate validity, and content delivery, automating the 'Butler Test' and log monitoring.