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   "source": [
    "# Ansible\n",
    "\n",
    "Ansible is a configuration management software.\n",
    "\n",
    "Connects via ssh or docker to a list of inventory machines and executes a series of tasks eventually grouped in playbooks.\n",
    "\n",
    "At first, create an inventory file with all your hosts."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "cd ansible"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "cat inventory"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Now check if you can ping the local host."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "# Check connections versus the local host in the \"course\" group\n",
    "\n",
    "!ansible -i inventory -m ping course"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "# Pinging all hosts gives some errors too, due to missing hosts or no ssh-key exchange\n",
    "!ansible -i inventory -m ping all"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Further on inventories"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    " You can split your servers in many inventory files, like\n",
    "\n",
    " - staging\n",
    " \n",
    "```\n",
    "# staging inventory file\n",
    "# run with\n",
    "# ansible -i staging ...\n",
    " [ws]\n",
    " staging-ws-[0:3]\n",
    " \n",
    " [jboss]\n",
    " staging-boss-[0:6]\n",
    "```\n",
    " \n",
    " - production\n",
    " \n",
    "```\n",
    "# production inventory file\n",
    "# run with\n",
    "# ansible -i production ...\n",
    " [ws]\n",
    " ws-[0:3]\n",
    " \n",
    " [jboss]\n",
    " boss-[0:6]\n",
    "```\n",
    " \n",
    " "
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Playbooks\n",
    "\n",
    "To run a group of tasks with ansible, just:\n",
    "\n",
    "  - create a playbook.yml\n",
    "  - run ansible-playbook -i inventory playbook.yml\n",
    "  \n",
    "\n",
    "A playbook is a list of tasks in yml format, something like\n",
    "\n",
    "```\n",
    "#\n",
    "# playbook.yml\n",
    "#\n",
    "- name: All public traffic is redirected via https\n",
    "  uri:\n",
    "    url: http://{{server_host}}/\n",
    "    validate_certs: false\n",
    "    follow_redirects: none\n",
    "    status_code: 301\n",
    "    \n",
    "- name: This webapp  is served\n",
    "  uri:\n",
    "    url: https://{{server_host}}/webapp-1\n",
    "    validate_certs: false\n",
    "    status_code: 200\n",
    "    HEADER_testflag: test\n",
    "\n",
    "- name: The WS is serverd and requires authentication\n",
    "  uri:\n",
    "    url: https://{{server_host}}/rest/v1/method\n",
    "    validate_certs: false\n",
    "    status_code: 401\n",
    "\n",
    "```\n",
    "\n",
    "In this case, instead of making actual installation|setup tasks, we just created a testsuite validating our deployment. Now we must write another playbook which takes care of deployng the actual machine.\n",
    "\n"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Testing our course environment\n",
    "\n",
    "We can write a playbook to test our course environment."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "!cat python-course-test.yml"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "!ansible-playbook -i inventory python-course-test.yml "
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "As you can see something is missing: this playbook is not going to modify our machine but only test that everything is in place. \n",
    "\n",
    "See ```ansible-playbook --check ``` and ``` --diff ``` for further infos.\n",
    "\n",
    "We can run a setup playbook, conventionally named site.yml.\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "!cat site.yml"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "!ansible-playbook -i inventory site.yml --limit=course  # in this case the --limit does not change anything ;)"
   ]
  }
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