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menu: workshop
title: Validated Patterns
weight: 50
---

:toc:
include::modules/comm-attributes.adoc[]
:imagesdir: /images/workshop

== Consuming Validated Patterns
[#workflow]

Let's dive into what happens when we deploy a pattern! Take a look at the following graphic to see what is deployed on the `hub` clusterGroup cluster.

image::consuming-vpWorkflow-hub.png[Hub Cluster]

1. The patterns operator deploys an instance of {rh-gitops} and creates the initial application
2. ArgoCD then deploys the operators, namespaces, projects and applications defined in the values files
3. If deploying across multiple clusters, the framework uses {rhacm} policies to create the instance of {rh-gitops} on the remote cluster

NOTE: `values-hub.yaml` is the primary values file for the `hub` cluster

image::consuming-vpWorkflow-managedCluster.png[Managed Cluster]

1. When a managed cluster is joined to {rhacm} it needs to have a clusterGroup label applied to it for the correct policies and applications to be deployed.
2. {rhacm} will confirm the cluster is managed then deploy a rhacm agent
3. A placement policy is then deployed to the managed cluster which installs an instances of {rh-gitops}
4. The managed cluster's instance of ArgoCD will then deploy the resources declared in `values-clustergroup.yaml`

IMPORTANT: Deploying the pattern through the OpenShift Console or via `pattern.sh` will deploy the patterns operator.

== Element Layering
[#layering]

Architecturally, Patterns share a very similar base structure, as seen below.

image::consuming-common.png[common]

Your specific industry or use-case is layered into the framework and utilizes the underlying base structure. In this example, the solution includes a bespoke application, cloud-native cluster storage, {rhacs}, and an enterprise container registry. The framework will deploy and configure these components through Helm charts, Kustomize manifests or Ansible if necessary.

image::consuming-common-solution-layering.png[]

What if we wanted to swap these products out with a similar or like-in-kind solution? The workflow remains the same:

- remove the undesired application declaration
- declare the new application in your values file
- declare where the helm charts reside (path, repo)

The following graphic illustrates swapping components in the framework:

image::consuming-common-solution-layering-modular.png[]

== The Base Architecture
[#skeleton]

So where exactly are these different architectural components defined?

=== GitOps

link:https://github.com/validatedpatterns/patterns-operator[The {validated-patterns-op}] automatically deploys an instance of {rh-gitops-short} when a Pattern CR is installed on the cluster.

Check out an example Pattern CR for an {mcg-pattern} installation:

[source,yaml]
----
apiVersion: gitops.hybrid-cloud-patterns.io/v1alpha1
kind: Pattern
metadata:
  name: multicloud-gitops
  namespace: openshift-operators
spec:
  clusterGroupName: hub
  gitSpec:
    targetRepo: https://github.com/validatedpatterns/multicloud-gitops.git
    targetRevision: main
----

When the {validated-patterns-op} reconciles this CR, it creates an Argo Application using link:https://github.com/validatedpatterns/clustergroup-chart[the Validated Patterns Clustergroup Chart] and link:https://github.com/validatedpatterns/multicloud-gitops/blob/main/values-hub.yaml[the values-`<.spec.clusterGroupName>`.yaml values] from the CR above.

=== Secrets Management

The default secrets backend uses link:https://charts.validatedpatterns.io/charts/hashicorp-vault[Vault] and link:https://charts.validatedpatterns.io/charts/openshift-external-secrets[ESO].

As you can see in our link:https://github.com/validatedpatterns/multicloud-gitops/blob/main/values-hub.yaml[values-hub.yaml], we provide a namespace, subscription and an application for both of these components.

When we run `./pattern.sh make install` it ultimately calls link:https://github.com/validatedpatterns/rhvp.cluster_utils/blob/main/playbooks/load_secrets.yml[the rhvp.cluster_utils.load_secrets playbook] and loads a secrets file from our home directory into Vault as part of the pattern installation process.

=== ACM

Similar to the secrets management, link:https://charts.validatedpatterns.io/charts/acm[ACM] is provided in `values-hub.yaml` as a namespace, subscription and an application. By providing a `managedClusterGroups` block in our `values-hub.yaml` we are able to provision spoke clusters with the Validated Patterns framework as well.

[source,yaml]
----
clusterGroup:
  managedClusterGroups:
    exampleRegion:
      name: group-one
      acmlabels:
        - name: clusterGroup
          value: group-one
----

Any cluster that ACM sees labeled with `clusterGroup=group-one` will be provisioned with our link:https://github.com/validatedpatterns/clustergroup-chart[Clustergroup chart] and linkhttps://github.com/validatedpatterns/multicloud-gitops/blob/main/values-group-one.yaml[values-group-one.yaml].

=== Imperative Jobs

The example imperative job in the {mcg-pattern} is

[source,yaml]
----
clusterGroup:
  imperative:
    jobs:
      - name: hello-world
        playbook: rhvp.cluster_utils.hello_world
        timeout: 234
----

This gets transformed by link:https://github.com/validatedpatterns/clustergroup-chart/tree/main/templates/imperative[the Clustergroup chart] into several resources. This process is a bit complex and we will cover it in more detail later.