Adding example on how to access secrets and add them to the container…

… environment

Signed-off-by: Nick Beenham <[email protected]>

docs/content/guides/author-apps/kubernetes/how-to-access-secrets/index.md

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+---
+type: docs
+title: "How-To: Access Kubernetes secrets using PodSpec"
+linkTitle: "Secrets using PodSpec"
+description: "Learn how to patch Kubernetes secrets into the container environment using PodSpec definitions"
+weight: 300
+slug: 'secrets-podspec'
+categories: "How-To"
+tags: ["containers","Kubernetes", "secrets"]
+---
+
+This how-to guide will provide an overview of how to:
+
+- Patch existing Kubernetes secrets using [PodSpec](https://kubernetes.io/docs/reference/kubernetes-api/workload-resources/pod-v1/#PodSpec) definitions and provide them to the environment of a container.
+
+## Prerequisites
+
+- [rad CLI]({{< ref getting-started >}})
+- [Radius initialized with `rad init`]({{< ref howto-environment >}})
+- [kubectl](https://kubernetes.io/docs/tasks/tools/install-kubectl/)
+
+## Step 1: Define a container
+Begin by creating a file named `app.bicep` with a Radius [container]({{< ref "guides/author-apps/containers" >}}):
+
+{{< rad file="snippets/secrets-container.bicep" embed=true >}}
+
+## Step 2: Deploy the app and container
+```bash
+rad run ./app.bicep -a demo
+```
+
+Once the deployment completes successfully, you should see the following confirmation message along with some system logs:
+
+```bash
+Building app.bicep...
+Deploying template 'app.bicep' for application 'demo' and environment 'dev' from workspace 'dev'...
+
+Deployment In Progress...
+
+..                   demo            Applications.Core/containers
+Completed            demo            Applications.Core/applications
+
+Deployment Complete
+
+Resources:
+    demo            Applications.Core/applications
+    demo            Applications.Core/containers
+
+Starting log stream...
+
++ demo-7d94db59f6-ps6cf › demo
+demo-7d94db59f6-ps6cf demo No APPLICATIONINSIGHTS_CONNECTION_STRING found, skipping Azure Monitor setup
+demo-7d94db59f6-ps6cf demo Using in-memory store: no connection string found
+demo-7d94db59f6-ps6cf demo Server is running at http://localhost:3000
+dashboard-7f7db87c5-7d2jf dashboard [port-forward] connected from localhost:7007 -> ::7007
+demo-7d94db59f6-ps6cf demo [port-forward] connected from localhost:3000 -> ::3000
+```
+
+Verify the pod is running:
+
+```bash
+kubectl get pods -n dev-demo
+```
+
+## Step 3: Create a secret
+
+Create a secret in your Kubernetes cluster using the following command:
+
+```bash
+kubectl create secret generic my-secret --from-literal=secret-key=secret-value -n dev-demo
+```
+
+Verify the secret is created:
+
+```bash
+kubectl get secrets -n dev-demo
+```
+
+## Step 4: Patch the secret
+
+Patch the secret into the container by adding the following `runtimes` block to the `container` resource in your `app.bicep` file:
+
+{{< rad file="snippets/secrets-patch.bicep" embed=true >}}
+
+## Step 5: Redeploy the app and container
+
+Redeploy and run your app:
+
+```bash
+rad app deploy demo
+```
+
+Once the deployment completes successfully, you should see the environment variable in the container:
+First, get the pod name:
+```bash
+kubectl get pods -n dev-demo
+```
+
+Then, exec into the pod and check the environment variable (substitute the pod name with the one you got from the previous command):
+
+```bash
+kubectl -n dev-demo exec demo-d64cc4d6d-xjnjz -- env | grep MY_SECRET
+```
+
+## Cleanup
+
+Run the following command to [delete]({{< ref "guides/deploy-apps/howto-delete" >}}) your app and container:
+
+```bash
+rad app delete demo
+```
+
+## Further reading
+
+- [Kubernetes in Radius containers]({{< ref "guides/author-apps/containers/overview#kubernetes" >}})
+- [PodSpec in Radius containers]({{< ref "reference/resource-schema/core-schema/container-schema#runtimes" >}})

docs/content/guides/author-apps/kubernetes/how-to-access-secrets/snippets/secrets-container.bicep

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+import radius as radius
+
+@description('Specifies the environment for resources.')
+param environment string
+
+resource app 'Applications.Core/applications@2023-10-01-preview' = {
+  name: 'demo'
+  properties: {
+    environment: environment
+  }
+}
+
+resource demo 'Applications.Core/containers@2023-10-01-preview' = {
+  name: 'demo'
+  properties: {
+    application: app.id
+    container: {
+      image: 'ghcr.io/radius-project/samples/demo:latest'
+      ports: {
+        web: {
+          containerPort: 3000
+        }
+      }
+    }
+  }
+}

docs/content/guides/author-apps/kubernetes/how-to-access-secrets/snippets/secrets-patch.bicep

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+import radius as radius
+
+@description('Specifies the environment for resources.')
+param environment string
+
+resource app 'Applications.Core/applications@2023-10-01-preview' = {
+  name: 'demo'
+  properties: {
+    environment: environment
+  }
+}
+
+resource demo 'Applications.Core/containers@2023-10-01-preview' = {
+  name: 'demo'
+  properties: {
+    application: app.id
+    container: {
+      image: 'ghcr.io/radius-project/samples/demo:latest'
+      ports: {
+        web: {
+          containerPort: 3000
+        }
+      }
+    }
+    runtimes: {
+      kubernetes: {
+        pod: {
+          volumes: [ {
+              name: 'secrets-vol'
+              secret: {
+                secretName: 'my-secret'
+              }
+            }
+          ]
+          containers: [
+            {
+              name: 'demo'
+              volumeMounts: [ {
+                  name: 'secrets-vol'
+                  readOnly: true
+                  mountPath: '/etc/secrets-vol'
+                }
+              ]
+              env: [
+                {
+                  name: 'MY_SECRET'
+                  valueFrom: {
+                    secretKeyRef: {
+                      name: 'my-secret'
+                      key: 'secret-key'
+                    }
+                  }
+                }
+              ]
+            }
+          ]
+          hostNetwork: true
+        }
+      }
+    }
+  }
+}