chore: added example 02 - environment

examples/02-environment/README.md

@@ -0,0 +1,115 @@
+# 02 - Environment Variables
+
+It is common to pass a dynamic environment-specific configuration to the container during the deployment.
+
+In score specification a special `environment` resource type is used to support such cases:
+
+```yaml
+apiVersion: score.dev/v1b1
+
+metadata:
+  name: hello-world
+
+containers:
+  hello:
+    image: busybox
+    command: ["/bin/sh"]
+    args: ["-c", "while true; do echo Hello $${FRIEND}!; sleep 5; done"]
+    variables:
+      FRIEND: ${resources.env.NAME}
+
+resources:
+  env:
+    type: environment
+    properties:
+      NAME:
+        type: string
+        default: World
+```
+
+If there is a need to set the `NAME` variable value for the environment the workload would be deployed into, an `env.yaml` file can be used:
+
+```yaml
+env:
+  NAME: John
+```
+
+Now the source `score.yaml` file and the `env.yaml` file should be combined and converted into Helm values file with `score-helm` CLI tool:
+
+```console
+$ score-helm run -f ./score.yaml --values ./env.yaml -o ./values.yaml
+```
+
+Output `values.yaml` file would contain a workload configuration for the chart:
+
+```yaml
+containers:
+  hello:
+    args:
+      - -c
+      - while true; do echo Hello $${FRIEND}!; sleep 5; done
+    command:
+      - /bin/sh
+    env:
+      - name: FRIEND
+        value: John
+    image:
+      name: busybox
+```
+
+A generic chart template from `/examples/chart` can be used to prepare a Helm chart for this example:
+
+```console
+$ helm create -p ../examples/chart hello
+```
+
+Deploying the Helm chart:
+
+```console
+$ helm install --values ./values.yaml hello ./hello
+
+NAME: hello
+LAST DEPLOYED: Wed Nov 2 14:40:11 2022
+NAMESPACE: default
+STATUS: deployed
+REVISION: 1
+TEST SUITE: None
+```
+
+Resulting Kubernetes deployment object:
+
+```yaml
+# Source: hello/templates/deployment.yaml
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: hello
+  labels:
+    helm.sh/chart: hello-0.1.0
+    app.kubernetes.io/name: 
+    app.kubernetes.io/instance: hello
+    app.kubernetes.io/version: "0.1.0"
+    app.kubernetes.io/managed-by: Helm
+spec:
+  selector:
+    matchLabels:
+      app.kubernetes.io/name: 
+      app.kubernetes.io/instance: hello
+  template:
+    metadata:
+      labels:
+        app.kubernetes.io/name: 
+        app.kubernetes.io/instance: hello
+    spec:
+      containers:
+        - name: hello
+          image: "busybox"
+          command:
+            - /bin/sh
+          args:
+            - -c
+            - while true; do echo Hello $${FRIEND}!; sleep 5; done
+          env:
+            - name: FRIEND
+              value: John
+```

examples/02-environment/env.yaml

@@ -0,0 +1,2 @@
+env:
+  NAME: John

examples/02-environment/score.yaml

@@ -0,0 +1,17 @@
+apiVersion: score.dev/v1b1
+metadata:
+  name: hello-world
+containers:
+  hello:
+    image: busybox
+    command: ["/bin/sh"]
+    args: ["-c", "while true; do echo Hello $${FRIEND}!; sleep 5; done"]
+    variables:
+      FRIEND: ${resources.env.NAME}
+resources:
+  env:
+    type: environment
+    properties:
+      NAME:
+        type: string
+        default: World

examples/chart/templates/deployment.yaml

@@ -25,9 +25,9 @@ spec:
           args:
             {{- toYaml $container.args | nindent 12 }}
           {{- end }}
-          {{- with $container.variables }}
+          {{- with $container.env }}
           env:
-            {{- toYaml $container.variables | nindent 12 }}
+            {{- toYaml $container.env | nindent 12 }}
           {{- end }}
           {{- with $container.volumeMounts }}
           volumeMounts: