Added Environment variables propagation and mapping feature from ARGOCD_ENV_{VARIABLE} to {VARIABLE}

doc/parameter.md

@@ -40,6 +40,7 @@ Environment variables, are conventionally ALL_CAPS, and for our purposes
 | Helmfile Merge | LOVELY_HELMFILE_MERGE | Set to some yaml you'd like [strategic merged](https://kubectl.docs.kubernetes.io/references/kustomize/kustomization/patchesstrategicmerge/) into any helmfile.yaml used by helmfile. |  |
 | Helmfile Patch | LOVELY_HELMFILE_PATCH | to some yaml or json you'd like [json6902](https://kubectl.docs.kubernetes.io/references/kustomize/kustomization/patchesjson6902/) patched into any helmfile.yaml used by Helmfile. |  |
 | Helmfile Template Parameters | LOVELY_HELMFILE_TEMPLATE_PARAMS | Space separated extra parameters to `Helmfile template` as you might use on the command line. You're on your own here if you pass rubbish parameters. |  |
+| Environment variables propagation | LOVELY_ENV_PROPAGATION | Whether to propagate and map ARGOCD_ENV_{VARIABLE} environment variables as {VARIABLE} to the downstream processor (Helm, Kustomize or Helmfile). | false |
 ## Plugin Name
 
 You can set `PLUGIN_NAME` in the environment of the sidecar to override the default name of the plugin. This allows you to supply multiple pre-configured plugins (with different environment, but the same variation).

pkg/features/features.go

@@ -36,8 +36,9 @@ const (
 	HelmfileMerge
 	HelmfilePatch
 	HelmfileTemplateParams
+	EnvPropagation
 	FirstFeature = Plugins
-	LastFeature  = HelmfileTemplateParams
+	LastFeature  = EnvPropagation
 )
 
 // Feature is an individual configurable element of the plugin
@@ -179,5 +180,11 @@ func Features() map[FeatureID]Feature {
 			Name:        `lovely_helmfile_template_params`,
 			Description: "Space separated extra parameters to `Helmfile template` as you might use on the command line. You're on your own here if you pass rubbish parameters.",
 		},
+		EnvPropagation: {
+			Title:       `Environment variables propagation`,
+			Name:        `lovely_env_propagation`,
+			DefaultVal:  `false`,
+			Description: "Whether to propagate and map ARGOCD_ENV_{VARIABLE} environment variables as {VARIABLE} to the downstream processor (Helm, Kustomize or Helmfile).",
+		},
 	}
 }

pkg/features/getters.go

@@ -172,3 +172,10 @@ func GetHelmfileTemplateParams() ([]string, error) {
 	f := Features()[HelmfileTemplateParams]
 	return config.GetStringListParam(f.EnvName(), f.DefaultVal, ' ')
 }
+
+// GetEnvPropagation returns extra parameters to pass to processor stage
+// Set LOVELY_ENV_PROPAGATION to activate env propagation
+func GetEnvPropagation() bool {
+	f := Features()[EnvPropagation]
+	return config.GetBoolParam(f.EnvName(), f.DefaultVal)
+}

pkg/processor/execute.go

@@ -3,12 +3,24 @@ package processor
 import (
 	"bytes"
 	"fmt"
+	"github.com/crumbhole/argocd-lovely-plugin/pkg/features"
+	"os"
 	"os/exec"
+	"regexp"
+)
+
+const (
+	envPrefixArgoCD = "ARGOCD_ENV_"
 )
 
 func execute(path string, command string, params ...string) (string, error) {
 	cmd := exec.Command(command, params...)
 	cmd.Dir = path
+
+	if features.GetEnvPropagation() {
+		cmd.Env = filterEnvironment(os.Environ())
+	}
+
 	var stderr bytes.Buffer
 	cmd.Stderr = &stderr
 	out, err := cmd.Output()
@@ -18,3 +30,15 @@ func execute(path string, command string, params ...string) (string, error) {
 	}
 	return string(out), nil
 }
+
+func filterEnvironment(env []string) []string {
+	filtered := make([]string, 0, len(env))
+	argoRegex := regexp.MustCompile(`^` + regexp.QuoteMeta(envPrefixArgoCD))
+	for _, e := range env {
+		if argoRegex.MatchString(e) {
+			e = argoRegex.ReplaceAllString(e, "")
+		}
+		filtered = append(filtered, e)
+	}
+	return filtered
+}

test/helmfile_env_propagation/README.md

@@ -0,0 +1,2 @@
+This example:
+- Installs the helm chart defined in `helmfile.yaml` using helmfile using env propagation to substitute the replicaCount from a provided env var.

test/helmfile_env_propagation/env.txt

@@ -0,0 +1,2 @@
+LOVELY_ENV_PROPAGATION: true
+ARGOCD_ENV_REPLICA_COUNT: 2

test/helmfile_env_propagation/expected.txt

@@ -0,0 +1,76 @@
+---
+# Source: hello-world/templates/serviceaccount.yaml
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: test-hello-world
+  labels:
+    helm.sh/chart: hello-world-0.1.0
+    app.kubernetes.io/name: hello-world
+    app.kubernetes.io/instance: test
+    app.kubernetes.io/version: "1.16.0"
+    app.kubernetes.io/managed-by: Helm
+---
+# Source: hello-world/templates/service.yaml
+apiVersion: v1
+kind: Service
+metadata:
+  name: test-hello-world
+  labels:
+    helm.sh/chart: hello-world-0.1.0
+    app.kubernetes.io/name: hello-world
+    app.kubernetes.io/instance: test
+    app.kubernetes.io/version: "1.16.0"
+    app.kubernetes.io/managed-by: Helm
+spec:
+  type: ClusterIP
+  ports:
+    - port: 80
+      targetPort: http
+      protocol: TCP
+      name: http
+  selector:
+    app.kubernetes.io/name: hello-world
+    app.kubernetes.io/instance: test
+---
+# Source: hello-world/templates/deployment.yaml
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: test-hello-world
+  labels:
+    helm.sh/chart: hello-world-0.1.0
+    app.kubernetes.io/name: hello-world
+    app.kubernetes.io/instance: test
+    app.kubernetes.io/version: "1.16.0"
+    app.kubernetes.io/managed-by: Helm
+spec:
+  replicas: 2
+  selector:
+    matchLabels:
+      app.kubernetes.io/name: hello-world
+      app.kubernetes.io/instance: test
+  template:
+    metadata:
+      labels:
+        app.kubernetes.io/name: hello-world
+        app.kubernetes.io/instance: test
+    spec:
+      serviceAccountName: test-hello-world
+      containers:
+        - name: hello-world
+          image: "nginx:1.16.0"
+          imagePullPolicy: IfNotPresent
+          ports:
+            - name: http
+              containerPort: 80
+              protocol: TCP
+          livenessProbe:
+            httpGet:
+              path: /
+              port: http
+          readinessProbe:
+            httpGet:
+              path: /
+              port: http
+

test/helmfile_env_propagation/helmfile.yaml

@@ -0,0 +1,11 @@
+repositories:
+  - name: examples
+    url: https://helm.github.io/examples
+
+releases:
+  - name: test
+    namespace: default
+    chart: examples/hello-world
+    set:
+      - name: replicaCount
+        value: {{ requiredEnv "REPLICA_COUNT" }}