Merge pull request #55 from fluxcd/values-from-targetpaths

Support targeting a path in ValuesReferences

.github/workflows/e2e.yaml

@@ -72,7 +72,7 @@ jobs:
           kubectl -n helm-system wait helmreleases/valuesfrom --for=condition=ready --timeout=4m
 
           RESULT=$(helm -n helm-system get values valuesfrom)
-          EXPECTED=$(cat config/testdata/valuesfrom/result.txt)
+          EXPECTED=$(cat config/testdata/valuesfrom/golden.txt)
           if [ "$RESULT" != "$EXPECTED" ]; then
             echo -e "$RESULT\n\ndoes not equal\n\n$EXPECTED"
           fi

Makefile

@@ -14,7 +14,7 @@ all: manager
 
 # Run tests
 test: generate fmt vet manifests api-docs
-	find . -maxdepth 2 -type f -name 'go.mod' -execdir go test ./... \;
+	find . -maxdepth 2 -type f -name 'go.mod' -execdir go test ./... -coverprofile cover.out \;
 
 # Build manager binary
 manager: generate fmt vet

api/v2alpha1/reference_types.go

@@ -50,10 +50,16 @@ type ValuesReference struct {
 	// +required
 	Name string `json:"name"`
 
-	// ValuesKey is the key in the referent the values can be found at.
-	// Defaults to 'values.yaml'.
+	// ValuesKey is the data key where the values.yaml or a specific value can
+	// be found at. Defaults to 'values.yaml'.
 	// +optional
 	ValuesKey string `json:"valuesKey,omitempty"`
+
+	// TargetPath is the YAML dot notation path the value should be merged at.
+	// When set, the ValuesKey is expected to be a single flat value.
+	// Defaults to 'None', which results in the values getting merged at the root.
+	// +optional
+	TargetPath string `json:"targetPath,omitempty"`
 }
 
 // GetValuesKey returns the defined ValuesKey or the default ('values.yaml').

config/crd/bases/helm.toolkit.fluxcd.io_helmreleases.yaml

@@ -281,9 +281,15 @@ spec:
                       description: Name of the values referent. Should reside in the
                         same namespace as the referring resource.
                       type: string
+                    targetPath:
+                      description: TargetPath is the YAML dot notation path the value
+                        should be merged at. When set, the ValuesKey is expected to
+                        be a single flat value. Defaults to 'None', which results
+                        in the values getting merged at the root.
+                      type: string
                     valuesKey:
-                      description: ValuesKey is the key in the referent the values
-                        can be found at. Defaults to 'values.yaml'.
+                      description: ValuesKey is the data key where the values.yaml
+                        or a specific value can be found at. Defaults to 'values.yaml'.
                       type: string
                   required:
                   - kind

config/testdata/valuesfrom/configmap.yaml

@@ -13,3 +13,7 @@ data:
       requests:
         cpu: 100m
         memory: 64Mi
+  resources.limits.cpu: 400m
+  list.example: "{a,b,c}"
+  list.example.overwrite: d
+  podAnnotation.example.value: demo

config/testdata/valuesfrom/golden.txt

@@ -1,8 +1,15 @@
 USER-SUPPLIED VALUES:
+list:
+  example:
+  - a
+  - b
+  - d
+podAnnotations:
+  some.k8s.annotation/env: demo
 replicaCount: 2
 resources:
   limits:
-    cpu: 200m
+    cpu: 400m
     memory: 128Mi
   requests:
     cpu: 100m

config/testdata/valuesfrom/helmrelease.yaml

@@ -22,6 +22,22 @@ spec:
     - kind: ConfigMap
       name: valuesfrom-config
       valuesKey: resources.requests
+    - kind: ConfigMap
+      name: valuesfrom-config
+      valuesKey: resources.limits.cpu
+      targetPath: resources.limits.cpu
+    - kind: ConfigMap
+      name: valuesfrom-config
+      valuesKey: list.example
+      targetPath: list.example
+    - kind: ConfigMap
+      name: valuesfrom-config
+      valuesKey: list.example.overwrite
+      targetPath: list.example[2]
+    - kind: ConfigMap
+      name: valuesfrom-config
+      valuesKey: podAnnotation.example.value
+      targetPath: podAnnotations.some\.k8s\.annotation\/env
     - kind: Secret
       name: valuesfrom-secret
   values:

config/testdata/valuesfrom/secret.yaml

@@ -3,5 +3,7 @@ kind: Secret
 metadata:
   name: valuesfrom-secret
 type: Opaque
-data:
-  values.yaml: c2VydmljZUFjY291bnQ6CiAgZW5hYmxlZDogdHJ1ZQo=
+stringData:
+  values.yaml: |
+    serviceAccount:
+      enabled: true

controllers/helmrelease_controller.go

@@ -37,6 +37,7 @@ import (
 	"helm.sh/helm/v3/pkg/chartutil"
 	"helm.sh/helm/v3/pkg/release"
 	"helm.sh/helm/v3/pkg/storage/driver"
+	"helm.sh/helm/v3/pkg/strvals"
 	corev1 "k8s.io/api/core/v1"
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -472,11 +473,22 @@ func (r *HelmReleaseReconciler) composeValues(ctx context.Context, hr v2.HelmRel
 		default:
 			return nil, fmt.Errorf("unsupported ValuesReference kind '%s'", v.Kind)
 		}
-		values, err := chartutil.ReadValues(valsData)
-		if err != nil {
-			return nil, fmt.Errorf("unable to read values from key '%s' in %s '%s': %w", v.GetValuesKey(), v.Kind, namespacedName, err)
+		switch v.TargetPath {
+		case "":
+			values, err := chartutil.ReadValues(valsData)
+			if err != nil {
+				return nil, fmt.Errorf("unable to read values from key '%s' in %s '%s': %w", v.GetValuesKey(), v.Kind, namespacedName, err)
+			}
+			result = mergeMaps(result, values)
+		default:
+			// TODO(hidde): this is a bit of hack, as it mimics the way the option string is passed
+			// 	to Helm from a CLI perspective. Given the parser is however not publicly accessible
+			// 	while it contains all logic around parsing the target path, it is a fair trade-off.
+			singleVal := v.TargetPath + "=" + string(valsData)
+			if err := strvals.ParseInto(singleVal, result); err != nil {
+				return nil, fmt.Errorf("unable to merge value from key '%s' in %s '%s' into target path '%s': %w", v.GetValuesKey(), v.Kind, namespacedName, v.TargetPath, err)
+			}
 		}
-		result = mergeMaps(result, values)
 	}
 	return mergeMaps(result, hr.GetValues()), nil
 }

docs/api/helmrelease.md

@@ -1362,8 +1362,22 @@ string
 </td>
 <td>
 <em>(Optional)</em>
-<p>ValuesKey is the key in the referent the values can be found at.
-Defaults to &lsquo;values.yaml&rsquo;.</p>
+<p>ValuesKey is the data key where the values.yaml or a specific value can
+be found at. Defaults to &lsquo;values.yaml&rsquo;.</p>
+</td>
+</tr>
+<tr>
+<td>
+<code>targetPath</code><br>
+<em>
+string
+</em>
+</td>
+<td>
+<em>(Optional)</em>
+<p>TargetPath is the YAML dot notation path the value should be merged at.
+When set, the ValuesKey is expected to be a single flat value.
+Defaults to &lsquo;None&rsquo;, which results in the values getting merged at the root.</p>
 </td>
 </tr>
 </tbody>

docs/spec/v2alpha1/helmreleases.md

@@ -72,7 +72,7 @@ type HelmReleaseSpec struct {
 
 	// ValuesFrom holds references to resources containing Helm values, and information
 	// about how they should be merged.
-	ValuesFrom []ValuesReference `json:"valuesFrom,omitempty"
+	ValuesFrom []ValuesReference `json:"valuesFrom,omitempty"`
 
 	// Values holds the values for this Helm release.
 	// +optional
@@ -281,11 +281,17 @@ type ValuesReference struct {
 	// referring resource.
 	// +required
 	Name string `json:"name"`
-	
-	// ValuesKey is the key in the referent the values can be found at.
-	// Defaults to 'values.yaml'.
+
+	// ValuesKey is the data key where the values.yaml or a specific value can
+	// be found at. Defaults to 'values.yaml'.
 	// +optional
 	ValuesKey string `json:"valuesKey,omitempty"`
+
+	// TargetPath is the YAML dot notation path the value should be merged at.
+	// When set, the ValuesKey is expected to be a single flat value.
+	// Defaults to 'None', which results in the values getting merged at the root.
+	// +optional
+	TargetPath string `json:"targetPath,omitempty"`
 }
 ```