#53 Process helm metadata

Extend CR with field mappedValues to process helm values which need metadata from their charts

Author: nhinze23

config/samples/dogu-operator.yaml

@@ -4,4 +4,7 @@ metadata:
   name: k8s-dogu-operator
 spec:
   name: k8s-dogu-operator
-  namespace: k8s
+  namespace: k8s
+  version: 0.41.11-dev
+  mappedValues:
+    log-level: error

k8s/helm-crd/templates/k8s.cloudogu.com_components.yaml

@@ -38,6 +38,11 @@ spec:
                 deployNamespace:
                   description: DeployNamespace is the namespace where the helm chart should be deployed in. This value is optional. If it is empty the operator deploys the helm chart in the namespace where the operator is deployed.
                   type: string
+                mappedValues:
+                  additionalProperties:
+                    type: string
+                  description: MappedValues contains helm values which require a mapping. Components hold metadata information in a file `component-metadata-values.yaml` for these fields. The component-operator reads the file in install or upgrade process the sets the corresponding values in the chart spec. Possible values in this map are forbidden to set via the field ValuesYamlOverwrite.
+                  type: object
                 name:
                   description: Name of the component (e.g. k8s-dogu-operator)
                   type: string

pkg/api/v1/ces_component_types.go

@@ -48,6 +48,12 @@ type ComponentSpec struct {
 	// It can be used to overwrite specific configurations. Lists are overwritten, maps are merged.
 	// +optional
 	ValuesYamlOverwrite string `json:"valuesYamlOverwrite,omitempty"`
+	// MappedValues contains helm values which require a mapping.
+	// Components hold metadata information in a file `component-metadata-values.yaml` for these fields.
+	// The component-operator reads the file in install or upgrade process the sets the corresponding values in the chart spec.
+	// Possible values in this map are forbidden to set via the field ValuesYamlOverwrite.
+	// +optional
+	MappedValues map[string]string `json:"mappedValues,omitempty"`
 }
 
 type HealthStatus string

pkg/controllers/componentController.go

@@ -277,6 +277,7 @@ func (r *ComponentReconciler) isValuesChanged(deployedRelease *release.Release,
 		return false, fmt.Errorf("failed to get values.yaml from release %s: %w", deployedRelease.Name, err)
 	}
 
+	// TODO Check changes for mappedValues. Merge them here. Maybe extend chartSpec and reuse them later.
 	chartSpecValues, err := r.helmClient.GetChartSpecValues(component.GetHelmChartSpec())
 	if err != nil {
 		return false, fmt.Errorf("failed to get values.yaml from component %s: %w", component.GetHelmChartSpec().ChartName, err)

pkg/controllers/componentInstallManager.go

@@ -61,7 +61,7 @@ func (cim *ComponentInstallManager) Install(ctx context.Context, component *k8sv
 	// create a new context that does not get canceled immediately on SIGTERM
 	helmCtx := context.Background()
 
-	if err := cim.helmClient.InstallOrUpgrade(helmCtx, component.GetHelmChartSpec()); err != nil {
+	if err := cim.helmClient.InstallOrUpgradeWithMappedValues(helmCtx, component.GetHelmChartSpec(), component.Spec.MappedValues); err != nil {
 		return &genericRequeueableError{"failed to install chart for component " + component.Spec.Name, err}
 	}
 

pkg/controllers/componentUpgradeManager.go

@@ -50,7 +50,7 @@ func (cum *ComponentUpgradeManager) Upgrade(ctx context.Context, component *k8sv
 	// this allows self-upgrades
 	helmCtx := context.WithoutCancel(ctx)
 
-	if err := cum.helmClient.InstallOrUpgrade(helmCtx, component.GetHelmChartSpec()); err != nil {
+	if err := cum.helmClient.InstallOrUpgradeWithMappedValues(helmCtx, component.GetHelmChartSpec(), component.Spec.MappedValues); err != nil {
 		return fmt.Errorf("failed to upgrade chart for component %s: %w", component.Spec.Name, err)
 	}
 

pkg/controllers/interfaces.go

@@ -41,6 +41,8 @@ type healthManager interface {
 type helmClient interface {
 	// InstallOrUpgrade takes a helmChart and applies it.
 	InstallOrUpgrade(ctx context.Context, chart *client.ChartSpec) error
+	// InstallOrUpgradeWithMappedValues takes a helmChart and applies it with custom values which should be in the metadata file of the helm chart.
+	InstallOrUpgradeWithMappedValues(ctx context.Context, chart *client.ChartSpec, mappedValues map[string]string) error
 	// Uninstall removes the helmRelease for the given name
 	Uninstall(releaseName string) error
 	// ListDeployedReleases returns all deployed helm releases

pkg/helm/client.go

@@ -3,6 +3,8 @@ package helm
 import (
 	"context"
 	"fmt"
+	"helm.sh/helm/v3/pkg/chartutil"
+	"k8s.io/apimachinery/pkg/util/yaml"
 	"sort"
 	"strings"
 
@@ -19,10 +21,11 @@ import (
 )
 
 const (
-	helmRepositoryCache    = "/tmp/.helmcache"
-	helmRepositoryConfig   = "/tmp/.helmrepo"
-	helmRegistryConfigFile = "/tmp/.helmregistry/config.json"
-	ociSchemePrefix        = string(config.EndpointSchemaOCI + "://")
+	helmRepositoryCache        = "/tmp/.helmcache"
+	helmRepositoryConfig       = "/tmp/.helmrepo"
+	helmRegistryConfigFile     = "/tmp/.helmregistry/config.json"
+	ociSchemePrefix            = string(config.EndpointSchemaOCI + "://")
+	helmValuesMetadataFileName = "component-values-metadata.yaml"
 )
 
 // HelmClient embeds the client.Client interface for usage in this package.
@@ -67,6 +70,10 @@ func NewClient(namespace string, helmRepoData *config.HelmRepositoryData, debug
 
 // InstallOrUpgrade takes a helmChart and applies it.
 func (c *Client) InstallOrUpgrade(ctx context.Context, chart *client.ChartSpec) error {
+	return c.InstallOrUpgradeWithMappedValues(ctx, chart, nil)
+}
+
+func (c *Client) InstallOrUpgradeWithMappedValues(ctx context.Context, chart *client.ChartSpec, mappedValues map[string]string) error {
 	// This helm-client currently only works with OCI-Helm-Repositories.
 	// Therefore, the chartName has to include the FQDN of the repository (e.g. "oci://my.repo/...")
 	// If in the future non-oci-repositories need to be used, this should be done here...
@@ -76,6 +83,10 @@ func (c *Client) InstallOrUpgrade(ctx context.Context, chart *client.ChartSpec)
 		return fmt.Errorf("error patching chart-version for chart %s: %w", chart.ChartName, err)
 	}
 
+	if err := c.patchMappedValues(ctx, chart, mappedValues); err != nil {
+		return err
+	}
+
 	_, err := c.helmClient.InstallOrUpgradeChart(ctx, chart)
 	if err != nil {
 		return fmt.Errorf("error while installOrUpgrade chart %s: %w", chart.ChartName, err)
@@ -154,6 +165,107 @@ func (c *Client) GetChartSpecValues(spec *client.ChartSpec) (map[string]interfac
 	return c.helmClient.GetChartSpecValues(spec)
 }
 
+type helmValuesMetadata struct {
+	ApiVersion string                             `yaml:"apiVersion"`
+	Metadata   map[string]helmValuesMetadataEntry `yaml:"metadata"`
+}
+
+type helmValuesMetadataEntry struct {
+	Name        string                  `yaml:"name"`
+	Description string                  `yaml:"description"`
+	Keys        []helmValuesMetadataKey `yaml:"keys"`
+}
+
+type helmValuesMetadataKey struct {
+	Path string `yaml:"path"`
+}
+
+func (c *Client) patchMappedValues(ctx context.Context, chartSpec *client.ChartSpec, mappedValues map[string]string) error {
+	logger := log.FromContext(ctx)
+	if mappedValues == nil {
+		logger.Info("return patching values because mapped values are nil")
+		return nil
+	}
+
+	helmChart, err := c.getChart(ctx, chartSpec)
+	if err != nil {
+		return err
+	}
+
+	files := helmChart.Files
+	var metadataFile *helmValuesMetadata
+	for _, file := range files {
+		logger.Info(file.Name)
+		if file.Name == helmValuesMetadataFileName {
+			err := yaml.Unmarshal(file.Data, &metadataFile)
+			if err != nil {
+				return fmt.Errorf("failed to unmarshal %s: %w", helmValuesMetadataFileName, err)
+			}
+			logger.Info(fmt.Sprintf("found metadata file %q for chart %q", helmValuesMetadataFileName, chartSpec.ChartName))
+			logger.Info(fmt.Sprintf("%+v", metadataFile))
+			break
+		}
+	}
+
+	if metadataFile == nil {
+		logger.Info(fmt.Sprintf("found no metadata file %q for chart %q", helmValuesMetadataFileName, chartSpec.ChartName))
+		return nil
+	}
+
+	values, err := chartutil.ReadValues([]byte(chartSpec.ValuesYaml))
+	if err != nil {
+		return fmt.Errorf("failed to read current values: %w", err)
+	}
+
+	// TODO Exclude this check because it has to be done if the mappedValues are nil too
+	for _, metadataEntry := range metadataFile.Metadata {
+		// Check if metadata values are already set in valuesYamlOverwrite
+		for _, key := range metadataEntry.Keys {
+			// key.Path is somethings like controllerManager.env.logLevel (dot-separated)
+			path := key.Path
+			if isMetadataPathInValuesMap(path, values) {
+				return fmt.Errorf("values contains path %s which should only be set in field mappedValues", path)
+			}
+
+			value, ok := mappedValues[metadataEntry.Name]
+			if !ok {
+				// Return nil because metadata is nil in mappedValue
+				logger.Info(fmt.Sprintf("found no value in mappedValues for metadata %q", metadataEntry.Name))
+				return nil
+			}
+
+			setValueInChartSpec(ctx, chartSpec, path, value)
+		}
+	}
+
+	return nil
+}
+
+func setValueInChartSpec(ctx context.Context, chartSpec *client.ChartSpec, path string, value interface{}) {
+	// TODO Mapping
+	// This is easier than reading the current values as string and merging them.
+	logger := log.FromContext(ctx)
+	option := fmt.Sprintf("%s=%s", path, value)
+	logger.Info(fmt.Sprintf("set option %q for chart %q", option, chartSpec.ChartName))
+	chartSpec.ValuesOptions.Values = append(chartSpec.ValuesOptions.Values, option)
+}
+
+func isMetadataPathInValuesMap(path string, values chartutil.Values) bool {
+	before, after, _ := strings.Cut(path, ".")
+
+	i, ok := values[before]
+	if !ok {
+		return false
+	}
+
+	ii, ok := i.(map[string]interface{})
+	if !ok && after == "" {
+		return true
+	}
+
+	return isMetadataPathInValuesMap(after, ii)
+}
+
 func (c *Client) patchOciEndpoint(chart *client.ChartSpec) {
 	if strings.HasPrefix(chart.ChartName, ociSchemePrefix) {
 		return
@@ -173,7 +285,7 @@ func (c *Client) patchChartVersion(chart *client.ChartSpec) error {
 		return fmt.Errorf("error resolving tags for chart %s: %w", chart.ChartName, err)
 	}
 
-	//sort tags by version
+	// sort tags by version
 	sortedTags := sortByVersionDescending(tags)
 
 	if len(sortedTags) <= 0 {

pkg/helm/client_test.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"helm.sh/helm/v3/pkg/chartutil"
 	"strings"
 	"testing"
 
@@ -628,3 +629,28 @@ func TestClient_GetReleaseValues(t *testing.T) {
 		assert.Equal(t, "val", values["key"])
 	})
 }
+
+func Test_isMetadataPathInValuesMap(t *testing.T) {
+	type args struct {
+		path   string
+		values chartutil.Values
+	}
+	tests := []struct {
+		name string
+		args args
+		want bool
+	}{
+		{"empty path should result in false with empty values", args{"", map[string]interface{}{}}, false},
+		{"empty path should result in false", args{"", map[string]interface{}{"controllerManager": "value"}}, false},
+		{"simple path is in values", args{"controllerManager", map[string]interface{}{"controllerManager": "value"}}, true},
+		{"path is in values", args{"controllerManager.env", map[string]interface{}{"controllerManager": map[string]interface{}{"env": "value"}}}, true},
+		{"path is not in values", args{"controllerManager.env", map[string]interface{}{"controllerManager": "value"}}, false},
+		{"path is not in values because of bool value", args{"controllerManager.env", map[string]interface{}{"controllerManager": false}}, false},
+		{"path is not in values because of slice value", args{"controllerManager.env", map[string]interface{}{"controllerManager": []byte{}}}, false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert.Equalf(t, tt.want, isMetadataPathInValuesMap(tt.args.path, tt.args.values), "isMetadataPathInValuesMap(%v, %v)", tt.args.path, tt.args.values)
+		})
+	}
+}