Merge pull request #143 from reddec/feature/template-secrets

Add support for template secrets

README.md

@@ -39,6 +39,7 @@ None
 * Creates Kubernetes secret with postgres_uri in the same namespace as CR
 * Support for AWS RDS and Azure Database for PostgresSQL
 * Support for managing CRs in dynamically created namespaces
+* Template secret values
 
 ## Cloud specific configuration
 
@@ -173,6 +174,8 @@ spec:
   privileges: OWNER     # Can be OWNER/READ/WRITE
   annotations:          # Annotations to be propagated to the secrets metadata section (optional)
     foo: "bar"
+  secretTemplate:       # Output secrets can be customized using standard Go templates
+    PQ_URL: "host={{.Host}} user={{.Role}} password={{.Password}} dbname={{.Database}}"
 ```
 
 This creates a user role `username-<hash>` and grants role `test-db-group`, `test-db-writer` or `test-db-reader` depending on `privileges` property. Its credentials are put in secret `my-secret-my-db-user` (unless `KEEP_SECRET_NAME` is enabled).
@@ -203,6 +206,21 @@ With the help of annotations it is possible to create annotation-based copies of
 
 For more information and an example, see [kubernetes-replicator#pull-based-replication](https://github.com/mittwald/kubernetes-replicator#pull-based-replication)
 
+#### Template Use Case
+
+Users can specify the structure and content of secrets based on their unique requirements using standard 
+[Go templates](https://pkg.go.dev/text/template#hdr-Actions). This flexibility allows for a more tailored approach to
+meeting the specific needs of different applications.
+
+Available context:
+
+| Variable    | Meaning                  |
+|-------------|--------------------------|
+| `.Host`     | Database host            |
+| `.Role`     | Generated user/role name |
+| `.Database` | Referenced database name |
+| `.Password` | Generated role password  |
+
 ### Contribution
 
 You can contribute to this project by opening a PR to merge to `master`, or one of the `vX.X.X` branches.

charts/ext-postgres-operator/crds/db.movetokube.com_postgresusers_crd.yaml

@@ -31,6 +31,10 @@ spec:
           spec:
             description: PostgresUserSpec defines the desired state of PostgresUser
             properties:
+              annotations:
+                additionalProperties:
+                  type: string
+                type: object
               database:
                 type: string
               privileges:
@@ -39,6 +43,10 @@ spec:
                 type: string
               secretName:
                 type: string
+              template:
+                additionalProperties:
+                  type: string
+                type: object
             required:
             - database
             - role

deploy/crds/db.movetokube.com_postgresusers_crd.yaml

@@ -31,6 +31,10 @@ spec:
           spec:
             description: PostgresUserSpec defines the desired state of PostgresUser
             properties:
+              annotations:
+                additionalProperties:
+                  type: string
+                type: object
               database:
                 type: string
               privileges:
@@ -39,6 +43,10 @@ spec:
                 type: string
               secretName:
                 type: string
+              secretTemplate:
+                additionalProperties:
+                  type: string
+                type: object
             required:
             - database
             - role

pkg/apis/db/v1alpha1/postgresuser_types.go

@@ -14,6 +14,8 @@ type PostgresUserSpec struct {
 	Database   string `json:"database"`
 	SecretName string `json:"secretName"`
 	// +optional
+	SecretTemplate map[string]string `json:"secretTemplate,omitempty"` // key-value, where key is secret field, value is go template
+	// +optional
 	Privileges string `json:"privileges"`
 	// +optional
 	Annotations map[string]string `json:"annotations,omitempty"`

pkg/controller/postgresuser/postgresuser_controller.go

@@ -1,9 +1,11 @@
 package postgresuser
 
 import (
+	"bytes"
 	"context"
 	goerr "errors"
 	"fmt"
+	"text/template"
 
 	"github.com/movetokube/postgres-operator/pkg/config"
 
@@ -221,7 +223,10 @@ func (r *ReconcilePostgresUser) Reconcile(request reconcile.Request) (reconcile.
 		return r.requeue(instance, err)
 	}
 
-	secret := r.newSecretForCR(instance, role, password, login)
+	secret, err := r.newSecretForCR(instance, role, password, login)
+	if err != nil {
+		return r.requeue(instance, err)
+	}
 
 	// Set PostgresUser instance as the owner and controller
 	if err := controllerutil.SetControllerReference(instance, secret, r.scheme); err != nil {
@@ -270,7 +275,7 @@ func (r *ReconcilePostgresUser) addFinalizer(reqLogger logr.Logger, m *dbv1alpha
 	return nil
 }
 
-func (r *ReconcilePostgresUser) newSecretForCR(cr *dbv1alpha1.PostgresUser, role, password, login string) *corev1.Secret {
+func (r *ReconcilePostgresUser) newSecretForCR(cr *dbv1alpha1.PostgresUser, role, password, login string) (*corev1.Secret, error) {
 	pgUserUrl := fmt.Sprintf("postgresql://%s:%s@%s/%s", role, password, r.pgHost, cr.Status.DatabaseName)
 	pgJDBCUrl := fmt.Sprintf("jdbc:postgresql://%s/%s", r.pgHost, cr.Status.DatabaseName)
 	pgDotnetUrl := fmt.Sprintf("User ID=%s;Password=%s;Host=%s;Port=5432;Database=%s;", role, password, r.pgHost, cr.Status.DatabaseName)
@@ -283,24 +288,40 @@ func (r *ReconcilePostgresUser) newSecretForCR(cr *dbv1alpha1.PostgresUser, role
 		name = cr.Spec.SecretName
 	}
 
+	templateData, err := renderTemplate(cr.Spec.SecretTemplate, templateContext{
+		Role:     role,
+		Host:     r.pgHost,
+		Database: cr.Status.DatabaseName,
+		Password: password,
+	})
+	if err != nil {
+		return nil, fmt.Errorf("render templated keys: %w", err)
+	}
+
+	data := map[string][]byte{
+		"POSTGRES_URL":        []byte(pgUserUrl),
+		"POSTGRES_JDBC_URL":   []byte(pgJDBCUrl),
+		"POSTGRES_DOTNET_URL": []byte(pgDotnetUrl),
+		"HOST":                []byte(r.pgHost),
+		"DATABASE_NAME":       []byte(cr.Status.DatabaseName),
+		"ROLE":                []byte(role),
+		"PASSWORD":            []byte(password),
+		"LOGIN":               []byte(login),
+	}
+	// templates may override standard keys
+	for k, v := range templateData {
+		data[k] = v
+	}
+
 	return &corev1.Secret{
 		ObjectMeta: metav1.ObjectMeta{
 			Name:        name,
 			Namespace:   cr.Namespace,
 			Labels:      labels,
 			Annotations: annotations,
 		},
-		Data: map[string][]byte{
-			"POSTGRES_URL":        []byte(pgUserUrl),
-			"POSTGRES_JDBC_URL":   []byte(pgJDBCUrl),
-			"POSTGRES_DOTNET_URL": []byte(pgDotnetUrl),
-			"HOST":                []byte(r.pgHost),
-			"DATABASE_NAME":       []byte(cr.Status.DatabaseName),
-			"ROLE":                []byte(role),
-			"PASSWORD":            []byte(password),
-			"LOGIN":               []byte(login),
-		},
-	}
+		Data: data,
+	}, nil
 }
 
 func (r *ReconcilePostgresUser) requeue(cr *dbv1alpha1.PostgresUser, reason error) (reconcile.Result, error) {
@@ -354,3 +375,29 @@ func (r *ReconcilePostgresUser) addOwnerRef(reqLogger logr.Logger, instance *dbv
 	err = r.client.Update(context.TODO(), instance)
 	return err
 }
+
+type templateContext struct {
+	Host     string
+	Role     string
+	Database string
+	Password string
+}
+
+func renderTemplate(data map[string]string, tc templateContext) (map[string][]byte, error) {
+	if len(data) == 0 {
+		return nil, nil
+	}
+	var out = make(map[string][]byte, len(data))
+	for key, templ := range data {
+		parsed, err := template.New("").Parse(templ)
+		if err != nil {
+			return nil, fmt.Errorf("parse template %q: %w", key, err)
+		}
+		var content bytes.Buffer
+		if err := parsed.Execute(&content, tc); err != nil {
+			return nil, fmt.Errorf("execute template %q: %w", key, err)
+		}
+		out[key] = content.Bytes()
+	}
+	return out, nil
+}