feat: Add new Kubernetes Secret backend

Signed-off-by: Dennis Lapchenko <dennis.lapchenko@gmail.com>

docs/backends.md

@@ -705,3 +705,59 @@ type: Opaque
 data:
   password: <path:secret-id#key | base64encode>
 ```
+
+### Kubernets Secret
+
+**Note**: The Kubernetes secret backend does not support versioning
+
+##### Kubernetes Secret Authentication
+
+Refer to the "Configuring Plugin" section, as this backend uses same in-cluster service-account as the plugin itself.
+
+These are the parameters for Kubernetes Secret:
+
+```
+AVP_TYPE: kubernetessecret
+AVP_K8S_SECRET_SECRET: avp-secret-data
+```
+
+##### Examples
+
+###### Inline Path Reading from configured secret
+
+```yaml
+kind: Secret
+apiVersion: v1
+metadata:
+  name: test-secret
+type: Opaque
+data:
+  username: <path:~#key>
+  password: <path:default#key2>
+```
+
+###### Path Annotation
+
+```yaml
+kind: Secret
+apiVersion: v1
+metadata:
+  name: test-secret
+  annotations:
+    avp.kubernetes.io/path: "custom-secret-data"
+type: Opaque
+data:
+  password: <key>
+```
+
+###### Inline Path
+
+```yaml
+kind: Secret
+apiVersion: v1
+metadata:
+  name: test-secret
+type: Opaque
+data:
+  password: <path:custom-secret-data#key>
+```

go.mod

@@ -212,7 +212,7 @@ require (
 	github.com/pelletier/go-toml/v2 v2.0.1 // indirect
 	github.com/petermattis/goid v0.0.0-20180202154549-b0b1615b78e5 // indirect
 	github.com/pires/go-proxyproto v0.6.1 // indirect
-	github.com/pkg/errors v0.9.1 // indirect
+	github.com/pkg/errors v0.9.1
 	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
 	github.com/posener/complete v1.2.3 // indirect
 	github.com/power-devops/perfstat v0.0.0-20210106213030-5aafc221ea8c // indirect

pkg/backends/kubernetessecret.go

@@ -0,0 +1,70 @@
+package backends
+
+import (
+	"github.com/argoproj-labs/argocd-vault-plugin/pkg/kube"
+	"github.com/argoproj-labs/argocd-vault-plugin/pkg/utils"
+	"github.com/pkg/errors"
+)
+
+var useDefaultSecret = func(s string) bool { return s == "default" || s == "~" }
+
+type kubeSecretsClient interface {
+	ReadSecretData(string) (map[string][]byte, error)
+}
+
+// KubernetesSecret is a struct for working with a Kubernetes Secret backend
+type KubernetesSecret struct {
+	secretName string
+	client     kubeSecretsClient
+}
+
+// NewKubernetesSecret returns a new Kubernetes Secret backend.
+func NewKubernetesSecret(secretName string) *KubernetesSecret {
+	return &KubernetesSecret{
+		secretName: secretName,
+	}
+}
+
+// Login initiates kubernetes client
+func (k *KubernetesSecret) Login() error {
+	localClient, err := kube.NewClient()
+	if err != nil {
+		return errors.Wrap(err, "Failed to perform login for kubernetes secret backend")
+	}
+	k.client = localClient
+	return nil
+}
+
+// GetSecrets gets secrets from Kubernetes Secret and returns the formatted data
+func (k *KubernetesSecret) GetSecrets(path string, version string, annotations map[string]string) (map[string]interface{}, error) {
+	secretName := path
+	if useDefaultSecret(path) {
+		secretName = k.secretName
+	}
+	utils.VerboseToStdErr("K8s Secret getting secret: %s", secretName)
+
+	data, err := k.client.ReadSecretData(secretName)
+	if err != nil {
+		return nil, err
+	}
+
+	out := make(map[string]interface{}, len(data))
+	for k, v := range data {
+		out[k] = string(v)
+	}
+
+	utils.VerboseToStdErr("K8s Secret get secret response: %v", out)
+	return out, nil
+}
+
+// GetIndividualSecret will get the specific secret (placeholder) from the Kubernetes Secret backend
+// Kubernetes Secrets can only be wholly read,
+// So, we use GetSecrets and extract the specific placeholder we want
+func (k *KubernetesSecret) GetIndividualSecret(kvpath, secret, version string, annotations map[string]string) (interface{}, error) {
+	utils.VerboseToStdErr("K8s Secret getting secret %s and key %s", kvpath, secret)
+	data, err := k.GetSecrets(kvpath, version, annotations)
+	if err != nil {
+		return nil, err
+	}
+	return data[secret], nil
+}

pkg/backends/kubernetessecret_test.go

@@ -0,0 +1,75 @@
+package backends
+
+import (
+	"reflect"
+	"testing"
+)
+
+func newMockK8sClient(vals map[string]string, err error) *mockK8sClient {
+	encoded := make(map[string][]byte)
+	for k, v := range vals {
+		encoded[k] = []byte(v)
+	}
+	return &mockK8sClient{
+		response: encoded,
+		err:      err,
+	}
+}
+
+type mockK8sClient struct {
+	response map[string][]byte
+	err      error
+}
+
+func (m *mockK8sClient) ReadSecretData(path string) (map[string][]byte, error) {
+	return m.response, m.err
+}
+
+func TestKubernetesSecretGetSecrets(t *testing.T) {
+	sm := NewKubernetesSecret("test")
+	sm.client = newMockK8sClient(map[string]string{
+		"test-secret": "current-value",
+		"test2":       "bar",
+	}, nil)
+
+	t.Run("Get secrets", func(t *testing.T) {
+
+		data, err := sm.GetSecrets("test", "", map[string]string{})
+		if err != nil {
+			t.Fatalf("expected 0 errors but got: %s", err)
+		}
+
+		expected := map[string]interface{}{
+			"test-secret": "current-value",
+			"test2":       "bar",
+		}
+
+		if !reflect.DeepEqual(expected, data) {
+			t.Errorf("expected: %s, got: %s.", expected, data)
+		}
+	})
+
+	t.Run("GetIndividualSecret", func(t *testing.T) {
+		secret, err := sm.GetIndividualSecret("test", "test2", "", map[string]string{})
+		if err != nil {
+			t.Fatalf("expected 0 errors but got: %s", err)
+		}
+
+		expected := "bar"
+
+		if !reflect.DeepEqual(expected, secret) {
+			t.Errorf("expected: %s, got: %s.", expected, secret)
+		}
+	})
+
+	t.Run("GetIndividualSecretNotFound", func(t *testing.T) {
+		secret, err := sm.GetIndividualSecret("test", "22test2", "", map[string]string{})
+		if err != nil {
+			t.Fatalf("expected 0 errors but got: %s", err)
+		}
+
+		if secret != nil {
+			t.Errorf("expected: %s, got: %s.", "nil", secret)
+		}
+	})
+}

pkg/config/config.go

@@ -49,6 +49,7 @@ var backendPrefixes []string = []string{
 	"google",
 	"sops",
 	"op_connect",
+	"k8s_secret",
 }
 
 // New returns a new Config struct
@@ -278,6 +279,14 @@ func New(v *viper.Viper, co *Options) (*Config, error) {
 			}
 			backend = backends.NewDelineaSecretServerBackend(tss)
 		}
+	case types.KubernetesSecretBackend:
+		{
+			if !v.IsSet(types.EnvKubernetesSecretSecret) {
+				return nil, fmt.Errorf("%s is required for Kubernetes Secret backend", types.EnvKubernetesSecretSecret)
+			}
+			secretName := v.GetString(types.EnvKubernetesSecretSecret)
+			backend = backends.NewKubernetesSecret(secretName)
+		}
 	default:
 		return nil, fmt.Errorf("Must provide a supported Vault Type, received %s", v.GetString(types.EnvAvpType))
 	}

pkg/config/config_test.go

@@ -219,6 +219,13 @@ fDGt+yaf3RaZbVwHSVLzxiXGsu1WQJde3uJeNh5c6z+5
 			},
 			"*backends.DelineaSecretServer",
 		},
+		{
+			map[string]interface{}{
+				"AVP_TYPE":              "kubernetessecret",
+				"AVP_K8S_SECRET_SECRET": "argocd-vault-plugin-secret-data",
+			},
+			"*backends.KubernetesSecret",
+		},
 	}
 	for _, tc := range testCases {
 		for k, v := range tc.environment {
@@ -485,6 +492,12 @@ func TestNewConfigMissingParameter(t *testing.T) {
 			},
 			"*backends.DelineaSecretServer",
 		},
+		{
+			map[string]interface{}{
+				"AVP_TYPE": "kubernetessecret",
+			},
+			"*backends.KubernetesSecret",
+		},
 	}
 	for _, tc := range testCases {
 		for k, v := range tc.environment {

pkg/kube/client.go

@@ -32,9 +32,9 @@ func NewClient() (*Client, error) {
 	}, nil
 }
 
-// ReadSecret reads the specified Secret from the defined namespace, otherwise defaults to `argocd`
-// and returns a YAML []byte containing its data, decoded from base64
-func (c *Client) ReadSecret(name string) ([]byte, error) {
+// ReadSecretData reads the specified Secret from the defined namespace, otherwise defaults to `argocd`
+// and returns map[string][]byte containing its data
+func (c *Client) ReadSecretData(name string) (map[string][]byte, error) {
 	secretNamespace, secretName := secretNamespaceName(name)
 
 	utils.VerboseToStdErr("parsed secret name as %s from namespace %s", secretName, secretNamespace)
@@ -43,8 +43,20 @@ func (c *Client) ReadSecret(name string) ([]byte, error) {
 	if err != nil {
 		return nil, err
 	}
+
+	return s.Data, nil
+}
+
+// ReadSecret reads the specified Secret from the defined namespace, otherwise defaults to `argocd`
+// and returns a YAML []byte containing its data, decoded from base64
+func (c *Client) ReadSecret(name string) ([]byte, error) {
+	data, err := c.ReadSecretData(name)
+	if err != nil {
+		return nil, err
+	}
+
 	decoded := make(map[string]string)
-	for key, value := range s.Data {
+	for key, value := range data {
 		decoded[key] = string(value)
 	}
 	res, err := k8yaml.Marshal(&decoded)

pkg/types/constants.go

@@ -5,32 +5,33 @@ const (
 	EnvArgoCDPrefix = "ARGOCD_ENV"
 
 	// Environment Variable Constants
-	EnvAvpType             = "AVP_TYPE"
-	EnvAvpRoleID           = "AVP_ROLE_ID"
-	EnvAvpSecretID         = "AVP_SECRET_ID"
-	EnvAvpAuthType         = "AVP_AUTH_TYPE"
-	EnvAvpGithubToken      = "AVP_GITHUB_TOKEN"
-	EnvAvpK8sRole          = "AVP_K8S_ROLE"
-	EnvAvpK8sMountPath     = "AVP_K8S_MOUNT_PATH"
-	EnvAvpMountPath        = "AVP_MOUNT_PATH"
-	EnvAvpK8sTokenPath     = "AVP_K8S_TOKEN_PATH"
-	EnvAvpIBMAPIKey        = "AVP_IBM_API_KEY"
-	EnvAvpIBMInstanceURL   = "AVP_IBM_INSTANCE_URL"
-	EnvAvpKvVersion        = "AVP_KV_VERSION"
-	EnvAvpPathPrefix       = "AVP_PATH_PREFIX"
-	EnvAWSRegion           = "AWS_REGION"
-	EnvVaultAddress        = "VAULT_ADDR"
-	EnvYCLKeyID            = "AVP_YCL_KEY_ID"
-	EnvYCLServiceAccountID = "AVP_YCL_SERVICE_ACCOUNT_ID"
-	EnvYCLPrivateKey       = "AVP_YCL_PRIVATE_KEY"
-	EnvAvpUsername         = "AVP_USERNAME"
-	EnvAvpPassword         = "AVP_PASSWORD"
-	EnvPathValidation      = "AVP_PATH_VALIDATION"
-	EnvAvpKSMConfigPath    = "AVP_KEEPER_CONFIG_PATH"
-	EnvAvpDelineaURL       = "AVP_DELINEA_URL"
-	EnvAvpDelineaUser      = "AVP_DELINEA_USER"
-	EnvAvpDelineaPassword  = "AVP_DELINEA_PASSWORD"
-	EnvAvpDelineaDomain    = "AVP_DELINEA_DOMAIN"
+	EnvAvpType                = "AVP_TYPE"
+	EnvAvpRoleID              = "AVP_ROLE_ID"
+	EnvAvpSecretID            = "AVP_SECRET_ID"
+	EnvAvpAuthType            = "AVP_AUTH_TYPE"
+	EnvAvpGithubToken         = "AVP_GITHUB_TOKEN"
+	EnvAvpK8sRole             = "AVP_K8S_ROLE"
+	EnvAvpK8sMountPath        = "AVP_K8S_MOUNT_PATH"
+	EnvAvpMountPath           = "AVP_MOUNT_PATH"
+	EnvAvpK8sTokenPath        = "AVP_K8S_TOKEN_PATH"
+	EnvAvpIBMAPIKey           = "AVP_IBM_API_KEY"
+	EnvAvpIBMInstanceURL      = "AVP_IBM_INSTANCE_URL"
+	EnvAvpKvVersion           = "AVP_KV_VERSION"
+	EnvAvpPathPrefix          = "AVP_PATH_PREFIX"
+	EnvAWSRegion              = "AWS_REGION"
+	EnvVaultAddress           = "VAULT_ADDR"
+	EnvYCLKeyID               = "AVP_YCL_KEY_ID"
+	EnvYCLServiceAccountID    = "AVP_YCL_SERVICE_ACCOUNT_ID"
+	EnvYCLPrivateKey          = "AVP_YCL_PRIVATE_KEY"
+	EnvAvpUsername            = "AVP_USERNAME"
+	EnvAvpPassword            = "AVP_PASSWORD"
+	EnvPathValidation         = "AVP_PATH_VALIDATION"
+	EnvAvpKSMConfigPath       = "AVP_KEEPER_CONFIG_PATH"
+	EnvAvpDelineaURL          = "AVP_DELINEA_URL"
+	EnvAvpDelineaUser         = "AVP_DELINEA_USER"
+	EnvAvpDelineaPassword     = "AVP_DELINEA_PASSWORD"
+	EnvAvpDelineaDomain       = "AVP_DELINEA_DOMAIN"
+	EnvKubernetesSecretSecret = "AVP_K8S_SECRET_SECRET"
 
 	// Backend and Auth Constants
 	VaultBackend                = "vault"
@@ -43,6 +44,7 @@ const (
 	DelineaSecretServerbackend  = "delineasecretserver"
 	OnePasswordConnect          = "1passwordconnect"
 	KeeperSecretsManagerBackend = "keepersecretsmanager"
+	KubernetesSecretBackend     = "kubernetessecret"
 	K8sAuth                     = "k8s"
 	ApproleAuth                 = "approle"
 	GithubAuth                  = "github"