Write env variable for single key, if not also written to file

This fixes a bug where `SECRET_ENV=true` only worked if `DAYTONA_SECRET_DESTINATION_THING` is also set, even though that is not expected.

Fix cruise-automation#99

pkg/secrets/secrets.go

@@ -51,6 +51,7 @@ type SecretDefinition struct {
 	paths             []string
 	secrets           map[string]string
 	plural            bool
+	secretEnv         bool
 }
 
 // SecretFetcher inspects the environment for variables that
@@ -84,6 +85,7 @@ func SecretFetcher(client *api.Client, config cfg.Config) {
 			envkey:     envKey,
 			secretApex: apex,
 			secrets:    make(map[string]string),
+			secretEnv:  config.SecretEnv,
 		}
 
 		switch {
@@ -285,20 +287,23 @@ func (sd *SecretDefinition) addSecrets(secretResult *SecretResult) error {
 		return fmt.Errorf("vault listed a secret %s %s, but failed trying to read it; likely the rate-limiting retry attempts were exceeded", keyName, keyPath)
 	}
 
+	envKey := os.Getenv(secretValueKeyPrefix + sd.secretID)
+	if envKey != "" {
+		log.Info().Str("key", secretValueKeyPrefix+sd.secretID).Msg("Found an explicit vault value key, will read this value key instead of using the default")
+	}
+
+	if !sd.plural && sd.secretEnv && envKey != "" {
+		if err := sd.copyValue(secretData, envKey); err != nil {
+			return err
+		}
+	}
+
 	if !sd.plural && sd.outputDestination != "" {
 		singleValueKey := defaultKeyName
-		if envKey := os.Getenv(secretValueKeyPrefix + sd.secretID); envKey != "" {
-			log.Info().Str("key", secretValueKeyPrefix+sd.secretID).Str("value", singleValueKey).Msg("Found an explicit vault value key, will read this value key instead of using the default")
+		if envKey != "" {
 			singleValueKey = envKey
 		}
-		v, ok := secretData[singleValueKey]
-		if ok {
-			secretValue, err := valueConverter(v)
-			if err == nil {
-				sd.Lock()
-				sd.secrets[singleValueKey] = secretValue
-				sd.Unlock()
-			}
+		if err := sd.copyValue(secretData, singleValueKey); err != nil {
 			return err
 		}
 	}
@@ -321,6 +326,24 @@ func (sd *SecretDefinition) addSecrets(secretResult *SecretResult) error {
 	return nil
 }
 
+// copyValues copies a value from the secretData object returned by vault and writes it into the secrets map of the
+// SecretDefintion
+func (sd *SecretDefinition) copyValue(secretData map[string]interface{}, key string) error {
+	v, ok := secretData[key]
+	if ok {
+		secretValue, err := valueConverter(v)
+		if err == nil {
+			sd.Lock()
+			sd.secrets[key] = secretValue
+			sd.Unlock()
+			return nil
+		} else {
+			return err
+		}
+	}
+	return nil
+}
+
 // Walk walks a SecretDefintions SecretApex. This is used for iteration
 // of the provided apex path
 func (sd *SecretDefinition) Walk(client *api.Client) error {

pkg/secrets/secrets_test.go

@@ -804,3 +804,91 @@ func TestSecretSingularDestinationKeyOverride(t *testing.T) {
 
 	assert.Equal(t, "nonstandard", string(data))
 }
+
+func TestSecretSingularEnvKeyOverride(t *testing.T) {
+	var config cfg.Config
+
+	ts := httptest.NewTLSServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		fmt.Fprintln(w, `
+		{
+			"auth": null,
+			"data": {
+			  "username": "alice",
+			  "password": "p@ssw0rd"
+			},
+			"lease_duration": 3600,
+			"lease_id": "",
+			"renewable": false
+		  }
+		`)
+	}))
+	defer ts.Close()
+	client, err := testhelpers.GetTestClient(ts.URL)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	os.Setenv("VAULT_SECRET_APPLICATIONA", "secret/applicationA")
+	os.Setenv("VAULT_VALUE_KEY_APPLICATIONA", "password")
+
+	defer os.Unsetenv("VAULT_SECRET_APPLICATIONA")
+	defer os.Unsetenv("VAULT_VALUE_KEY_APPLICATIONA")
+	defer os.Unsetenv("password")
+
+	config.Workers = 3
+	config.SecretEnv = true
+	SecretFetcher(client, config)
+
+	assert.Equal(t, "p@ssw0rd", os.Getenv("password"))
+}
+
+func TestCopyValue(t *testing.T) {
+	tests := []struct {
+		name            string
+		secretData      map[string]interface{}
+		key             string
+		expectedSecrets map[string]string
+		expectedError   error
+	}{
+		{
+			name: "copy value",
+			secretData: map[string]interface{}{
+				"foo": "bar",
+			},
+			key: "foo",
+			expectedSecrets: map[string]string{
+				"foo": "bar",
+			},
+			expectedError: nil,
+		},
+		{
+			name: "value not found",
+			secretData: map[string]interface{}{
+				"foo": "bar",
+			},
+			key:             "baz",
+			expectedSecrets: map[string]string{},
+			expectedError:   nil,
+		},
+		{
+			name: "value conversion error",
+			secretData: map[string]interface{}{
+				"foo": 42,
+			},
+			key:             "foo",
+			expectedSecrets: map[string]string{},
+			expectedError:   fmt.Errorf("unsupported value type retrieved from vault: int"),
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			sd := &SecretDefinition{secrets: map[string]string{}}
+
+			err := sd.copyValue(tt.secretData, tt.key)
+
+			assert.Equal(t, tt.expectedSecrets, sd.secrets)
+			assert.Equal(t, tt.expectedError, err)
+		})
+	}
+}