create configmap from-env-file

pkg/kubectl/configmap.go

@@ -38,6 +38,8 @@ type ConfigMapGeneratorV1 struct {
 	FileSources []string
 	// LiteralSources to derive the configMap from (optional)
 	LiteralSources []string
+	// EnvFileSource to derive the configMap from (optional)
+	EnvFileSource string
 }
 
 // Ensure it supports the generator pattern that uses parameter injection.
@@ -79,6 +81,15 @@ func (s ConfigMapGeneratorV1) Generate(genericParams map[string]interface{}) (ru
 		}
 		params[key] = strVal
 	}
+	fromEnvFileString, found := genericParams["from-env-file"]
+	if found {
+		fromEnvFile, isString := fromEnvFileString.(string)
+		if !isString {
+			return nil, fmt.Errorf("expected string, found :%v", fromEnvFileString)
+		}
+		delegate.EnvFileSource = fromEnvFile
+		delete(genericParams, "from-env-file")
+	}
 	delegate.Name = params["name"]
 	delegate.Type = params["type"]
 	return delegate.StructuredGenerate()
@@ -91,6 +102,7 @@ func (s ConfigMapGeneratorV1) ParamNames() []GeneratorParam {
 		{"type", false},
 		{"from-file", false},
 		{"from-literal", false},
+		{"from-env-file", false},
 		{"force", false},
 	}
 }
@@ -113,6 +125,11 @@ func (s ConfigMapGeneratorV1) StructuredGenerate() (runtime.Object, error) {
 			return nil, err
 		}
 	}
+	if len(s.EnvFileSource) > 0 {
+		if err := handleConfigMapFromEnvFileSource(configMap, s.EnvFileSource); err != nil {
+			return nil, err
+		}
+	}
 	return configMap, nil
 }
 
@@ -121,6 +138,9 @@ func (s ConfigMapGeneratorV1) validate() error {
 	if len(s.Name) == 0 {
 		return fmt.Errorf("name must be specified")
 	}
+	if len(s.EnvFileSource) > 0 && (len(s.FileSources) > 0 || len(s.LiteralSources) > 0) {
+		return fmt.Errorf("from-env-file cannot be combined with from-file or from-literal")
+	}
 	return nil
 }
 
@@ -186,6 +206,24 @@ func handleConfigMapFromFileSources(configMap *api.ConfigMap, fileSources []stri
 	return nil
 }
 
+// handleConfigMapFromEnvFileSource adds the specified env file source information
+// into the provided configMap
+func handleConfigMapFromEnvFileSource(configMap *api.ConfigMap, envFileSource string) error {
+	info, err := os.Stat(envFileSource)
+	if err != nil {
+		switch err := err.(type) {
+		case *os.PathError:
+			return fmt.Errorf("error reading %s: %v", envFileSource, err.Err)
+		default:
+			return fmt.Errorf("error reading %s: %v", envFileSource, err)
+		}
+	}
+	if info.IsDir() {
+		return fmt.Errorf("must be a file")
+	}
+	return addFromEnvFileToConfigMap(configMap, envFileSource)
+}
+
 // addKeyFromFileToConfigMap adds a key with the given name to a ConfigMap, populating
 // the value with the content of the given file path, or returns an error.
 func addKeyFromFileToConfigMap(configMap *api.ConfigMap, keyName, filePath string) error {