Merge pull request #25 from evryn/feat/support-more-config-methods

[Feature] Support more config methods

.github/workflows/image.yaml

@@ -39,7 +39,7 @@ jobs:
             ghcr.io/evryn/kermoo
             quay.io/evryn/kermoo
           flavor: |
-            latest=true
+            latest=auto
           tags: |
             type=semver,pattern={{version}}
             type=semver,pattern={{major}}.{{minor}}

commands/start_command.go

@@ -13,12 +13,18 @@ func GetStartCommand() *cobra.Command {
 		Use:   "start",
 		Short: "Start the Kermoo foreground service",
 		Run: func(cmd *cobra.Command, args []string) {
+			config, _ := cmd.Flags().GetString("config")
 			filename, _ := cmd.Flags().GetString("filename")
 			verbosity, _ := cmd.Flags().GetString("verbosity")
 
 			logger.MustInitLogger(verbosity)
 
-			user_config.MustLoadProvidedConfig(filename)
+			if filename != "" {
+				logger.Log.Warn("`filename` flag is deprecated and will be removed in a future major release. use `config` flag instead.")
+				config = filename
+			}
+
+			user_config.MustLoadPreparedConfig(config)
 
 			user_config.Prepared.Start()
 
@@ -29,7 +35,8 @@ func GetStartCommand() *cobra.Command {
 		},
 	}
 
-	cmd.Flags().StringP("filename", "f", "", "Path to your .yaml or .json configuration file")
+	cmd.Flags().StringP("filename", "f", "", "Alias to `config` flag")
+	cmd.Flags().StringP("config", "c", "", "Your YAML or JSON config content or path to a config file")
 	cmd.Flags().StringP("verbosity", "v", "", "Verbosity level of logging output. Valid values are: debug, info")
 
 	return cmd

docs/examples/docker-compose/docker-compose.yaml → docs/examples/docker-compose/file-based/docker-compose.yaml

@@ -5,4 +5,4 @@ services:
     image: evryn/kermoo
     command: start
     volumes:
-      - "./config.yaml:/home/kerm/.kermoo/config.yaml"
+      - "./config.yaml:/home/kerm/.kermoo/config.yaml"

docs/examples/docker-compose/inline/docker-compose.yaml

@@ -0,0 +1,13 @@
+version: '3.7'
+
+services:
+  kermoo:
+    image: evryn/kermoo
+    command:
+    - start
+    - -f
+    - |
+      process:
+        exit:
+          after: 2s
+          code: 5

docs/examples/docker-swarm-inline/inline/stack.yaml

@@ -0,0 +1,13 @@
+version: '3.7'
+
+services:
+  kermoo:
+    image: evryn/kermoo
+    command:
+    - start
+    - -f
+    - |
+      process:
+        exit:
+          after: 2s
+          code: 5

modules/user_config/loader.go

@@ -8,65 +8,65 @@ import (
 	"kermoo/modules/utils"
 	"os"
 	"os/user"
+	"strings"
 
 	"go.uber.org/zap"
 )
 
-func MustLoadProvidedConfig(filename string) {
-	uc, err := LoadUserConfig(filename)
+func MustLoadPreparedConfig(config string) {
+	prepared, err := MakePreparedConfig(config)
 
 	if err != nil {
-		logger.Log.Fatal("invalid initial user-provided config", zap.Error(err))
+		logger.Log.Panic(err.Error())
 	}
 
-	logger.Log.Info("initial configuration is loaded", zap.Any("unprepared", *uc))
+	Prepared = *prepared
+}
 
-	prepared, err := uc.GetPreparedConfig()
+// MakePreparedConfig resolves the configuration content and prepares the config object in the following order:
+//
+// 1. When no config is provided, it autoloads it from `{userHome}/.kermoo/config.[yaml|yml|json]`
+//
+// 2. When it couldn't autoload from file, it tries to load from `KERMOO_CONFIG` environment variable
+//
+// 3. When config is given and equals to "-", it tries to read from stdin (Standard Input) pipe
+//
+// 4. When the config is a file path, it tries to load it from that file.
+//
+// 5. Otherwise, it considers the content of config as the actual config and tries to parse that.
+func MakePreparedConfig(config string) (*PreparedConfigType, error) {
+	uc, err := makeUserConfig(config)
 
 	if err != nil {
-		logger.Log.Fatal("invalid prepared user-provided config", zap.Error(err))
+		return nil, fmt.Errorf("invalid config: %v", err)
 	}
 
-	logger.Log.Info("prepared configuration is loaded", zap.Any("prepared", prepared))
+	prepared, err := uc.GetPreparedConfig()
 
-	Prepared = *prepared
+	if err != nil {
+		return nil, fmt.Errorf("unable to preapre parsed config: %v", err)
+	}
+
+	return prepared, nil
 }
 
-func LoadUserConfig(filename string) (*UserConfigType, error) {
+func makeUserConfig(config string) (*UserConfigType, error) {
 	var err error
 	var uc UserConfigType
 
-	if filename == "" {
-		u, err := user.Current()
-		if err != nil {
-			return nil, fmt.Errorf("unable to determine current user to autoload config: %v", err)
-		}
-		filename = u.HomeDir + "/.kermoo/config.yaml"
-	}
-
-	if filename == "-" {
-		logger.Log.Debug("loading configuration from stdin...")
+	config, err = getResolvedConfig(config)
 
-		content, err := readStdin()
-		if err != nil {
-			return nil, err
-		}
+	if err != nil {
+		return nil, err
+	}
 
-		uc, err = unmarshal(content)
-		if err != nil {
-			return nil, err
-		}
-	} else {
-		logger.Log.Debug("loading configuration from file...", zap.String("filename", filename))
-		content, err := readFile(filename)
-		if err != nil {
-			return nil, err
-		}
+	if config == "" {
+		return nil, fmt.Errorf("resolved config is empty")
+	}
 
-		uc, err = unmarshal(content)
-		if err != nil {
-			return nil, err
-		}
+	uc, err = unmarshal(config)
+	if err != nil {
+		return nil, err
 	}
 
 	err = uc.Validate()
@@ -78,8 +78,58 @@ func LoadUserConfig(filename string) (*UserConfigType, error) {
 	return &uc, nil
 }
 
+func getResolvedConfig(config string) (string, error) {
+	if config == "" {
+		return getAutoloadedConfig()
+	}
+
+	if config == "-" {
+		logger.Log.Debug("loading configuration from stdin...")
+
+		return readStdin()
+	}
+
+	// TODO: Change the following to something more sophisticated
+	if !strings.ContainsAny(config, "\n\t{}") {
+		return readFile(config)
+	}
+
+	return config, nil
+}
+
+func getAutoloadedConfig() (string, error) {
+	u, err := user.Current()
+	if err != nil {
+		return "", fmt.Errorf("unable to determine current user to autoload config: %v", err)
+	}
+
+	pathes := []string{
+		u.HomeDir + "/.kermoo/config.yaml",
+		u.HomeDir + "/.kermoo/config.yml",
+		u.HomeDir + "/.kermoo/config.json",
+		u.HomeDir + "/.config/kermoo/config.yaml",
+		u.HomeDir + "/.config/kermoo/config.yml",
+		u.HomeDir + "/.config/kermoo/config.json",
+	}
+
+	for _, path := range pathes {
+		content, err := readFile(u.HomeDir + path)
+
+		if err == nil {
+			return content, nil
+		}
+	}
+
+	content := os.Getenv("KERMOO_CONFIG")
+	if content != "" {
+		return content, nil
+	}
+
+	return "", fmt.Errorf("no config is specified so we tried to autoload config but was unable to load it either from default path (%v) or from the environment variable. kermoo can not live without a config :(", u.HomeDir+"/.kermoo/")
+}
+
 func readFile(filename string) (string, error) {
-	logger.Log.Debug("reading file", zap.String("filename", filename))
+	logger.Log.Debug("reading file ...", zap.String("filename", filename))
 
 	body, err := os.ReadFile(filename)
 	if err != nil {
@@ -90,6 +140,8 @@ func readFile(filename string) (string, error) {
 }
 
 func readStdin() (string, error) {
+	logger.Log.Debug("reading stdin ...")
+
 	stat, _ := os.Stdin.Stat()
 	if (stat.Mode() & os.ModeCharDevice) != 0 {
 		return "", fmt.Errorf("stdin is not available to read from")
@@ -109,6 +161,8 @@ func readStdin() (string, error) {
 }
 
 func unmarshal(content string) (UserConfigType, error) {
+	logger.Log.Debug("unmarshaling config ...", zap.Any("config", content))
+
 	firstChar := string(content[0])
 
 	// Content is probably JSON

tests/e2e/webserver_test.go

@@ -211,7 +211,7 @@ func TestWebserverEndToEnd(t *testing.T) {
                 content:
                   static: hello-world
                 fault:
-                  interval: 100ms
+                  interval: 50ms
                   percentage: 50
 		`, 3*time.Second)
 
@@ -237,7 +237,7 @@ func TestWebserverEndToEnd(t *testing.T) {
 		e2e.Start(`
             plans:
             - name: readiness
-              interval: 100ms
+              interval: 50ms
               percentage: 40
             webServers:
             - port: 8080

tests/units/stubs/invalid_structure.json

@@ -1,8 +1,7 @@
 {
-  "schemaVersion": "invalid-schema-version",
   "process": {
       "exit": {
-        "after": "10ms to 1s100ms",
+        "after": "something invalid",
         "code": 2
       }
   }

tests/units/stubs/invalid_structure.yaml

@@ -1,5 +1,4 @@
-schemaVersion: "invalid-schema-version"
 process:
   exit:
-    after: 10ms to 1s100ms
+    after: something invalid
     code: 2

tests/units/stubs/valid.json

@@ -1,5 +1,4 @@
 {
-  "schemaVersion": "1",
   "process": {
       "exit": {
         "after": "10ms to 1s100ms",

tests/units/stubs/valid.yaml

@@ -1,4 +1,3 @@
-schemaVersion: "1"
 process:
   exit:
     after: 10ms to 1s100ms