Merge pull request #134 from mnottale/init-single-comments

init: Add section comments in single-file mode.

Author: mnottale

e2e/testdata/init-singlefile.dockerapp

@@ -1,3 +1,4 @@
+# This section contains your application metadata.
 version: 0.1.0
 name: tac
 description: my cool app
@@ -11,11 +12,13 @@ targets:
   kubernetes: true
 
 --
+# This section contains the Compose file that describes your application services.
 services:
   nginx:
     image: nginx:${NGINX_VERSION}
     command: nginx $NGINX_ARGS
 
 --
+# This section contains the default values for your application settings.
 NGINX_ARGS: FILL ME
 NGINX_VERSION: latest

examples/hello-world/README.md

@@ -14,9 +14,7 @@ $ ls -l
 -rw-r--r-- 1 README.md
 -rw-r--r-- 1 hello-world.dockerapp
 $ cat hello-world.dockerapp
-#
-# Metadata.
-#
+# This section contains your application metadata.
 version: 0.1.0
 name: hello-world
 description: ""
@@ -28,16 +26,12 @@ targets:
   kubernetes: true
 
 --
-#
-# Services.
-#
+# This section contains the Compose file that describes your application services.
 version: "3.6"
 services: {}
 
 --
-#
-# Settings.
-#
+# This section contains the default values for your application settings.
 ```
 
 Open `hello-world.dockerapp` with your favorite text editor.
@@ -56,9 +50,7 @@ Add a service `hello` to the `services` section.
 ```yml
 [...]
 ---
-#
-# Services.
-#
+# This section contains the Compose file that describes your application services.
 services:
   hello:
     image: hashicorp/http-echo
@@ -80,9 +72,7 @@ In the settings section, add every variables with the default value you want, e.
 ```yml
 [...]
 ---
-#
-# Settings.
-#
+# This section contains the default values for your application settings.
 port: 8080
 text: hello world!
 ```

packager/init.go

@@ -15,6 +15,12 @@ import (
 	"gopkg.in/yaml.v2"
 )
 
+func prependToFile(filename, text string) {
+	content, _ := ioutil.ReadFile(filename)
+	content = []byte(text + string(content))
+	ioutil.WriteFile(filename, content, 0644)
+}
+
 // Init is the entrypoint initialization function.
 // It generates a new application package based on the provided parameters.
 func Init(name string, composeFile string, description string, maintainers []string, singleFile bool) error {
@@ -52,6 +58,10 @@ func Init(name string, composeFile string, description string, maintainers []str
 		return nil
 	}
 	// Merge as a single file
+	// Add some helfpful comments to distinguish the sections
+	prependToFile(filepath.Join(dirName, "docker-compose.yml"), "# This section contains the Compose file that describes your application services.\n")
+	prependToFile(filepath.Join(dirName, "settings.yml"), "# This section contains the default values for your application settings.\n")
+	prependToFile(filepath.Join(dirName, "metadata.yml"), "# This section contains your application metadata.\n")
 	temp := "_temp_dockerapp__.dockerapp"
 	err = os.Rename(dirName, temp)
 	if err != nil {