Examples: Make hello-world a single file application.

Signed-off-by: Antony MECHIN <[email protected]>

Author: Antony MECHIN

examples/hello-world/README.md

@@ -4,40 +4,86 @@
 
 In this example, we will create a single service application that deploys a web page displaying a message.
 
-Initialize the project using `docker-app init hello-world`.
+Initialize the single file project using `docker-app init -s hello-world`. A single file application contains the three sections, `metadata` corresponding `metadata.yml`, `settings` corresponding `settings.yml` and `services` corresponding `docker-compose.yml`.
+
+```
+$ ls -l
+-rw-r--r-- 1 README.md
+$ docker-app init -s hello-world
+$ ls -l
+-rw-r--r-- 1 README.md
+-rw-r--r-- 1 hello-world.dockerapp
+$ cat hello-world.dockerapp
+#
+# Metadata.
+#
+version: 0.1.0
+name: hello-world
+description: ""
+maintainers:
+- name: dimrok
+  email: ""
+targets:
+  swarm: true
+  kubernetes: true
+
+--
+#
+# Services.
+#
+version: "3.6"
+services: {}
+
+--
+#
+# Settings.
+#
+```
+
+Open `hello-world.dockerapp` with your favorite text editor.
 
 ### Edit metadata
 
-Go to `hello-world.dockerapp/` and open `metadata.yml` and fill the following fields:
-- description
-- maintainers
+Edit the `description` and `maintainers` fields in the metadata section.
 
 ### Add variables to the compose file
 
-Open `docker-compose.yml` and add a service `hello`.
+Add a service `hello` to the `services` section.
 
 ```
+[...]
+---
+#
+# Services.
+#
 services:
   hello:
     image: hashicorp/http-echo
     command: ["-text", "${text}"]
     ports:
       - ${port}:5678
+
+---
+[...]
 ```
 
 ### Give variables their default value
 
-Open `settings.yml` and add every variables with the default value you want, e.g.:
+In the settings section, add every variables with the default value you want, e.g.:
 
 ```
-$ cat settings.yml
+[...]
+---
+#
+# Settings.
+#
 port: 8080
-text: world
+text: hello world!
 ```
 
 ### Render
 
-You can now render your application by running `docker-app render` or even personalize the rendered compose file by running `docker-app render -s text="hello user"`.
+You can now render your application by running `docker-app render` or even personalize the rendered compose file by running `docker-app render -s text="hello user!"`.
 
 Create a `render` directory and redirect the output of `docker-app render ...` to `render/docker-compose.yml`.
 
@@ -48,4 +94,6 @@ docker-app render -s text="hello user" > render/docker-compose.yml
 
 ### Deploy
 
-Deploy your application by running `docker-app deploy -c render/docker-compose.yml`. http://<ip_of_your_node>:8080 will display your message, e.g. http://127.0.0.1:8080 if you deployed locally.
+You directly deploy your application by running `docker-app deploy -s text="hello user!"` or you can use the rendered version and run `docker stack deploy render/docker-compose.yml`.
+
+`http://<ip_of_your_node>:8080` will display your message, e.g. http://127.0.0.1:8080 if you deployed locally.

examples/hello-world/hello-world.dockerapp

@@ -0,0 +1,31 @@
+#
+# Metadata.
+#
+version: 0.1.0
+name: hello-world
+description: "Hello world!"
+maintainers:
+- name: user
+  email: "[email protected]"
+targets:
+  swarm: true
+  kubernetes: true
+
+--
+#
+# Services.
+#
+version: "3.6"
+services:
+  hello:
+    image: hashicorp/http-echo
+    command: ["-text", "${text}"]
+    ports:
+      - ${port}:5678
+
+--
+#
+# Settings.
+#
+port: 8080
+text: hello world!