Merge pull request #13 from vosmann/master

ApplicationId as parameter and readme expansion.

etcd-cluster-appliance/README.md

@@ -17,5 +17,36 @@ Currently the following scenarios are supported:
 Usage
 =====
 
-    senza create etcd-cluster.yaml STACK_VERSION HOSTED_ZONE DOCKER_IMAGE MINT_BUCKET SCALYR_KEY
-    senza create etcd-cluster.yaml 1 myteam.example.org pierone.example.org/myteam/etcd:0.1-SNAPSHOT zalando-stups-mint-123456789123-eu-west-1 abc123def
+## Step 1: Define an application
+Before starting with clusters, you will need to define an application under whose name your clusters will be created.
+This is done in [Kio](https://github.com/zalando-stups/kio) or its graphical interface [Yourturn](https://github.com/zalando-stups/yourturn). Assuming for the example that the application is being
+created under the team `elephant`, we might choose this app ID: `elephant-etcd`.
+
+## Step 2: Create an etcd cluster
+A cluster can be creating by issuing such a command:
+
+    senza create etcd-cluster.yaml STACK_VERSION APP_ID HOSTED_ZONE DOCKER_IMAGE MINT_BUCKET SCALYR_KEY
+
+For example, if you made are making an etcd cluster to be used by a service called `foo`, you could issue the following:
+
+    senza create etcd-cluster.yaml for-foo \
+                                   elephant-etcd \
+                                   elephant.example.org \
+                                   pierone.example.org/elephant/etcd:0.1-SNAPSHOT \
+                                   zalando-stups-mint-123456789123-eu-west-1 abc123def
+
+The idea is to have a single application ID, here it is `elephant-etcd`, and then create different versions, i.e. 
+different clusters by varying the `STACK_VERSION` parameter depending on the purpose you want to use that specific 
+cluster for.
+
+## Step 3: Confirm successful cluster creation
+Running this `senza create` command should have created:
+- the required amount of EC2 instances
+    - with stack name `elephant-etcd`
+    - with instance name `elephant-etcd-for-foo`
+- a security group allowing etcd's ports 2379 and 2380
+- a role that allows reading `elephant-etcd` app's Mint bucket
+- DNS records
+    - an A record of the form `for-foo.elephant.example.org.`
+    - a SRV record of the form `_etcd-server._tcp.for-foo.elephant.example.org.`
+

etcd-cluster-appliance/etcd-cluster.yaml

@@ -10,6 +10,7 @@ SenzaComponents:
       - EtcdSecurityGroup
       - GroupId
     TaupageConfig:
+      application_id: "{{Arguments.ApplicationId}}"
       ports:
         2379: 2379
         2380: 2380
@@ -32,6 +33,8 @@ SenzaComponents:
       MetricType: CPU
 SenzaInfo:
   Parameters:
+  - ApplicationId:
+      Description: Name of your etcd application from Kio/Yourturn
   - HostedZone:
       Description: AWS Hosted Zone to work with
   - DockerImage: