Various fixes

playbooks/edx-east/edx_service.yml

@@ -6,7 +6,6 @@
   gather_facts: False
   vars:
     state: "present"
-    auto_scaling_service: True
   tasks:
     - name: Manage IAM Role and Profile
       ec2_iam_role:
@@ -233,6 +232,17 @@
         tags: "{{ asg_instance_tags }}"
       register: potential_existing_instances
 
+    - name: Transform tags to the format ec2 module expects
+      util_map:
+        function: zip_to_dict
+        input: "{{ asg_instance_tags }}"
+        args: ['key', 'value']
+      register: reformatted_asg_instance_tags
+
+    #This task will create the number of instances requested (create_instances parameter). 
+    # By default, it will create instances equaling the number of subnets specified.
+    #Modulo logic explained: The subnet specified will be the instance number modulo the number of subnets, 
+    # so that instances are balanced across subnets.
     - name: Manage instances
       ec2:
         profile: "{{ profile }}"
@@ -240,21 +250,22 @@
         wait: "yes"
         group_id: "{{ service_sec_group.group_id }}"
         key_name: "{{ service_config.key_name }}"
-        vpc_subnet_id: "{{ created_service.subnets.results[item|int % created_service.subnets.results|length].subnet_id }}"
+        vpc_subnet_id: "{{ created_service_subnets.results[item | int % created_service_subnets.results | length].subnet_id }}"
         instance_type: "{{ service_config.instance_type }}"
-        instance_tags: "{{ asg_instance_tags }}"
+        instance_tags: "{{ reformatted_asg_instance_tags.function_output }}"
         image: "{{ service_config.ami }}"
         instance_profile_name: "{{ instance_profile_name }}"
         volumes: "{{ service_config.volumes }}"
-      with_sequence: count={{create_instances|default(created_service.subnets.results|length) }}
+      with_sequence: count={{ create_instances | default(created_service_subnets.results | length) }}
       when: not auto_scaling_service and potential_existing_instances.instances|length == 0
       register: created_instances
 
     - name: Add new instances to host group
       add_host:
-        hostname: "{{ item.1.public_ip }}"
-        groups: created_instances
+        hostname: "{{ item.1.private_ip }}"
+        groups: created_instances_group
         #might need ansible_ssh_private_key_file and/or ansible_ssh_user
+        ansible_ssh_user: ubuntu
         volumes: "{{ service_config.volumes }}"
       with_subelements:
         - created_instances.results
@@ -263,7 +274,7 @@
 
 
 - name: Configure launched instances
-  hosts: created_instances
+  hosts: created_instances_group
   gather_facts: False
   become: True
   tasks:
@@ -275,6 +286,7 @@
         host: "{{ inventory_hostname }}"
         port: 22
 
+    #Must wait for the instance to be ready before gathering facts
     - name: Gather facts
       setup:
 
@@ -289,7 +301,16 @@
         - ansible_mounts
         - volumes
 
-    - name: Mount ephemeral disks
+    #Must use force=yes because AWS gives some ephemeral disks the wrong fstype and mounts them by default.
+    #Since we don't do this task if any prior instances were found in the ec2_lookup task, it's safe to force.
+    - name: Create filesystems
+      filesystem:
+        dev: "{{ item.device_name }}"
+        fstype: ext4
+        force: yes
+      with_items: volumes
+
+    - name: Mount disks
       mount:
         fstype: ext4
         name: "{{ item.mount }}"