Use Tower v2 API when available, falling back to v1 where necessary (#36663)

* Use Tower v2 API when available, falling back to v1 where necessary

lib/ansible/modules/cloud/amazon/ec2_instance.py

@@ -47,11 +47,20 @@ options:
       - Opaque blob of data which is made available to the ec2 instance
   tower_callback:
     description:
-      - Preconfigured user-data to enable an instance to perform a Tower callback.
-      - Requires parameters I(tower_callback.tower_address), I(tower_callback.job_template_id), and I(tower_callback.host_config_key).
+      - Preconfigured user-data to enable an instance to perform a Tower callback (Linux only).
       - Mutually exclusive with I(user_data).
       - For Windows instances, to enable remote access via Ansible set I(tower_callback.windows) to true, and optionally set an admin password.
       - If using 'windows' and 'set_password', callback to Tower will not be performed but the instance will be ready to receive winrm connections from Ansible.
+    suboptions:
+      tower_address:
+        description:
+        - IP address or DNS name of Tower server. Must be accessible via this address from the VPC that this instance will be launched in.
+      template_id:
+        description:
+        - Either the integer ID of the Tower Job Template, or the name (name supported only for Tower 3.2+)
+      host_config_key:
+        description:
+        - Host configuration secret key generated by the Tower job template.
   tags:
     description:
       - A hash/dictionary of tags to add to the new instance or to add/remove from an existing one.
@@ -600,6 +609,7 @@ except ImportError:
     pass
 
 from ansible.module_utils.six import text_type
+from ansible.module_utils.six.moves.urllib import parse as urlparse
 from ansible.module_utils._text import to_bytes, to_native
 import ansible.module_utils.ec2 as ec2_utils
 from ansible.module_utils.ec2 import (boto3_conn,
@@ -639,6 +649,8 @@ def tower_callback_script(tower_conf, windows=False, passwd=None):
             if p not in tower_conf:
                 module.fail_json(msg="Incomplete tower_callback configuration. tower_callback.{0} not set.".format(p))
 
+        if isinstance(tower_conf['job_template_id'], text_type):
+            tower_conf['job_template_id'] = urlparse.quote(tower_conf['job_template_id'])
         tpl = string.Template(textwrap.dedent("""#!/bin/bash
         set -x
 
@@ -648,9 +660,18 @@ def tower_callback_script(tower_conf, windows=False, passwd=None):
         do
           status_code=`curl --max-time 10 -v -k -s -i \
             --data "host_config_key=${host_config_key}" \
-                  https://${tower_address}/api/v1/job_templates/${template_id}/callback/ \
+            'https://${tower_address}/api/v2/job_templates/${template_id}/callback/' \
             | head -n 1 \
             | awk '{print $2}'`
+          if [[ $status_code == 404 ]]
+            then
+            status_code=`curl --max-time 10 -v -k -s -i \
+              --data "host_config_key=${host_config_key}" \
+              'https://${tower_address}/api/v1/job_templates/${template_id}/callback/' \
+              | head -n 1 \
+              | awk '{print $2}'`
+            # fall back to using V1 API for Tower 3.1 and below, since v2 API will always 404
+          fi
           if [[ $status_code == 201 ]]
             then
             exit 0