[FFU] Hook to allow user to pass a custom script for repo switching.

This allow the user to use whatever script is necessary to switch repo
in its own infrastructure during fast forward upgrade.

Change-Id: Ie74106de7a4d5cd761c2bd836c2aa03efa7ac091
(cherry picked from commit 2587cb4acf)

puppet/services/tripleo-packages.yaml

@@ -37,9 +37,20 @@ parameters:
   FastForwardRepoType:
     default: 'tripleo-repos'
     type: string
+    constraints:
+      - allowed_values: ['tripleo-repos', 'custom-script']
   FastForwardRepoArgs:
     default: {'tripleo_repos': {'ocata': '-b ocata current', 'pike': '-b pike current', 'queens': '-b queens current'}}
     type: json
+  FastForwardCustomRepoScriptContent:
+    default: |
+      #!/bin/bash
+      set -e
+      echo "If you use FastForwardRepoType 'custom-script' you have to provide the upgrade repo script content."
+      echo "It will be installed as /root/ffu_upgrade_repo.sh on the node"
+      echo "and passed the upstream name (ocata, pike, queens) of the release as first argument"
+      exit 1
+    type: string
 
 outputs:
   role_data:
@@ -119,6 +130,18 @@ outputs:
           - step|int == 3
           - ffu_packages_apply|bool
           - fast_forward_repo_type == 'tripleo-repos'
+        - block:
+            - name: Create custom Script for upgrading repo.
+              copy:
+                dest: /root/ffu_update_repo.sh
+                content: {get_param: FastForwardCustomRepoScriptContent}
+                mode: 0700
+            - name: Execute custom script for upgrading repo.
+              shell: "/root/ffu_update_repo.sh {{release}}"
+          when:
+            - step|int == 3
+            - ffu_packages_apply|bool
+            - fast_forward_repo_type == 'custom-script'
       fast_forward_post_upgrade_tasks:
         - name: Register repo type and args
           set_fact:
@@ -140,3 +163,15 @@ outputs:
           when:
           - ffu_packages_apply|bool
           - fast_forward_repo_type == 'tripleo-repos'
+
+        - block:
+            - name: Create custom Script for upgrading repo.
+              copy:
+                dest: /root/ffu_update_repo.sh
+                content: {get_param: FastForwardCustomRepoScriptContent}
+                mode: 0700
+            - name: Execute custom script for upgrading repo.
+              shell: "/root/ffu_update_repo.sh {{release}}"
+          when:
+            - ffu_packages_apply|bool
+            - fast_forward_repo_type == 'custom-script'

releasenotes/notes/ffu-custom-script-to-switch-repo-a65db91760b46ec2.yaml

@@ -0,0 +1,30 @@
+---
+features:
+
+  - |
+    The user can now use a custom script to switch repo during the
+    fast forward upgrade.  He/She has to set ``FastForwardRepoType``
+    to ``custom-script`` and set
+    ``FastForwardCustomRepoScriptContent`` to a string representing a
+    shell script.  That script will be executed on each node and given
+    the upstream name of the release as the first argument (ocata,
+    pike, queens in that order).  Here is an example that describes
+    its interface.
+
+    .. code-block:: bash
+
+        #!/bin/bash
+        case $1 in
+          ocata)
+            curl -o /etc/yum.repos.d/ocata.repo http://somewhere.com/my-Ocata.repo;
+            yum clean metadata;
+          pike)
+            curl -o /etc/yum.repos.d/pike.repo http://somewhere.com/my-Pike.repo;
+            yum clean metadata;
+          queens)
+            curl -o /etc/yum.repos.d/pike.repo http://somewhere.com/my-Queens.repo;
+            yum clean metadata;
+          *)
+            echo "unknown release $1" >&2
+            exit 1
+        esac