Check md5sum of swift ring .builder files before adjusting ring.

For safety - if the ring on the remote hosts is not empty, or the same as the local
host, we should abort and ask the user to check the consistency of the rings.

This will prevent a situation where the rings are inconsistent, but still allow new hosts
to be added to the ring. E.g. if the rings are removed from the local host for some reason,
this will cause the run to fail. Or if the rings aren't moved to the nodes in a uniform way.

Allows the user to manually intervene and fix the inconsistencies.

rpc_deployment/playbooks/openstack/swift-build-rings.yml

@@ -1,4 +1,23 @@
 ---
+# Copyright 2014, Rackspace US, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+- hosts: swift_hosts:swift_proxy
+  user: root
+  roles:
+    - swift_ring_md5sum
+
 - hosts: local
   user: root
   roles:

rpc_deployment/roles/swift_ring_builder/tasks/check_ring.yml

@@ -0,0 +1,30 @@
+---
+# Copyright 2014, Rackspace US, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+- name: Get md5sum of local builder files
+  shell: cat /etc/swift/rings/*.builder 2>/dev/null | md5sum | cut -d " " -f1
+  register: md5sum
+
+- name: Get empty md5sum
+  shell: echo -n | md5sum | cut -d " " -f1
+  register: empty_md5sum
+
+# Fail if the remote hosts builder files is not empty AND
+# does not match the md5sum of the local host.
+- name: Check md5sum of builder files
+  fail:
+    msg: "The builder files on the remote host {{ item }} do not match the local host, and are not empty on the remote host"
+  when: ("{{ hostvars[item]['builder_md5sum'] }}" != "{{ empty_md5sum.stdout }}") and ("{{ hostvars[item]['builder_md5sum'] }}" != "{{ md5sum.stdout }}")
+  with_items: groups['swift_proxy'] + groups['swift_hosts']

rpc_deployment/roles/swift_ring_builder/tasks/main.yml

@@ -13,6 +13,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+- include: check_ring.yml
+
 - name: "make sure scripts directory exists"
   file: >
     state=directory

rpc_deployment/roles/swift_ring_md5sum/tasks/main.yml

@@ -0,0 +1,22 @@
+---
+# Copyright 2014, Rackspace US, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+- name: Get md5sum of builder files
+  shell: cat /etc/swift/*.builder 2>/dev/null | md5sum | cut -d " " -f1
+  register: md5sum
+
+- name: Register a fact for the md5sum
+  set_fact:
+     builder_md5sum: "{{ md5sum.stdout }}"