[ceph] Document the use of mon_allow_pool_size_one

This is simply to document the fact that mon_allow_pooL_size_one
must be configured via cluster_commands in the ceph-client chart.
Adding it to ceph.conf via the conf values in the ceph-mon chart
doesn't seem to configure the mons effectively.

Change-Id: Ic7e9a0eade9c0b4028ec232ff7ad574b8574615d

ceph-client/Chart.yaml

@@ -15,6 +15,6 @@ apiVersion: v1
 appVersion: v1.0.0
 description: OpenStack-Helm Ceph Client
 name: ceph-client
-version: 0.1.42
+version: 0.1.43
 home: https://github.com/ceph/ceph-client
 ...

ceph-client/values.yaml

@@ -233,6 +233,9 @@ conf:
       unset: ""
     cluster_commands:
       # Add additional commands to run against the Ceph cluster here
+      # NOTE: Beginning with Pacific, mon_allow_pool_size_one must be
+      #       configured here to allow gate scripts to use 1x replication.
+      #       Adding it to /etc/ceph/ceph.conf doesn't seem to be effective.
       - config set global mon_allow_pool_size_one true
       - osd require-osd-release quincy
       - status

ceph-mon/Chart.yaml

@@ -15,6 +15,6 @@ apiVersion: v1
 appVersion: v1.0.0
 description: OpenStack-Helm Ceph Mon
 name: ceph-mon
-version: 0.1.27
+version: 0.1.28
 home: https://github.com/ceph/ceph
 ...

ceph-mon/values.yaml

@@ -269,6 +269,15 @@ conf:
       mon_data_avail_warn: 15
       log_file: /dev/stdout
       mon_cluster_log_file: /dev/stdout
+      # Beginning with the Pacific release, this config setting is necessary
+      # to allow pools to use 1x replication, which is disabled by default. The
+      # openstack-helm gate scripts use 1x replication for automated testing,
+      # so this is required. It doesn't seem to be sufficient to add this to
+      # /etc/ceph/ceph.conf, however. It must also be set explicitly via the
+      # 'ceph config' command, so this must also be added to the
+      # cluster_commands value in the ceph-client chart so it will be set
+      # before pools are created and configured there.
+      mon_allow_pool_size_one: true
     osd:
       osd_mkfs_type: xfs
       osd_mkfs_options_xfs: -f -i size=2048

releasenotes/notes/ceph-client.yaml

@@ -43,4 +43,5 @@ ceph-client:
   - 0.1.40 Fix OSD count checks in the ceph-rbd-pool job
   - 0.1.41 Allow gate scripts to use 1x replication in Ceph
   - 0.1.42 Update all Ceph images to Focal
+  - 0 1.43 Document the use of mon_allow_pool_size_one
 ...

releasenotes/notes/ceph-mon.yaml

@@ -28,4 +28,5 @@ ceph-mon:
   - 0.1.25 Allow for unconditional mon restart
   - 0.1.26 Added OCI registry authentication
   - 0.1.27 Update all Ceph images to Focal
+  - 0.1.28 Document the use of mon_allow_pool_size_one
 ...