Add a playbook that tests collectd 6 vs collectd5

The playbook will:

* build collectd-6, collectd-latest and flask app
  containers
* generate a set of collectd configs
* launch the collectd-6, collectd-latest with the generated configs
* run the flask app which has a http_server that receives metrics from
  collectd v5 and collectd v6
* display the received metrics from both versions of collectd
  Collectd v5 shows PUTVAL
  Collectd v6 shows PUTMETRIC

The playbook takes the following parameters:
* PR (optional)
  The PRID for an upstream collectd pull request that will be
  passed to the collectd 6 container build

* plugin (optional)
  The name of the plugin that is bneing ported
  This will filter the received metrics to show the value passed.

Additional updates to existing roles include:
* run_collectd
  parameterises the collectd container name so that the role can be reused for
  launching multiple collectd containers by passing distinct names.

Change-Id: Ia62196c347387d380aae69e14ed0dd8e2c76d9c9
Signed-off-by: Emma Foley <efoley@redhat.com>

2 files changed, 89 insertions, 1 deletions

diff --git a/docs/release/release-notes/notes/collectd-5-v-6-testing-cc821b32bad2794c.yaml b/docs/release/release-notes/notes/collectd-5-v-6-testing-cc821b32bad2794c.yaml
new file mode 100644
index 00000000..20013147
--- /dev/null
+++ b/docs/release/release-notes/notes/collectd-5-v-6-testing-cc821b32bad2794c.yaml
@@ -0,0 +1,10 @@
+release_summary: >
+  Testing playbooks were added to compare collectd5 vs collectd6, for the
+  purpose of helping to review new PRs by comparing the generated metrics
+  between versions.
+testing:
+  - |
+    Added a playbook to compare collectd 5 and collectd 6. The playbook uses
+    existing ansible roles to build both collectd 5 and collectd 6 container
+    images, creates a common configuration, then runs the containers and shows
+    the outputs to let the user inspect the metrics and whether they match.
diff --git a/docs/testing/index.rst b/docs/testing/index.rst
index 392b39f4..f763ca64 100644
--- a/docs/testing/index.rst
+++ b/docs/testing/index.rst
@@ -1 +1,79 @@
-.. To be decided
+.. This work is licensed under a Creative Commons Attribution 4.0 International License.
+.. http://creativecommons.org/licenses/by/4.0
+.. (c) Anuket and others
+
+==============================
+Anuket Barometer testing guide
+==============================
+
+This document will describe how to use different tests in this repo.
+
+There are a number of tools and scripts in Barometer that can be used for testing, whether that is during development, building, code reviews, or run regularly in CI.
+Some of the tests are automated, and cover building collectd, others cover particular plugins.
+
+.. TODO: This guide should also include how to manually verify that collectd plugins are working as expected.
+
+.. TODO: There might be some troubleshooting guide in here too.
+
+Porting collectd to version 6
+=============================
+
+Thre is an ansible playbook for building and running collectd 5 and 6 together to compare the collected metrics.
+This is intended to help test porting from collectd 5 to 6, and confirm equivalency across the versions.
+
+The playbook will::
+
+  * build collectd-6, collectd-latest and flask app containers
+  * generate a set of collectd configs
+  * launch the collectd-6, collectd-latest with the generated configs
+  * run the flask app which has a http server that receives metrics from
+    collectd v5 and collectd v6
+  * display the received metrics from both versions of collectd
+    Collectd v5 shows PUTVAL
+    Collectd v6 shows PUTMETRIC
+
+To run this comparison, use the following command::
+
+  $ cd docker/ansible/
+  $ sudo ansible-playbook -i default.inv collectd6_test.yml
+
+The playbook takes the following parameters:
+
+  * PR (optional)
+    The PRID for an upstream collectd pull request that will be
+    passed to the collectd 6 container build
+
+  * plugin (optional)
+    The name of the plugin that is bneing ported
+    This will filter the received metrics to show the value passed.
+
+To run the playbook with these configs, pass the extra var to ansible::
+
+  sudo ansible-playbook -i default.inv -e PR=<PR_ID> -e plugin=<plugin_name> collectd6_test.yml
+
+The metrics can then be viewed by inspecting the container logs or attaching to the container to view the output::
+
+  $ docker attach <webserver-container>
+  $ #OR
+  $ docker logs <webserver-container>
+
+Metrics from collectd 5 will appear preceeded with ``PUTVAL``, and metrics from collectd 6 will appear preceeded by ``PUTMETRIC``.
+
+::
+
+  PUTVAL fbae30cc-2f20-11b2-a85c-819293100691/hugepages-mm-2048Kb/vmpage_number-free interval=10.000 1629466502.664:0
+  PUTVAL fbae30cc-2f20-11b2-a85c-819293100691/hugepages-mm-2048Kb/vmpage_number-used interval=10.000 1629466502.664:0
+  PUTVAL fbae30cc-2f20-11b2-a85c-819293100691/hugepages-mm-1048576Kb/vmpage_number-free interval=10.000 1629466502.664:0
+  PUTVAL fbae30cc-2f20-11b2-a85c-819293100691/hugepages-mm-1048576Kb/vmpage_number-used interval=10.000 1629466502.664:0
+  PUTVAL fbae30cc-2f20-11b2-a85c-819293100691/hugepages-node0-2048Kb/vmpage_number-free interval=10.000 1629466502.664:0
+  PUTVAL fbae30cc-2f20-11b2-a85c-819293100691/hugepages-node0-2048Kb/vmpage_number-used interval=10.000 1629466502.664:0
+  PUTVAL fbae30cc-2f20-11b2-a85c-819293100691/hugepages-node0-1048576Kb/vmpage_number-used interval=10.000 1629466502.665:0
+  PUTVAL fbae30cc-2f20-11b2-a85c-819293100691/hugepages-node0-1048576Kb/vmpage_number-free interval=10.000 1629466502.665:0
+  PUTMETRIC collectd_hugepages_vmpage_number type=GAUGE time=1629466501.807 interval=10.000 label:hugepages="mm-2048Kb" label:instance="fbae30cc-2f20-11b2-a85c-819293100691" label:type="free" 0
+  PUTMETRIC collectd_hugepages_vmpage_number type=GAUGE time=1629466501.807 interval=10.000 label:hugepages="mm-2048Kb" label:instance="fbae30cc-2f20-11b2-a85c-819293100691" label:type="used" 0
+  PUTMETRIC collectd_hugepages_vmpage_number type=GAUGE time=1629466501.808 interval=10.000 label:hugepages="mm-1048576Kb" label:instance="fbae30cc-2f20-11b2-a85c-819293100691" label:type="free" 0
+  PUTMETRIC collectd_hugepages_vmpage_number type=GAUGE time=1629466501.808 interval=10.000 label:hugepages="node0-2048Kb" label:instance="fbae30cc-2f20-11b2-a85c-819293100691" label:type="free" 0
+  PUTMETRIC collectd_hugepages_vmpage_number type=GAUGE time=1629466501.808 interval=10.000 label:hugepages="node0-2048Kb" label:instance="fbae30cc-2f20-11b2-a85c-819293100691" label:type="used" 0
+  PUTMETRIC collectd_hugepages_vmpage_number type=GAUGE time=1629466501.809 interval=10.000 label:hugepages="node0-1048576Kb" label:instance="fbae30cc-2f20-11b2-a85c-819293100691" label:type="free" 0
+  PUTMETRIC collectd_hugepages_vmpage_number type=GAUGE time=1629466501.809 interval=10.000 label:hugepages="node0-1048576Kb" label:instance="fbae30cc-2f20-11b2-a85c-819293100691" label:type="used" 0
+  PUTMETRIC collectd_hugepages_vmpage_number type=GAUGE time=1629466501.808 interval=10.000 label:hugepages="mm-1048576Kb" label:instance="fbae30cc-2f20-11b2-a85c-819293100691" label:type="used" 0