bogdando / openstack-must-gather

openstack-must-gather

must-gather is a tool built on top of OpenShift must-gather that provides the scripts for an OpenStack control plane logs and data collection.

Usage

oc adm must-gather --image=quay.io/openstack-k8s-operators/openstack-must-gather

The command above will create a local directory where logs, configs and status of the OpenStack control plane services are dumped.

In particular the openstack-must-gather will get a dump of:

• Service logs: Retrieved by the output of the pods (and operators) associated to the deployed services
• Services config: Retrieved for each component by the deployed ConfigMaps and Secrets
• Status of the services deployed in the OpenStack control plane
• Deployed CRs and CRDs
• CSVs, pkgmanifests, subscriptions, installplans, operatorgroup
• Pods, Deployments, Statefulsets, ReplicaSets, Service, Routes, ConfigMaps, (part of / relevant) Secrets
• Network related info (Metallb info, IPAddressPool, L2Advertisements, NetConfig, IPSet)

Development

Building container

You can build the image locally using the Dockerfile included. A Makefile is also provided. To use it, you must pass:

• an image name using the variable MUST_GATHER_IMAGE.
• an image registry using the variable IMAGE_REGISTRY (default is quay.io/openstack-k8s-operators)
• an image tag using the variable IMAGE_TAG (default is latest)

The targets for make are as follows:

• check-image: Check if the MUST_GATHER_IMAGE variable is set
• build: build the image with the supplied name and pushes it
• check: Run sanity check against the script collection
• pytest: Run sanity check and unit tests against the python script collection
• podman-build: builds the must-gather image
• podman-push: pushes an already-built must-gather image

Debugging container

One possible workflow that can be used for development is to run the openstack must-gather in debug mode:

$ oc adm must-gather --image=quay.io/openstack-k8s-operators/openstack-must-gather -- gather_debug
[must-gather      ] OUT Using must-gather plug-in image: quay.io/openstack-k8s-operators/openstack-must-gather:latest
When opening a support case, bugzilla, or issue please include the following summary data along with any other requested information:
ClusterID: 6ffe21e8-7dc9-4719-926f-f34ec33e6916
ClusterVersion: Stable at "4.12.35"
ClusterOperators:
	All healthy and stable


[must-gather      ] OUT namespace/openshift-must-gather-b9fpw created
[must-gather      ] OUT clusterrolebinding.rbac.authorization.k8s.io/must-gather-mq6st created
[must-gather      ] OUT pod for plug-in image quay.io/openstack-k8s-operators/openstack-must-gather:latest created
[must-gather-mxc7k] POD 2023-09-29T09:56:24.995284210Z Must gather entering debug mode, will sleep until file /tmp/rm-to-finish-gathering is deleted
[must-gather-mxc7k] POD 2023-09-29T09:56:24.995284210Z

Running in debug mode makes the must gather container just sit waiting for a file to be removed, allowing us to go into the container and test our scripts. In the above case, where the namespace is openshift-must-gather-b9fpw and the pod name is must-gather-mxc7k we would enter the container with:

$ oc -n openshift-must-gather-b9fpw rsh must-gather-mxc7k

And then if we were debugging a bash script called gather_trigger_gmr, we would run it in debug mode:

sh-5.1# bash -x /usr/bin/gather_trigger_gmr

And once we had the script working as intended we would copy the file from a terminal:

$ oc cp openshift-must-gather-b9fpw/must-gather-mxc7k:usr/bin/gather_trigger_gmr collection-scripts/gather_trigger_gmr

And finally, from inside the container shell we let the oc adm must-gather command complete, optionally running everything to ensure we haven't inadvertently broken anything in the process:

sh-5.1# gather
sh-5.1# rm /tmp/rm-to-finish-gathering

Component specifics

Besides the generic OpenShift etcd objects that must-gather scripts are currently gathering there's also component specific code that gather other information, so when adding or improving a component we should look into:

• collection-scripts/common.sh: Services are in the OSP_SERVICES variable to indicate that the script must gather its config maps, secrets, additional information, trigger Guru Mediation Reports, etc.

• collection-scripts/gather_services_status: Runs OpenStack commands to gather additional information. For example for Cinder it gather state of the services, volume types, qos specs, volume transfer requests, summary of existing volumes, pool information, etc.

• collection-scripts/gather_trigger_gmr: Triggers Guru Meditation Reports on the services so they are present in the logs when those are gathered afterwards.

Example

(optional) Build and push the must-gather image to a registry:

git clone ssh://[e-mail]/openstack-k8s-operators/openstack-must-gather.git
cd openstack-must-gather
IMAGE_TAG=<tag> IMAGE_REGISTRY=<registry> MUST_GATHER_IMAGE=openstack-must-gather make build

On a machine where you have oc adm access, do the following:

oc adm must-gather --image=<registry>/openstack-must-gather:<tag>

When generation is finished, you will find the dump in the current directory under must-gather.local.XXXXXXXXXX.

It is possible to gather debugging information about specific features by adding to the oc adm must-gather command the --image-stream argument. The must-gather tool supports multiple images, so you can gather data about more than one feature by running a single command. Adding --image-stream assumes that an image has been imported in an OpenShift namespace and the associated imagestream is available. To import an image as an imagestream, run the following commands:

oc project <namespace>
oc import-image <registry>/<image>:<tag> --confirm

and double check the imagestream exists in the specified namespace. At this point, run the oc adm must-gather command passing one or more imagestream parameters. For instance, assuming we import the kubevirt must-gather image: within the existing openstack namespace:

oc project openstack
oc import-image kubevirt-must-gather --from=quay.io/kubevirt/must-gather:latest --confirm

we can combine, in a single command, three different containers executions that gather different aspects of the same environement.

oc adm must-gather --image-stream=openstack/kubevirt-must-gather \
   --image-stream=openshift/must-gather \
   --image=quay.io/openstack-k8s-operators/openstack-must-gather:latest

The command above will create three pods associated to the existing imagestream objects that point to openstack, openshift and kubevirt must-gather container images.

[must-gather] OUT pod for plug-in image quay.io/openstack-k8s-operators/openstack-must-gather:latest created
[must-gather] OUT pod for plug-in image quay.io/kubevirt/must-gather@sha256:501e30ac7d5b9840a918bb9e5aa830686288ccfeee37d70aaf99cd2e302a2bb0 created
[must-gather] OUT pod for plug-in image quay.io/openshift-release-dev/ocp-v4.0-art-dev@sha256:e9601b492cbb375f0a05310efa6025691f8bba6a97667976cd4baf4adf0f244c created
...
...

Note

If the image is pushed to quay.io registry, make sure it's set to public, otherwise it can't be consumed by the must-gather tool.