Custom ConfigMaps

[tobias-nawa]

Feature Request

What problem are you trying to solve?

When running linkerd upgrade the ConfigMaps are part of the output. By using this output, all custom changes in the ConfigMaps are overwritten.

In my case I was changing the Grafana configuration to enable the login. After every upgrade the login is disabled again.

How should the problem be solved?

Maybe it's ok to not touch certain configurations, like the Grafana configuration which shouldn't change so often. But this is open for discussion.

Any alternatives you've considered?

Maybe a command like linkerd upgrade --no-configs grafana would work to exclude certain configurations.

How would users interact with this feature?

linkerd upgrade
or
linkerd upgrade --no-configs grafana

[ihcsim]

We should be able to do this by extending the --from-manifest option of the linkerd upgrade command to read the Grafana config map from a YAML file, generated from a previous installation. (See #2697). AFAICT, atm, the --from-manifest option only works for the linkerd-config config map, identity secret, and webhooks secrets.

@Bullettoothtobi Will this approach work for you?

[grampelberg]

@Bullettoothtobi I just put some docs together around this, does linkerd/website#384 work for you?

[tobias-nawa]

That's exactly what I needed! Thanks for your great work!