remove nginx initialDelaySeconds

[klml]

What this PR does / why we need it

The readiness-probe nginx delays accepting traffic for 30 seconds with initialDelaySeconds, but nginx is ready after 1-2 seconds, this unnecessarily delays my deploy or restart.

The initialDelaySeconds: 30 on the readiness-probe can make sense for rails, because rails needs about 30 seconds to accept traffic, but the readiness-probe checks on port 3000 anyway.

Additional changes

Currently I would also suggest

• removeinitialDelaySeconds: 30 on the readiness-probe, it checks on port 3000 anyway.
• remove successThreshold: 1 Default is already to 1
• remove periodSeconds: 10 Default is already to 10

Checklist

• Chart Version bumped
• Upgrading instructions are documented in the zammad/README.md

[mgruner]

@klml thanks for your research. It looks like the readiness probe is somewhat abused to make for the long rails startup time. Wouldn't it be better to add a startup probe for that?

• startup probe: short interval, but high failure threshold to make for 30s startup time or more - this way it would complete earlier than 30s in case the stack is faster (e.g. in case of patchlevel update without migrations)
• readiness probe: short interval (perhaps defaults are fine?), no initialDelay needed
• liveness probe: same

We could choose a similar approach for all 3 affected pods: nginx, railsserver and websocket-server.

I tend to also agree that we can remove any values which don't change the defaults from k8s.

What do you think?

[klml]

@martini

Wouldn't it be better to add a startup probe for that?

fullack

startup probe: short interval, but high failure threshold to make for 30s startup time or more - this way it would complete earlier than 30s in case the stack is faster (e.g. in case of patchlevel update without migrations)

I used high failureThreshold: 10 (default is 3) with short periodSeconds: 4 (default is 10), so I get 40 secs. In this time even rails is running

readiness probe: short interval (perhaps defaults are fine?), no initialDelay needed
liveness probe: same

removed it

This stack works great for my openshift, nginx is running now in 5 secs (before 32) 😁 and rails still needs 30 secs, but better than 45 before, if I give it a full 4 GB of RAM even in 20 seconds.

[mgruner]

Looks good at first sight! Will try it.

[mgruner]

👏

[mgruner]

Thanks a lot @klml!