Force agent labels to be set on pipelines as well

[xoxys]

Fixes: #2634

[qwerty287]

Wouldn't this be a breaking change?

[xoxys]

Yes it would. We can still decide to introduce another config option but as said in the issue the current behavior doesnt make sense to me.

[qwerty287]

Yes, I agree to you, but then I think we should either make it non-breaking or wait for next major. Maybe we can keep the current behavior and log a deprecation warning if a label is missing?

[xoxys]

What's the best way to make it none-breaking?

What I tried is to add a flag WOODPECKER_FILTER_LABELS_REQUIRED=true/false but how to pass it to the grpc.Next method? I think the attribute can be added to the rpc.Filter struct, but either way this would require changes to protobuf or am I wrong?

[qwerty287]

Adding a new config var is one option, you could also just add a deprecation for now and change it in next major.
Can't help you with the grpc part though...

[xoxys]

I thought about it again and to might be helpful for some use cases to keep the current behavior but make it configurable. @anbraten can you guide me a bit with the gRPC part?

[anbraten]

What I tried is to add a flag WOODPECKER_FILTER_LABELS_REQUIRED=true/false but how to pass it to the grpc.Next method? I think the attribute can be added to the rpc.Filter struct, but either way this would require changes to protobuf or am I wrong?

To simplify it we could even make this a server setting (so no adjustments to grpc etc are needed) and change it to the new way with the next major.

As the agent sets some labels by default, hostname: * needs to be added as default to all tasks.

[qwerty287]

@xoxys Now with 3.0 next, we could merge this I think?

[xoxys]

Sure we could, I still think this should be better configurable but open for other decisions.

[6543]

this is not easy as the labels are currently used to let agents "advertice capabilitys/propertys" the pipelines can target.

so make them mandatory by default will break all existing pipelines and add unnecessary complexytiy to the config.

to make an label required should be optional!

I think we could either add some prefix like ! to indicate such .... etc

[6543]

ontop of #4141:

 ### `WOODPECKER_AGENT_LABELS`
 
 > Default: empty
 
 Configures custom labels for the agent, to let workflows filter by it.
 Use a list of key-value pairs like `key=value,second-key=*`. `*` can be used as a wildcard.
+If you use `!` as key prefix it is mandatory for the workflow to have that label set (without !) set and matched.
 By default, agents provide three additional labels `platform=os/arch`, `hostname=my-agent` and `repo=*` which can be overwritten if needed.
 To learn how labels work, check out the [pipeline syntax page](../20-usage/20-workflow-syntax.md#labels).