Check my rationale please

[m-castaldo]

Hey all,

I'm quite new to rollouts and gatewayapi and as wondering if you experts might be able to help me please :) If I set this in my canary steps:

      canary:
        steps:
        - setCanaryScale:
            replicas: 1

        - setHeaderRoute:
            match:
                - headerName: X-Canary
                  headerValue:
                    exact: "true"
            name: canary-header
        - setWeight: 1
        - pause: {}
        - setCanaryScale:
            matchTrafficWeight: true
        - setWeight: 20
        - pause: {}
        - setWeight: 50
        - pause: {duration: 30}

Then the header rule works 100% of the time but also sends normal traffic 1% of the time to canary which I dont want, but if I set this:

      canary:
        steps:
        - setCanaryScale:
            replicas: 1

        - setHeaderRoute:
            match:
                - headerName: X-Canary
                  headerValue:
                    exact: "true"
            name: canary-header
        - pause: {}
        - setCanaryScale:
            matchTrafficWeight: true
        - setWeight: 20
        - pause: {}
        - setWeight: 50
        - pause: {duration: 30}

Then it returns nothing at all and when looking in the httproute its setting weight to 0 which means that its not allowing any traffic to the canary deployment.

I was wondering what I might be doing wrong?

Thanks!

[kostis-codefresh]

Hello

For the first part it is an open issue (and PR in progress)

For the second part, I would say this works by design. You haven't sent ANY traffic to the canary so the headerroute will never work. This is similar to #147

If you just want to have traffic to the canary even when no traffic actually reaches the canary, you can do it outside of Argo Rollouts. See docs here https://rollouts-plugin-trafficrouter-gatewayapi.readthedocs.io/en/latest/features/advanced-deployments/#scenario-pinning-clients-to-a-specific-version
Would that work in your case?

[m-castaldo]

@kostis-codefresh Thanks for responding, its really appreciated alot :)

Yer I agree and I'm glad that there is an open PR for the first part, hope to see it in a release soon.

Yes you are right with the second part, I guess I was just pointing out that if you set traffic to 1% then the header value works without any issues.

Yes that solution would work, but its a lot of changes to app httproutes that we would need to change as we run quite a few applications which I would rather have the above Pr solution implemented instead of having to setup multiple new app sub domains for applications.

[kostis-codefresh]

instead of having to setup multiple new app sub domains for applications.

Subdomains were just an example.
You can have normal URLs such example.com/stable, example.com/canary, example.com/preview
No extra subdomain needed at all.

Otherwise, just monitor the status of the PR to see when it gets into the next release.