Output a URL with instructions after running linkerd upgrade

[scottcarol]

Fixes #2575. When a user successfully runs linkerd upgrade in the CLI, they will see a message after the yaml output pointing to a URL with full upgrade instructions.

[l5d-bot]

Integration test results for 805e230: success 🎉
Log output: https://gist.github.com/25e98b9edd7c9f503ed3bfa94ee25bfd

[ihcsim]

👍 Two comments below.

[alpeb]

What do you all think about appending an anchor with the version into that url? We could link directly to the upgrade notice for that version (if any). The downside is that if the user is upgrading from a much older version they'll require to check not only the current upgrade notice but also previous ones.

[grampelberg]

@alpeb sounds great to me. I've got an outstanding issue to start versioning the docs, so we could use the anchor to redirect to the correct version.

[scottcarol]

@grampelberg @alpeb I like the ⚓️ idea. I separated them out into success and failure, would that work with the doc architecture?
https://linkerd.io/upgrade/#nextsteps
https://linkerd.io/upgrade/#troubleshooting

Re: specific version numbers, when running linkerd upgrade can you specify version numbers? Or will you always get the latest upgrade?

[l5d-bot]

Integration test results for 7f22e2f: success 🎉
Log output: https://gist.github.com/9129d25f4c91aa12b8acc2f703c38c1c

[ihcsim]

Re: specific version numbers, when running linkerd upgrade can you specify version numbers? Or will you always get the latest upgrade?

It looks like I can decide which version number to upgrade/downgrade to with linkerd upgrade --linkerd-version=edge-19.3.3

$ linkerd upgrade --linkerd-version edge-19.3.3
...
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  annotations:
    linkerd.io/created-by: linkerd/cli edge-19.4.1 # original
  creationTimestamp: null
  labels:
    linkerd.io/control-plane-component: identity
  name: linkerd-identity
  namespace: linkerd
...
    spec:
      containers:
      - args:
        - identity
        - -log-level=info
        image: gcr.io/linkerd-io/controller:edge-19.3.3 # downgrade version
...

@olix0r Does this look right to you?

[grampelberg]

Big overall improvement! One minor nit:

$ bin/go-run cli upgrade | kubectl apply -f -
namespace/linkerd unchanged
configmap/linkerd-config configured
serviceaccount/linkerd-identity unchanged
clusterrole.rbac.authorization.k8s.io/linkerd-linkerd-identity unchanged

√ You're on your way to upgrading Linkerd!
Visit this URL for further instructions: https://linkerd.io/upgrade/#nextsteps
clusterrolebinding.rbac.authorization.k8s.io/linkerd-linkerd-identity unchanged
service/linkerd-identity configured
secret/linkerd-identity-issuer configured
deployment.extensions/linkerd-identity configured
serviceaccount/linkerd-controller unchanged
clusterrole.rbac.authorization.k8s.io/linkerd-linkerd-controller unchanged
clusterrolebinding.rbac.authorization.k8s.io/linkerd-linkerd-controller unchanged
service/linkerd-controller-api configured
service/linkerd-destination configured
deployment.extensions/linkerd-controller configured
customresourcedefinition.apiextensions.k8s.io/serviceprofiles.linkerd.io configured
serviceaccount/linkerd-web unchanged
service/linkerd-web configured
deployment.extensions/linkerd-web configured
serviceaccount/linkerd-prometheus unchanged
clusterrole.rbac.authorization.k8s.io/linkerd-linkerd-prometheus unchanged
clusterrolebinding.rbac.authorization.k8s.io/linkerd-linkerd-prometheus unchanged
service/linkerd-prometheus configured
deployment.extensions/linkerd-prometheus configured
configmap/linkerd-prometheus-config configured
serviceaccount/linkerd-grafana unchanged
service/linkerd-grafana configured
deployment.extensions/linkerd-grafana configured
configmap/linkerd-grafana-config configured

The instructions get lost in the wall of text (and loose the colors because of pipes). How about a couple newlines afterwards? Maybe a separator?

[klingerf]

@grampelberg Interesting find. It also looks like linkerd upgrade must be writing the YAML to stdout before writing the success message to stderr, so kubectl gets a head start on printing its output before the success message shows up. @scottcarol, maybe we can update this PR to write to stderr first?

[l5d-bot]

Integration test results for cc41777: success 🎉
Log output: https://gist.github.com/f272dc0a049bf74b71ccde5f9ee33a55

[scottcarol]

Ok, now we're rendering values to a buffer, which prints when the render is complete. That way the okStatus string prints separately. Thanks @klingerf for the help.

(Unfortunately the colors won't print when piping to kubectl which is a Unix thing)

Outstanding question @grampelberg @ihcsim are the URLs ok? Right now they are:
https://linkerd.io/upgrade/#nextsteps
https://linkerd.io/upgrade/#troubleshooting

[grampelberg]

URLs work for me!

[klingerf]

Those URLs 404 for me. Should they be https://linkerd.io/2/tasks/upgrade/#upgrade-the-data-plane for success and https://linkerd.io/2/tasks/upgrade/#step-by-step-instructions for failure?

[ihcsim]

The URLs LGTM.

@grampelberg Are we setting URL redirects for these URLs?

[klingerf]

Re: redirects -- hugo strips anchors when redirecting, so it won't work for https://linkerd.io/upgrade/#nextsteps to redirect to a #nextsteps anchor on a different page. We'd need to link to that page directly for the anchor to work.

By way of example, see how https://linkerd.io/2/ha/#setup redirects to https://linkerd.io/2/features/ha/, which drops the #setup anchor.

[siggy]

@klingerf Re: redirects, I had assumed that we could set up https://linkerd.io/upgrade/#foo links similar to the checks URLs, for example: https://linkerd.io/checks/#pre-k8s-cluster-k8s

Implemented as static HTML:
https://github.com/linkerd/website/blob/master/linkerd.io/static/checks/index.html

I've found this approach useful for linkerd check, as it creates a stable URL that's independent of any changes in hugo or the docs.

[klingerf]

@siggy Ah, that's a good approach. I wasn't aware that we were doing non-hugo redirects. Carry on.

[klingerf]

⭐️ Nice work! I like this approach a lot, and had just a few tiny style nits.

[grampelberg]

URLs look good to me. @scottcarol do you mind adding those when this PR merges?

[scottcarol]

URLs look good to me. @scottcarol do you mind adding those when this PR merges?

@grampelberg To clarify, you're saying the URLs look good as written:

success: https://linkerd.io/upgrade/#nextsteps
failure: https://linkerd.io/upgrade/#troubleshooting

and that I should add the URL forwarding to linkerd.io after this PR merges?

Can do! There have been a lot of different URLs mentioned in this PR so I want to be sure I've got it right.

[grampelberg]

@scottcarol yup, and yes please!

[l5d-bot]

Integration test results for 5fc8238: success 🎉
Log output: https://gist.github.com/fd4b834e9c506a320be41ea30ee85de8

[ihcsim]

👍 💯