[dashboard] Gracefully handle websocket connection disposal

[geropl]

Description

This avoids Error("Connection got disposed") errors which gobble up to the frontend and block users. Also, it makes the frontend's websocket connection more resilient in general: Instead of dropping calls, those are buffered and re-issued once the connection is reestablished.

Related Issue(s)

Fixes #5042.

How to test

Login to preview env

1. go here and login
2. note how you're re-directed on successful login with GitHub/GitLab

Start a workspace

1. open devtools (console and network)
2. start any workspace
3. note how websocket connections work and open as expected

View build logs

1. open a context that requires an image build
2. wait until you see the log appearing
3. terminate the websocket connection (by killing server)
4. notice how the logs re-start scrolling automatically once server and the websocket connection is up-and-running again

Ensure closing websocket connections works

1. kubectl port-forward deployment/server 9500
2. curl -s localhost:9500/metrics | grep "gitpod_server_api_connections_closed_total " and remember the number
3. close a dashboard tab for the preview environment
4. curl -s localhost:9500/metrics | grep "gitpod_server_api_connections_closed_total " again and note how the count increased

Release Notes

improve websocket reconnection handling in the frontend

• /werft with-clean-slate-deployment

[akosyakov]

@geropl What is the difference to previous version?

[geropl]

@akosyakov The previous version removed this section entirely, thus we never fired closed in server: https://github.com/gitpod-io/gitpod/pull/6006/files#diff-b8847df09095afd1fed8277f763df0e828b40f2e071d73f3bbc4ed8c131903f9R107-R109

[akosyakov]

/werft run

👍 started the job as gitpod-build-gpl-5042-conn-disposed-2.2

[akosyakov]

/lgtm

It makes sense. Too bad we overlooked the server part initially.

[roboquat]

LGTM label has been added.

Git tree hash: 930a29dc722e1f0704886cb3088c20b5c749b3ae

[geropl]

/approve

[roboquat]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: akosyakov, geropl

Associated issue: #5042

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• components/dashboard/OWNERS [geropl]
• components/gitpod-protocol/OWNERS [geropl]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment