obsservice: ui handler serves db console assets

[dhartunian]

This change enables the Observabilty Service to serve the DB Console UI
itself. Endpoints that CRDB can handle are proxied (/_admin/,
/_status/, /ts/) but the base URL will return a blank HTML page with
JS assets that load the DB Console.

In order to build with the ui code, the --config=with_ui flag must be
passed to bazel.

This commit also adds a shortcut to the dev command to build
obsservice which includes the --config=with_ui flag just as we do by
default in cockroach builds.

Release note: None

[cockroach-teamcity]

This change is 

[dhartunian]

First commit is from #78216 Rebased

[abarganier]

modulo some tiny nits.

Reviewable status: complete! 1 of 0 LGTMs obtained (waiting on @dhartunian and @sjbarag)

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pkg/obsservice/obslib/lib.go line 101 at r1 (raw file):

func (c *noOIDCConfigured) GetOIDCConf() ui.OIDCUIConf {
	return ui.OIDCUIConf{

nit: brief comments on this function

Code quote:

func (c *noOIDCConfigured) GetOIDCConf() ui.OIDCUIConf {
	return ui.OIDCUIConf{
		Enabled: false,
	}
}

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pkg/obsservice/obslib/lib.go line 128 at r1 (raw file):

		nodeID := &base.NodeIDContainer{}
		nodeID.Set(ctx, 123456)

nit: can we use a constant here instead so we can accompany it with some comments?

Code quote:

123456

[sjbarag]

Reviewable status: complete! 1 of 0 LGTMs obtained (waiting on @abarganier, @dhartunian, and @sjbarag)

a discussion (no related file):
Good stuff @dhartunian ! Sorry for being slow on the review here 😓

---

---

pkg/cmd/dev/build.go line 92 at r1 (raw file):

	"geos":             geosTarget,
	"libgeos":          geosTarget,
	"obsservice":       "//pkg/obsservice/cmd/obsservice",

Do we have a make target set up for this as well? I can't remember if we need to also support make builds

Code quote:

		if target.fullName == buildTargetMapping["cockroach"] ||
			target.fullName == buildTargetMapping["cockroach-oss"] ||

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pkg/obsservice/obslib/lib.go line 137 at r1 (raw file):

TODO(davidh): Previously, the / handler was the proxy to CRDB. This is now broken because we've started serving the UI from the same endpoint. We should find some way to serve the UI and proxy to CRDB at the same time. Unclear how this should work at the moment.

I assume it's the ambiguity of paths (is it a file, an SPA fallback to index.html, or a proxyable path?) that's the issue right? I wouldn't mind having /api/** routes or something to separate UI paths from data-only paths 🤔

[dhartunian]

Reviewable status: complete! 1 of 0 LGTMs obtained (waiting on @abarganier, @dhartunian, and @sjbarag)

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pkg/cmd/dev/build.go line 92 at r1 (raw file):

Previously, sjbarag (Sean Barag) wrote…

Do we have a make target set up for this as well? I can't remember if we need to also support make builds

We do not have a Makefile target. I'd prefer not to since we will never backport this code but I'll check with #dev-inf.

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pkg/obsservice/obslib/lib.go line 101 at r1 (raw file):

Previously, abarganier (Alex Barganier) wrote…

nit: brief comments on this function

Done.

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pkg/obsservice/obslib/lib.go line 128 at r1 (raw file):

Previously, abarganier (Alex Barganier) wrote…

nit: can we use a constant here instead so we can accompany it with some comments?

Done. Ended up just adding logic to be able to omit the NodeID since it makes no sense in this context.

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pkg/obsservice/obslib/lib.go line 137 at r1 (raw file):

Previously, sjbarag (Sean Barag) wrote…

TODO(davidh): Previously, the / handler was the proxy to CRDB. This is now broken because we've started serving the UI from the same endpoint. We should find some way to serve the UI and proxy to CRDB at the same time. Unclear how this should work at the moment.

I assume it's the ambiguity of paths (is it a file, an SPA fallback to index.html, or a proxyable path?) that's the issue right? I wouldn't mind having /api/** routes or something to separate UI paths from data-only paths 🤔

This comment is actually out of date as I've added proxying below this. I'll extract the list of CRDB paths for clarity.

[dhartunian]

Reviewable status: complete! 0 of 0 LGTMs obtained (and 1 stale) (waiting on @abarganier, @dhartunian, and @sjbarag)

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pkg/cmd/dev/build.go line 92 at r1 (raw file):

dev-inf

I have confirmation that we do not need to support the Makefile

[sjbarag]

Reviewable status: complete! 0 of 0 LGTMs obtained (and 1 stale) (waiting on @abarganier, @dhartunian, and @sjbarag)

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pkg/obsservice/obslib/lib.go line 137 at r1 (raw file):

Previously, dhartunian (David Hartunian) wrote…

This comment is actually out of date as I've added proxying below this. I'll extract the list of CRDB paths for clarity.

Perfect, thank you!

[dhartunian]

TFTRs!

bors r=sjbarag,abarganier

[craig]

Build succeeded:

• GitHub CI (Cockroach)