obsservice: ui handler serves db console assets

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

dev

@@ -3,7 +3,7 @@
 set -euo pipefail
 
 # Bump this counter to force rebuilding `dev` on all machines.
-DEV_VERSION=37
+DEV_VERSION=38
 
 THIS_DIR=$(cd "$(dirname "$0")" && pwd)
 BINARY_DIR=$THIS_DIR/bin/dev-versions

pkg/ccl/oidcccl/authentication_oidc.go

@@ -137,10 +137,9 @@ type oidcAuthenticationConf struct {
 	autoLogin       bool
 }
 
-// GetUIConf is used to extract certain parts of the OIDC
-// configuration at run-time for embedding into the
-// Admin UI HTML in order to manage the login experience
-// the UI provides.
+// GetOIDCConf is used to extract certain parts of the OIDC
+// configuration at run-time for embedding into the DB Console in order
+// to manage the login experience the UI provides.
 func (s *oidcAuthenticationServer) GetOIDCConf() ui.OIDCUIConf {
 	return ui.OIDCUIConf{
 		ButtonText: s.conf.buttonText,

pkg/cmd/dev/build.go

@@ -89,6 +89,7 @@ var buildTargetMapping = map[string]string{
 	"label-merged-pr":  "//pkg/cmd/label-merged-pr:label-merged-pr",
 	"geos":             geosTarget,
 	"libgeos":          geosTarget,
+	"obsservice":       "//pkg/obsservice/cmd/obsservice",
 	"optgen":           "//pkg/sql/opt/optgen/cmd/optgen:optgen",
 	"optfmt":           "//pkg/sql/opt/optgen/cmd/optfmt:optfmt",
 	"oss":              "//pkg/cmd/cockroach-oss:cockroach-oss",
@@ -412,7 +413,9 @@ func (d *dev) getBasicBuildArgs(
 
 	// Add --config=with_ui iff we're building a target that needs it.
 	for _, target := range buildTargets {
-		if target.fullName == buildTargetMapping["cockroach"] || target.fullName == buildTargetMapping["cockroach-oss"] {
+		if target.fullName == buildTargetMapping["cockroach"] ||
+			target.fullName == buildTargetMapping["cockroach-oss"] ||
+			target.fullName == buildTargetMapping["obsservice"] {
 			args = append(args, "--config=with_ui")
 			break
 		}

pkg/obsservice/cmd/obsservice/BUILD.bazel

@@ -8,6 +8,7 @@ go_library(
     deps = [
         "//pkg/cli/exit",
         "//pkg/obsservice/obslib",
+        "//pkg/ui/distoss",
         "@com_github_spf13_cobra//:cobra",
     ],
 )

pkg/obsservice/cmd/obsservice/main.go

@@ -14,6 +14,7 @@ import (
 
 	"github.com/cockroachdb/cockroach/pkg/cli/exit"
 	"github.com/cockroachdb/cockroach/pkg/obsservice/obslib"
+	_ "github.com/cockroachdb/cockroach/pkg/ui/distoss" // web UI init hooks
 	"github.com/spf13/cobra"
 )
 

pkg/obsservice/obslib/BUILD.bazel

@@ -6,6 +6,8 @@ go_library(
     importpath = "github.com/cockroachdb/cockroach/pkg/obsservice/obslib",
     visibility = ["//visibility:public"],
     deps = [
+        "//pkg/base",
+        "//pkg/ui",
         "//pkg/util/log",
         "//pkg/util/syncutil",
         "@com_github_cockroachdb_cmux//:cmux",

pkg/obsservice/obslib/lib.go

@@ -23,6 +23,7 @@ import (
 	"time"
 
 	"github.com/cockroachdb/cmux"
+	"github.com/cockroachdb/cockroach/pkg/ui"
 	"github.com/cockroachdb/cockroach/pkg/util/log"
 	"github.com/cockroachdb/cockroach/pkg/util/syncutil"
 	"github.com/cockroachdb/errors"
@@ -93,6 +94,25 @@ to trust the certificate presented by CockroachDB.`)
 	}
 }
 
+// We define our own copy of this struct that also exists in
+// pkg/server/authentication.go because we don't want to import that
+// package. This struct is used to define a null OIDC configuration for
+// the UI Config. DB Console uses information present here to show
+// different login UI when OIDC is present.
+type noOIDCConfigured struct{}
+
+var _ ui.OIDCUI = &noOIDCConfigured{}
+
+// GetOIDCConf implements the `ui.OIDCUI` interface with a configuration
+// that disables OIDC login options for the UI server.
+func (c *noOIDCConfigured) GetOIDCConf() ui.OIDCUIConf {
+	return ui.OIDCUIConf{
+		Enabled: false,
+	}
+}
+
+var CRDBProxyPaths = []string{"/_admin/", "/_status/", "/ts/", "/api/v2/"}
+
 // RunAsync runs an HTTP proxy server in a goroutine. The returned channel is
 // closed when the server terminates.
 //
@@ -117,7 +137,21 @@ func (p *ReverseHTTPProxy) RunAsync(ctx context.Context) <-chan struct{} {
 		// Create the HTTP mux. Requests will generally be forwarded to p.proxy,
 		// except the /debug/pprof ones which will be served locally.
 		mux := http.NewServeMux()
-		mux.Handle("/", p.proxy)
+		// TODO(davidh): Ideally, the UI handler should probably be
+		// configured in `obsservice` and not hardcoded into `obslib`. This
+		// gives lib users a chance to do whatever they want with the UI.
+		mux.Handle("/", ui.Handler(ui.Config{
+			ExperimentalUseLogin: false,
+			LoginEnabled:         false,
+			GetUser: func(ctx context.Context) *string {
+				u := "Observability Service"
+				return &u
+			},
+			OIDC: &noOIDCConfigured{},
+		}))
+		for _, path := range CRDBProxyPaths {
+			mux.Handle(path, p.proxy)
+		}
 		// This seems to be the minimal set of handlers that we need to register in
 		// order to get all the pprof functionality. The pprof.Index handler handles
 		// some types of profiles itself.

pkg/server/authentication.go

@@ -62,6 +62,8 @@ const (
 
 type noOIDCConfigured struct{}
 
+var _ ui.OIDCUI = &noOIDCConfigured{}
+
 func (c *noOIDCConfigured) GetOIDCConf() ui.OIDCUIConf {
 	return ui.OIDCUIConf{
 		Enabled: false,

pkg/ui/ui.go

@@ -138,11 +138,13 @@ func Handler(cfg Config) http.Handler {
 			LoggedInUser:         cfg.GetUser(r.Context()),
 			Tag:                  buildInfo.Tag,
 			Version:              build.BinaryVersionPrefix(),
-			NodeID:               cfg.NodeID.String(),
 			OIDCAutoLogin:        oidcConf.AutoLogin,
 			OIDCLoginEnabled:     oidcConf.Enabled,
 			OIDCButtonText:       oidcConf.ButtonText,
 		}
+		if cfg.NodeID != nil {
+			args.NodeID = cfg.NodeID.String()
+		}
 		if uiConfigPath.MatchString(r.URL.Path) {
 			argBytes, err := json.Marshal(args)
 			if err != nil {