tools: Add buildbucket package

Wraps the luci package to make it a bit friendlier.

Bug: dawn:1342
Change-Id: I80e02344ea1ecd95134a719f21eb8bd2a1cb1997
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/86527
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>

tools/src/buildbucket/buildbucket.go

@@ -0,0 +1,229 @@
+// Copyright 2022 The Tint Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package buildbucket provides helpers for interfacing with build-bucket
+package buildbucket
+
+import (
+	"context"
+	"fmt"
+	"net/url"
+
+	"dawn.googlesource.com/dawn/tools/src/gerrit"
+	"dawn.googlesource.com/dawn/tools/src/utils"
+	"go.chromium.org/luci/auth"
+	bbpb "go.chromium.org/luci/buildbucket/proto"
+	"go.chromium.org/luci/grpc/prpc"
+	"go.chromium.org/luci/hardcoded/chromeinfra"
+)
+
+// Buildbucket is the client to communicate with Buildbucket.
+type Buildbucket struct {
+	client bbpb.BuildsClient
+}
+
+// Builder describes a buildbucket builder
+type Builder struct {
+	Project string
+	Bucket  string
+	Builder string
+}
+
+// BuildID is a unique identifier of a build
+type BuildID int64
+
+// Build describes a buildbucket build
+type Build struct {
+	ID      BuildID
+	Status  BuildStatus
+	Builder Builder
+}
+
+// BuildStatus is the status of a build
+type BuildStatus string
+
+// Enumerator values for BuildStatus
+const (
+	// Unspecified state. Meaning depends on the context.
+	StatusUnknown BuildStatus = "unknown"
+	// Build was scheduled, but did not start or end yet.
+	StatusScheduled BuildStatus = "scheduled"
+	// Build/step has started.
+	StatusStarted BuildStatus = "started"
+	// A build/step ended successfully.
+	// This is a terminal status. It may not transition to another status.
+	StatusSuccess BuildStatus = "success"
+	// A build/step ended unsuccessfully due to its Build.Input,
+	// e.g. tests failed, and NOT due to a build infrastructure failure.
+	// This is a terminal status. It may not transition to another status.
+	StatusFailure BuildStatus = "failure"
+	// A build/step ended unsuccessfully due to a failure independent of the
+	// input, e.g. swarming failed, not enough capacity or the recipe was unable
+	// to read the patch from gerrit.
+	// start_time is not required for this status.
+	// This is a terminal status. It may not transition to another status.
+	StatusInfraFailure BuildStatus = "infra-failure"
+	// A build was cancelled explicitly, e.g. via an RPC.
+	// This is a terminal status. It may not transition to another status.
+	StatusCanceled BuildStatus = "canceled"
+)
+
+// Running returns true if the build is still running
+func (s BuildStatus) Running() bool {
+	switch s {
+	case StatusScheduled, StatusStarted:
+		return true
+	default:
+		return false
+	}
+}
+
+// pb returns a protobuf BuilderID constructed from the Builder
+func (b Builder) pb() *bbpb.BuilderID {
+	return &bbpb.BuilderID{
+		Project: b.Project,
+		Bucket:  b.Bucket,
+		Builder: b.Builder,
+	}
+}
+
+// toBuilder returns a Builder constructed from the protobuf BuilderID
+func toBuilder(b *bbpb.BuilderID) Builder {
+	return Builder{
+		Project: b.Project,
+		Bucket:  b.Bucket,
+		Builder: b.Builder,
+	}
+}
+
+// gerritChange returns the protobuf GerritChange from a gerrit.Patchset
+func gerritChange(ps gerrit.Patchset) *bbpb.GerritChange {
+	host := ps.Host
+	if u, err := url.Parse(ps.Host); err == nil && u.Host != "" {
+		host = u.Host // Strip scheme from URL
+	}
+	return &bbpb.GerritChange{
+		Host:     host,
+		Project:  ps.Project,
+		Change:   int64(ps.Change),
+		Patchset: int64(ps.Patchset),
+	}
+}
+
+// toBuildStatus returns a BuildStatus from a protobuf Status
+func toBuildStatus(s bbpb.Status) BuildStatus {
+	switch s {
+	default:
+		return StatusUnknown
+	case bbpb.Status_SCHEDULED:
+		return StatusScheduled
+	case bbpb.Status_STARTED:
+		return StatusStarted
+	case bbpb.Status_SUCCESS:
+		return StatusSuccess
+	case bbpb.Status_FAILURE:
+		return StatusFailure
+	case bbpb.Status_INFRA_FAILURE:
+		return StatusInfraFailure
+	case bbpb.Status_CANCELED:
+		return StatusCanceled
+	}
+}
+
+// toBuild returns a Build from a protobuf Build
+func toBuild(b *bbpb.Build) Build {
+	return Build{BuildID(b.Id), toBuildStatus(b.Status), toBuilder(b.Builder)}
+}
+
+// New creates a client to communicate with Buildbucket.
+func New(ctx context.Context, credentials auth.Options) (*Buildbucket, error) {
+	http, err := auth.NewAuthenticator(ctx, auth.InteractiveLogin, credentials).Client()
+	if err != nil {
+		return nil, err
+	}
+	client, err := bbpb.NewBuildsClient(
+		&prpc.Client{
+			C:       http,
+			Host:    chromeinfra.BuildbucketHost,
+			Options: prpc.DefaultOptions(),
+		}), nil
+	if err != nil {
+		return nil, err
+	}
+
+	return &Buildbucket{client}, nil
+}
+
+// SearchBuilds queries the list of builds performed for the given gerrit change.
+func (r *Buildbucket) SearchBuilds(ctx context.Context, ps gerrit.Patchset, f func(Build) error) error {
+	pageToken := ""
+	for {
+		rsp, err := r.client.SearchBuilds(ctx, &bbpb.SearchBuildsRequest{
+			Predicate: &bbpb.BuildPredicate{
+				GerritChanges: []*bbpb.GerritChange{gerritChange(ps)},
+			},
+			PageSize:  1000, // Maximum page size.
+			PageToken: pageToken,
+		})
+		if err != nil {
+			return err
+		}
+
+		for _, res := range rsp.Builds {
+			if err := f(toBuild(res)); err != nil {
+				return err
+			}
+		}
+
+		pageToken = rsp.GetNextPageToken()
+		if pageToken == "" {
+			// No more test variants with unexpected result.
+			break
+		}
+	}
+
+	return nil
+}
+
+// StartBuild starts a build.
+func (r *Buildbucket) StartBuild(
+	ctx context.Context,
+	ps gerrit.Patchset,
+	builder Builder,
+	forceBuild bool) (Build, error) {
+
+	id := ""
+	if !forceBuild {
+		id = utils.Hash(ps, builder)
+	}
+
+	build, err := r.client.ScheduleBuild(ctx, &bbpb.ScheduleBuildRequest{
+		RequestId:     id,
+		Builder:       builder.pb(),
+		GerritChanges: []*bbpb.GerritChange{gerritChange(ps)},
+	})
+	if err != nil {
+		return Build{}, fmt.Errorf("failed to start build for patchset %+v on builder %+v: %w", ps, builder, err)
+	}
+	return toBuild(build), nil
+}
+
+// QueryBuild queries the status of a build.
+func (r *Buildbucket) QueryBuild(ctx context.Context, id BuildID) (Build, error) {
+	b, err := r.client.GetBuild(ctx, &bbpb.GetBuildRequest{Id: int64(id)})
+	if err != nil {
+		return Build{}, fmt.Errorf("failed to query build with id %v: %w", id, err)
+	}
+	return toBuild(b), nil
+}