cmd/autocorrelator/check_ci.go

// Copyright 2021 The Fuchsia Authors.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

package main

import (
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"io/ioutil"
	"os"
	"strconv"

	"github.com/maruel/subcommands"
	"github.com/texttheater/golang-levenshtein/levenshtein"
	"go.chromium.org/luci/auth"
	buildbucketpb "go.chromium.org/luci/buildbucket/proto"
	"go.chromium.org/luci/common/proto/git"
	"go.chromium.org/luci/grpc/prpc"
	"google.golang.org/genproto/protobuf/field_mask"

	"go.fuchsia.dev/infra/buildbucket"
	"go.fuchsia.dev/infra/cmd/autocorrelator/compare"
	"go.fuchsia.dev/infra/cmd/autocorrelator/findings"
	"go.fuchsia.dev/infra/gitiles"
)

func cmdCheckCI(authOpts auth.Options) *subcommands.Command {
	return &subcommands.Command{
		UsageLine: "check-ci -base-commit <sha1> -builder <project/bucket/builder> -build-status <build-status-code> -search-range <search-range> -summary-markdown-path <path/to/summary/markdown> -json-output <json-output>",
		ShortDesc: "Compare text similarity between a summary markdown and recent CI builds' summary markdowns.",
		LongDesc:  "Compare text similarity between the provided -summary-markdown and the summary markdowns of -search-range recent builds of a CI -builder.",
		CommandRun: func() subcommands.CommandRun {
			c := &checkCIRun{}
			c.Init(authOpts)
			return c
		},
	}
}

type checkCIRun struct {
	commonFlags
	baseCommit string
	// TODO(atyfto): Fix the buildbucket library to return a BuilderID instead
	// of a flag.
	builder             buildbucket.BuilderIDFlag
	buildStatus         int
	searchRange         int
	summaryMarkdownPath string
	jsonOutput          string
}

func (c *checkCIRun) Init(defaultAuthOpts auth.Options) {
	c.commonFlags.Init(defaultAuthOpts)
	c.Flags.StringVar(&c.baseCommit, "base-commit", "", "Base commit as sha1.")
	c.Flags.Var(&c.builder, "builder", "Fully-qualified Buildbucket CI builder name to inspect.")
	c.Flags.IntVar(&c.buildStatus, "build-status", 20, "Build status to filter on. Defaults to FAILURE.")
	c.Flags.IntVar(&c.searchRange, "search-range", 10, "Inspect up to this many recent builds.")
	c.Flags.StringVar(&c.summaryMarkdownPath, "summary-markdown-path", "", "Path to summary markdown input file.")
	c.Flags.StringVar(&c.jsonOutput, "json-output", "-", "Path to output finding to.")
}

func (c *checkCIRun) Parse() error {
	if err := c.commonFlags.Parse(); err != nil {
		return err
	}
	if c.baseCommit == "" {
		return errors.New("-base-commit is required")
	}
	if &c.builder == nil {
		return errors.New("-builder is required")
	}
	if c.summaryMarkdownPath == "" {
		return errors.New("-summary-markdown-path is required")
	}
	if c.jsonOutput == "" {
		return errors.New("-json-output is required")
	}
	return nil
}

// checkCI is the main algorithm which backs this subcommand.
//
// Given a git log and a list of builds, return a summary similarity finding.
// This function assumes the list of builds is "CI-like": the builds should
// be in a git history order.
//
// The `comparator` argument is a text-based comparator that returns a
// similarity score between the input summary markdown and a build's summary
// markdown.
func checkCI(log []*git.Commit, builds []*buildbucketpb.Build, status buildbucketpb.Status, summaryMarkdown string, comparator compare.TextComparator) *findings.SummarySimilarity {
	// Create a dual-purpose commit map for efficient existence checks and
	// commit distance computation.
	commitMap := make(map[string]int)
	for idx, commit := range log {
		commitMap[commit.Id] = idx
	}
	// Search the list of builds for a matching status.
	for _, build := range builds {
		// Ignore builds which aren't in the base build's log, i.e. equal to
		// the base commit or older.
		if _, ok := commitMap[build.Input.GitilesCommit.Id]; !ok {
			continue
		}
		// If we encounter a green build, short-circuit immediately and return
		// a finding which indicates as such.
		if build.Status == buildbucketpb.Status_SUCCESS {
			return &findings.SummarySimilarity{
				BuildId: strconv.FormatInt(build.Id, 10),
				// Commit distance is the commit's position in the log.
				CommitDist: commitMap[build.Input.GitilesCommit.Id],
				IsGreen:    true,
			}
		}
		// If we encounter a build with a matching status, compute the summary
		// markdown similarity.
		if build.Status == status {
			return &findings.SummarySimilarity{
				BuildId: strconv.FormatInt(build.Id, 10),
				// Commit distance is the commit's position in the log.
				CommitDist: commitMap[build.Input.GitilesCommit.Id],
				Score:      comparator.Compare(build.SummaryMarkdown, summaryMarkdown),
			}
		}
	}
	// If we've exhausted the search, we do not have a finding.
	return nil
}

func (c *checkCIRun) main() error {
	ctx := context.Background()
	authClient, err := auth.NewAuthenticator(ctx, auth.OptionalLogin, c.parsedAuthOpts).Client()
	if err != nil {
		return fmt.Errorf("failed to initialize auth client: %v", err)
	}

	// Fetch the last -search-range completed builds of -builder.
	buildsClient := buildbucketpb.NewBuildsPRPCClient(&prpc.Client{
		C:    authClient,
		Host: c.bbHost,
	})
	// TODO(atyfto): Fix the `buildbucket` library so we can get rid of this
	// type assertion.
	builder, ok := c.builder.Get().(*buildbucketpb.BuilderID)
	if !ok {
		return errors.New("builder input is invalid")
	}
	resp, err := buildsClient.SearchBuilds(ctx, &buildbucketpb.SearchBuildsRequest{
		Predicate: &buildbucketpb.BuildPredicate{
			Builder: builder,
			Status:  buildbucketpb.Status_ENDED_MASK,
		},
		Fields: &field_mask.FieldMask{Paths: []string{
			"builds.*.id",
			"builds.*.input.gitiles_commit",
			"builds.*.status",
			"builds.*.summary_markdown",
		}},
		PageSize: int32(c.searchRange),
	})
	if err != nil {
		return fmt.Errorf("failed to query builds for %s: %v", c.builder.String(), err)
	}
	builds := resp.Builds
	if len(builds) == 0 {
		return fmt.Errorf("no builds found for %s", c.builder.String())
	}

	// Grab the git log. Since we cannot know upfront how many commits will
	// capture the entire range of builds, fetch a large multiplier of the
	// search range.
	gitilesHost := builds[0].Input.GitilesCommit.Host
	gitilesProject := builds[0].Input.GitilesCommit.Project
	gitilesClient, err := gitiles.NewClient(ctx, gitilesHost, gitilesProject, authClient)
	if err != nil {
		return fmt.Errorf("failed to initialize gitiles client for %s/%s: %v", gitilesHost, gitilesProject, err)
	}
	log, err := gitilesClient.Log(ctx, c.baseCommit, int32(c.searchRange*20))
	if err != nil {
		return fmt.Errorf("failed to fetch git log for %s: %v", c.baseCommit, err)
	}

	// Run the main algorithm.
	summaryMarkdown, err := ioutil.ReadFile(c.summaryMarkdownPath)
	if err != nil {
		return fmt.Errorf("could not read summary markdown input: %v", err)
	}
	ss := checkCI(log, builds, buildbucketpb.Status(c.buildStatus), string(summaryMarkdown), compare.LevenshteinComparator{Opts: levenshtein.DefaultOptions})

	// Emit summary similarity finding to -json-output.
	out := os.Stdout
	if c.jsonOutput != "-" {
		out, err := os.Create(c.jsonOutput)
		if err != nil {
			return err
		}
		defer out.Close()
	}
	if err := json.NewEncoder(out).Encode(ss); err != nil {
		return fmt.Errorf("failed to encode: %v", err)
	}
	return nil
}

func (c *checkCIRun) Run(a subcommands.Application, args []string, env subcommands.Env) int {
	if err := c.Parse(); err != nil {
		fmt.Fprintf(a.GetErr(), "%s: %s\n", a.GetName(), err)
		return 1
	}

	if err := c.main(); err != nil {
		fmt.Fprintf(a.GetErr(), "%s: %s\n", a.GetName(), err)
		return 1
	}
	return 0
}