blob: f2b08bf105ea778c9270ba048c00042a26eec886 [file] [log] [blame]
// Copyright 2023 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package worker
import (
"context"
"encoding/json"
"errors"
"fmt"
"io"
"net/http"
"os"
"os/exec"
"path/filepath"
"runtime/debug"
"strconv"
"strings"
"sync/atomic"
"cloud.google.com/go/storage"
"golang.org/x/pkgsite-metrics/internal/bigquery"
"golang.org/x/pkgsite-metrics/internal/config"
"golang.org/x/pkgsite-metrics/internal/derrors"
"golang.org/x/pkgsite-metrics/internal/log"
"golang.org/x/pkgsite-metrics/internal/modules"
"golang.org/x/pkgsite-metrics/internal/proxy"
)
const (
// sandboxRoot is the root of the sandbox, relative to the docker container.
sandboxRoot = "/bundle/rootfs"
// sandboxGoModCache is where the Go module cache resides in its default
// location, $HOME/go/pkg/mod.
sandboxGoModCache = "root/go/pkg/mod"
// modulesDir is the directory where input modules live. The sandbox mounts
// this directory to the same path internally, so this path works for both
// secure and insecure modes.
modulesDir = "/tmp/modules"
)
var activeScans atomic.Int32
func doScan(ctx context.Context, modulePath, version string, insecure bool, f func() error) (err error) {
defer derrors.Wrap(&err, "doScan(%q, %q)", modulePath, version)
defer func() {
if e := recover(); e != nil {
err = fmt.Errorf("%w: %v\n\n%s", derrors.ScanModulePanicError, e, debug.Stack())
}
}()
logMemory(ctx, fmt.Sprintf("before scanning %s@%s", modulePath, version))
defer logMemory(ctx, fmt.Sprintf("after scanning %s@%s", modulePath, version))
activeScans.Add(1)
defer func() {
if activeScans.Add(-1) == 0 {
logMemory(ctx, fmt.Sprintf("before 'go clean' for %s@%s", modulePath, version))
cleanGoCaches(ctx, insecure)
logMemory(ctx, "after 'go clean'")
}
}()
return f()
}
func cleanGoCaches(ctx context.Context, insecure bool) {
var (
out []byte
err error
)
logDiskUsage := func(msg string) {
log.Debugf(ctx, "sandbox disk usage %s clean:\n%s",
msg, diskUsage(filepath.Join(sandboxRoot, "root"), modulesDir))
}
if insecure {
if !config.OnCloudRun() {
// Avoid cleaning the developer's local caches.
log.Infof(ctx, "not on Cloud Run, so not cleaning caches")
return
}
out, err = exec.Command("go", "clean", "-cache", "-modcache").CombinedOutput()
} else {
logDiskUsage("before")
// We need to clear Go caches after a scan to avoid memory issues. The caches
// are created and populated outside of the sandbox. We cannot clear them from
// within the sandbox since "any modifications to the root filesystem are destroyed
// with the container" (https://gvisor.dev/docs/user_guide/filesystem/). We hence
// also clean the caches from the outside.
c := exec.Command("go", "clean", "-cache", "-modcache")
c.Env = append(os.Environ(), "GOCACHE=/bundle/rootfs/"+sandboxGoCache, "GOMODCACHE=/bundle/rootfs/"+sandboxGoModCache)
out, err = c.CombinedOutput()
if err == nil {
logDiskUsage("after")
}
}
output := ""
if len(out) > 0 {
output = fmt.Sprintf(" with output %s", out)
}
if err != nil {
log.Errorf(ctx, errors.New(derrors.IncludeStderr(err)), "'go clean' failed%s", output)
} else {
log.Infof(ctx, "'go clean' succeeded%s", output)
}
}
func logMemory(ctx context.Context, prefix string) {
if !config.OnCloudRun() {
return
}
readIntFile := func(filename string) (int, error) {
data, err := os.ReadFile(filename)
if err != nil {
return 0, err
}
return strconv.Atoi(strings.TrimSpace(string(data)))
}
const (
curFilename = "/sys/fs/cgroup/memory/memory.usage_in_bytes"
maxFilename = "/sys/fs/cgroup/memory/memory.limit_in_bytes"
)
cur, err := readIntFile(curFilename)
if err != nil {
log.Errorf(ctx, err, "reading %s", curFilename)
}
max, err := readIntFile(maxFilename)
if err != nil {
log.Errorf(ctx, err, "reading %s", maxFilename)
}
const G float64 = 1024 * 1024 * 1024
log.Infof(ctx, "%s: using %.1fG out of %.1fG", prefix, float64(cur)/G, float64(max)/G)
}
// diskUsage runs the du command to determine how much disk space the given
// directories occupy.
func diskUsage(dirs ...string) string {
out, err := exec.Command("du", append([]string{"-h", "-s"}, dirs...)...).Output()
if err != nil {
return fmt.Sprintf("ERROR: %s", derrors.IncludeStderr(err))
}
return strings.TrimSpace(string(out))
}
func writeResult(ctx context.Context, serve bool, w http.ResponseWriter, client *bigquery.Client, table string, row bigquery.Row) (err error) {
defer derrors.Wrap(&err, "writeResult")
if serve {
// Write the result to the client instead of uploading to BigQuery.
log.Infof(ctx, "serving result to client")
data, err := json.MarshalIndent(row, "", " ")
if err != nil {
return fmt.Errorf("marshaling result: %w", err)
}
_, err = w.Write(data)
if err != nil {
log.Errorf(ctx, err, "writing to client")
}
return nil // No point serving an error, the write already happened.
}
// Upload to BigQuery.
if client == nil {
log.Infof(ctx, "bigquery disabled, not uploading")
return nil
}
return client.Upload(ctx, table, row)
}
type openFileFunc func(filename string) (io.ReadCloser, error)
// copyToLocalFile opens destPath for writing locally, making it executable if specified.
// It then uses openFile to open srcPath and copies it to the local file.
func copyToLocalFile(destPath string, executable bool, srcPath string, openFile openFileFunc) (err error) {
defer derrors.Wrap(&err, "copyToFile(%q, %q)", destPath, srcPath)
var mode os.FileMode
if executable {
mode = 0755
} else {
mode = 0644
}
destf, err := os.OpenFile(destPath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, mode)
if err != nil {
return err
}
rc, err := openFile(srcPath)
if err != nil {
return err
}
defer rc.Close()
return copyAndClose(destf, rc)
}
// copyAndClose copies r to wc and closes wc.
func copyAndClose(wc io.WriteCloser, r io.Reader) error {
_, err := io.Copy(wc, r)
err2 := wc.Close()
if err == nil {
err = err2
}
return err
}
func gcsOpenFileFunc(ctx context.Context, bucket *storage.BucketHandle) openFileFunc {
return func(name string) (io.ReadCloser, error) {
return bucket.Object(name).NewReader(ctx)
}
}
// prepareModule prepares a module for scanning. It downloads the module to the given
// directory and takes other actions that increase the chance that package loading will succeed.
// If init is true, those other actions include calling `go mod init` and `go mod tidy` on modules
// that don't have go.mod files.
func prepareModule(ctx context.Context, modulePath, version, dir string, proxyClient *proxy.Client, insecure, init bool) error {
log.Debugf(ctx, "downloading %s@%s to %s", modulePath, version, dir)
if err := modules.Download(ctx, modulePath, version, dir, proxyClient, true); err != nil {
log.Debugf(ctx, "download error: %v (%[1]T)", err)
return err
}
hasGoMod := fileExists(filepath.Join(dir, "go.mod"))
if !init || hasGoMod {
// Download all dependencies, using the given directory for the Go module cache
// if it is non-empty.
opts := &goCommandOptions{
dir: dir,
insecure: insecure,
}
return runGoCommand(ctx, modulePath, version, opts, "mod", "download")
}
// Run `go mod init` and `go mod tidy`.
if err := goModInit(ctx, modulePath, version, dir, "synthetic", insecure); err != nil {
return err
}
return goModTidy(ctx, modulePath, version, dir, insecure)
}
// moduleDir returns a the path of a directory where the module can be downloaded.
func moduleDir(modulePath, version string) string {
return filepath.Join(modulesDir, modulePath+"@"+version)
}
func goModInit(ctx context.Context, modulePath, version, dir, name string, insecure bool) error {
return runGoCommand(ctx, modulePath, version, &goCommandOptions{dir: dir, insecure: insecure}, "mod", "init", name)
}
// goModTidy runs "go mod tidy" on a module in dir.
func goModTidy(ctx context.Context, modulePath, version, dir string, insecure bool) error {
opts := &goCommandOptions{
dir: dir,
insecure: insecure,
}
return runGoCommand(ctx, modulePath, version, opts, "mod", "tidy")
}
type goCommandOptions struct {
dir string
insecure bool
}
// runGoModCommand runs the command `go args...`.
// modulePath and version are present only for messages.
func runGoCommand(ctx context.Context, modulePath, version string, opts *goCommandOptions, args ...string) (err error) {
argstring := strings.Join(args, " ")
defer derrors.Wrap(&err, "runGoCommand(%s@%s, %q, %v)", modulePath, version, argstring, opts)
if opts == nil {
opts = &goCommandOptions{}
}
log.Infof(ctx, "running `go %s` on %s@%s", argstring, modulePath, version)
cmd := exec.Command("go", args...)
cmd.Dir = opts.dir
cmd.Env = cmd.Environ()
cmd.Env = append(cmd.Env, "GOPROXY=https://proxy.golang.org/cached-only")
if !opts.insecure {
// Use sandbox mod cache.
cmd.Env = append(cmd.Env, "GOMODCACHE="+filepath.Join(sandboxRoot, sandboxGoModCache))
}
if _, err := cmd.Output(); err != nil {
return fmt.Errorf("%w: 'go %s' for %s@%s returned %s",
derrors.BadModule, argstring, modulePath, version, derrors.IncludeStderr(err))
}
log.Infof(ctx, "'go %s' succeeded", argstring)
return nil
}
func fileExists(filename string) bool {
_, err := os.Stat(filename)
return err == nil
}