utils: rm exec.go

This change also adds a dependency check at startup, rather than
runtime.

cmd/clair/main.go

@@ -18,6 +18,7 @@ import (
 	"flag"
 	"math/rand"
 	"os"
+	"os/exec"
 	"os/signal"
 	"runtime/pprof"
 	"strings"
@@ -127,6 +128,14 @@ func main() {
 	flagLogLevel := flag.String("log-level", "info", "Define the logging level.")
 	flag.Parse()
 
+	// Check for dependencies.
+	for _, bin := range []string{"git", "bzr", "rpm", "xz"} {
+		_, err := exec.LookPath(bin)
+		if err != nil {
+			log.Fatalf("failed to find dependency: %s", bin)
+		}
+	}
+
 	// Load configuration
 	config, err := config.Load(*flagConfigPath)
 	if err != nil {

ext/featurefmt/rpm/rpm.go

@@ -19,6 +19,7 @@ import (
 	"bufio"
 	"io/ioutil"
 	"os"
+	"os/exec"
 	"strings"
 
 	"github.com/coreos/pkg/capnslog"
@@ -29,7 +30,6 @@ import (
 	"github.com/coreos/clair/ext/versionfmt/rpm"
 	"github.com/coreos/clair/pkg/commonerr"
 	"github.com/coreos/clair/pkg/tarutil"
-	"github.com/coreos/clair/utils"
 )
 
 var log = capnslog.NewPackageLogger("github.com/coreos/clair", "ext/featurefmt/rpm")
@@ -63,10 +63,8 @@ func (l lister) ListFeatures(files tarutil.FilesMap) ([]database.FeatureVersion,
 		return []database.FeatureVersion{}, commonerr.ErrFilesystem
 	}
 
-	// Query RPM
-	// We actually extract binary package names instead of source package names here because RHSA refers to package names
-	// In the dpkg system, we extract the source instead
-	out, err := utils.Exec(tmpDir, "rpm", "--dbpath", tmpDir, "-qa", "--qf", "%{NAME} %{EPOCH}:%{VERSION}-%{RELEASE}\n")
+	// Extract binary package names because RHSA refers to binary package names.
+	out, err := exec.Command("rpm", "--dbpath", tmpDir, "-qa", "--qf", "%{NAME} %{EPOCH}:%{VERSION}-%{RELEASE}\n").CombinedOutput()
 	if err != nil {
 		log.Errorf("could not query RPM: %s. output: %s", err, string(out))
 		// Do not bubble up because we probably won't be able to fix it,

ext/vulnsrc/alpine/alpine.go

@@ -21,6 +21,7 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
+	"os/exec"
 	"strings"
 
 	"gopkg.in/yaml.v2"
@@ -33,7 +34,6 @@ import (
 	"github.com/coreos/clair/ext/versionfmt/dpkg"
 	"github.com/coreos/clair/ext/vulnsrc"
 	"github.com/coreos/clair/pkg/commonerr"
-	"github.com/coreos/clair/utils"
 )
 
 const (
@@ -169,20 +169,25 @@ func (u *updater) pullRepository() (commit string, err error) {
 			return "", vulnsrc.ErrFilesystem
 		}
 
-		if out, err := utils.Exec(u.repositoryLocalPath, "git", "clone", secdbGitURL, "."); err != nil {
+		cmd := exec.Command("git", "clone", secdbGitURL, ".")
+		cmd.Dir = u.repositoryLocalPath
+		if out, err := cmd.CombinedOutput(); err != nil {
 			u.Clean()
 			log.Errorf("could not pull alpine-secdb repository: %s. output: %s", err, out)
 			return "", commonerr.ErrCouldNotDownload
 		}
 	} else {
-		// The repository exists and it needs to be refreshed via a pull.
-		_, err := utils.Exec(u.repositoryLocalPath, "git", "pull")
-		if err != nil {
+		// The repository already exists and it needs to be refreshed via a pull.
+		cmd := exec.Command("git", "pull")
+		cmd.Dir = u.repositoryLocalPath
+		if _, err := cmd.CombinedOutput(); err != nil {
 			return "", vulnsrc.ErrGitFailure
 		}
 	}
 
-	out, err := utils.Exec(u.repositoryLocalPath, "git", "rev-parse", "HEAD")
+	cmd := exec.Command("git", "rev-parse", "HEAD")
+	cmd.Dir = u.repositoryLocalPath
+	out, err := cmd.CombinedOutput()
 	if err != nil {
 		return "", vulnsrc.ErrGitFailure
 	}

ext/vulnsrc/ubuntu/ubuntu.go

@@ -23,6 +23,7 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
+	"os/exec"
 	"regexp"
 	"strconv"
 	"strings"
@@ -35,7 +36,6 @@ import (
 	"github.com/coreos/clair/ext/versionfmt/dpkg"
 	"github.com/coreos/clair/ext/vulnsrc"
 	"github.com/coreos/clair/pkg/commonerr"
-	"github.com/coreos/clair/utils"
 )
 
 const (
@@ -174,7 +174,9 @@ func (u *updater) pullRepository() (err error) {
 		}
 
 		// Branch repository.
-		if out, err := utils.Exec(u.repositoryLocalPath, "bzr", "branch", "--use-existing-dir", trackerRepository, "."); err != nil {
+		cmd := exec.Command("bzr", "branch", "--use-existing-dir", trackerRepository, ".")
+		cmd.Dir = u.repositoryLocalPath
+		if out, err := cmd.CombinedOutput(); err != nil {
 			log.Errorf("could not branch Ubuntu repository: %s. output: %s", err, out)
 			return commonerr.ErrCouldNotDownload
 		}
@@ -183,7 +185,9 @@ func (u *updater) pullRepository() (err error) {
 	}
 
 	// Pull repository.
-	if out, err := utils.Exec(u.repositoryLocalPath, "bzr", "pull", "--overwrite"); err != nil {
+	cmd := exec.Command("bzr", "pull", "--overwrite")
+	cmd.Dir = u.repositoryLocalPath
+	if out, err := cmd.CombinedOutput(); err != nil {
 		os.RemoveAll(u.repositoryLocalPath)
 
 		log.Errorf("could not pull Ubuntu repository: %s. output: %s", err, out)
@@ -194,16 +198,20 @@ func (u *updater) pullRepository() (err error) {
 }
 
 func getRevisionNumber(pathToRepo string) (int, error) {
-	out, err := utils.Exec(pathToRepo, "bzr", "revno")
+	cmd := exec.Command("bzr", "revno")
+	cmd.Dir = pathToRepo
+	out, err := cmd.CombinedOutput()
 	if err != nil {
 		log.Errorf("could not get Ubuntu repository's revision number: %s. output: %s", err, out)
 		return 0, commonerr.ErrCouldNotDownload
 	}
+
 	revno, err := strconv.Atoi(strings.TrimSpace(string(out)))
 	if err != nil {
 		log.Errorf("could not parse Ubuntu repository's revision number: %s. output: %s", err, out)
 		return 0, commonerr.ErrCouldNotDownload
 	}
+
 	return revno, nil
 }
 
@@ -252,7 +260,9 @@ func collectModifiedVulnerabilities(revision int, dbRevision, repositoryLocalPat
 	}
 
 	// Handle a database that needs upgrading.
-	out, err := utils.Exec(repositoryLocalPath, "bzr", "log", "--verbose", "-r"+strconv.Itoa(dbRevisionInt+1)+"..", "-n0")
+	cmd := exec.Command("bzr", "log", "--verbose", "-r"+strconv.Itoa(dbRevisionInt+1)+"..", "-n0")
+	cmd.Dir = repositoryLocalPath
+	out, err := cmd.CombinedOutput()
 	if err != nil {
 		log.Errorf("could not get Ubuntu vulnerabilities repository logs: %s. output: %s", err, out)
 		return nil, commonerr.ErrCouldNotDownload

utils/exec.go

@@ -1,39 +0,0 @@
-// Copyright 2015 clair 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 utils simply defines utility functions and types.
-package utils
-
-import (
-	"bytes"
-	"os/exec"
-)
-
-// Exec runs the given binary with arguments
-func Exec(dir string, bin string, args ...string) ([]byte, error) {
-	_, err := exec.LookPath(bin)
-	if err != nil {
-		return nil, err
-	}
-
-	cmd := exec.Command(bin, args...)
-	cmd.Dir = dir
-
-	var buf bytes.Buffer
-	cmd.Stdout = &buf
-	cmd.Stderr = &buf
-
-	err = cmd.Run()
-	return buf.Bytes(), err
-}