Add more helpers for running skopeo, use them in existing tests

- consumeAndLogOutputs
- assertSkopeoSucceeds
- assertSkopeoFails
- runCommandWithInput
All of these allow running commands as one-liners with no call-site
error handling, making tests much more readable.

Also modifies TestNoNeedAuthToPrivateRegistryV2ImageNotFound to use
check.Matches instead of manual strings.Contains conditions, which is
shorter and more consistent with the assertSkopeo... calls.

integration/check_test.go

@@ -3,7 +3,6 @@ package main
 import (
 	"fmt"
 	"os/exec"
-	"strings"
 	"testing"
 
 	"github.com/go-check/check"
@@ -15,8 +14,6 @@ const (
 	privateRegistryURL2 = "127.0.0.1:5002"
 	privateRegistryURL3 = "127.0.0.1:5003"
 	privateRegistryURL4 = "127.0.0.1:5004"
-
-	skopeoBinary = "skopeo"
 )
 
 func Test(t *testing.T) {
@@ -73,38 +70,26 @@ func (s *SkopeoSuite) TearDownTest(c *check.C) {
 //func skopeoCmd()
 
 func (s *SkopeoSuite) TestVersion(c *check.C) {
-	out, err := exec.Command(skopeoBinary, "--version").CombinedOutput()
-	c.Assert(err, check.IsNil, check.Commentf(string(out)))
-	wanted := skopeoBinary + " version "
-	if !strings.Contains(string(out), wanted) {
-		c.Fatalf("wanted %s, got %s", wanted, string(out))
-	}
+	wanted := fmt.Sprintf(".*%s version .*", skopeoBinary)
+	assertSkopeoSucceeds(c, wanted, "--version")
 }
 
-var (
-	errFetchManifest = "error fetching manifest: status code: %s"
+const (
+	errFetchManifestRegexp = ".*error fetching manifest: status code: %s.*"
 )
 
 func (s *SkopeoSuite) TestCanAuthToPrivateRegistryV2WithoutDockerCfg(c *check.C) {
 	// TODO(runcom)
 	c.Skip("we need to restore --username --password flags!")
-	out, err := exec.Command(skopeoBinary, "--docker-cfg=''", "--username="+s.regV2WithAuth.username, "--password="+s.regV2WithAuth.password, "inspect", fmt.Sprintf("docker://%s/busybox:latest", s.regV2WithAuth.url)).CombinedOutput()
-	c.Assert(err, check.NotNil, check.Commentf(string(out)))
-	wanted := fmt.Sprintf(errFetchManifest, "401")
-	if !strings.Contains(string(out), wanted) {
-		c.Fatalf("wanted %s, got %s", wanted, string(out))
-	}
+	wanted := fmt.Sprintf(errFetchManifestRegexp, "401")
+	assertSkopeoFails(c, wanted, "--docker-cfg=''", "--username="+s.regV2WithAuth.username, "--password="+s.regV2WithAuth.password, "inspect", fmt.Sprintf("docker://%s/busybox:latest", s.regV2WithAuth.url))
 }
 
 func (s *SkopeoSuite) TestNeedAuthToPrivateRegistryV2WithoutDockerCfg(c *check.C) {
 	// TODO(runcom): mock the empty docker-cfg by removing it in the test itself (?)
 	c.Skip("mock empty docker config")
-	out, err := exec.Command(skopeoBinary, "--docker-cfg=''", "inspect", fmt.Sprintf("docker://%s/busybox:latest", s.regV2WithAuth.url)).CombinedOutput()
-	c.Assert(err, check.NotNil, check.Commentf(string(out)))
-	wanted := fmt.Sprintf(errFetchManifest, "401")
-	if !strings.Contains(string(out), wanted) {
-		c.Fatalf("wanted %s, got %s", wanted, string(out))
-	}
+	wanted := fmt.Sprintf(errFetchManifestRegexp, "401")
+	assertSkopeoFails(c, wanted, "--docker-cfg=''", "inspect", fmt.Sprintf("docker://%s/busybox:latest", s.regV2WithAuth.url))
 }
 
 // TODO(runcom): as soon as we can push to registries ensure you can inspect here
@@ -112,12 +97,8 @@ func (s *SkopeoSuite) TestNeedAuthToPrivateRegistryV2WithoutDockerCfg(c *check.C
 func (s *SkopeoSuite) TestNoNeedAuthToPrivateRegistryV2ImageNotFound(c *check.C) {
 	out, err := exec.Command(skopeoBinary, "inspect", fmt.Sprintf("docker://%s/busybox:latest", s.regV2.url)).CombinedOutput()
 	c.Assert(err, check.NotNil, check.Commentf(string(out)))
-	wanted := fmt.Sprintf(errFetchManifest, "404")
-	if !strings.Contains(string(out), wanted) {
-		c.Fatalf("wanted %s, got %s", wanted, string(out))
-	}
-	wanted = fmt.Sprintf(errFetchManifest, "401")
-	if strings.Contains(string(out), wanted) {
-		c.Fatalf("not wanted %s, got %s", wanted, string(out))
-	}
+	wanted := fmt.Sprintf(errFetchManifestRegexp, "404")
+	c.Assert(string(out), check.Matches, "(?s)"+wanted) // (?s) : '.' will also match newlines
+	wanted = fmt.Sprintf(errFetchManifestRegexp, "401")
+	c.Assert(string(out), check.Not(check.Matches), "(?s)"+wanted) // (?s) : '.' will also match newlines
 }

integration/signing_test.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"errors"
+	"fmt"
 	"io/ioutil"
 	"os"
 	"os/exec"
@@ -42,21 +43,7 @@ func (s *SigningSuite) SetUpTest(c *check.C) {
 	c.Assert(err, check.IsNil)
 	os.Setenv("GNUPGHOME", s.gpgHome)
 
-	cmd := exec.Command(gpgBinary, "--homedir", s.gpgHome, "--batch", "--gen-key")
-	stdin, err := cmd.StdinPipe()
-	c.Assert(err, check.IsNil)
-	stdout, err := cmd.StdoutPipe()
-	consumeAndLogOutput(c, "gen-key stdout", stdout, err)
-	stderr, err := cmd.StderrPipe()
-	consumeAndLogOutput(c, "gen-key stderr", stderr, err)
-	err = cmd.Start()
-	c.Assert(err, check.IsNil)
-	_, err = stdin.Write([]byte("Key-Type: RSA\nName-Real: Testing user\n%commit\n"))
-	c.Assert(err, check.IsNil)
-	err = stdin.Close()
-	c.Assert(err, check.IsNil)
-	err = cmd.Wait()
-	c.Assert(err, check.IsNil)
+	runCommandWithInput(c, "Key-Type: RSA\nName-Real: Testing user\n%commit\n", gpgBinary, "--homedir", s.gpgHome, "--batch", "--gen-key")
 
 	lines, err := exec.Command(gpgBinary, "--homedir", s.gpgHome, "--with-colons", "--no-permission-warning", "--fingerprint").Output()
 	c.Assert(err, check.IsNil)
@@ -81,13 +68,10 @@ func (s *SigningSuite) TestSignVerifySmoke(c *check.C) {
 	sigOutput, err := ioutil.TempFile("", "sig")
 	c.Assert(err, check.IsNil)
 	defer os.Remove(sigOutput.Name())
-	out, err := exec.Command(skopeoBinary, "standalone-sign", "-o", sigOutput.Name(),
-		manifestPath, dockerReference, s.fingerprint).CombinedOutput()
-	c.Assert(err, check.IsNil, check.Commentf("%s", out))
-	c.Assert(string(out), check.Equals, "")
+	assertSkopeoSucceeds(c, "^$", "standalone-sign", "-o", sigOutput.Name(),
+		manifestPath, dockerReference, s.fingerprint)
 
-	out, err = exec.Command(skopeoBinary, "standalone-verify", manifestPath,
-		dockerReference, s.fingerprint, sigOutput.Name()).CombinedOutput()
-	c.Assert(err, check.IsNil, check.Commentf("%s", out))
-	c.Assert(string(out), check.Equals, "Signature verified, digest "+TestImageManifestDigest+"\n")
+	expected := fmt.Sprintf("^Signature verified, digest %s\n$", TestImageManifestDigest)
+	assertSkopeoSucceeds(c, expected, "standalone-verify", manifestPath,
+		dockerReference, s.fingerprint, sigOutput.Name())
 }

integration/utils.go

@@ -2,13 +2,16 @@ package main
 
 import (
 	"io"
+	"os/exec"
 	"strings"
 
 	"github.com/go-check/check"
 )
 
-// consumeAndLogOutput takes (f, err) from an exec.*Pipe(), and causes all output to it to be logged to c.
-func consumeAndLogOutput(c *check.C, id string, f io.ReadCloser, err error) {
+const skopeoBinary = "skopeo"
+
+// consumeAndLogOutputStream takes (f, err) from an exec.*Pipe(), and causes all output to it to be logged to c.
+func consumeAndLogOutputStream(c *check.C, id string, f io.ReadCloser, err error) {
 	c.Assert(err, check.IsNil)
 	go func() {
 		defer func() {
@@ -26,3 +29,51 @@ func consumeAndLogOutput(c *check.C, id string, f io.ReadCloser, err error) {
 		}
 	}()
 }
+
+// consumeAndLogOutputs causes all output to stdout and stderr from an *exec.Cmd to be logged to c
+func consumeAndLogOutputs(c *check.C, id string, cmd *exec.Cmd) {
+	stdout, err := cmd.StdoutPipe()
+	consumeAndLogOutputStream(c, id+" stdout", stdout, err)
+	stderr, err := cmd.StderrPipe()
+	consumeAndLogOutputStream(c, id+" stderr", stderr, err)
+}
+
+// assertSkopeoSucceeds runs a skopeo command as if exec.Command().CombinedOutput, verifies that the exit status is 0,
+// and optionally that the output matches a multi-line regexp if it is nonempty;
+// or terminates c on failure
+func assertSkopeoSucceeds(c *check.C, regexp string, args ...string) {
+	c.Logf("Running %s %s", skopeoBinary, strings.Join(args, " "))
+	out, err := exec.Command(skopeoBinary, args...).CombinedOutput()
+	c.Assert(err, check.IsNil, check.Commentf("%s", out))
+	if regexp != "" {
+		c.Assert(string(out), check.Matches, "(?s)"+regexp) // (?s) : '.' will also match newlines
+	}
+}
+
+// assertSkopeoFails runs a skopeo command as if exec.Command().CombinedOutput, verifies that the exit status is 0,
+// and that the output matches a multi-line regexp;
+// or terminates c on failure
+func assertSkopeoFails(c *check.C, regexp string, args ...string) {
+	c.Logf("Running %s %s", skopeoBinary, strings.Join(args, " "))
+	out, err := exec.Command(skopeoBinary, args...).CombinedOutput()
+	c.Assert(err, check.NotNil, check.Commentf("%s", out))
+	c.Assert(string(out), check.Matches, "(?s)"+regexp) // (?s) : '.' will also match newlines
+}
+
+// runCommandWithInput runs a command as if exec.Command(), sending it the input to stdin,
+// and verifies that the exit status is 0, or terminates c on failure.
+func runCommandWithInput(c *check.C, input string, name string, args ...string) {
+	c.Logf("Running %s %s", name, strings.Join(args, " "))
+	cmd := exec.Command(name, args...)
+	consumeAndLogOutputs(c, name+" "+strings.Join(args, " "), cmd)
+	stdin, err := cmd.StdinPipe()
+	c.Assert(err, check.IsNil)
+	err = cmd.Start()
+	c.Assert(err, check.IsNil)
+	_, err = stdin.Write([]byte(input))
+	c.Assert(err, check.IsNil)
+	err = stdin.Close()
+	c.Assert(err, check.IsNil)
+	err = cmd.Wait()
+	c.Assert(err, check.IsNil)
+}