Add more integration tests for ARG caching

test/buildarg_test.go

@@ -1,6 +1,10 @@
 package tests
 
-import "testing"
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
 
 func TestBuildArg_Simple(t *testing.T) {
 	rockerfileContent := `
@@ -9,10 +13,72 @@ RUN export | grep proxy`
 
 	err := runRockerBuildWithOptions(rockerBuildOptions{
 		rockerfileContent: rockerfileContent,
-		buildParams:       []string{"--no-cache", "--build-arg", "http_proxy=http://host:3128"},
+		buildParams:       []string{"--build-arg", "http_proxy=http://host:3128", "--no-cache", "--no-garbage"},
 		testLines:         []string{"export http_proxy='http://host:3128'"},
 	})
 	if err != nil {
 		t.Fatal(err)
 	}
 }
+
+func TestBuildArg_CacheHit(t *testing.T) {
+	var sha1, sha2 string
+
+	rockerfileContent := `
+FROM alpine
+ENV test_cache=` + randomString() + `
+RUN export | grep proxy`
+
+	err := runRockerBuildWithOptions(rockerBuildOptions{
+		rockerfileContent: rockerfileContent,
+		buildParams:       []string{"--build-arg", "http_proxy=http://host:3128"},
+		sha:               &sha1,
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer removeImage(sha1)
+
+	err = runRockerBuildWithOptions(rockerBuildOptions{
+		rockerfileContent: rockerfileContent,
+		buildParams:       []string{"--build-arg", "http_proxy=http://host:3128"},
+		sha:               &sha2,
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer removeImage(sha2)
+
+	assert.Equal(t, sha1, sha2, "same build-arg should not invalidate cache")
+}
+
+func TestBuildArg_CacheInvalidate(t *testing.T) {
+	var sha1, sha2 string
+
+	rockerfileContent := `
+FROM alpine
+ENV test_cache=` + randomString() + `
+RUN export | grep proxy`
+
+	err := runRockerBuildWithOptions(rockerBuildOptions{
+		rockerfileContent: rockerfileContent,
+		buildParams:       []string{"--build-arg", "http_proxy=http://host:3128"},
+		sha:               &sha1,
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer removeImage(sha1)
+
+	err = runRockerBuildWithOptions(rockerBuildOptions{
+		rockerfileContent: rockerfileContent,
+		buildParams:       []string{"--build-arg", "http_proxy=http://host:3129"}, // note different port
+		sha:               &sha2,
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer removeImage(sha2)
+
+	assert.NotEqual(t, sha1, sha2, "different build-arg values should invalidate cache")
+}

test/pull_test.go

@@ -2,7 +2,6 @@ package tests
 
 import (
 	"fmt"
-	"strconv"
 	"testing"
 	"time"
 
@@ -22,7 +21,7 @@ func TestPull_Simple(t *testing.T) {
 }
 
 func TestPull_PushAndPull(t *testing.T) {
-	randomData := strconv.Itoa(int(time.Now().UnixNano() % int64(100000001)))
+	randomData := randomString()
 
 	auth, err := docker.NewAuthConfigurationsFromDockerCfg()
 	if err != nil {

test/utils.go

@@ -9,6 +9,8 @@ import (
 	"os"
 	"os/exec"
 	"path"
+	"regexp"
+	"strconv"
 	"strings"
 	"testing"
 	"time"
@@ -19,6 +21,10 @@ import (
 	"github.com/mitchellh/go-homedir"
 )
 
+var (
+	outputShaRe = regexp.MustCompile("Successfully built (sha256:[a-f0-9]+)")
+)
+
 func runCmd(command string, args ...string) (string, error) {
 	return runCmdWithOptions(cmdOptions{
 		command: command,
@@ -136,6 +142,7 @@ type rockerBuildOptions struct {
 	testLines         []string
 	workdir           string
 	stdout            io.Writer
+	sha               *string
 }
 
 func runRockerBuildWithOptions(opts rockerBuildOptions) error {
@@ -187,6 +194,14 @@ func runRockerBuildWithOptions(opts rockerBuildOptions) error {
 		return fmt.Errorf("Failed to run rocker build, error: %s", err)
 	}
 
+	if opts.sha != nil {
+		if match := outputShaRe.FindStringSubmatch(output); match != nil {
+			*opts.sha = match[1]
+		} else {
+			return fmt.Errorf("Expected rocker build to return image SHA, got nothing.\n\nRocker build output:\n%s", output)
+		}
+	}
+
 	if len(opts.testLines) > 0 {
 		linesMap := map[string]int{}
 		for _, l := range strings.Split(output, "\n") {
@@ -260,6 +275,10 @@ func makeTempDir(t *testing.T, prefix string, files map[string]string) string {
 	return tmpDir
 }
 
+func randomString() string {
+	return strconv.Itoa(int(time.Now().UnixNano() % int64(100000001)))
+}
+
 func debugf(format string, args ...interface{}) {
 	if *verbosityLevel >= 2 {
 		fmt.Printf(format, args...)