Support for onbuild and unit test

executor/cmd/root.go

@@ -23,6 +23,8 @@ import (
 	"github.com/GoogleCloudPlatform/k8s-container-builder/pkg/image"
 	"github.com/GoogleCloudPlatform/k8s-container-builder/pkg/snapshot"
 	"github.com/GoogleCloudPlatform/k8s-container-builder/pkg/util"
+	"github.com/containers/image/manifest"
+	"github.com/docker/docker/builder/dockerfile/instructions"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
@@ -141,6 +143,9 @@ func execute() error {
 	imageConfig := sourceImage.Config()
 	// Currently only supports single stage builds
 	for _, stage := range stages {
+		if err := resolveOnBuild(&stage, imageConfig); err != nil {
+			return err
+		}
 		for _, cmd := range stage.Commands {
 			dockerCommand, err := commands.GetCommand(cmd, srcContext)
 			if err != nil {
@@ -173,6 +178,21 @@ func execute() error {
 	return image.PushImage(sourceImage, destination)
 }
 
+func resolveOnBuild(stage *instructions.Stage, config *manifest.Schema2Config) error {
+	if config.OnBuild == nil {
+		return nil
+	}
+	// Otherwise, parse into commands
+	cmds, err := dockerfile.ParseCommands(config.OnBuild)
+	if err != nil {
+		return err
+	}
+	// Append to the beginning of the commands in the stage
+	stage.Commands = append(cmds, stage.Commands...)
+	logrus.Infof("Executing %v build triggers", len(cmds))
+	return nil
+}
+
 // setDefaultEnv sets default values for HOME and PATH so that
 // config.json and docker-credential-gcr can be accessed
 func setDefaultEnv() error {

pkg/commands/commands.go

@@ -56,6 +56,8 @@ func GetCommand(cmd instructions.Command, buildcontext string) (DockerCommand, e
 		return &LabelCommand{cmd: c}, nil
 	case *instructions.UserCommand:
 		return &UserCommand{cmd: c}, nil
+	case *instructions.OnbuildCommand:
+		return &OnBuildCommand{cmd: c}, nil
 	}
 	return nil, errors.Errorf("%s is not a supported command", cmd.Name())
 }

pkg/commands/onbuild.go

@@ -0,0 +1,52 @@
+/*
+Copyright 2018 Google LLC
+
+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 commands
+
+import (
+	"github.com/GoogleCloudPlatform/k8s-container-builder/pkg/util"
+	"github.com/containers/image/manifest"
+	"github.com/docker/docker/builder/dockerfile/instructions"
+	"github.com/sirupsen/logrus"
+)
+
+type OnBuildCommand struct {
+	cmd *instructions.OnbuildCommand
+}
+
+func (o *OnBuildCommand) ExecuteCommand(config *manifest.Schema2Config) error {
+	logrus.Info("cmd: ONBUILD")
+	resolvedExpression, err := util.ResolveEnvironmentReplacement(o.cmd.Expression, config.Env, false)
+	if err != nil {
+		return err
+	}
+	if config.OnBuild == nil {
+		config.OnBuild = []string{resolvedExpression}
+	} else {
+		config.OnBuild = append(config.OnBuild, resolvedExpression)
+	}
+	return nil
+}
+
+// No files have changed, this command only touches metadata.
+func (o *OnBuildCommand) FilesToSnapshot() []string {
+	return []string{}
+}
+
+// CreatedBy returns some information about the command for the image config history
+func (o *OnBuildCommand) CreatedBy() string {
+	return o.cmd.Expression
+}

pkg/commands/onbuild_test.go

@@ -0,0 +1,69 @@
+/*
+Copyright 2018 Google LLC
+
+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 commands
+
+import (
+	"github.com/GoogleCloudPlatform/k8s-container-builder/testutil"
+	"github.com/containers/image/manifest"
+	"github.com/docker/docker/builder/dockerfile/instructions"
+	"testing"
+)
+
+var onbuildTests = []struct {
+	expression    string
+	onbuildArray  []string
+	expectedArray []string
+}{
+	{
+		expression:   "RUN echo \\\"hi\\\" > $dir",
+		onbuildArray: nil,
+		expectedArray: []string{
+			"RUN echo \"hi\" > /some/dir",
+		},
+	},
+	{
+		expression: "COPY foo foo",
+		onbuildArray: []string{
+			"RUN echo \"hi\" > /some/dir",
+		},
+		expectedArray: []string{
+			"RUN echo \"hi\" > /some/dir",
+			"COPY foo foo",
+		},
+	},
+}
+
+func TestExecuteOnbuild(t *testing.T) {
+	for _, test := range onbuildTests {
+		cfg := &manifest.Schema2Config{
+			Env: []string{
+				"dir=/some/dir",
+			},
+			OnBuild: test.onbuildArray,
+		}
+
+		onbuildCmd := &OnBuildCommand{
+			&instructions.OnbuildCommand{
+				Expression: test.expression,
+			},
+		}
+
+		err := onbuildCmd.ExecuteCommand(cfg)
+		testutil.CheckErrorAndDeepEqual(t, false, err, test.expectedArray, cfg.OnBuild)
+	}
+
+}

pkg/dockerfile/dockerfile.go

@@ -18,6 +18,7 @@ package dockerfile
 
 import (
 	"bytes"
+	"strings"
 
 	"github.com/docker/docker/builder/dockerfile/instructions"
 	"github.com/docker/docker/builder/dockerfile/parser"
@@ -35,3 +36,21 @@ func Parse(b []byte) ([]instructions.Stage, error) {
 	}
 	return stages, err
 }
+
+// ParseCommands parses an array of commands into an array of instructions.Command; used for onbuild
+func ParseCommands(cmdArray []string) ([]instructions.Command, error) {
+	var cmds []instructions.Command
+	cmdString := strings.Join(cmdArray, "\n")
+	ast, err := parser.Parse(strings.NewReader(cmdString))
+	if err != nil {
+		return nil, err
+	}
+	for _, child := range ast.AST.Children {
+		cmd, err := instructions.ParseCommand(child)
+		if err != nil {
+			return nil, err
+		}
+		cmds = append(cmds, cmd)
+	}
+	return cmds, nil
+}