init kind

pkg/build/images.go

@@ -0,0 +1,108 @@
+/*
+Copyright 2018 The Kubernetes 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 build implements functionality to build the kind images
+// TODO(bentheelder): and k8s
+package build
+
+import (
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+
+	"github.com/golang/glog"
+)
+
+// NodeImageBuildContext is used to build the kind node image, and contains
+// build configuration
+type NodeImageBuildContext struct {
+	SourceDir string
+	ImageTag  string
+	GoCmd     string
+	Arch      string
+}
+
+// NewNodeImageBuildContext creates a new NodeImageBuildContext with
+// default configuration
+func NewNodeImageBuildContext() *NodeImageBuildContext {
+	return &NodeImageBuildContext{
+		ImageTag: "kind-node",
+		GoCmd:    "go",
+		Arch:     "amd64",
+	}
+}
+
+func runCmd(cmd *exec.Cmd) error {
+	glog.Infof("Running: %v %v", cmd.Path, cmd.Args)
+	// TODO(bentheelder): reconsider this / make it configurable
+	cmd.Stderr = os.Stderr
+	cmd.Stdout = os.Stdout
+	return cmd.Run()
+}
+
+// TODO(bentheelder): vendor a portable go library for this and use instead
+func copyDir(src, dst string) error {
+	src = filepath.Clean(src) + string(filepath.Separator) + "."
+	dst = filepath.Clean(dst)
+	cmd := exec.Command("cp", "-r", src, dst)
+	return runCmd(cmd)
+}
+
+// Build builds the cluster node image, the sourcedir must be set on
+// the NodeImageBuildContext
+func (c *NodeImageBuildContext) Build() (err error) {
+	// create tempdir to build in
+	dir, err := ioutil.TempDir("", "kind-build")
+	if err != nil {
+		return err
+	}
+	defer os.RemoveAll(dir)
+
+	// populate with image sources
+	err = copyDir(c.SourceDir, dir)
+	if err != nil {
+		glog.Errorf("failed to copy sources to build dir %v", err)
+		return err
+	}
+
+	glog.Infof("Building node image in: %s", dir)
+
+	// build entrypoint binary
+	// NOTE: this binary only uses the go1 stdlib, and is a single file
+	glog.Info("Building entrypoint binary ...")
+	entrypointSrc := filepath.Join(dir, "entrypoint", "main.go")
+	entrypointDest := filepath.Join(dir, "entrypoint", "entrypoint")
+	cmd := exec.Command(c.GoCmd, "build", "-o", entrypointDest, entrypointSrc)
+	// TODO(bentheelder): we may need to map between docker image arch and GOARCH
+	cmd.Env = []string{"GOOS=linux", "GOARCH=" + c.Arch}
+	err = runCmd(cmd)
+	if err != nil {
+		glog.Errorf("Entrypoint build Failed! %v", err)
+		return err
+	}
+	glog.Info("Entrypoint build completed.")
+
+	glog.Info("Starting Docker build ...")
+	// build the image, tagged as tagImageAs, using the our tempdir as the context
+	err = runCmd(exec.Command("docker", "build", "-t", c.ImageTag, dir))
+	if err != nil {
+		glog.Errorf("Docker build Failed! %v", err)
+		return err
+	}
+	glog.Info("Docker build completed.")
+	return nil
+}