commands/operator-sdk/cmd/build.go: operator-sdk build uses buildah instead of docker

`buildah` is a tool that builds OCI images, from its CLI interface or by interpreting
Dockerfiles. RHEL does not support docker-ce above v1.13, preventing the SDK from leveraging
the multi-stage build Dockerfile feature; `buildah` supports this feature, and will continue
to be supported in RHEL. See #431 for relevant discussion.

Author: estroz

commands/operator-sdk/cmd/build.go

@@ -161,8 +161,12 @@ func buildFunc(cmd *cobra.Command, args []string) {
 	if enableTests {
 		baseImageName += "-intermediate"
 	}
-	dbcmd := exec.Command("docker", "build", ".", "-f", "tmp/build/Dockerfile", "-t", baseImageName)
-	o, err := dbcmd.CombinedOutput()
+
+	dbcmd := exec.Command("buildah", "bud",
+		"-f", "tmp/build/Dockerfile",
+		"--isolation", "rootless",
+		"-t", baseImageName)
+	o, err = dbcmd.CombinedOutput()
 	if err != nil {
 		if enableTests {
 			cmdError.ExitWithError(cmdError.ExitError, fmt.Errorf("failed to build intermediate image for %s image: (%s)", image, string(o)))
@@ -173,7 +177,12 @@ func buildFunc(cmd *cobra.Command, args []string) {
 	fmt.Fprintln(os.Stdout, string(o))
 
 	if enableTests {
-		testDbcmd := exec.Command("docker", "build", ".", "-f", "tmp/build/test-framework/Dockerfile", "-t", image, "--build-arg", "NAMESPACEDMAN="+namespacedManBuild, "--build-arg", "BASEIMAGE="+baseImageName)
+		testDbcmd := exec.Command("buildah", "bud",
+			"-f", "tmp/build/test-framework/Dockerfile",
+			"--isolation", "rootless",
+			"-t", image,
+			"--build-arg", "NAMESPACEDMAN="+namespacedManBuild,
+			"--build-arg", "BASEIMAGE="+baseImageName)
 		o, err = testDbcmd.CombinedOutput()
 		if err != nil {
 			cmdError.ExitWithError(cmdError.ExitError, fmt.Errorf("failed to output build image %v: (%v)", image, string(o)))

pkg/generator/generator.go

@@ -526,6 +526,7 @@ func renderBuildFiles(buildDir, repoPath, projectName, operatorType string, gene
 	dTd := tmplData{
 		ProjectName:      projectName,
 		GeneratePlaybook: generatePlaybook,
+		RepoPath:         repoPath,
 	}
 
 	if err := renderWriteFile(filepath.Join(buildDir, dockerfile), "tmp/build/Dockerfile", dockerFileTmplName, dTd); err != nil {

pkg/generator/templates.go

@@ -581,12 +581,29 @@ const goTestScript = `#!/bin/sh
 memcached-operator-test -test.parallel=1 -test.failfast -root=/ -kubeconfig=incluster -namespacedMan=namespaced.yaml -test.v
 `
 
-const dockerFileTmpl = `FROM alpine:3.6
+const dockerFileTmpl = `# Binary builder image
+FROM golang:1.10.3 AS builder
+
+ENV GOPATH /go
+ENV CGO_ENABLED 0
+ENV GOOS linux
+ENV GOARCH amd64
+
+WORKDIR /go/src/{{.RepoPath}}
+COPY . /go/src/{{.RepoPath}}
+
+RUN go build -o /go/bin/{{.ProjectName}} {{.RepoPath}}/cmd/{{.ProjectName}}/main.go
+
+# Base image
+FROM alpine:3.6
+COPY --from=builder /go/bin/{{.ProjectName}} /usr/local/bin/{{.ProjectName}}
 
 RUN adduser -D {{.ProjectName}}
 USER {{.ProjectName}}
 
-ADD tmp/_output/bin/{{.ProjectName}} /usr/local/bin/{{.ProjectName}}
+# Add customizations here.
+
+ENTRYPOINT ["{{.ProjectName}}"]
 `
 
 const testingDockerFileTmpl = `ARG BASEIMAGE