env/android-amd64-emu: add new Android emulator container + VM image

Now that we can do nested virtualization on GCE, that means we can run
the Android emulator (which requires KVM) on GCE and at least get
fast trybots and such for android-amd64.

Updates golang/go#23824

Change-Id: I0da38c7fa0f15492230a31291d2921ba72f2151d
Reviewed-on: https://go-review.googlesource.com/c/163738
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

cmd/buildlet/buildlet.go

@@ -108,12 +108,15 @@ var (
 )
 
 func main() {
-	switch os.Getenv("GO_BUILDER_ENV") {
+	builderEnv := os.Getenv("GO_BUILDER_ENV")
+
+	switch builderEnv {
 	case "macstadium_vm":
 		configureMacStadium()
 	case "linux-arm-arm5spacemonkey":
 		initBaseUnixEnv() // Issue 28041
 	}
+
 	onGCE := metadata.OnGCE()
 	switch runtime.GOOS {
 	case "plan9":
@@ -133,6 +136,10 @@ func main() {
 	log.Printf("buildlet starting.")
 	flag.Parse()
 
+	if builderEnv == "android-amd64-emu" {
+		startAndroidEmulator()
+	}
+
 	if *reverse == "solaris-amd64-smartosbuildlet" {
 		// These machines were setup without GO_BUILDER_ENV
 		// set in their base image, so do init work here after
@@ -860,6 +867,10 @@ func handleExec(w http.ResponseWriter, r *http.Request) {
 			return
 		}
 	}
+	if err := checkAndroidEmulator(); err != nil {
+		http.Error(w, "android emulator not running: "+err.Error(), http.StatusInternalServerError)
+		return
+	}
 
 	w.Header().Set("Trailer", hdrProcessState) // declare it so we can set it
 
@@ -1799,3 +1810,44 @@ func removeAllAndMkdir(dir string) {
 		log.Fatal(err)
 	}
 }
+
+var (
+	androidEmuDead = make(chan error) // closed on death
+	androidEmuErr  error              // set prior to channel close
+)
+
+func startAndroidEmulator() {
+	cmd := exec.Command("/android/sdk/emulator/emulator",
+		"@android-avd",
+		"-no-audio",
+		"-no-window",
+		"-no-boot-anim",
+		"-no-snapshot-save",
+		"-wipe-data", // required to prevent a hang with -no-window when recovering from a snapshot?
+	)
+	log.Printf("running Android emulator: %v", cmd.Args)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	if err := cmd.Start(); err != nil {
+		log.Fatalf("failed to start Android emulator: %v", err)
+	}
+	go func() {
+		err := cmd.Wait()
+		if err == nil {
+			err = errors.New("exited without error")
+		}
+		androidEmuErr = err
+		close(androidEmuDead)
+	}()
+}
+
+// checkAndroidEmulator returns an error if this machine is an Android builder
+// and the Android emulator process has exited.
+func checkAndroidEmulator() error {
+	select {
+	case <-androidEmuDead:
+		return androidEmuErr
+	default:
+		return nil
+	}
+}

cmd/buildlet/stage0/Dockerfile

@@ -0,0 +1,33 @@
+# Copyright 2017 The Go Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+FROM golang:1.11
+LABEL maintainer "golang-dev@googlegroups.com"
+
+ENV CGO_ENABLED=0
+
+# BEGIN deps (run `make update-deps` to update)
+
+# Repo cloud.google.com/go at 5c31045 (2018-05-08)
+ENV REV=5c31045bc3f4855c97f997a1940dfefc1598aa2d
+RUN go get -d cloud.google.com/go/compute/metadata &&\
+    (cd /go/src/cloud.google.com/go && (git cat-file -t $REV 2>/dev/null || git fetch -q origin $REV) && git reset --hard $REV)
+
+# Repo golang.org/x/net at d11bb6c (2018-05-07)
+ENV REV=d11bb6cd8e3c4e60239c9cb20ef68586d74500d0
+RUN go get -d golang.org/x/net/context `#and 2 other pkgs` &&\
+    (cd /go/src/golang.org/x/net && (git cat-file -t $REV 2>/dev/null || git fetch -q origin $REV) && git reset --hard $REV)
+
+# Optimization to speed up iterative development, not necessary for correctness:
+RUN go install cloud.google.com/go/compute/metadata \
+	golang.org/x/net/context \
+	golang.org/x/net/context/ctxhttp
+# END deps.
+
+COPY . /go/src/golang.org/x/build/
+
+# Install static binary to /go/bin/stage0
+RUN go install golang.org/x/build/cmd/buildlet/stage0
+
+

cmd/coordinator/coordinator.go

@@ -1594,6 +1594,10 @@ func (st *buildStatus) expectedBuildletStartDuration() time.Duration {
 	pool := st.buildletPool()
 	switch pool.(type) {
 	case *gceBuildletPool:
+		if strings.HasPrefix(st.Name, "android-") {
+			// about a minute for buildlet + minute for Android emulator to be usable
+			return 2 * time.Minute
+		}
 		return time.Minute
 	case *reverseBuildletPool:
 		goos, arch := st.conf.GOOS(), st.conf.GOARCH()

cmd/xb/xb.go

@@ -147,8 +147,11 @@ func runDocker() {
 			case "golang/buildlet-stage0":
 				log.Printf("building dependent layer %q", layer)
 				buildStage0Container()
-			case "debian:stretch":
-				// TODO: validate version of stretch
+			case "debian:stretch", "debian:buster":
+				// TODO: validate version? probably doesn't matter, as they're
+				// pretty frozen and just get security/bug updates, and most of
+				// our Dockerfiles start with apt-get update && upgrade steps
+				// anyway.
 			default:
 				log.Fatalf("unsupported layer %q; don't know how to validate or build", layer)
 			}

dashboard/builders.go

@@ -530,6 +530,15 @@ var Hosts = map[string]*HostConfig{
 		ExpectNum:   1,
 		env:         []string{"GOROOT_BOOTSTRAP=/opt/freeware/lib/golang"},
 	},
+	"host-android-amd64-emu": &HostConfig{
+		Notes:           "Debian Buster w/ Android SDK + emulator (use nested virt)",
+		ContainerImage:  "android-amd64-emu:ba38cc4f0c38",
+		KonletVMImage:   "android-amd64-emu",
+		NestedVirt:      true,
+		buildletURLTmpl: "http://storage.googleapis.com/$BUCKET/buildlet.linux-amd64",
+		env:             []string{"GOROOT_BOOTSTRAP=/go1.4"},
+		SSHUsername:     "root",
+	},
 }
 
 func init() {
@@ -860,10 +869,13 @@ func (c *BuildConfig) SplitMakeRun() bool {
 		// These we've verified to work.
 		return true
 	}
-	// TODO(bradfitz): make androidtest.bash and iotest.bash work
-	// too. And buildall.bash should really just be N small
-	// container jobs instead of a "buildall.bash". Then we can
-	// delete this whole method.
+	if c.GOOS() == "android" && c.HostType == "host-android-amd64-emu" {
+		return true
+	}
+	// TODO(bradfitz): make iotest.bash work too. And
+	// buildall.bash should really just be N small container jobs
+	// instead of a "buildall.bash". Then we can delete this whole
+	// method.
 	return false
 }
 
@@ -873,7 +885,9 @@ func (c *BuildConfig) buildSubrepos() bool {
 	}
 	// TODO(bradfitz,dmitshur): move this into BuildConfig bools, rather than this Name switch.
 	switch c.Name {
-	case "darwin-amd64-10_11",
+	case "android-amd64-emu",
+		"android-386-emu",
+		"darwin-amd64-10_11",
 		"darwin-386-10_11",
 		// TODO: add darwin-amd64-10_12 when we have a build scheduler
 		"freebsd-amd64-93",
@@ -1731,6 +1745,34 @@ func init() {
 			"CC_FOR_TARGET=/Users/elias/android-ndk-standalone-arm64/bin/clang",
 		},
 	})
+	addBuilder(BuildConfig{
+		Name:     "android-386-emu",
+		HostType: "host-android-amd64-emu", // same amd64 host is used for 386 builder
+		Notes:    "Android emulator on GCE",
+		TryOnly:  true, // but not in trybot set for now
+		tryBot:   nil,
+		env: []string{
+			"GOARCH=386",
+			"GOOS=android",
+			"GOHOSTARCH=amd64",
+			"GOHOSTOS=linux",
+			"CGO_ENABLED=1",
+		},
+	})
+	addBuilder(BuildConfig{
+		Name:     "android-amd64-emu",
+		HostType: "host-android-amd64-emu",
+		Notes:    "Android emulator on GCE",
+		TryOnly:  true, // but not in trybot set for now
+		tryBot:   nil,
+		env: []string{
+			"GOARCH=amd64",
+			"GOOS=android",
+			"GOHOSTARCH=amd64",
+			"GOHOSTOS=linux",
+			"CGO_ENABLED=1",
+		},
+	})
 	addBuilder(BuildConfig{
 		Name:     "android-386-emulator",
 		HostType: "host-darwin-amd64-eliasnaur-android",

env/android-amd64-emu/Dockerfile

@@ -0,0 +1,81 @@
+# Copyright 2019 The Go Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+FROM golang/buildlet-stage0 AS stage0
+
+FROM debian:buster
+MAINTAINER golang-dev <golang-dev@googlegroups.com>
+
+ENV DEBIAN_FRONTEND noninteractive
+
+ENV GO_BUILDER_ENV android-amd64-emu
+ENV PATH="${PATH}:/android/sdk/platform-tools"
+ENV CC_FOR_android_386=/android/sdk/ndk-bundle/toolchains/llvm/prebuilt/linux-x86_64/bin/i686-linux-android26-clang
+ENV CC_FOR_android_amd64=/android/sdk/ndk-bundle/toolchains/llvm/prebuilt/linux-x86_64/bin/x86_64-linux-android26-clang
+
+# gdb: optionally used by runtime tests for gdb
+# strace: optionally used by some net/http tests
+# gcc libc6-dev: for building Go's bootstrap 'dist' prog
+# libc6-dev-i386 gcc-multilib: for 32-bit builds
+# procps lsof psmisc: misc basic tools
+# libgles2-mesa-dev libopenal-dev fonts-noto: required by x/mobile repo
+# unzip openjdk-8-jdk python lib32z1: required by the Android SDK
+RUN apt-get update && apt-get install -y \
+	--no-install-recommends \
+	ca-certificates \
+	curl \
+	gdb \
+	strace \
+	gcc \
+	libc6-dev \
+	libc6-dev-i386 \
+	gcc-multilib \
+	procps \
+	lsof \
+	psmisc \
+	libgles2-mesa-dev \
+	libopenal-dev \
+	fonts-noto \
+	fonts-noto-mono \
+	openssh-server \
+	unzip \
+	openjdk-8-jdk \
+	python \
+	lib32z1 \
+	&& rm -rf /var/lib/apt/lists/*
+
+RUN mkdir -p /go1.4-amd64 \
+	&& ( \
+		curl --silent https://storage.googleapis.com/golang/go1.4.linux-amd64.tar.gz | tar -C /go1.4-amd64 -zxv \
+	) \
+	&& mv /go1.4-amd64/go /go1.4 \
+	&& rm -rf /go1.4-amd64 \
+	&& rm -rf /go1.4/pkg/linux_amd64_race \
+		/go1.4/api \
+		/go1.4/blog \
+		/go1.4/doc \
+		/go1.4/misc \
+		/go1.4/test \
+	&& find /go1.4 -type d -name testdata | xargs rm -rf
+RUN mkdir -p /android/sdk \
+	&& curl -o /android/sdk/sdk-tools-linux.zip https://dl.google.com/android/repository/sdk-tools-linux-3859397.zip \
+	&& unzip -d /android/sdk /android/sdk/sdk-tools-linux.zip \
+	&& rm -rf /android/sdk/sdk-tools-linux.zip
+
+RUN yes | /android/sdk/tools/bin/sdkmanager --licenses \
+	&& /android/sdk/tools/bin/sdkmanager ndk-bundle "system-images;android-26;default;x86_64" \
+	&& /android/sdk/tools/bin/sdkmanager "build-tools;21.1.2" "platforms;android-26" \
+	&& /android/sdk/tools/bin/sdkmanager --update
+
+# Gradle for gomobile
+RUN curl -L -o /android/gradle-5.2.1-bin.zip https://services.gradle.org/distributions/gradle-5.2.1-bin.zip \
+	&& unzip -d /android /android/gradle-5.2.1-bin.zip \
+	&& rm /android/gradle-5.2.1-bin.zip
+
+# Create emulator
+RUN echo no | /android/sdk/tools/bin/avdmanager create avd --force --name android-avd --package "system-images;android-26;default;x86_64"
+
+COPY --from=stage0 /go/bin/stage0 /usr/local/bin/stage0
+
+CMD ["/usr/local/bin/stage0"]

env/android-amd64-emu/Makefile

@@ -0,0 +1,27 @@
+# Copyright 2018 The Go Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+IMAGE_NAME=$(shell basename $(CURDIR))
+
+usage:
+	echo "see Makefile for usage for building $(IMAGE_NAME)"
+
+docker: Dockerfile
+	go install golang.org/x/build/cmd/xb
+	xb docker build -t golang/$(IMAGE_NAME) .
+
+push-staging: docker
+	go install golang.org/x/build/cmd/xb
+	$(eval REV := $(shell docker images --format={{.ID}} golang/android-amd64-emu:latest))
+	xb --staging docker tag golang/$(IMAGE_NAME) REPO/$(IMAGE_NAME):$(REV)
+	xb --staging docker push REPO/$(IMAGE_NAME):$(REV)
+
+push-prod: docker
+	go install golang.org/x/build/cmd/xb
+	$(eval REV := $(shell docker images --format={{.ID}} golang/android-amd64-emu:latest))
+	xb --prod docker tag golang/$(IMAGE_NAME) REPO/$(IMAGE_NAME):$(REV)
+	xb --prod docker push REPO/$(IMAGE_NAME):$(REV)
+
+vm-prod: push-prod
+	./create-vm.sh

env/android-amd64-emu/README.md

@@ -0,0 +1,6 @@
+The android-amd64-emu builder is built in two parts:
+
+* first, a large Docker container
+* second, a VMX+konlet-based VM image with that Docker image pre-pulled
+
+