Simplify Docker test infrastructure.

This change adds a layer of abstraction around the internal Docker APIs,
and eliminates all direct dependencies on Dockerfiles in the infrastructure.

A subsequent change will automated the generation of local images (with
efficient caching). Note that this change drops the use of bazel container
rules, as that experiment does not seem to be viable.

PiperOrigin-RevId: 308095430

2 files changed, 320 insertions, 0 deletions

diff --git a/pkg/test/criutil/BUILD b/pkg/test/criutil/BUILD
new file mode 100644
index 000000000..a7b082cee
--- /dev/null
+++ b/pkg/test/criutil/BUILD
@@ -0,0 +1,14 @@
+load("//tools:defs.bzl", "go_library")
+
+package(licenses = ["notice"])
+
+go_library(
+    name = "criutil",
+    testonly = 1,
+    srcs = ["criutil.go"],
+    visibility = ["//:sandbox"],
+    deps = [
+        "//pkg/test/dockerutil",
+        "//pkg/test/testutil",
+    ],
+)
diff --git a/pkg/test/criutil/criutil.go b/pkg/test/criutil/criutil.go
new file mode 100644
index 000000000..bebebb48e
--- /dev/null
+++ b/pkg/test/criutil/criutil.go
@@ -0,0 +1,306 @@
+// Copyright 2018 The gVisor 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 criutil contains utility functions for interacting with the
+// Container Runtime Interface (CRI), principally via the crictl command line
+// tool. This requires critools to be installed on the local system.
+package criutil
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+	"time"
+
+	"gvisor.dev/gvisor/pkg/test/dockerutil"
+	"gvisor.dev/gvisor/pkg/test/testutil"
+)
+
+// Crictl contains information required to run the crictl utility.
+type Crictl struct {
+	logger   testutil.Logger
+	endpoint string
+	cleanup  []func()
+}
+
+// resolvePath attempts to find binary paths. It may set the path to invalid,
+// which will cause the execution to fail with a sensible error.
+func resolvePath(executable string) string {
+	guess, err := exec.LookPath(executable)
+	if err != nil {
+		guess = fmt.Sprintf("/usr/local/bin/%s", executable)
+	}
+	return guess
+}
+
+// NewCrictl returns a Crictl configured with a timeout and an endpoint over
+// which it will talk to containerd.
+func NewCrictl(logger testutil.Logger, endpoint string) *Crictl {
+	// Attempt to find the executable, but don't bother propagating the
+	// error at this point. The first command executed will return with a
+	// binary not found error.
+	return &Crictl{
+		logger:   logger,
+		endpoint: endpoint,
+	}
+}
+
+// CleanUp executes cleanup functions.
+func (cc *Crictl) CleanUp() {
+	for _, c := range cc.cleanup {
+		c()
+	}
+	cc.cleanup = nil
+}
+
+// RunPod creates a sandbox. It corresponds to `crictl runp`.
+func (cc *Crictl) RunPod(sbSpecFile string) (string, error) {
+	podID, err := cc.run("runp", sbSpecFile)
+	if err != nil {
+		return "", fmt.Errorf("runp failed: %v", err)
+	}
+	// Strip the trailing newline from crictl output.
+	return strings.TrimSpace(podID), nil
+}
+
+// Create creates a container within a sandbox. It corresponds to `crictl
+// create`.
+func (cc *Crictl) Create(podID, contSpecFile, sbSpecFile string) (string, error) {
+	podID, err := cc.run("create", podID, contSpecFile, sbSpecFile)
+	if err != nil {
+		return "", fmt.Errorf("create failed: %v", err)
+	}
+	// Strip the trailing newline from crictl output.
+	return strings.TrimSpace(podID), nil
+}
+
+// Start starts a container. It corresponds to `crictl start`.
+func (cc *Crictl) Start(contID string) (string, error) {
+	output, err := cc.run("start", contID)
+	if err != nil {
+		return "", fmt.Errorf("start failed: %v", err)
+	}
+	return output, nil
+}
+
+// Stop stops a container. It corresponds to `crictl stop`.
+func (cc *Crictl) Stop(contID string) error {
+	_, err := cc.run("stop", contID)
+	return err
+}
+
+// Exec execs a program inside a container. It corresponds to `crictl exec`.
+func (cc *Crictl) Exec(contID string, args ...string) (string, error) {
+	a := []string{"exec", contID}
+	a = append(a, args...)
+	output, err := cc.run(a...)
+	if err != nil {
+		return "", fmt.Errorf("exec failed: %v", err)
+	}
+	return output, nil
+}
+
+// Rm removes a container. It corresponds to `crictl rm`.
+func (cc *Crictl) Rm(contID string) error {
+	_, err := cc.run("rm", contID)
+	return err
+}
+
+// StopPod stops a pod. It corresponds to `crictl stopp`.
+func (cc *Crictl) StopPod(podID string) error {
+	_, err := cc.run("stopp", podID)
+	return err
+}
+
+// containsConfig is a minimal copy of
+// https://github.com/kubernetes/kubernetes/blob/master/pkg/kubelet/apis/cri/runtime/v1alpha2/api.proto
+// It only contains fields needed for testing.
+type containerConfig struct {
+	Status containerStatus
+}
+
+type containerStatus struct {
+	Network containerNetwork
+}
+
+type containerNetwork struct {
+	IP string
+}
+
+// PodIP returns a pod's IP address.
+func (cc *Crictl) PodIP(podID string) (string, error) {
+	output, err := cc.run("inspectp", podID)
+	if err != nil {
+		return "", err
+	}
+	conf := &containerConfig{}
+	if err := json.Unmarshal([]byte(output), conf); err != nil {
+		return "", fmt.Errorf("failed to unmarshal JSON: %v, %s", err, output)
+	}
+	if conf.Status.Network.IP == "" {
+		return "", fmt.Errorf("no IP found in config: %s", output)
+	}
+	return conf.Status.Network.IP, nil
+}
+
+// RmPod removes a container. It corresponds to `crictl rmp`.
+func (cc *Crictl) RmPod(podID string) error {
+	_, err := cc.run("rmp", podID)
+	return err
+}
+
+// Import imports the given container from the local Docker instance.
+func (cc *Crictl) Import(image string) error {
+	// Note that we provide a 10 minute timeout after connect because we may
+	// be pushing a lot of bytes in order to import the image. The connect
+	// timeout stays the same and is inherited from the Crictl instance.
+	cmd := testutil.Command(cc.logger,
+		resolvePath("ctr"),
+		fmt.Sprintf("--connect-timeout=%s", 30*time.Second),
+		fmt.Sprintf("--address=%s", cc.endpoint),
+		"-n", "k8s.io", "images", "import", "-")
+	cmd.Stderr = os.Stderr // Pass through errors.
+
+	// Create a pipe and start the program.
+	w, err := cmd.StdinPipe()
+	if err != nil {
+		return err
+	}
+	if err := cmd.Start(); err != nil {
+		return err
+	}
+
+	// Save the image on the other end.
+	if err := dockerutil.Save(cc.logger, image, w); err != nil {
+		cmd.Wait()
+		return err
+	}
+
+	// Close our pipe reference & see if it was loaded.
+	if err := w.Close(); err != nil {
+		return w.Close()
+	}
+
+	return cmd.Wait()
+}
+
+// StartContainer pulls the given image ands starts the container in the
+// sandbox with the given podID.
+//
+// Note that the image will always be imported from the local docker daemon.
+func (cc *Crictl) StartContainer(podID, image, sbSpec, contSpec string) (string, error) {
+	if err := cc.Import(image); err != nil {
+		return "", err
+	}
+
+	// Write the specs to files that can be read by crictl.
+	sbSpecFile, cleanup, err := testutil.WriteTmpFile("sbSpec", sbSpec)
+	if err != nil {
+		return "", fmt.Errorf("failed to write sandbox spec: %v", err)
+	}
+	cc.cleanup = append(cc.cleanup, cleanup)
+	contSpecFile, cleanup, err := testutil.WriteTmpFile("contSpec", contSpec)
+	if err != nil {
+		return "", fmt.Errorf("failed to write container spec: %v", err)
+	}
+	cc.cleanup = append(cc.cleanup, cleanup)
+
+	return cc.startContainer(podID, image, sbSpecFile, contSpecFile)
+}
+
+func (cc *Crictl) startContainer(podID, image, sbSpecFile, contSpecFile string) (string, error) {
+	contID, err := cc.Create(podID, contSpecFile, sbSpecFile)
+	if err != nil {
+		return "", fmt.Errorf("failed to create container in pod %q: %v", podID, err)
+	}
+
+	if _, err := cc.Start(contID); err != nil {
+		return "", fmt.Errorf("failed to start container %q in pod %q: %v", contID, podID, err)
+	}
+
+	return contID, nil
+}
+
+// StopContainer stops and deletes the container with the given container ID.
+func (cc *Crictl) StopContainer(contID string) error {
+	if err := cc.Stop(contID); err != nil {
+		return fmt.Errorf("failed to stop container %q: %v", contID, err)
+	}
+
+	if err := cc.Rm(contID); err != nil {
+		return fmt.Errorf("failed to remove container %q: %v", contID, err)
+	}
+
+	return nil
+}
+
+// StartPodAndContainer starts a sandbox and container in that sandbox. It
+// returns the pod ID and container ID.
+func (cc *Crictl) StartPodAndContainer(image, sbSpec, contSpec string) (string, string, error) {
+	if err := cc.Import(image); err != nil {
+		return "", "", err
+	}
+
+	// Write the specs to files that can be read by crictl.
+	sbSpecFile, cleanup, err := testutil.WriteTmpFile("sbSpec", sbSpec)
+	if err != nil {
+		return "", "", fmt.Errorf("failed to write sandbox spec: %v", err)
+	}
+	cc.cleanup = append(cc.cleanup, cleanup)
+	contSpecFile, cleanup, err := testutil.WriteTmpFile("contSpec", contSpec)
+	if err != nil {
+		return "", "", fmt.Errorf("failed to write container spec: %v", err)
+	}
+	cc.cleanup = append(cc.cleanup, cleanup)
+
+	podID, err := cc.RunPod(sbSpecFile)
+	if err != nil {
+		return "", "", err
+	}
+
+	contID, err := cc.startContainer(podID, image, sbSpecFile, contSpecFile)
+
+	return podID, contID, err
+}
+
+// StopPodAndContainer stops a container and pod.
+func (cc *Crictl) StopPodAndContainer(podID, contID string) error {
+	if err := cc.StopContainer(contID); err != nil {
+		return fmt.Errorf("failed to stop container %q in pod %q: %v", contID, podID, err)
+	}
+
+	if err := cc.StopPod(podID); err != nil {
+		return fmt.Errorf("failed to stop pod %q: %v", podID, err)
+	}
+
+	if err := cc.RmPod(podID); err != nil {
+		return fmt.Errorf("failed to remove pod %q: %v", podID, err)
+	}
+
+	return nil
+}
+
+// run runs crictl with the given args.
+func (cc *Crictl) run(args ...string) (string, error) {
+	defaultArgs := []string{
+		resolvePath("crictl"),
+		"--image-endpoint", fmt.Sprintf("unix://%s", cc.endpoint),
+		"--runtime-endpoint", fmt.Sprintf("unix://%s", cc.endpoint),
+	}
+	fullArgs := append(defaultArgs, args...)
+	out, err := testutil.Command(cc.logger, fullArgs...).CombinedOutput()
+	return string(out), err
+}