Refactor container_test in preparation for sandbox_test

Common code to setup and run sandbox is moved to testutil. Also, don't
link "boot" and "gofer" commands with test binary. Instead, use runsc
binary from the build. This not only make the test setup simpler, but
also resolves a dependency issue with sandbox_tests not depending on
container package.

PiperOrigin-RevId: 199164478
Change-Id: I27226286ca3f914d4d381358270dd7d70ee8372f

2 files changed, 150 insertions, 0 deletions

diff --git a/runsc/test/testutil/BUILD b/runsc/test/testutil/BUILD
new file mode 100644
index 000000000..2c2555d98
--- /dev/null
+++ b/runsc/test/testutil/BUILD
@@ -0,0 +1,17 @@
+package(licenses = ["notice"])  # Apache 2.0
+
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "testutil",
+    srcs = ["testutil.go"],
+    importpath = "gvisor.googlesource.com/gvisor/runsc/test/testutil",
+    visibility = [
+        "//runsc:__subpackages__",
+    ],
+    deps = [
+        "//runsc/boot",
+        "//runsc/specutils",
+        "@com_github_opencontainers_runtime-spec//specs-go:go_default_library",
+    ],
+)
diff --git a/runsc/test/testutil/testutil.go b/runsc/test/testutil/testutil.go
new file mode 100644
index 000000000..87db0a170
--- /dev/null
+++ b/runsc/test/testutil/testutil.go
@@ -0,0 +1,133 @@
+// Copyright 2018 Google Inc.
+//
+// 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 testutil contains utility functions for runsc tests.
+package testutil
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"time"
+
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+	"gvisor.googlesource.com/gvisor/runsc/boot"
+	"gvisor.googlesource.com/gvisor/runsc/specutils"
+)
+
+// ConfigureExePath configures the executable for runsc in the test environment.
+func ConfigureExePath() error {
+
+	// runsc is in a directory like: 'runsc/linux_amd64_pure_stripped/runsc'.
+	// Since I don't want to construct 'linux_amd64_pure_stripped' based on the
+	// build type, do a quick search for: 'runsc/*/runsc'
+	exePath := ""
+	lv1 := "./runsc"
+	lv1fis, err := ioutil.ReadDir(lv1)
+	if err != nil {
+		return err
+	}
+	for _, fi := range lv1fis {
+		if !fi.IsDir() {
+			continue
+		}
+		lv2fis, err := ioutil.ReadDir(filepath.Join(lv1, fi.Name()))
+		if err != nil {
+			return err
+		}
+		for _, candidate := range lv2fis {
+			if !candidate.IsDir() && candidate.Name() == "runsc" {
+				exePath, err = filepath.Abs(filepath.Join(lv1, fi.Name(), candidate.Name()))
+				if err != nil {
+					return err
+				}
+				break
+			}
+		}
+	}
+	if exePath == "" {
+		return fmt.Errorf("path to runsc not found")
+	}
+	specutils.ExePath = exePath
+	return nil
+}
+
+// NewSpecWithArgs creates a simple spec with the given args suitable for use
+// in tests.
+func NewSpecWithArgs(args ...string) *specs.Spec {
+	spec := &specs.Spec{
+		// The host filesystem root is the container root.
+		Root: &specs.Root{
+			Path:     "/",
+			Readonly: true,
+		},
+		Process: &specs.Process{
+			Args: args,
+			Env: []string{
+				"PATH=" + os.Getenv("PATH"),
+			},
+		},
+	}
+	return spec
+}
+
+// SetupContainer creates a bundle and root dir for the container, generates a
+// test config, and writes the spec to config.json in the bundle dir.
+func SetupContainer(spec *specs.Spec) (rootDir, bundleDir string, conf *boot.Config, err error) {
+	rootDir, err = ioutil.TempDir("", "containers")
+	if err != nil {
+		return "", "", nil, fmt.Errorf("error creating root dir: %v", err)
+	}
+
+	bundleDir, err = ioutil.TempDir("", "bundle")
+	if err != nil {
+		return "", "", nil, fmt.Errorf("error creating bundle dir: %v", err)
+	}
+
+	if err = writeSpec(bundleDir, spec); err != nil {
+		return "", "", nil, fmt.Errorf("error writing spec: %v", err)
+	}
+
+	conf = &boot.Config{
+		RootDir: rootDir,
+		Network: boot.NetworkNone,
+		// Don't add flags when calling subprocesses, since the test
+		// runner does not know about all the flags. We control the
+		// Config in the subprocess anyways, so it does not matter.
+		TestModeNoFlags: true,
+	}
+
+	return rootDir, bundleDir, conf, nil
+}
+
+// writeSpec writes the spec to disk in the given directory.
+func writeSpec(dir string, spec *specs.Spec) error {
+	b, err := json.Marshal(spec)
+	if err != nil {
+		return err
+	}
+	return ioutil.WriteFile(filepath.Join(dir, "config.json"), b, 0755)
+}
+
+// UniqueContainerID generates a unique container id for each test.
+//
+// The container id is used to create an abstract unix domain socket, which must
+// be unique.  While the container forbids creating two containers with the same
+// name, sometimes between test runs the socket does not get cleaned up quickly
+// enough, causing container creation to fail.
+func UniqueContainerID() string {
+	return fmt.Sprintf("test-container-%d", time.Now().UnixNano())
+}