Impose order on test scripts.

The simple test script has gotten out of control. Shard this script into
different pieces and attempt to impose order on overall test structure. This
change helps lay some of the foundations for future improvements.

 * The runsc/test directories are moved into just test/.
 * The runsc/test/testutil package is split into logical pieces.
 * The scripts/ directory contains new top-level targets.
 * Each test is now responsible for building targets it requires.
 * The install functionality is moved into `runsc` itself for simplicity.
 * The existing kokoro run_tests.sh file now just calls all (can be split).

After this change is merged,  I will create multiple distinct workflows for
Kokoro, one for each of the scripts currently targeted by `run_tests.sh` today,
which should dramatically reduce the time-to-run for the Kokoro tests, and
provides a better foundation for further improvements to the infrastructure.

PiperOrigin-RevId: 267081397

1 files changed, 158 insertions, 0 deletions

diff --git a/test/root/chroot_test.go b/test/root/chroot_test.go
new file mode 100644
index 000000000..f47f8e2c2
--- /dev/null
+++ b/test/root/chroot_test.go
@@ -0,0 +1,158 @@
+// 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 root is used for tests that requires sysadmin privileges run.
+package root
+
+import (
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"testing"
+
+	"github.com/syndtr/gocapability/capability"
+	"gvisor.dev/gvisor/runsc/dockerutil"
+	"gvisor.dev/gvisor/runsc/specutils"
+)
+
+// TestChroot verifies that the sandbox is chroot'd and that mounts are cleaned
+// up after the sandbox is destroyed.
+func TestChroot(t *testing.T) {
+	d := dockerutil.MakeDocker("chroot-test")
+	if err := d.Run("alpine", "sleep", "10000"); err != nil {
+		t.Fatalf("docker run failed: %v", err)
+	}
+	defer d.CleanUp()
+
+	pid, err := d.SandboxPid()
+	if err != nil {
+		t.Fatalf("Docker.SandboxPid(): %v", err)
+	}
+
+	// Check that sandbox is chroot'ed.
+	procRoot := filepath.Join("/proc", strconv.Itoa(pid), "root")
+	chroot, err := filepath.EvalSymlinks(procRoot)
+	if err != nil {
+		t.Fatalf("error resolving /proc/<pid>/root symlink: %v", err)
+	}
+	if chroot != "/" {
+		t.Errorf("sandbox is not chroot'd, it should be inside: /, got: %q", chroot)
+	}
+
+	path, err := filepath.EvalSymlinks(filepath.Join("/proc", strconv.Itoa(pid), "cwd"))
+	if err != nil {
+		t.Fatalf("error resolving /proc/<pid>/cwd symlink: %v", err)
+	}
+	if chroot != path {
+		t.Errorf("sandbox current dir is wrong, want: %q, got: %q", chroot, path)
+	}
+
+	fi, err := ioutil.ReadDir(procRoot)
+	if err != nil {
+		t.Fatalf("error listing %q: %v", chroot, err)
+	}
+	if want, got := 1, len(fi); want != got {
+		t.Fatalf("chroot dir got %d entries, want %d", got, want)
+	}
+
+	// chroot dir is prepared by runsc and should contains only /proc.
+	if fi[0].Name() != "proc" {
+		t.Errorf("chroot got children %v, want %v", fi[0].Name(), "proc")
+	}
+
+	d.CleanUp()
+}
+
+func TestChrootGofer(t *testing.T) {
+	d := dockerutil.MakeDocker("chroot-test")
+	if err := d.Run("alpine", "sleep", "10000"); err != nil {
+		t.Fatalf("docker run failed: %v", err)
+	}
+	defer d.CleanUp()
+
+	// It's tricky to find gofers. Get sandbox PID first, then find parent. From
+	// parent get all immediate children, remove the sandbox, and everything else
+	// are gofers.
+	sandPID, err := d.SandboxPid()
+	if err != nil {
+		t.Fatalf("Docker.SandboxPid(): %v", err)
+	}
+
+	// Find sandbox's parent PID.
+	cmd := fmt.Sprintf("grep PPid /proc/%d/status | awk '{print $2}'", sandPID)
+	parent, err := exec.Command("sh", "-c", cmd).CombinedOutput()
+	if err != nil {
+		t.Fatalf("failed to fetch runsc (%d) parent PID: %v, out:\n%s", sandPID, err, string(parent))
+	}
+	parentPID, err := strconv.Atoi(strings.TrimSpace(string(parent)))
+	if err != nil {
+		t.Fatalf("failed to parse PPID %q: %v", string(parent), err)
+	}
+
+	// Get all children from parent.
+	childrenOut, err := exec.Command("/usr/bin/pgrep", "-P", strconv.Itoa(parentPID)).CombinedOutput()
+	if err != nil {
+		t.Fatalf("failed to fetch containerd-shim children: %v", err)
+	}
+	children := strings.Split(strings.TrimSpace(string(childrenOut)), "\n")
+
+	// This where the root directory is mapped on the host and that's where the
+	// gofer must have chroot'd to.
+	root := "/root"
+
+	for _, child := range children {
+		childPID, err := strconv.Atoi(child)
+		if err != nil {
+			t.Fatalf("failed to parse child PID %q: %v", child, err)
+		}
+		if childPID == sandPID {
+			// Skip the sandbox, all other immediate children are gofers.
+			continue
+		}
+
+		// Check that gofer is chroot'ed.
+		chroot, err := filepath.EvalSymlinks(filepath.Join("/proc", child, "root"))
+		if err != nil {
+			t.Fatalf("error resolving /proc/<pid>/root symlink: %v", err)
+		}
+		if root != chroot {
+			t.Errorf("gofer chroot is wrong, want: %q, got: %q", root, chroot)
+		}
+
+		path, err := filepath.EvalSymlinks(filepath.Join("/proc", child, "cwd"))
+		if err != nil {
+			t.Fatalf("error resolving /proc/<pid>/cwd symlink: %v", err)
+		}
+		if root != path {
+			t.Errorf("gofer current dir is wrong, want: %q, got: %q", root, path)
+		}
+	}
+}
+
+func TestMain(m *testing.M) {
+	dockerutil.EnsureSupportedDockerVersion()
+
+	if !specutils.HasCapabilities(capability.CAP_SYS_ADMIN, capability.CAP_DAC_OVERRIDE) {
+		fmt.Println("Test requires sysadmin privileges to run. Try again with sudo.")
+		os.Exit(1)
+	}
+
+	flag.Parse()
+	os.Exit(m.Run())
+}