path: root/test/e2e/exec_test.go

// 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 integration provides end-to-end integration tests for runsc. These
// tests require docker and runsc to be installed on the machine.
//
// Each test calls docker commands to start up a container, and tests that it
// is behaving properly, with various runsc commands. The container is killed
// and deleted at the end.

package integration

import (
	"fmt"
	"os"
	"os/exec"
	"strconv"
	"strings"
	"syscall"
	"testing"
	"time"

	"gvisor.dev/gvisor/pkg/abi/linux"
	"gvisor.dev/gvisor/pkg/bits"
	"gvisor.dev/gvisor/pkg/test/dockerutil"
	"gvisor.dev/gvisor/runsc/specutils"
)

// Test that exec uses the exact same capability set as the container.
func TestExecCapabilities(t *testing.T) {
	d := dockerutil.MakeDocker(t)
	defer d.CleanUp()

	// Start the container.
	if err := d.Spawn(dockerutil.RunOpts{
		Image: "basic/alpine",
	}, "sh", "-c", "cat /proc/self/status; sleep 100"); err != nil {
		t.Fatalf("docker run failed: %v", err)
	}

	// Check that capability.
	matches, err := d.WaitForOutputSubmatch("CapEff:\t([0-9a-f]+)\n", 5*time.Second)
	if err != nil {
		t.Fatalf("WaitForOutputSubmatch() timeout: %v", err)
	}
	if len(matches) != 2 {
		t.Fatalf("There should be a match for the whole line and the capability bitmask")
	}
	want := fmt.Sprintf("CapEff:\t%s\n", matches[1])
	t.Log("Root capabilities:", want)

	// Now check that exec'd process capabilities match the root.
	got, err := d.Exec(dockerutil.RunOpts{}, "grep", "CapEff:", "/proc/self/status")
	if err != nil {
		t.Fatalf("docker exec failed: %v", err)
	}
	t.Logf("CapEff: %v", got)
	if got != want {
		t.Errorf("wrong capabilities, got: %q, want: %q", got, want)
	}
}

// Test that 'exec --privileged' adds all capabilities, except for CAP_NET_RAW
// which is removed from the container when --net-raw=false.
func TestExecPrivileged(t *testing.T) {
	d := dockerutil.MakeDocker(t)
	defer d.CleanUp()

	// Start the container with all capabilities dropped.
	if err := d.Spawn(dockerutil.RunOpts{
		Image:   "basic/alpine",
		CapDrop: []string{"all"},
	}, "sh", "-c", "cat /proc/self/status; sleep 100"); err != nil {
		t.Fatalf("docker run failed: %v", err)
	}

	// Check that all capabilities where dropped from container.
	matches, err := d.WaitForOutputSubmatch("CapEff:\t([0-9a-f]+)\n", 5*time.Second)
	if err != nil {
		t.Fatalf("WaitForOutputSubmatch() timeout: %v", err)
	}
	if len(matches) != 2 {
		t.Fatalf("There should be a match for the whole line and the capability bitmask")
	}
	containerCaps, err := strconv.ParseUint(matches[1], 16, 64)
	if err != nil {
		t.Fatalf("failed to convert capabilities %q: %v", matches[1], err)
	}
	t.Logf("Container capabilities: %#x", containerCaps)
	if containerCaps != 0 {
		t.Fatalf("Container should have no capabilities: %x", containerCaps)
	}

	// Check that 'exec --privileged' adds all capabilities, except for
	// CAP_NET_RAW.
	got, err := d.Exec(dockerutil.RunOpts{
		Privileged: true,
	}, "grep", "CapEff:", "/proc/self/status")
	if err != nil {
		t.Fatalf("docker exec failed: %v", err)
	}
	t.Logf("Exec CapEff: %v", got)
	want := fmt.Sprintf("CapEff:\t%016x\n", specutils.AllCapabilitiesUint64()&^bits.MaskOf64(int(linux.CAP_NET_RAW)))
	if got != want {
		t.Errorf("Wrong capabilities, got: %q, want: %q. Make sure runsc is not using '--net-raw'", got, want)
	}
}

func TestExecJobControl(t *testing.T) {
	d := dockerutil.MakeDocker(t)
	defer d.CleanUp()

	// Start the container.
	if err := d.Spawn(dockerutil.RunOpts{
		Image: "basic/alpine",
	}, "sleep", "1000"); err != nil {
		t.Fatalf("docker run failed: %v", err)
	}

	// Exec 'sh' with an attached pty.
	if _, err := d.Exec(dockerutil.RunOpts{
		Pty: func(cmd *exec.Cmd, ptmx *os.File) {
			// Call "sleep 100 | cat" in the shell. We pipe to cat
			// so that there will be two processes in the
			// foreground process group.
			if _, err := ptmx.Write([]byte("sleep 100 | cat\n")); err != nil {
				t.Fatalf("error writing to pty: %v", err)
			}

			// Give shell a few seconds to start executing the sleep.
			time.Sleep(2 * time.Second)

			// Send a ^C to the pty, which should kill sleep and
			// cat, but not the shell.  \x03 is ASCII "end of
			// text", which is the same as ^C.
			if _, err := ptmx.Write([]byte{'\x03'}); err != nil {
				t.Fatalf("error writing to pty: %v", err)
			}

			// The shell should still be alive at this point. Sleep
			// should have exited with code 2+128=130. We'll exit
			// with 10 plus that number, so that we can be sure
			// that the shell did not get signalled.
			if _, err := ptmx.Write([]byte("exit $(expr $? + 10)\n")); err != nil {
				t.Fatalf("error writing to pty: %v", err)
			}

			// Exec process should exit with code 10+130=140.
			ps, err := cmd.Process.Wait()
			if err != nil {
				t.Fatalf("error waiting for exec process: %v", err)
			}
			ws := ps.Sys().(syscall.WaitStatus)
			if !ws.Exited() {
				t.Errorf("ws.Exited got false, want true")
			}
			if got, want := ws.ExitStatus(), 140; got != want {
				t.Errorf("ws.ExitedStatus got %d, want %d", got, want)
			}
		},
	}, "sh"); err != nil {
		t.Fatalf("docker exec failed: %v", err)
	}
}

// Test that failure to exec returns proper error message.
func TestExecError(t *testing.T) {
	d := dockerutil.MakeDocker(t)
	defer d.CleanUp()

	// Start the container.
	if err := d.Spawn(dockerutil.RunOpts{
		Image: "basic/alpine",
	}, "sleep", "1000"); err != nil {
		t.Fatalf("docker run failed: %v", err)
	}

	// Attempt to exec a binary that doesn't exist.
	out, err := d.Exec(dockerutil.RunOpts{}, "no_can_find")
	if err == nil {
		t.Fatalf("docker exec didn't fail")
	}
	if want := `error finding executable "no_can_find" in PATH`; !strings.Contains(out, want) {
		t.Fatalf("docker exec wrong error, got: %s, want: .*%s.*", out, want)
	}
}

// Test that exec inherits environment from run.
func TestExecEnv(t *testing.T) {
	d := dockerutil.MakeDocker(t)
	defer d.CleanUp()

	// Start the container with env FOO=BAR.
	if err := d.Spawn(dockerutil.RunOpts{
		Image: "basic/alpine",
		Env:   []string{"FOO=BAR"},
	}, "sleep", "1000"); err != nil {
		t.Fatalf("docker run failed: %v", err)
	}

	// Exec "echo $FOO".
	got, err := d.Exec(dockerutil.RunOpts{}, "/bin/sh", "-c", "echo $FOO")
	if err != nil {
		t.Fatalf("docker exec failed: %v", err)
	}
	if got, want := strings.TrimSpace(got), "BAR"; got != want {
		t.Errorf("bad output from 'docker exec'. Got %q; Want %q.", got, want)
	}
}

// TestRunEnvHasHome tests that run always has HOME environment set.
func TestRunEnvHasHome(t *testing.T) {
	// Base alpine image does not have any environment variables set.
	d := dockerutil.MakeDocker(t)
	defer d.CleanUp()

	// Exec "echo $HOME". The 'bin' user's home dir is '/bin'.
	got, err := d.Run(dockerutil.RunOpts{
		Image: "basic/alpine",
		User:  "bin",
	}, "/bin/sh", "-c", "echo $HOME")
	if err != nil {
		t.Fatalf("docker run failed: %v", err)
	}

	// Check that the directory matches.
	if got, want := strings.TrimSpace(got), "/bin"; got != want {
		t.Errorf("bad output from 'docker run'. Got %q; Want %q.", got, want)
	}
}

// Test that exec always has HOME environment set, even when not set in run.
func TestExecEnvHasHome(t *testing.T) {
	// Base alpine image does not have any environment variables set.
	d := dockerutil.MakeDocker(t)
	defer d.CleanUp()

	if err := d.Spawn(dockerutil.RunOpts{
		Image: "basic/alpine",
	}, "sleep", "1000"); err != nil {
		t.Fatalf("docker run failed: %v", err)
	}

	// Exec "echo $HOME", and expect to see "/root".
	got, err := d.Exec(dockerutil.RunOpts{}, "/bin/sh", "-c", "echo $HOME")
	if err != nil {
		t.Fatalf("docker exec failed: %v", err)
	}
	if want := "/root"; !strings.Contains(got, want) {
		t.Errorf("wanted exec output to contain %q, got %q", want, got)
	}

	// Create a new user with a home directory.
	newUID := 1234
	newHome := "/foo/bar"
	cmd := fmt.Sprintf("mkdir -p -m 777 %q && adduser foo -D -u %d -h %q", newHome, newUID, newHome)
	if _, err := d.Exec(dockerutil.RunOpts{}, "/bin/sh", "-c", cmd); err != nil {
		t.Fatalf("docker exec failed: %v", err)
	}

	// Execute the same as the new user and expect newHome.
	got, err = d.Exec(dockerutil.RunOpts{
		User: strconv.Itoa(newUID),
	}, "/bin/sh", "-c", "echo $HOME")
	if err != nil {
		t.Fatalf("docker exec failed: %v", err)
	}
	if want := newHome; !strings.Contains(got, want) {
		t.Errorf("wanted exec output to contain %q, got %q", want, got)
	}
}