tests/acceptance: Add virtiofs_submounts.py

This test invokes several shell scripts to create a random directory
tree full of submounts, and then check in the VM whether every submount
has its own ID and the structure looks as expected.

(Note that the test scripts must be non-executable, so Avocado will not
try to execute them as if they were tests on their own, too.)

Because at this commit's date it is unlikely that the Linux kernel on
the image provided by boot_linux.py supports submounts in virtio-fs, the
test will be cancelled if no custom Linux binary is provided through the
vmlinuz parameter.  (The on-image kernel can be used by providing an
empty string via vmlinuz=.)

So, invoking the test can be done as follows:
$ avocado run \
    tests/acceptance/virtiofs_submounts.py \
    -p vmlinuz=/path/to/linux/build/arch/x86/boot/bzImage

This test requires root privileges (through passwordless sudo -n),
because at this point, virtiofsd requires them.  (If you have a
timestamp_timeout period for sudoers (e.g. the default of 5 min), you
can provide this by executing something like "sudo true" before invoking
Avocado.)

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200909184028.262297-9-mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

1 files changed, 289 insertions, 0 deletions

diff --git a/tests/acceptance/virtiofs_submounts.py b/tests/acceptance/virtiofs_submounts.py
new file mode 100644
index 0000000000..8b207b3e57
--- /dev/null
+++ b/tests/acceptance/virtiofs_submounts.py
@@ -0,0 +1,289 @@
+import logging
+import re
+import os
+import subprocess
+import time
+
+from avocado import skipUnless
+from avocado_qemu import Test, BUILD_DIR
+from avocado_qemu import wait_for_console_pattern
+from avocado.utils import ssh
+
+from qemu.accel import kvm_available
+
+from boot_linux import BootLinux
+
+
+def run_cmd(args):
+    subp = subprocess.Popen(args,
+                            stdout=subprocess.PIPE,
+                            stderr=subprocess.PIPE,
+                            universal_newlines=True)
+    stdout, stderr = subp.communicate()
+    ret = subp.returncode
+
+    return (stdout, stderr, ret)
+
+def has_passwordless_sudo():
+    """
+    This function is for use in a @avocado.skipUnless decorator, e.g.:
+
+        @skipUnless(*has_passwordless_sudo())
+        def test_something_that_needs_sudo(self):
+            ...
+    """
+
+    _, stderr, exitcode = run_cmd(('sudo', '-n', 'true'))
+    if exitcode != 0:
+        return (False, f'Failed to use sudo -n: {stderr.strip()}')
+    else:
+        return (True, '')
+
+
+class VirtiofsSubmountsTest(BootLinux):
+    """
+    :avocado: tags=arch:x86_64
+    """
+
+    def get_portfwd(self):
+        port = None
+
+        res = self.vm.command('human-monitor-command',
+                              command_line='info usernet')
+        for line in res.split('\r\n'):
+            match = \
+                re.search(r'TCP.HOST_FORWARD.*127\.0\.0\.1\s*(\d+)\s+10\.',
+                          line)
+            if match is not None:
+                port = match[1]
+                break
+
+        self.assertIsNotNone(port)
+        self.log.debug('sshd listening on port: ' + port)
+        return port
+
+    def ssh_connect(self, username, keyfile):
+        self.ssh_logger = logging.getLogger('ssh')
+        port = self.get_portfwd()
+        self.ssh_session = ssh.Session('127.0.0.1', port=int(port),
+                                       user=username, key=keyfile)
+        for i in range(10):
+            try:
+                self.ssh_session.connect()
+                return
+            except:
+                time.sleep(4)
+                pass
+        self.fail('sshd timeout')
+
+    def ssh_command(self, command):
+        self.ssh_logger.info(command)
+        result = self.ssh_session.cmd(command)
+        stdout_lines = [line.rstrip() for line
+                        in result.stdout_text.splitlines()]
+        for line in stdout_lines:
+            self.ssh_logger.info(line)
+        stderr_lines = [line.rstrip() for line
+                        in result.stderr_text.splitlines()]
+        for line in stderr_lines:
+            self.ssh_logger.warning(line)
+
+        self.assertEqual(result.exit_status, 0,
+                         f'Guest command failed: {command}')
+        return stdout_lines, stderr_lines
+
+    def run(self, args, ignore_error=False):
+        stdout, stderr, ret = run_cmd(args)
+
+        if ret != 0:
+            cmdline = ' '.join(args)
+            if not ignore_error:
+                self.fail(f'{cmdline}: Returned {ret}: {stderr}')
+            else:
+                self.log.warn(f'{cmdline}: Returned {ret}: {stderr}')
+
+        return (stdout, stderr, ret)
+
+    def set_up_shared_dir(self):
+        atwd = os.getenv('AVOCADO_TEST_WORKDIR')
+        self.shared_dir = os.path.join(atwd, 'virtiofs-shared')
+
+        os.mkdir(self.shared_dir)
+
+        self.run(('cp', self.get_data('guest.sh'),
+                 os.path.join(self.shared_dir, 'check.sh')))
+
+        self.run(('cp', self.get_data('guest-cleanup.sh'),
+                 os.path.join(self.shared_dir, 'cleanup.sh')))
+
+    def set_up_virtiofs(self):
+        attmp = os.getenv('AVOCADO_TESTS_COMMON_TMPDIR')
+        self.vfsdsock = os.path.join(attmp, 'vfsdsock')
+
+        self.run(('sudo', '-n', 'rm', '-f', self.vfsdsock), ignore_error=True)
+
+        self.virtiofsd = \
+            subprocess.Popen(('sudo', '-n',
+                              'tools/virtiofsd/virtiofsd',
+                              f'--socket-path={self.vfsdsock}',
+                              '-o', f'source={self.shared_dir}',
+                              '-o', 'cache=always',
+                              '-o', 'xattr',
+                              '-o', 'announce_submounts',
+                              '-f'),
+                             stdout=subprocess.DEVNULL,
+                             stderr=subprocess.PIPE,
+                             universal_newlines=True)
+
+        while not os.path.exists(self.vfsdsock):
+            if self.virtiofsd.poll() is not None:
+                self.fail('virtiofsd exited prematurely: ' +
+                          self.virtiofsd.communicate()[1])
+            time.sleep(0.1)
+
+        self.run(('sudo', '-n', 'chmod', 'go+rw', self.vfsdsock))
+
+        self.vm.add_args('-chardev',
+                         f'socket,id=vfsdsock,path={self.vfsdsock}',
+                         '-device',
+                         'vhost-user-fs-pci,queue-size=1024,chardev=vfsdsock' \
+                             ',tag=host',
+                         '-object',
+                         'memory-backend-file,id=mem,size=1G,' \
+                             'mem-path=/dev/shm,share=on',
+                         '-numa',
+                         'node,memdev=mem')
+
+    def launch_vm(self):
+        self.launch_and_wait()
+        self.ssh_connect('root', self.ssh_key)
+
+    def set_up_nested_mounts(self):
+        scratch_dir = os.path.join(self.shared_dir, 'scratch')
+        try:
+            os.mkdir(scratch_dir)
+        except FileExistsError:
+            pass
+
+        args = ['bash', self.get_data('host.sh'), scratch_dir]
+        if self.seed:
+            args += [self.seed]
+
+        out, _, _ = self.run(args)
+        seed = re.search(r'^Seed: \d+', out)
+        self.log.info(seed[0])
+
+    def mount_in_guest(self):
+        self.ssh_command('mkdir -p /mnt/host')
+        self.ssh_command('mount -t virtiofs host /mnt/host')
+
+    def check_in_guest(self):
+        self.ssh_command('bash /mnt/host/check.sh /mnt/host/scratch/share')
+
+    def live_cleanup(self):
+        self.ssh_command('bash /mnt/host/cleanup.sh /mnt/host/scratch')
+
+        # It would be nice if the above was sufficient to make virtiofsd clear
+        # all references to the mounted directories (so they can be unmounted
+        # on the host), but unfortunately it is not.  To do so, we have to
+        # resort to a remount.
+        self.ssh_command('mount -o remount /mnt/host')
+
+        scratch_dir = os.path.join(self.shared_dir, 'scratch')
+        self.run(('bash', self.get_data('cleanup.sh'), scratch_dir))
+
+    @skipUnless(*has_passwordless_sudo())
+    def setUp(self):
+        vmlinuz = self.params.get('vmlinuz')
+        if vmlinuz is None:
+            self.cancel('vmlinuz parameter not set; you must point it to a '
+                        'Linux kernel binary to test (to run this test with ' \
+                        'the on-image kernel, set it to an empty string)')
+
+        self.seed = self.params.get('seed')
+
+        atwd = os.getenv('AVOCADO_TEST_WORKDIR')
+        self.ssh_key = os.path.join(atwd, 'id_ed25519')
+
+        self.run(('ssh-keygen', '-t', 'ed25519', '-f', self.ssh_key))
+
+        pubkey = open(self.ssh_key + '.pub').read()
+
+        super(VirtiofsSubmountsTest, self).setUp(pubkey)
+
+        if len(vmlinuz) > 0:
+            self.vm.add_args('-kernel', vmlinuz,
+                             '-append', 'console=ttyS0 root=/dev/sda1')
+
+        # Allow us to connect to SSH
+        self.vm.add_args('-netdev', 'user,id=vnet,hostfwd=:127.0.0.1:0-:22',
+                         '-device', 'e1000,netdev=vnet')
+
+        if not kvm_available(self.arch, self.qemu_bin):
+            self.cancel(KVM_NOT_AVAILABLE)
+        self.vm.add_args('-accel', 'kvm')
+
+    def tearDown(self):
+        try:
+            self.vm.shutdown()
+        except:
+            pass
+
+        scratch_dir = os.path.join(self.shared_dir, 'scratch')
+        self.run(('bash', self.get_data('cleanup.sh'), scratch_dir),
+                 ignore_error=True)
+
+    def test_pre_virtiofsd_set_up(self):
+        self.set_up_shared_dir()
+
+        self.set_up_nested_mounts()
+
+        self.set_up_virtiofs()
+        self.launch_vm()
+        self.mount_in_guest()
+        self.check_in_guest()
+
+    def test_pre_launch_set_up(self):
+        self.set_up_shared_dir()
+        self.set_up_virtiofs()
+
+        self.set_up_nested_mounts()
+
+        self.launch_vm()
+        self.mount_in_guest()
+        self.check_in_guest()
+
+    def test_post_launch_set_up(self):
+        self.set_up_shared_dir()
+        self.set_up_virtiofs()
+        self.launch_vm()
+
+        self.set_up_nested_mounts()
+
+        self.mount_in_guest()
+        self.check_in_guest()
+
+    def test_post_mount_set_up(self):
+        self.set_up_shared_dir()
+        self.set_up_virtiofs()
+        self.launch_vm()
+        self.mount_in_guest()
+
+        self.set_up_nested_mounts()
+
+        self.check_in_guest()
+
+    def test_two_runs(self):
+        self.set_up_shared_dir()
+
+        self.set_up_nested_mounts()
+
+        self.set_up_virtiofs()
+        self.launch_vm()
+        self.mount_in_guest()
+        self.check_in_guest()
+
+        self.live_cleanup()
+        self.set_up_nested_mounts()
+
+        self.check_in_guest()