ansible/test/lib/ansible_test/_internal/docker_util.py
Matt Clay 3bd6daa4a4 [stable-2.10] Fix ansible-test handling of user-defined docker networks. (#72256)
* Fix ansible-test docker container detection.

* Attach test containers to the correct network.

* Do not assume `localhost` for accesing Docker.

* Look for containers on current network.

* Always map /var/run/docker.sock into containers.

This fixes issues when using a remote Docker host.

* Support container IP lookup from networks list.

* Fix container network attachment.

* Remove redundant container detection messages.

* Limit DOCKER_HOST parsing to TCP.

* Restore docker socket existence check.

The check is skipped if the docker hostname is not localhost.

* Correct changelog entry..
(cherry picked from commit 3c2e8b99be)

Co-authored-by: Matt Clay <mclay@redhat.com>
2020-10-22 21:40:23 -07:00

399 lines
12 KiB
Python

"""Functions for accessing docker via the docker cli."""
from __future__ import (absolute_import, division, print_function)
__metaclass__ = type
import json
import os
import time
from .io import (
open_binary_file,
read_text_file,
)
from .util import (
ApplicationError,
common_environment,
display,
find_executable,
SubprocessError,
)
from .http import (
urlparse,
)
from .util_common import (
run_command,
)
from .config import (
EnvironmentConfig,
)
BUFFER_SIZE = 256 * 256
def docker_available():
"""
:rtype: bool
"""
return find_executable('docker', required=False)
def get_docker_hostname(): # type: () -> str
"""Return the hostname of the Docker service."""
try:
return get_docker_hostname.hostname
except AttributeError:
pass
docker_host = os.environ.get('DOCKER_HOST')
if docker_host and docker_host.startswith('tcp://'):
try:
hostname = urlparse(docker_host)[1].split(':')[0]
display.info('Detected Docker host: %s' % hostname, verbosity=1)
except ValueError:
hostname = 'localhost'
display.warning('Could not parse DOCKER_HOST environment variable "%s", falling back to localhost.' % docker_host)
else:
hostname = 'localhost'
display.info('Assuming Docker is available on localhost.', verbosity=1)
get_docker_hostname.hostname = hostname
return hostname
def get_docker_container_id():
"""
:rtype: str | None
"""
try:
return get_docker_container_id.container_id
except AttributeError:
pass
path = '/proc/self/cpuset'
container_id = None
if os.path.exists(path):
# File content varies based on the environment:
# No Container: /
# Docker: /docker/c86f3732b5ba3d28bb83b6e14af767ab96abbc52de31313dcb1176a62d91a507
# Azure Pipelines (Docker): /azpl_job/0f2edfed602dd6ec9f2e42c867f4d5ee640ebf4c058e6d3196d4393bb8fd0891
# Podman: /../../../../../..
contents = read_text_file(path)
cgroup_path, cgroup_name = os.path.split(contents.strip())
if cgroup_path in ('/docker', '/azpl_job'):
container_id = cgroup_name
get_docker_container_id.container_id = container_id
if container_id:
display.info('Detected execution in Docker container: %s' % container_id, verbosity=1)
return container_id
def get_docker_container_ip(args, container_id):
"""
:type args: EnvironmentConfig
:type container_id: str
:rtype: str
"""
results = docker_inspect(args, container_id)
network_settings = results[0]['NetworkSettings']
networks = network_settings.get('Networks')
if networks:
network_name = get_docker_preferred_network_name(args)
ipaddress = networks[network_name]['IPAddress']
else:
# podman doesn't provide Networks, fall back to using IPAddress
ipaddress = network_settings['IPAddress']
if not ipaddress:
raise ApplicationError('Cannot retrieve IP address for container: %s' % container_id)
return ipaddress
def get_docker_network_name(args, container_id): # type: (EnvironmentConfig, str) -> str
"""
Return the network name of the specified container.
Raises an exception if zero or more than one network is found.
"""
networks = get_docker_networks(args, container_id)
if not networks:
raise ApplicationError('No network found for Docker container: %s.' % container_id)
if len(networks) > 1:
raise ApplicationError('Found multiple networks for Docker container %s instead of only one: %s' % (container_id, ', '.join(networks)))
return networks[0]
def get_docker_preferred_network_name(args): # type: (EnvironmentConfig) -> str
"""
Return the preferred network name for use with Docker. The selection logic is:
- the network selected by the user with `--docker-network`
- the network of the currently running docker container (if any)
- the default docker network (returns None)
"""
network = None
if args.docker_network:
network = args.docker_network
else:
current_container_id = get_docker_container_id()
if current_container_id:
# Make sure any additional containers we launch use the same network as the current container we're running in.
# This is needed when ansible-test is running in a container that is not connected to Docker's default network.
network = get_docker_network_name(args, current_container_id)
return network
def is_docker_user_defined_network(network): # type: (str) -> bool
"""Return True if the network being used is a user-defined network."""
return network and network != 'bridge'
def get_docker_networks(args, container_id):
"""
:param args: EnvironmentConfig
:param container_id: str
:rtype: list[str]
"""
results = docker_inspect(args, container_id)
# podman doesn't return Networks- just silently return None if it's missing...
networks = results[0]['NetworkSettings'].get('Networks')
if networks is None:
return None
return sorted(networks)
def docker_pull(args, image):
"""
:type args: EnvironmentConfig
:type image: str
"""
if ('@' in image or ':' in image) and docker_images(args, image):
display.info('Skipping docker pull of existing image with tag or digest: %s' % image, verbosity=2)
return
if not args.docker_pull:
display.warning('Skipping docker pull for "%s". Image may be out-of-date.' % image)
return
for _iteration in range(1, 10):
try:
docker_command(args, ['pull', image])
return
except SubprocessError:
display.warning('Failed to pull docker image "%s". Waiting a few seconds before trying again.' % image)
time.sleep(3)
raise ApplicationError('Failed to pull docker image "%s".' % image)
def docker_put(args, container_id, src, dst):
"""
:type args: EnvironmentConfig
:type container_id: str
:type src: str
:type dst: str
"""
# avoid 'docker cp' due to a bug which causes 'docker rm' to fail
with open_binary_file(src) as src_fd:
docker_exec(args, container_id, ['dd', 'of=%s' % dst, 'bs=%s' % BUFFER_SIZE],
options=['-i'], stdin=src_fd, capture=True)
def docker_get(args, container_id, src, dst):
"""
:type args: EnvironmentConfig
:type container_id: str
:type src: str
:type dst: str
"""
# avoid 'docker cp' due to a bug which causes 'docker rm' to fail
with open_binary_file(dst, 'wb') as dst_fd:
docker_exec(args, container_id, ['dd', 'if=%s' % src, 'bs=%s' % BUFFER_SIZE],
options=['-i'], stdout=dst_fd, capture=True)
def docker_run(args, image, options, cmd=None):
"""
:type args: EnvironmentConfig
:type image: str
:type options: list[str] | None
:type cmd: list[str] | None
:rtype: str | None, str | None
"""
if not options:
options = []
if not cmd:
cmd = []
network = get_docker_preferred_network_name(args)
if is_docker_user_defined_network(network):
# Only when the network is not the default bridge network.
# Using this with the default bridge network results in an error when using --link: links are only supported for user-defined networks
options.extend(['--network', network])
for _iteration in range(1, 3):
try:
return docker_command(args, ['run'] + options + [image] + cmd, capture=True)
except SubprocessError as ex:
display.error(ex)
display.warning('Failed to run docker image "%s". Waiting a few seconds before trying again.' % image)
time.sleep(3)
raise ApplicationError('Failed to run docker image "%s".' % image)
def docker_images(args, image):
"""
:param args: CommonConfig
:param image: str
:rtype: list[dict[str, any]]
"""
try:
stdout, _dummy = docker_command(args, ['images', image, '--format', '{{json .}}'], capture=True, always=True)
except SubprocessError as ex:
if 'no such image' in ex.stderr:
stdout = '' # podman does not handle this gracefully, exits 125
else:
raise ex
results = [json.loads(line) for line in stdout.splitlines()]
return results
def docker_rm(args, container_id):
"""
:type args: EnvironmentConfig
:type container_id: str
"""
try:
docker_command(args, ['rm', '-f', container_id], capture=True)
except SubprocessError as ex:
if 'no such container' in ex.stderr:
pass # podman does not handle this gracefully, exits 1
else:
raise ex
def docker_inspect(args, container_id):
"""
:type args: EnvironmentConfig
:type container_id: str
:rtype: list[dict]
"""
if args.explain:
return []
try:
stdout = docker_command(args, ['inspect', container_id], capture=True)[0]
return json.loads(stdout)
except SubprocessError as ex:
if 'no such image' in ex.stderr:
return [] # podman does not handle this gracefully, exits 125
try:
return json.loads(ex.stdout)
except Exception:
raise ex
def docker_network_disconnect(args, container_id, network):
"""
:param args: EnvironmentConfig
:param container_id: str
:param network: str
"""
docker_command(args, ['network', 'disconnect', network, container_id], capture=True)
def docker_network_inspect(args, network):
"""
:type args: EnvironmentConfig
:type network: str
:rtype: list[dict]
"""
if args.explain:
return []
try:
stdout = docker_command(args, ['network', 'inspect', network], capture=True)[0]
return json.loads(stdout)
except SubprocessError as ex:
try:
return json.loads(ex.stdout)
except Exception:
raise ex
def docker_exec(args, container_id, cmd, options=None, capture=False, stdin=None, stdout=None):
"""
:type args: EnvironmentConfig
:type container_id: str
:type cmd: list[str]
:type options: list[str] | None
:type capture: bool
:type stdin: BinaryIO | None
:type stdout: BinaryIO | None
:rtype: str | None, str | None
"""
if not options:
options = []
return docker_command(args, ['exec'] + options + [container_id] + cmd, capture=capture, stdin=stdin, stdout=stdout)
def docker_info(args):
"""
:param args: CommonConfig
:rtype: dict[str, any]
"""
stdout, _dummy = docker_command(args, ['info', '--format', '{{json .}}'], capture=True, always=True)
return json.loads(stdout)
def docker_version(args):
"""
:param args: CommonConfig
:rtype: dict[str, any]
"""
stdout, _dummy = docker_command(args, ['version', '--format', '{{json .}}'], capture=True, always=True)
return json.loads(stdout)
def docker_command(args, cmd, capture=False, stdin=None, stdout=None, always=False):
"""
:type args: CommonConfig
:type cmd: list[str]
:type capture: bool
:type stdin: file | None
:type stdout: file | None
:type always: bool
:rtype: str | None, str | None
"""
env = docker_environment()
return run_command(args, ['docker'] + cmd, env=env, capture=capture, stdin=stdin, stdout=stdout, always=always)
def docker_environment():
"""
:rtype: dict[str, str]
"""
env = common_environment()
env.update(dict((key, os.environ[key]) for key in os.environ if key.startswith('DOCKER_')))
return env