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ansible/test/lib/ansible_test/_internal/docker_util.py

490 lines
17 KiB
Python

"""Functions for accessing docker via the docker cli."""
from __future__ import annotations
import json
import os
import random
import socket
import time
import urllib.parse
import typing as t
from .io import (
read_text_file,
)
from .util import (
ApplicationError,
common_environment,
display,
find_executable,
SubprocessError,
cache,
)
from .util_common import (
run_command,
raw_command,
)
from .config import (
CommonConfig,
EnvironmentConfig,
)
DOCKER_COMMANDS = [
'docker',
'podman',
]
# Max number of open files in a docker container.
# Passed with --ulimit option to the docker run command.
MAX_NUM_OPEN_FILES = 10240
class DockerCommand:
"""Details about the available docker command."""
def __init__(self, command, executable, version): # type: (str, str, str) -> None
self.command = command
self.executable = executable
self.version = version
@staticmethod
def detect(): # type: () -> t.Optional[DockerCommand]
"""Detect and return the available docker command, or None."""
if os.environ.get('ANSIBLE_TEST_PREFER_PODMAN'):
commands = list(reversed(DOCKER_COMMANDS))
else:
commands = DOCKER_COMMANDS
for command in commands:
executable = find_executable(command, required=False)
if executable:
version = raw_command([command, '-v'], capture=True)[0].strip()
if command == 'docker' and 'podman' in version:
continue # avoid detecting podman as docker
display.info('Detected "%s" container runtime version: %s' % (command, version), verbosity=1)
return DockerCommand(command, executable, version)
return None
def require_docker(): # type: () -> DockerCommand
"""Return the docker command to invoke. Raises an exception if docker is not available."""
if command := get_docker_command():
return command
raise ApplicationError(f'No container runtime detected. Supported commands: {", ".join(DOCKER_COMMANDS)}')
@cache
def get_docker_command(): # type: () -> t.Optional[DockerCommand]
"""Return the docker command to invoke, or None if docker is not available."""
return DockerCommand.detect()
def docker_available(): # type: () -> bool
"""Return True if docker is available, otherwise return False."""
return bool(get_docker_command())
@cache
def get_docker_host_ip(): # type: () -> str
"""Return the IP of the Docker host."""
docker_host_ip = socket.gethostbyname(get_docker_hostname())
display.info('Detected docker host IP: %s' % docker_host_ip, verbosity=1)
return docker_host_ip
@cache
def get_docker_hostname(): # type: () -> str
"""Return the hostname of the Docker service."""
docker_host = os.environ.get('DOCKER_HOST')
if docker_host and docker_host.startswith('tcp://'):
try:
hostname = urllib.parse.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)
return hostname
@cache
def get_docker_container_id(): # type: () -> t.Optional[str]
"""Return the current container ID if running in a container, otherwise return None."""
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
if container_id:
display.info('Detected execution in Docker container: %s' % container_id, verbosity=1)
return container_id
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)
"""
try:
return get_docker_preferred_network_name.network
except AttributeError:
pass
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.
container = docker_inspect(args, current_container_id, always=True)
network = container.get_network_name()
get_docker_preferred_network_name.network = network
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 docker_pull(args, image): # type: (EnvironmentConfig, str) -> None
"""
Pull the specified image if it is not available.
Images without a tag or digest will not be pulled.
Retries up to 10 times if the pull fails.
"""
if '@' not in image and ':' not in image:
display.info('Skipping pull of image without tag or digest: %s' % image, verbosity=2)
return
if docker_image_exists(args, image):
display.info('Skipping pull of existing image: %s' % image, verbosity=2)
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_cp_to(args, container_id, src, dst): # type: (EnvironmentConfig, str, str, str) -> None
"""Copy a file to the specified container."""
docker_command(args, ['cp', src, '%s:%s' % (container_id, dst)])
def docker_run(
args, # type: EnvironmentConfig
image, # type: str
options, # type: t.Optional[t.List[str]]
cmd=None, # type: t.Optional[t.List[str]]
create_only=False, # type: bool
): # type: (...) -> str
"""Run a container using the given docker image."""
if not options:
options = []
if not cmd:
cmd = []
if create_only:
command = 'create'
else:
command = 'run'
network = get_docker_preferred_network_name(args)
if is_docker_user_defined_network(network):
# Only when the network is not the default bridge network.
options.extend(['--network', network])
options.extend(['--ulimit', 'nofile=%s' % MAX_NUM_OPEN_FILES])
for _iteration in range(1, 3):
try:
stdout = docker_command(args, [command] + options + [image] + cmd, capture=True)[0]
if args.explain:
return ''.join(random.choice('0123456789abcdef') for _iteration in range(64))
return stdout.strip()
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_start(args, container_id, options=None): # type: (EnvironmentConfig, str, t.Optional[t.List[str]]) -> t.Tuple[t.Optional[str], t.Optional[str]]
"""
Start a docker container by name or ID
"""
if not options:
options = []
for _iteration in range(1, 3):
try:
return docker_command(args, ['start'] + options + [container_id], capture=True)
except SubprocessError as ex:
display.error(ex)
display.warning('Failed to start docker container "%s". Waiting a few seconds before trying again.' % container_id)
time.sleep(3)
raise ApplicationError('Failed to run docker container "%s".' % container_id)
def docker_rm(args, container_id): # type: (EnvironmentConfig, str) -> None
"""Remove the specified container."""
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
class DockerError(Exception):
"""General Docker error."""
class ContainerNotFoundError(DockerError):
"""The container identified by `identifier` was not found."""
def __init__(self, identifier):
super().__init__('The container "%s" was not found.' % identifier)
self.identifier = identifier
class DockerInspect:
"""The results of `docker inspect` for a single container."""
def __init__(self, args, inspection): # type: (EnvironmentConfig, t.Dict[str, t.Any]) -> None
self.args = args
self.inspection = inspection
# primary properties
@property
def id(self): # type: () -> str
"""Return the ID of the container."""
return self.inspection['Id']
@property
def network_settings(self): # type: () -> t.Dict[str, t.Any]
"""Return a dictionary of the container network settings."""
return self.inspection['NetworkSettings']
@property
def state(self): # type: () -> t.Dict[str, t.Any]
"""Return a dictionary of the container state."""
return self.inspection['State']
@property
def config(self): # type: () -> t.Dict[str, t.Any]
"""Return a dictionary of the container configuration."""
return self.inspection['Config']
# nested properties
@property
def ports(self): # type: () -> t.Dict[str, t.List[t.Dict[str, str]]]
"""Return a dictionary of ports the container has published."""
return self.network_settings['Ports']
@property
def networks(self): # type: () -> t.Optional[t.Dict[str, t.Dict[str, t.Any]]]
"""Return a dictionary of the networks the container is attached to, or None if running under podman, which does not support networks."""
return self.network_settings.get('Networks')
@property
def running(self): # type: () -> bool
"""Return True if the container is running, otherwise False."""
return self.state['Running']
@property
def env(self): # type: () -> t.List[str]
"""Return a list of the environment variables used to create the container."""
return self.config['Env']
@property
def image(self): # type: () -> str
"""Return the image used to create the container."""
return self.config['Image']
# functions
def env_dict(self): # type: () -> t.Dict[str, str]
"""Return a dictionary of the environment variables used to create the container."""
return dict((item[0], item[1]) for item in [e.split('=', 1) for e in self.env])
def get_tcp_port(self, port): # type: (int) -> t.Optional[t.List[t.Dict[str, str]]]
"""Return a list of the endpoints published by the container for the specified TCP port, or None if it is not published."""
return self.ports.get('%d/tcp' % port)
def get_network_names(self): # type: () -> t.Optional[t.List[str]]
"""Return a list of the network names the container is attached to."""
if self.networks is None:
return None
return sorted(self.networks)
def get_network_name(self): # type: () -> str
"""Return the network name the container is attached to. Raises an exception if no network, or more than one, is attached."""
networks = self.get_network_names()
if not networks:
raise ApplicationError('No network found for Docker container: %s.' % self.id)
if len(networks) > 1:
raise ApplicationError('Found multiple networks for Docker container %s instead of only one: %s' % (self.id, ', '.join(networks)))
return networks[0]
def get_ip_address(self): # type: () -> t.Optional[str]
"""Return the IP address of the container for the preferred docker network."""
if self.networks:
network_name = get_docker_preferred_network_name(self.args)
if not network_name:
# Sort networks and use the first available.
# This assumes all containers will have access to the same networks.
network_name = sorted(self.networks.keys()).pop(0)
ipaddress = self.networks[network_name]['IPAddress']
else:
ipaddress = self.network_settings['IPAddress']
if not ipaddress:
return None
return ipaddress
def docker_inspect(args, identifier, always=False): # type: (EnvironmentConfig, str, bool) -> DockerInspect
"""
Return the results of `docker container inspect` for the specified container.
Raises a ContainerNotFoundError if the container was not found.
"""
try:
stdout = docker_command(args, ['container', 'inspect', identifier], capture=True, always=always)[0]
except SubprocessError as ex:
stdout = ex.stdout
if args.explain and not always:
items = []
else:
items = json.loads(stdout)
if len(items) == 1:
return DockerInspect(args, items[0])
raise ContainerNotFoundError(identifier)
def docker_network_disconnect(args, container_id, network): # type: (EnvironmentConfig, str, str) -> None
"""Disconnect the specified docker container from the given network."""
docker_command(args, ['network', 'disconnect', network, container_id], capture=True)
def docker_image_exists(args, image): # type: (EnvironmentConfig, str) -> bool
"""Return True if the image exists, otherwise False."""
try:
docker_command(args, ['image', 'inspect', image], capture=True)
except SubprocessError:
return False
return True
def docker_exec(
args, # type: EnvironmentConfig
container_id, # type: str
cmd, # type: t.List[str]
options=None, # type: t.Optional[t.List[str]]
capture=False, # type: bool
stdin=None, # type: t.Optional[t.BinaryIO]
stdout=None, # type: t.Optional[t.BinaryIO]
data=None, # type: t.Optional[str]
): # type: (...) -> t.Tuple[t.Optional[str], t.Optional[str]]
"""Execute the given command in the specified container."""
if not options:
options = []
if data or stdin or stdout:
options.append('-i')
return docker_command(args, ['exec'] + options + [container_id] + cmd, capture=capture, stdin=stdin, stdout=stdout, data=data)
def docker_info(args): # type: (CommonConfig) -> t.Dict[str, t.Any]
"""Return a dictionary containing details from the `docker info` command."""
stdout, _dummy = docker_command(args, ['info', '--format', '{{json .}}'], capture=True, always=True)
return json.loads(stdout)
def docker_version(args): # type: (CommonConfig) -> t.Dict[str, t.Any]
"""Return a dictionary containing details from the `docker version` command."""
stdout, _dummy = docker_command(args, ['version', '--format', '{{json .}}'], capture=True, always=True)
return json.loads(stdout)
def docker_command(
args, # type: CommonConfig
cmd, # type: t.List[str]
capture=False, # type: bool
stdin=None, # type: t.Optional[t.BinaryIO]
stdout=None, # type: t.Optional[t.BinaryIO]
always=False, # type: bool
data=None, # type: t.Optional[str]
): # type: (...) -> t.Tuple[t.Optional[str], t.Optional[str]]
"""Run the specified docker command."""
env = docker_environment()
command = require_docker().command
return run_command(args, [command] + cmd, env=env, capture=capture, stdin=stdin, stdout=stdout, always=always, data=data)
def docker_environment(): # type: () -> t.Dict[str, str]
"""Return a dictionary of docker related environment variables found in the current environment."""
env = common_environment()
env.update(dict((key, os.environ[key]) for key in os.environ if key.startswith('DOCKER_')))
return env