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ansible-podman-collections/plugins/connection/buildah.py
Sagi Shnaidman 3aa2a46c94 Fix file copy in buildah
Signed-off-by: Sagi Shnaidman <sshnaidm@redhat.com>
2025-09-11 20:25:32 +03:00

490 lines
19 KiB
Python

# Based on modern Ansible connection plugin patterns
# Copyright (c) 2017 Ansible Project
# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
#
# Connection plugin for building container images using buildah tool
# https://github.com/containers/buildah
#
# Rewritten with modern patterns and enhanced functionality
from __future__ import absolute_import, division, print_function
__metaclass__ = type
DOCUMENTATION = """
author: Tomas Tomecek (@TomasTomecek)
name: buildah
short_description: Interact with an existing buildah container
description:
- Run commands or put/fetch files to an existing container using buildah tool.
- Supports container building workflows with enhanced error handling and performance.
options:
remote_addr:
description:
- The ID or name of the buildah working container you want to access.
default: inventory_hostname
vars:
- name: ansible_host
- name: inventory_hostname
- name: ansible_buildah_host
env:
- name: ANSIBLE_BUILDAH_HOST
ini:
- section: defaults
key: remote_addr
remote_user:
description:
- User specified via name or UID which is used to execute commands inside the container.
- For buildah, this affects both run commands and copy operations.
ini:
- section: defaults
key: remote_user
env:
- name: ANSIBLE_REMOTE_USER
vars:
- name: ansible_user
buildah_executable:
description:
- Executable for buildah command.
default: buildah
type: str
vars:
- name: ansible_buildah_executable
env:
- name: ANSIBLE_BUILDAH_EXECUTABLE
ini:
- section: defaults
key: buildah_executable
buildah_extra_args:
description:
- Extra arguments to pass to the buildah command line.
default: ''
type: str
ini:
- section: defaults
key: buildah_extra_args
vars:
- name: ansible_buildah_extra_args
env:
- name: ANSIBLE_BUILDAH_EXTRA_ARGS
container_timeout:
description:
- Timeout in seconds for container operations.
default: 30
type: int
vars:
- name: ansible_buildah_timeout
env:
- name: ANSIBLE_BUILDAH_TIMEOUT
ini:
- section: defaults
key: buildah_timeout
connection_retries:
description:
- Number of retries for failed container operations.
default: 3
type: int
vars:
- name: ansible_buildah_retries
env:
- name: ANSIBLE_BUILDAH_RETRIES
mount_detection:
description:
- Enable automatic detection and use of container mount points for file operations.
default: true
type: bool
vars:
- name: ansible_buildah_mount_detection
env:
- name: ANSIBLE_BUILDAH_MOUNT_DETECTION
ignore_mount_errors:
description:
- Continue with copy operations even if container mounting fails.
default: true
type: bool
vars:
- name: ansible_buildah_ignore_mount_errors
extra_env_vars:
description:
- Additional environment variables to set in the container.
default: {}
type: dict
vars:
- name: ansible_buildah_extra_env
working_directory:
description:
- Set working directory for commands executed in the container.
type: str
vars:
- name: ansible_buildah_working_directory
env:
- name: ANSIBLE_BUILDAH_WORKING_DIRECTORY
auto_commit:
description:
- Automatically commit changes after successful operations.
default: false
type: bool
vars:
- name: ansible_buildah_auto_commit
"""
import json
import os
import shlex
import shutil
import subprocess
import time
from ansible.errors import AnsibleConnectionFailure
from ansible.module_utils.common.process import get_bin_path
from ansible.module_utils._text import to_bytes, to_native, to_text
from ansible.plugins.connection import ConnectionBase, ensure_connect
from ansible.utils.display import Display
display = Display()
class BuildahConnectionError(AnsibleConnectionFailure):
"""Specific exception for buildah connection issues"""
pass
class ContainerNotFoundError(BuildahConnectionError):
"""Exception for when container cannot be found"""
pass
class Connection(ConnectionBase):
"""
Modern connection plugin for buildah with enhanced error handling and performance optimizations
"""
transport = "containers.podman.buildah"
has_pipelining = True
def __init__(self, play_context, new_stdin, *args, **kwargs):
super(Connection, self).__init__(play_context, new_stdin, *args, **kwargs)
self._container_id = self._play_context.remote_addr
self._connected = False
self._container_info = None
self._mount_point = None
self._executable_path = None
self._task_uuid = to_text(kwargs.get("task_uuid", ""))
# Initialize caches
self._command_cache = {}
self._container_validation_cache = {}
display.vvvv("Using buildah connection from collection", host=self._container_id)
def _get_buildah_executable(self):
"""Get and cache buildah executable path with validation"""
if self._executable_path is None:
executable = self.get_option("buildah_executable")
try:
self._executable_path = get_bin_path(executable)
display.vvvv(f"Found buildah executable: {self._executable_path}", host=self._container_id)
except ValueError as e:
raise BuildahConnectionError(f"Could not find {executable} in PATH: {e}")
return self._executable_path
def _build_buildah_command(self, cmd_args, include_container=True):
"""Build complete buildah command with all options"""
cmd = [self._get_buildah_executable()]
# Add global options
if self.get_option("buildah_extra_args"):
extra_args = shlex.split(to_native(self.get_option("buildah_extra_args"), errors="surrogate_or_strict"))
cmd.extend(extra_args)
# Add subcommand and arguments
if isinstance(cmd_args, str):
cmd.append(cmd_args)
else:
cmd.extend(cmd_args)
# Add container ID if needed
if include_container:
cmd.append(self._container_id)
return cmd
def _run_buildah_command(
self, cmd_args, input_data=None, check_rc=True, include_container=True, retries=None, output_file=None
):
"""Execute buildah command with comprehensive error handling and retries"""
if retries is None:
retries = self.get_option("connection_retries")
cmd = self._build_buildah_command(cmd_args, include_container)
cmd_bytes = [to_bytes(arg, errors="surrogate_or_strict") for arg in cmd]
display.vvv(f"BUILDAH EXEC: {' '.join(cmd)}", host=self._container_id)
last_exception = None
for attempt in range(retries + 1):
try:
# Handle output redirection
stdout_fd = subprocess.PIPE
if output_file:
stdout_fd = open(output_file, "wb")
process = subprocess.Popen(
cmd_bytes, stdin=subprocess.PIPE, stdout=stdout_fd, stderr=subprocess.PIPE, shell=False
)
stdout, stderr = process.communicate(input=input_data, timeout=self.get_option("container_timeout"))
if output_file:
stdout_fd.close()
stdout = b"" # No stdout when redirected to file
display.vvvvv(f"STDOUT: {stdout}", host=self._container_id)
display.vvvvv(f"STDERR: {stderr}", host=self._container_id)
display.vvvvv(f"RC: {process.returncode}", host=self._container_id)
stdout = to_bytes(stdout, errors="surrogate_or_strict")
stderr = to_bytes(stderr, errors="surrogate_or_strict")
if check_rc and process.returncode != 0:
error_msg = to_text(stderr, errors="surrogate_or_strict").strip()
if "no such container" in error_msg.lower() or "container not known" in error_msg.lower():
raise ContainerNotFoundError(f"Container '{self._container_id}' not found")
raise BuildahConnectionError(f"Command failed (rc={process.returncode}): {error_msg}")
return process.returncode, stdout, stderr
except subprocess.TimeoutExpired:
if output_file and "stdout_fd" in locals():
stdout_fd.close()
process.kill()
timeout = self.get_option("container_timeout")
last_exception = BuildahConnectionError(f"Command timeout after {timeout}s")
if attempt < retries:
display.vvv(f"Command timeout, retrying ({attempt + 1}/{retries + 1})", host=self._container_id)
time.sleep(1)
continue
except Exception as e:
if output_file and "stdout_fd" in locals():
stdout_fd.close()
last_exception = BuildahConnectionError(f"Command execution failed: {e}")
if attempt < retries:
display.vvv(f"Command failed, retrying ({attempt + 1}/{retries + 1})", host=self._container_id)
time.sleep(1)
continue
raise last_exception
def _validate_container(self):
"""Validate that the container exists and is accessible"""
if self._container_id in self._container_validation_cache:
return self._container_validation_cache[self._container_id]
try:
# Check if container exists by inspecting it
unused, stdout, unused1 = self._run_buildah_command(
["inspect", self._container_id], include_container=False, retries=1
)
self._container_info = json.loads(to_text(stdout, errors="surrogate_or_strict"))
# Validate container is in a working state
if not self._container_info:
raise BuildahConnectionError("Container inspection returned empty data")
self._container_validation_cache[self._container_id] = True
display.vvv("Container validation successful", host=self._container_id)
return True
except (json.JSONDecodeError, IndexError, KeyError) as e:
raise BuildahConnectionError(f"Failed to parse container information: {e}")
def _setup_mount_point(self):
"""Attempt to mount container filesystem for direct access"""
if not self.get_option("mount_detection"):
return
try:
unused, stdout, unused1 = self._run_buildah_command(["mount"], retries=1)
mount_point = to_text(stdout, errors="surrogate_or_strict").strip()
if mount_point and os.path.isdir(mount_point):
# Ensure mount point has trailing separator for consistency
self._mount_point = mount_point.rstrip(os.sep) + os.sep
display.vvv(f"Container mounted at: {self._mount_point}", host=self._container_id)
else:
display.vvv("Container mount point is invalid", host=self._container_id)
except Exception as e:
if not self.get_option("ignore_mount_errors"):
raise BuildahConnectionError(f"Mount setup failed: {e}")
display.vvv(f"Mount setup failed, continuing without mount: {e}", host=self._container_id)
def _connect(self):
"""Establish connection to container with validation and setup"""
super(Connection, self)._connect()
if self._connected:
return
display.vvv(f"Connecting to buildah container: {self._container_id}", host=self._container_id)
# Validate container exists and is accessible
self._validate_container()
# Setup mount point for file operations
self._setup_mount_point()
self._connected = True
display.vvv("Connection established successfully", host=self._container_id)
@ensure_connect
def exec_command(self, cmd, in_data=None, sudoable=False):
"""Execute command in container with enhanced error handling"""
super(Connection, self).exec_command(cmd, in_data=in_data, sudoable=sudoable)
display.vvv(f"EXEC: {cmd}", host=self._container_id)
cmd_args_list = shlex.split(to_native(cmd, errors="surrogate_or_strict"))
run_cmd = ["run"]
# Handle user specification
if self.get_option("remote_user") and self.get_option("remote_user") != "root":
run_cmd.extend(["--user", self.get_option("remote_user")])
# Add extra environment variables
extra_env = self.get_option("extra_env_vars")
if extra_env:
for key, value in extra_env.items():
run_cmd.extend(["--env", f"{key}={value}"])
# Set working directory if specified
working_dir = self.get_option("working_directory")
if working_dir:
run_cmd.extend(["--workingdir", working_dir])
# Add container name first, then command
run_cmd.append(self._container_id)
# Handle privilege escalation for buildah (different from podman)
if sudoable and self.get_option("remote_user") != "root":
# For buildah, privilege escalation means running as root user
# Remove the --user option and don't use sudo inside container
run_cmd = [arg for arg in run_cmd if not (arg == "--user" or arg == self.get_option("remote_user"))]
run_cmd.extend(cmd_args_list)
try:
# Use include_container=False since we already added container name
rc, stdout, stderr = self._run_buildah_command(run_cmd, input_data=in_data, include_container=False)
# Auto-commit if enabled and command succeeded
if rc == 0 and self.get_option("auto_commit"):
self._auto_commit_changes()
return rc, stdout, stderr
except ContainerNotFoundError:
# Container might have been removed, invalidate cache and retry once
if self._container_id in self._container_validation_cache:
del self._container_validation_cache[self._container_id]
self._connected = False
self._connect()
rc, stdout, stderr = self._run_buildah_command(run_cmd, input_data=in_data, include_container=False)
return rc, stdout, stderr
raise
def _auto_commit_changes(self):
"""Automatically commit changes if enabled"""
try:
display.vvv("Auto-committing container changes", host=self._container_id)
self._run_buildah_command(["commit"], check_rc=False, retries=1)
except Exception as e:
display.warning(f"Auto-commit failed: {e}")
def put_file(self, in_path, out_path):
"""Transfer file to container using optimal method"""
super(Connection, self).put_file(in_path, out_path)
display.vvv(f"PUT: {in_path} -> {out_path}", host=self._container_id)
# Use direct filesystem copy if mount point is available
if self._mount_point:
try:
real_out_path = os.path.join(self._mount_point, out_path.lstrip("/"))
os.makedirs(os.path.dirname(real_out_path), exist_ok=True)
shutil.copy2(in_path, real_out_path)
display.vvvv(f"File copied via mount: {real_out_path}", host=self._container_id)
# Handle ownership when user is specified
if self.get_option("remote_user") and self.get_option("remote_user") != "root":
try:
shutil.chown(real_out_path, user=self.get_option("remote_user"))
except (OSError, LookupError) as e:
display.vvv(f"Could not change ownership via mount: {e}", host=self._container_id)
# Remove the file and fall back to buildah copy
try:
os.remove(real_out_path)
except OSError:
pass
raise Exception("Ownership change failed, falling back to buildah copy")
return
except Exception as e:
display.vvv(f"Mount copy failed, falling back to buildah copy: {e}", host=self._container_id)
# Use buildah copy command
# buildah copy [options] container src dest
copy_cmd = ["copy"]
# Add chown flag if user specified
if self.get_option("remote_user") and self.get_option("remote_user") != "root":
copy_cmd.extend(["--chown", self.get_option("remote_user")])
copy_cmd.extend([self._container_id, in_path, out_path])
self._run_buildah_command(copy_cmd, include_container=False)
def fetch_file(self, in_path, out_path):
"""Retrieve file from container using optimal method"""
super(Connection, self).fetch_file(in_path, out_path)
display.vvv(f"FETCH: {in_path} -> {out_path}", host=self._container_id)
# Use direct filesystem copy if mount point is available
if self._mount_point:
try:
real_in_path = os.path.join(self._mount_point, in_path.lstrip("/"))
if os.path.exists(real_in_path):
os.makedirs(os.path.dirname(out_path), exist_ok=True)
shutil.copy2(real_in_path, out_path)
display.vvvv(f"File fetched via mount: {real_in_path}", host=self._container_id)
return
except Exception as e:
display.vvv(f"Mount fetch failed, falling back to buildah run: {e}", host=self._container_id)
# Use buildah run with cat command and output redirection
os.makedirs(os.path.dirname(out_path), exist_ok=True)
cat_cmd = ["run", self._container_id, "cat", in_path]
self._run_buildah_command(cat_cmd, output_file=out_path, include_container=False)
def close(self):
"""Close connection and cleanup resources"""
super(Connection, self).close()
if self._mount_point:
try:
# Attempt to unmount the container
self._run_buildah_command(["umount"], retries=1, check_rc=False)
display.vvvv("Container unmounted successfully", host=self._container_id)
except Exception as e:
display.vvvv(f"Unmount failed: {e}", host=self._container_id)
# Auto-commit on close if enabled
if self.get_option("auto_commit"):
self._auto_commit_changes()
# Clear caches
self._command_cache.clear()
self._connected = False
display.vvv("Connection closed", host=self._container_id)