path: root/cloudinit/config/cc_apk_configure.py

# Copyright (c) 2020 Dermot Bradley
#
# Author: Dermot Bradley <dermot_bradley@yahoo.com>
#
# This file is part of cloud-init. See LICENSE file for license information.

"""Apk Configure: Configures apk repositories file."""

from textwrap import dedent

from cloudinit import log as logging
from cloudinit import temp_utils, templater, util
from cloudinit.config.schema import get_meta_doc, validate_cloudconfig_schema
from cloudinit.settings import PER_INSTANCE

LOG = logging.getLogger(__name__)


# If no mirror is specified then use this one
DEFAULT_MIRROR = "https://alpine.global.ssl.fastly.net/alpine"


REPOSITORIES_TEMPLATE = """\
## template:jinja
#
# Created by cloud-init
#
# This file is written on first boot of an instance
#

{{ alpine_baseurl }}/{{ alpine_version }}/main
{% if community_enabled -%}
{{ alpine_baseurl }}/{{ alpine_version }}/community
{% endif -%}
{% if testing_enabled -%}
{% if alpine_version != 'edge' %}
#
# Testing - using with non-Edge installation may cause problems!
#
{% endif %}
{{ alpine_baseurl }}/edge/testing
{% endif %}
{% if local_repo != '' %}

#
# Local repo
#
{{ local_repo }}/{{ alpine_version }}
{% endif %}

"""


frequency = PER_INSTANCE
distros = ["alpine"]
meta = {
    "id": "cc_apk_configure",
    "name": "APK Configure",
    "title": "Configure apk repositories file",
    "description": dedent(
        """\
        This module handles configuration of the /etc/apk/repositories file.

        .. note::
          To ensure that apk configuration is valid yaml, any strings
          containing special characters, especially ``:`` should be quoted.
    """
    ),
    "distros": distros,
    "examples": [
        dedent(
            """\
        # Keep the existing /etc/apk/repositories file unaltered.
        apk_repos:
            preserve_repositories: true
        """
        ),
        dedent(
            """\
        # Create repositories file for Alpine v3.12 main and community
        # using default mirror site.
        apk_repos:
            alpine_repo:
                community_enabled: true
                version: 'v3.12'
        """
        ),
        dedent(
            """\
        # Create repositories file for Alpine Edge main, community, and
        # testing using a specified mirror site and also a local repo.
        apk_repos:
            alpine_repo:
                base_url: 'https://some-alpine-mirror/alpine'
                community_enabled: true
                testing_enabled: true
                version: 'edge'
            local_repo_base_url: 'https://my-local-server/local-alpine'
        """
        ),
    ],
    "frequency": frequency,
}

schema = {
    "type": "object",
    "properties": {
        "apk_repos": {
            "type": "object",
            "properties": {
                "preserve_repositories": {
                    "type": "boolean",
                    "default": False,
                    "description": dedent(
                        """\
                        By default, cloud-init will generate a new repositories
                        file ``/etc/apk/repositories`` based on any valid
                        configuration settings specified within a apk_repos
                        section of cloud config. To disable this behavior and
                        preserve the repositories file from the pristine image,
                        set ``preserve_repositories`` to ``true``.

                        The ``preserve_repositories`` option overrides
                        all other config keys that would alter
                        ``/etc/apk/repositories``.
                    """
                    ),
                },
                "alpine_repo": {
                    "type": ["object", "null"],
                    "properties": {
                        "base_url": {
                            "type": "string",
                            "default": DEFAULT_MIRROR,
                            "description": dedent(
                                """\
                                The base URL of an Alpine repository, or
                                mirror, to download official packages from.
                                If not specified then it defaults to ``{}``
                            """.format(
                                    DEFAULT_MIRROR
                                )
                            ),
                        },
                        "community_enabled": {
                            "type": "boolean",
                            "default": False,
                            "description": dedent(
                                """\
                                Whether to add the Community repo to the
                                repositories file. By default the Community
                                repo is not included.
                            """
                            ),
                        },
                        "testing_enabled": {
                            "type": "boolean",
                            "default": False,
                            "description": dedent(
                                """\
                                Whether to add the Testing repo to the
                                repositories file. By default the Testing
                                repo is not included. It is only recommended
                                to use the Testing repo on a machine running
                                the ``Edge`` version of Alpine as packages
                                installed from Testing may have dependancies
                                that conflict with those in non-Edge Main or
                                Community repos."
                            """
                            ),
                        },
                        "version": {
                            "type": "string",
                            "description": dedent(
                                """\
                                The Alpine version to use (e.g. ``v3.12`` or
                                ``edge``)
                            """
                            ),
                        },
                    },
                    "required": ["version"],
                    "minProperties": 1,
                    "additionalProperties": False,
                },
                "local_repo_base_url": {
                    "type": "string",
                    "description": dedent(
                        """\
                        The base URL of an Alpine repository containing
                        unofficial packages
                    """
                    ),
                },
            },
            "minProperties": 1,  # Either preserve_repositories or alpine_repo
            "additionalProperties": False,
        }
    },
}

__doc__ = get_meta_doc(meta, schema)


def handle(name, cfg, cloud, log, _args):
    """
    Call to handle apk_repos sections in cloud-config file.

    @param name: The module name "apk-configure" from cloud.cfg
    @param cfg: A nested dict containing the entire cloud config contents.
    @param cloud: The CloudInit object in use.
    @param log: Pre-initialized Python logger object to use for logging.
    @param _args: Any module arguments from cloud.cfg
    """

    # If there is no "apk_repos" section in the configuration
    # then do nothing.
    apk_section = cfg.get("apk_repos")
    if not apk_section:
        LOG.debug(
            "Skipping module named %s, no 'apk_repos' section found", name
        )
        return

    validate_cloudconfig_schema(cfg, schema)

    # If "preserve_repositories" is explicitly set to True in
    # the configuration do nothing.
    if util.get_cfg_option_bool(apk_section, "preserve_repositories", False):
        LOG.debug(
            "Skipping module named %s, 'preserve_repositories' is set", name
        )
        return

    # If there is no "alpine_repo" subsection of "apk_repos" present in the
    # configuration then do nothing, as at least "version" is required to
    # create valid repositories entries.
    alpine_repo = apk_section.get("alpine_repo")
    if not alpine_repo:
        LOG.debug(
            "Skipping module named %s, no 'alpine_repo' configuration found",
            name,
        )
        return

    # If there is no "version" value present in configuration then do nothing.
    alpine_version = alpine_repo.get("version")
    if not alpine_version:
        LOG.debug(
            "Skipping module named %s, 'version' not specified in alpine_repo",
            name,
        )
        return

    local_repo = apk_section.get("local_repo_base_url", "")

    _write_repositories_file(alpine_repo, alpine_version, local_repo)


def _write_repositories_file(alpine_repo, alpine_version, local_repo):
    """
    Write the /etc/apk/repositories file with the specified entries.

    @param alpine_repo: A nested dict of the alpine_repo configuration.
    @param alpine_version: A string of the Alpine version to use.
    @param local_repo: A string containing the base URL of a local repo.
    """

    repo_file = "/etc/apk/repositories"

    alpine_baseurl = alpine_repo.get("base_url", DEFAULT_MIRROR)

    params = {
        "alpine_baseurl": alpine_baseurl,
        "alpine_version": alpine_version,
        "community_enabled": alpine_repo.get("community_enabled"),
        "testing_enabled": alpine_repo.get("testing_enabled"),
        "local_repo": local_repo,
    }

    tfile = temp_utils.mkstemp(prefix="template_name-", suffix=".tmpl")
    template_fn = tfile[1]  # Filepath is second item in tuple
    util.write_file(template_fn, content=REPOSITORIES_TEMPLATE)

    LOG.debug("Generating Alpine repository configuration file: %s", repo_file)
    templater.render_to_file(template_fn, repo_file, params)
    # Clean up temporary template
    util.del_file(template_fn)


# vi: ts=4 expandtab