Implement snap packaging module

PR #44939

Fixes #39155
Closes #40852

Co-authored-by: Victor Carceler <vcarceler@iespuigcastellar.xeill.net>
Co-authored-by: Stanislas Lange <angristan@pm.me>
Co-authored-by: Sviatoslav Sydorenko <wk@sydorenko.org.ua>

.github/BOTMETA.yml

@@ -297,6 +297,7 @@ files:
   $modules/packaging/os/redhat_subscription.py: alikins kahowell
   $modules/packaging/os/rhn_channel.py: alikins
   $modules/packaging/os/rhn_register.py: $team_rhn
+  $modules/packaging/os/snap.py: angristan
   $modules/packaging/os/yum.py: $team_ansible kustodian
   $modules/packaging/os/zypper.py:
     ignored: dirtyharrycallahan

lib/ansible/modules/packaging/os/snap.py

@@ -0,0 +1,260 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+# Copyright: (c) 2018, Stanislas Lange (angristan) <angristan@pm.me>
+# Copyright: (c) 2018, Victor Carceler <vcarceler@iespuigcastellar.xeill.net>
+
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+from __future__ import absolute_import, division, print_function
+__metaclass__ = type
+
+ANSIBLE_METADATA = {
+    'metadata_version': '1.1',
+    'status': ['preview'],
+    'supported_by': 'community'
+}
+
+DOCUMENTATION = '''
+---
+module: snap
+
+short_description: Manages snaps
+
+version_added: "2.8"
+
+description:
+    - "Manages snaps packages."
+
+options:
+    name:
+        description:
+            - Name of the snap to install or remove. Can be a list of snaps.
+        required: true
+    state:
+        description:
+            - Desired state of the package.
+        required: false
+        default: present
+        choices: [ absent, present ]
+    classic:
+        description:
+            - Confinement policy. The classic confinment allows a snap to have
+              the same level of access to the system as "classic" packages,
+              like those managed by APT. This option corresponds to the --classic argument.
+              This option can only be specified if there is a single snap in the task.
+        type: bool
+        required: false
+        default: False
+    channel:
+        description:
+            - Define which release of a snap is installed and tracked for updates.
+              This option can only be specified if there is a single snap in the task.
+        type: str
+        required: false
+        default: stable
+
+author:
+    - Victor Carceler (vcarceler@iespuigcastellar.xeill.net)
+    - Stanislas Lange (angristan) <angristan@pm.me>
+'''
+
+EXAMPLES = '''
+# Install "foo" and "bar" snap
+- name: Install foo
+  snap:
+    name:
+      - foo
+      - bar
+
+# Remove "foo" snap
+- name: Remove foo
+  snap:
+    name: foo
+    state: absent
+
+# Install a snap with classic confinement
+- name: Install "foo" with option --classic
+  snap:
+    name: foo
+    classic: yes
+
+# Install a snap with from a specific channel
+- name: Install "foo" with option --channel=latest/edge
+  snap:
+    name: foo
+    channel: latest/edge
+'''
+
+RETURN = '''
+classic:
+    description: Whether or not the snaps were installed with the classic confinement
+    type: boolean
+    returned: When snaps are installed
+channel:
+    description: The channel the snaps were installed from
+    type: string
+    returned: When snaps are installed
+cmd:
+    description: The command that was executed on the host
+    type: string
+    returned: When changed is true
+snaps_installed:
+    description: The list of actually installed snaps
+    type: list
+    returned: When any snaps have been installed
+snaps_removed:
+    description: The list of actually removed snaps
+    type: list
+    returned: When any snaps have been removed
+'''
+
+import operator
+import re
+
+from ansible.module_utils.basic import AnsibleModule
+
+
+def validate_input_snaps(module):
+    """Ensure that all exist."""
+    for snap_name in module.params['name']:
+        if not snap_exists(module, snap_name):
+            module.fail_json(msg="No snap matching '%s' available." % snap_name)
+
+
+def snap_exists(module, snap_name):
+    snap_path = module.get_bin_path("snap", True)
+    cmd_parts = [snap_path, 'info', snap_name]
+    cmd = ' '.join(cmd_parts)
+    rc, out, err = module.run_command(cmd, check_rc=False)
+
+    return rc == 0
+
+
+def is_snap_installed(module, snap_name):
+    snap_path = module.get_bin_path("snap", True)
+    cmd_parts = [snap_path, 'list', snap_name]
+    cmd = ' '.join(cmd_parts)
+    rc, out, err = module.run_command(cmd, check_rc=False)
+
+    return rc == 0
+
+
+def get_snap_for_action(module):
+    """Construct a list of snaps to use for current action."""
+    snaps = module.params['name']
+
+    is_present_state = module.params['state'] == 'present'
+    negation_predicate = operator.not_ if is_present_state else bool
+
+    def predicate(s):
+        return negation_predicate(is_snap_installed(module, s))
+
+    return [s for s in snaps if predicate(s)]
+
+
+def get_base_cmd_parts(module):
+    action_map = {
+        'present': 'install',
+        'absent': 'remove',
+    }
+
+    state = module.params['state']
+
+    classic = ['--classic'] if module.params['classic'] else []
+    channel = ['--channel', module.params['channel']] if module.params['channel'] and module.params['channel'] != 'stable' else []
+
+    snap_path = module.get_bin_path("snap", True)
+    snap_action = action_map[state]
+
+    cmd_parts = [snap_path, snap_action]
+    if snap_action == 'install':
+        cmd_parts += classic + channel
+
+    return cmd_parts
+
+
+def get_cmd_parts(module, snap_names):
+    """Return list of cmds to run in exec format."""
+    is_install_mode = module.params['state'] == 'present'
+    has_multiple_snaps = len(snap_names) > 1
+
+    cmd_parts = get_base_cmd_parts(module)
+    has_one_pkg_params = '--classic' in cmd_parts or '--channel' in cmd_parts
+
+    if not (is_install_mode and has_one_pkg_params and has_multiple_snaps):
+        return [cmd_parts + snap_names]
+
+    return [cmd_parts + [s] for s in snap_names]
+
+
+def run_cmd_for(module, snap_names):
+    cmds_parts = get_cmd_parts(module, snap_names)
+    cmd = '; '.join(' '.join(c) for c in cmds_parts)
+    cmd = 'sh -c "{0}"'.format(cmd)
+
+    # Actually execute the snap command
+    return (cmd, ) + module.run_command(cmd, check_rc=False)
+
+
+def execute_action(module):
+    is_install_mode = module.params['state'] == 'present'
+    exit_kwargs = {
+        'classic': module.params['classic'],
+        'channel': module.params['channel'],
+    } if is_install_mode else {}
+
+    actionable_snaps = get_snap_for_action(module)
+    if not actionable_snaps:
+        module.exit_json(changed=False, **exit_kwargs)
+
+    changed_def_args = {
+        'changed': True,
+        'snaps_{result}'.
+        format(result='installed' if is_install_mode
+               else 'removed'): actionable_snaps,
+    }
+
+    if module.check_mode:
+        module.exit_json(**dict(changed_def_args, **exit_kwargs))
+
+    cmd, rc, out, err = run_cmd_for(module, actionable_snaps)
+    cmd_out_args = {
+        'cmd': cmd,
+        'rc': rc,
+        'stdout': out,
+        'stderr': err,
+    }
+
+    if rc == 0:
+        module.exit_json(**dict(changed_def_args, **dict(cmd_out_args, **exit_kwargs)))
+    else:
+        msg = "Ooops! Snap installation failed while executing '{cmd}', please examine logs and error output for more details.".format(cmd=cmd)
+        if is_install_mode:
+            m = re.match(r'^error: This revision of snap "(?P<package_name>\w+)" was published using classic confinement', err)
+            if m is not None:
+                err_pkg = m.group('package_name')
+                msg = "Couldn't install {name} because it requires classic confinement".format(name=err_pkg)
+        module.fail_json(msg=msg, **dict(cmd_out_args, **exit_kwargs))
+
+
+def main():
+    module_args = {
+        'name': dict(type='list', required=True),
+        'state': dict(type='str', required=False, default='present', choices=['absent', 'present']),
+        'classic': dict(type='bool', required=False, default=False),
+        'channel': dict(type='str', required=False, default='stable'),
+    }
+    module = AnsibleModule(
+        argument_spec=module_args,
+        supports_check_mode=True,
+    )
+
+    validate_input_snaps(module)
+
+    # Apply changes to the snaps
+    execute_action(module)
+
+
+if __name__ == '__main__':
+    main()