Merge ~afreiberger/charm-local-users:bug/1964807 into charm-local-users:main

[Drew Freiberger]

Remove charmhelpers requirement and import group add functions

[🤖 Canonical IS Merge Bot (canonical-is-mergebot)]

This merge proposal is being monitored by mergebot. Change the status to Approved to merge.

[Xav Paice (xavpaice)]

lgtm, we really really need this charm to have proper test coverage

review: Approve

[🤖 Canonical IS Merge Bot (canonical-is-mergebot)]

Change successfully merged at revision 84de21ec629938836f80a110ea235509ab00157f

diff --git a/charmcraft.yaml b/charmcraft.yaml
index fd5e934..663c211 100644
--- a/charmcraft.yaml
+++ b/charmcraft.yaml
@@ -1,9 +1,15 @@
 type: "charm"
 bases:
-  - name: "ubuntu"
-    channel: "20.04"
-  - name: "ubuntu"
-    channel: "18.04"
-parts:
-  charm:
-    charm-python-packages: [setuptools < 58]
+  - build-on:
+      - name: ubuntu
+        channel: "20.04"
+        architectures: ["amd64"]
+      run-on:
+          - name: ubuntu
+            channel: "20.04"
+            architectures:
+              - amd64
+          - name: ubuntu
+            channel: "18.04"
+            architectures:
+              - amd64
diff --git a/requirements.txt b/requirements.txt
index 7d3a551..5d6fa96 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1 @@
 ops >= 1.2.0
-charmhelpers >= 0.20.24
 \ No newline at end of file
diff --git a/src/charm.py b/src/charm.py
index f71608d..e9875e5 100755
--- a/src/charm.py
+++ b/src/charm.py
@@ -23,13 +23,13 @@ from ops.framework import StoredState
 from ops.main import main
 from ops.model import ActiveStatus, BlockedStatus
 
-from charmhelpers.core import host
-
 from lib.local_users import (
+    add_group,
     configure_user,
     check_sudoers_file,
     delete_user,
     get_group_users,
+    group_exists,
     is_unmanaged_user,
     parse_gecos,
     remove_group,
@@ -76,7 +76,7 @@ class CharmLocalUsersCharm(CharmBase):
             self.unit.status = BlockedStatus("'group' config option value is required")
             return
 
-        if not host.group_exists(group):
+        if not group_exists(group):
             if self._stored.group and self._stored.group != group:
                 log.debug(
                     "renaming charm managed group: '%s' to '%s'",
@@ -85,7 +85,7 @@ class CharmLocalUsersCharm(CharmBase):
                 )
                 rename_group(self._stored.group, group)
             else:
-                host.add_group(group)
+                add_group(group)
 
         # save the current managed group name in StoredState so that the charm can detect if rename
         # is needed on future config_changed events
diff --git a/src/lib/local_users.py b/src/lib/local_users.py
index 531458f..dba53e7 100755
--- a/src/lib/local_users.py
+++ b/src/lib/local_users.py
@@ -20,6 +20,7 @@ import re
 import subprocess
 import logging
 import tempfile
+import grp
 from collections import namedtuple
 
 from charmhelpers.core import host
@@ -179,7 +180,7 @@ def update_gecos(user):
 
 
 def parse_gecos(raw):
-    """Helper to convert a raw GECOS string into a 5 elements list."""
+    """Convert a raw GECOS string into a 5 elements list."""
     gecos = [""] * 5
     fields = raw.split(",")
     for i in range(5):
@@ -220,3 +221,49 @@ def write_sudoers_file(sudoers):
             sudoers_file.close()
         os.chmod(NEW_FILE, 0o440)
         os.replace(NEW_FILE, SUDOERS_FILE)
+
+
+def group_exists(groupname):
+    """Check if a group exists."""
+    try:
+        grp.getgrnam(groupname)
+        group_exists = True
+    except KeyError:
+        group_exists = False
+    return group_exists
+
+
+def add_group(group_name, system_group=False, gid=None):
+    """Add a group to the system.
+
+    Will log but otherwise succeed if the group already exists.
+    :param str group_name: group to create
+    :param bool system_group: Create system group
+    :param int gid: GID for user being created
+    :returns: The password database entry struct, as returned by `grp.getgrnam`
+    """
+    try:
+        group_info = grp.getgrnam(group_name)
+        log('group {0} already exists!'.format(group_name))
+        if gid:
+            group_info = grp.getgrgid(gid)
+            log('group with gid {0} already exists!'.format(gid))
+    except KeyError:
+        log('creating group {0}'.format(group_name))
+        add_new_group(group_name, system_group, gid)
+        group_info = grp.getgrnam(group_name)
+    return group_info
+
+
+def add_new_group(group_name, system_group=False, gid=None):
+    cmd = ['addgroup']
+    if gid:
+        cmd.extend(['--gid', str(gid)])
+    if system_group:
+        cmd.append('--system')
+    else:
+        cmd.extend([
+            '--group',
+        ])
+    cmd.append(group_name)
+    subprocess.check_call(cmd)