Merge ~ksdziekonski/charm-juju-backup-all:omit-models into charm-juju-backup-all:master

[Ksawery Dziekoński]

Allow for model omission in controller-wide backups

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

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

[Robert Gildein (rgildein)]

I think this is quite a straightforward feature. However, we should at
least add unittests for these changes.

[Eric Chen (eric-chen)]

Change the status to WIP until the unit test available.

Unmerged commits

92f8691... by Ksawery Dziekoński on 2022-06-29

Allow for model omission in controller-wide backups

Related: LP#1980215

diff --git a/actions.yaml b/actions.yaml
index 2ecaac8..3ae2418 100644
--- a/actions.yaml
+++ b/actions.yaml
@@ -3,5 +3,11 @@
 
 do-backup:
   description: Performs a backup against all configured controllers/models
+  params:
+    omit-models:
+      type: string
+      default: ""
+      description: |
+        Comma-delimited list of model names to omit during this backup run
 push-ssh-keys:
   description: Push the charm ssh keys to all models in configured controllers
diff --git a/config.yaml b/config.yaml
index acc98af..dd7e418 100644
--- a/config.yaml
+++ b/config.yaml
@@ -60,6 +60,10 @@ options:
     description: |
       Whether to backup the juju client data (accounts, controllers, ssh keys)
       as part of the backup operations.
+  exclude-models:
+    type: string
+    default: ""
+    description: Comma-delimited list of model names to omit during backup runs
   timeout:
     type: int
     default: 60
diff --git a/scripts/templates/auto_backup.py b/scripts/templates/auto_backup.py
index 17f3c02..a569941 100644
--- a/scripts/templates/auto_backup.py
+++ b/scripts/templates/auto_backup.py
@@ -59,7 +59,7 @@ class AutoJujuBackupAll:
         if "JUJUDATA_DIR" not in os.environ:
             os.environ["JUJU_DATA"] = str(Paths.JUJUDATA_DIR)
 
-    def perform_backup(self):
+    def perform_backup(self, omit_models=None):
         """Perform backups."""
         # first ensure the ssh key is in all models, then perform the backup
         accounts_yaml = (Paths.JUJUDATA_DIR / "accounts.yaml").read_text()
@@ -68,7 +68,7 @@ class AutoJujuBackupAll:
         ssh_helper.push_ssh_keys_to_models()
 
         backup_processor = BackupProcessor(self.config)
-        backup_results = backup_processor.process_backups()
+        backup_results = backup_processor.process_backups(omit_models=omit_models)
         logger.info("backup results = '{}'".format(backup_results))
         return backup_results
 
@@ -124,6 +124,14 @@ class AutoJujuBackupAll:
             help="Individual task timeout length",
         )
 
+        parser.add_argument(
+            "--omit-models"
+            action="append",
+            dest="omit_models",
+            metavar="MODEL_NAME",
+            help="Names of models to omit during backup run"
+        )
+
         args = parser.parse_args()
 
         log_level = logging.DEBUG if args.debug else logging.ERROR
@@ -141,7 +149,7 @@ class AutoJujuBackupAll:
         PID_FILENAME.write_text(pid)
 
         try:
-            backup_results = self.perform_backup()
+            backup_results = self.perform_backup(omit_models=args.omit_models)
             Paths.AUTO_BACKUP_RESULTS_PATH.write_text(backup_results)
 
             # purge old backups if requested
diff --git a/src/charm.py b/src/charm.py
index 57f9c6d..f71855f 100755
--- a/src/charm.py
+++ b/src/charm.py
@@ -4,6 +4,8 @@
 
 import logging
 
+from charmhelpers.core import hookenv
+
 from ops.charm import CharmBase
 from ops.framework import StoredState
 from ops.main import main
@@ -42,7 +44,8 @@ class JujuBackupAllCharm(CharmBase):
 
     def _on_do_backup_action(self, event):
         """Handle the dobackup action."""
-        backup_results = self.helper.perform_backup()
+        backup_results = self.helper.perform_backup(omit_models=[
+            name for name in hookenv.action_get("omit-models").split(",") if name])
         event.set_results({"result": backup_results})
 
     def _on_push_ssh_keys_action(self, event):
diff --git a/src/utils.py b/src/utils.py
index dae3635..aa276a1 100644
--- a/src/utils.py
+++ b/src/utils.py
@@ -141,12 +141,12 @@ class JujuBackupAllHelper:
 
         self._update_dir_owner(Paths.JUJUDATA_DIR)
 
-    def perform_backup(self):
+    def perform_backup(self, omit_models=None):
         """Perform backups."""
         # first ensure the ssh key is in all models, then perform the backup
         self.push_ssh_keys()
         backup_processor = BackupProcessor(self.config)
-        backup_results = backup_processor.process_backups()
+        backup_results = backup_processor.process_backups(omit_models=omit_models)
         logging.info("backup results = '{}'".format(backup_results))
         self._update_dir_owner(self.charm_config["backup-dir"])
         return backup_results
@@ -160,15 +160,25 @@ class JujuBackupAllHelper:
     def update_crontab(self):
         """Update crontab "/etc/cron.d/juju-backup-all" that runs "auto_backup.py"."""
         path = "PATH=/usr/bin:/bin:/snap/bin"
-        cron_job = "{}\n{} {} {} --debug --purge {} --task-timeout {} >> {} 2>&1\n".format(  # noqa E501
+        cron_job = "{}\n{} {} {} --debug".format(
             path,
             self.charm_config["crontab"],
             BACKUP_USERNAME,
             Paths.AUTO_BACKUP_SCRIPT_PATH,
-            self.charm_config["backup-retention-period"],
-            self.charm_config["timeout"],
-            Paths.AUTO_BACKUP_LOG_PATH,
         )
+
+        if self.charm_config["backup-retention-period"]:
+            cron_job += " --purge {}".format(self.charm_config["backup-retention-period"])
+
+        if self.charm_config["timeout"]:
+            cron_job += " --task-timeout {}".format(self.charm_config["timeout"])
+
+        if self.charm_config["exclude-models"]:
+            cron_job += " --omit-models {}".format(",".join([
+                name for name in self.charm_config["exclude-models"].split(",") if name
+            ]))
+
+        cron_job += " >> {} 2>&1\n".format(Paths.AUTO_BACKUP_LOG_PATH)
         Paths.AUTO_BACKUP_CRONTAB_PATH.write_text(cron_job)
 
     def update_jujudata_config(self):