[MISC] Set Pgbackrest spool dir to archive mount

src/backups.py

@@ -31,6 +31,7 @@
     BACKUP_TYPE_OVERRIDES,
     BACKUP_USER,
     PGBACKREST_LOGROTATE_FILE,
+    POSTGRESQL_ARCHIVE_PATH,
     WORKLOAD_OS_GROUP,
     WORKLOAD_OS_USER,
 )
@@ -1184,6 +1185,7 @@ def _render_pgbackrest_conf_file(self) -> bool:
         # Open the template pgbackrest.conf file.
         with open("templates/pgbackrest.conf.j2") as file:
             template = Template(file.read())
+        cpu_count, _ = self.charm.get_available_resources()
         # Render the template file with the correct values.
         rendered = template.render(
             enable_tls=self.charm.is_tls_enabled and len(self.charm.peer_members_endpoints) > 0,
@@ -1200,7 +1202,8 @@ def _render_pgbackrest_conf_file(self) -> bool:
             storage_path=self.charm._storage_path,
             user=BACKUP_USER,
             retention_full=s3_parameters["delete-older-than-days"],
-            process_max=max(os.cpu_count() - 2, 1),
+            process_max=max(cpu_count - 2, 1),
+            archive_path=POSTGRESQL_ARCHIVE_PATH,
         )
         # Delete the original file and render the one with the right info.
         filename = "/etc/pgbackrest.conf"

src/constants.py

@@ -19,6 +19,7 @@
 METRICS_PORT = "9187"
 POSTGRESQL_DATA_PATH = "/var/lib/postgresql/data/pgdata"
 POSTGRESQL_LOGS_PATH = "/var/log/postgresql"
+POSTGRESQL_ARCHIVE_PATH = "/var/lib/postgresql/archive"
 POSTGRESQL_LOGS_PATTERN = "postgresql*.log"
 POSTGRES_LOG_FILES = [
     "/var/log/pgbackrest/*",

templates/pgbackrest.conf.j2

@@ -1,6 +1,7 @@
 [global]
 backup-standby=y
 compress-type=zst
+spool-path={{ archive_path }}
 repo1-retention-full-type=time
 repo1-retention-full={{ retention_full }}
 repo1-retention-history=365

tests/unit/test_backups.py

@@ -1,7 +1,6 @@
 # Copyright 2023 Canonical Ltd.
 # See LICENSE file for licensing details.
 import datetime
-from os import cpu_count
 from unittest.mock import MagicMock, PropertyMock, call, mock_open, patch
 
 import pytest
@@ -14,7 +13,7 @@
 from tenacity import RetryError, wait_fixed
 
 from charm import PostgresqlOperatorCharm
-from constants import PEER
+from constants import PEER, POSTGRESQL_ARCHIVE_PATH
 from tests.unit.helpers import _FakeApiError
 
 ANOTHER_CLUSTER_REPOSITORY_ERROR_MESSAGE = "the S3 repository has backups from another cluster"
@@ -1762,6 +1761,7 @@ def test_render_pgbackrest_conf_file(harness, tls_ca_chain_filename):
             new_callable=PropertyMock(return_value=tls_ca_chain_filename),
         ) as _tls_ca_chain_filename,
         patch("charm.PostgreSQLBackups._retrieve_s3_parameters") as _retrieve_s3_parameters,
+        patch("charm.PostgresqlOperatorCharm.get_available_resources", return_value=(4, 1024)),
     ):
         # Set up a mock for the `open` method, set returned data to postgresql.conf template.
         with open("templates/pgbackrest.conf.j2") as f:
@@ -1813,7 +1813,8 @@ def test_render_pgbackrest_conf_file(harness, tls_ca_chain_filename):
             storage_path=harness.charm._storage_path,
             user="backup",
             retention_full=30,
-            process_max=max(cpu_count() - 2, 1),
+            process_max=2,
+            archive_path=POSTGRESQL_ARCHIVE_PATH,
         )
 
         # Patch the `open` method with our mock.