Add support for custom backup provider patterns

Author: mrwogu

README.md

@@ -17,6 +17,18 @@ A script to automatically back up all databases running under docker on a host,
   - [pgautoupgrade](https://github.com/pgautoupgrade/docker-pgautoupgrade))
 - Redis
 
+### Custom Backup Providers
+
+You can extend the existing backup providers with additional container patterns by setting environment variables:
+
+```
+CUSTOM_BACKUP_PROVIDER_POSTGRES_PATTERNS=immich-app/postgres,my-custom-postgres
+CUSTOM_BACKUP_PROVIDER_MYSQL_PATTERNS=my-custom-mysql,another-mysql-container
+CUSTOM_BACKUP_PROVIDER_REDIS_PATTERNS=my-custom-redis
+```
+
+Each variable should contain a comma-separated list of container patterns to match.
+
 ## Installation
 
 This container requires access to the docker socket. This can be done either by mounting `/var/lib/docker.sock`, or using a HTTP proxy to provide it through `$DOCKER_HOST`.
@@ -55,6 +67,9 @@ services:
     environment:
       - SUCCESS_HOOK_URL=https://hc-ping.com/1234
       - INCLUDE_LOGS=true
+      # Custom backup provider patterns
+      - CUSTOM_BACKUP_PROVIDER_POSTGRES_PATTERNS=immich-app/postgres,custom-postgres
+      - CUSTOM_BACKUP_PROVIDER_MYSQL_PATTERNS=my-custom-mysql
 ```
 
 ### Oneshot

db-auto-backup.py

@@ -155,6 +155,29 @@ def backup_redis(container: Container) -> str:
     ),
 ]
 
+# Extend backup providers with custom patterns from environment variables
+# Format: CUSTOM_BACKUP_PROVIDER_<provider_name>_PATTERNS=pattern1,pattern2,...
+for env_var, value in os.environ.items():
+    if env_var.startswith("CUSTOM_BACKUP_PROVIDER_") and env_var.endswith("_PATTERNS"):
+        provider_name = env_var.replace("CUSTOM_BACKUP_PROVIDER_", "").replace("_PATTERNS", "").lower()
+        custom_patterns = [pattern.strip() for pattern in value.split(",") if pattern.strip()]
+        
+        # Find the provider and extend its patterns
+        for provider in BACKUP_PROVIDERS:
+            if provider.name.lower() == provider_name:
+                # Create a new BackupProvider with extended patterns
+                index = BACKUP_PROVIDERS.index(provider)
+                BACKUP_PROVIDERS[index] = BackupProvider(
+                    name=provider.name,
+                    patterns=provider.patterns + custom_patterns,
+                    backup_method=provider.backup_method,
+                    file_extension=provider.file_extension,
+                )
+                print(f"Extended {provider.name} backup provider with patterns: {', '.join(custom_patterns)}")
+                break
+        else:
+            print(f"Warning: Custom backup provider {provider_name} not found, skipping patterns: {', '.join(custom_patterns)}")
+
 
 BACKUP_DIR = Path(os.environ.get("BACKUP_DIR", "/var/backups"))
 SCHEDULE = os.environ.get("SCHEDULE", "0 0 * * *")

tests/tests.py

@@ -130,3 +130,45 @@ def test_get_backup_provider(container_name: str, name: str) -> None:
 
     assert provider is not None
     assert provider.name == name
+
+
+def test_custom_backup_provider_patterns(monkeypatch: Any) -> None:
+    # Save original backup providers
+    original_providers = db_auto_backup.BACKUP_PROVIDERS.copy()
+
+    try:
+        # Set custom patterns environment variable
+        monkeypatch.setenv("CUSTOM_BACKUP_PROVIDER_POSTGRES_PATTERNS", "immich-app/postgres,custom-postgres")
+
+        # Create a copy of the original providers
+        test_providers = original_providers.copy()
+        db_auto_backup.BACKUP_PROVIDERS = test_providers
+
+        # Run the code that processes environment variables
+        for env_var, value in {"CUSTOM_BACKUP_PROVIDER_POSTGRES_PATTERNS": "immich-app/postgres,custom-postgres"}.items():
+            if env_var.startswith("CUSTOM_BACKUP_PROVIDER_") and env_var.endswith("_PATTERNS"):
+                provider_name = env_var.replace("CUSTOM_BACKUP_PROVIDER_", "").replace("_PATTERNS", "").lower()
+                custom_patterns = [pattern.strip() for pattern in value.split(",") if pattern.strip()]
+
+                for provider in db_auto_backup.BACKUP_PROVIDERS:
+                    if provider.name.lower() == provider_name:
+                        index = db_auto_backup.BACKUP_PROVIDERS.index(provider)
+                        db_auto_backup.BACKUP_PROVIDERS[index] = db_auto_backup.BackupProvider(
+                            name=provider.name,
+                            patterns=provider.patterns + custom_patterns,
+                            backup_method=provider.backup_method,
+                            file_extension=provider.file_extension,
+                        )
+                        break
+
+        # Test with the new custom pattern
+        provider = db_auto_backup.get_backup_provider(["immich-app/postgres"])
+        assert provider is not None
+        assert provider.name == "postgres"
+
+        provider = db_auto_backup.get_backup_provider(["custom-postgres"])
+        assert provider is not None
+        assert provider.name == "postgres"
+    finally:
+        # Restore original backup providers
+        db_auto_backup.BACKUP_PROVIDERS = original_providers