Added compression option for backup command (#35)

This commit introduces a new feature to the backup command in the CLI tool,
allowing users to compress their backups for more efficient storage management.
The --compress flag can be used to enable this option, which compresses
the backup directory into a tar.gz file and places it in the specified output directory.

Signed-off-by: Anton Kremenetsky <anton.kremenetsky@gmail.com>

Author: akremenetsky

README.md

@@ -295,3 +295,11 @@ genesis backup -oneshot
 ```
 
 This command will backup the current installation to the specified directory once and exit.
+
+### Compuressed Backup
+
+Run backup of all libvirt domains and store a compressed archive of the backup in the current directory:
+
+```bash
+genesis backup --compress
+```

genesis_devtools/cmd/cli.py

@@ -399,17 +399,27 @@ def get_project_version_cmd(element_dir: str) -> None:
     is_flag=True,
     help="Do a backup once and exit",
 )
+@click.option(
+    "-c",
+    "--compress",
+    default=False,
+    type=bool,
+    show_default=True,
+    is_flag=True,
+    help="Compress the backup.",
+)
 def bakcup_cmd(
     name: tp.List[str] | None,
     backup_dir: str,
     period: c.BackupPeriod,
     oneshot: bool,
+    compress: bool,
 ) -> None:
     # Do a single backup and exit
     if oneshot:
         domains = _domains_for_backup(name, raise_on_domain_absence=True)
         backup_path = utils.backup_path(backup_dir)
-        _do_backup(backup_path, domains)
+        _do_backup(backup_path, domains, compress)
         click.secho("Backup done", fg="green")
         return
 
@@ -428,7 +438,7 @@ def bakcup_cmd(
 
         click.secho(f"Backup started at {time.strftime('%Y-%m-%d %H:%M:%S')}")
         backup_path = utils.backup_path(backup_dir)
-        _do_backup(backup_path, domains)
+        _do_backup(backup_path, domains, compress)
 
         click.secho(
             f"Next backup at: {time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(next_ts))}"
@@ -441,7 +451,9 @@ def bakcup_cmd(
         time.sleep(timeout)
 
 
-def _do_backup(backup_path: str, domains: tp.List[str]) -> None:
+def _do_backup(
+    backup_path: str, domains: tp.List[str], compress: bool = False
+) -> None:
     os.makedirs(backup_path, exist_ok=True)
 
     table = prettytable.PrettyTable()
@@ -481,6 +493,20 @@ def _do_backup(backup_path: str, domains: tp.List[str]) -> None:
     click.echo(f"Summary: {backup_path}")
     click.echo(table)
 
+    if not compress:
+        return
+
+    click.echo(f"Compressing {backup_path}")
+    compress_directory = os.path.dirname(backup_path)
+    try:
+        utils.compress_dir(backup_path, compress_directory)
+    except Exception:
+        click.secho(f"Compression of {backup_path} failed", fg="red")
+        return
+
+    click.secho(f"Compression of {backup_path} done", fg="green")
+    shutil.rmtree(backup_path)
+
 
 def _domains_for_backup(
     names: tp.List[str] | None = None, raise_on_domain_absence: bool = False

genesis_devtools/utils.py

@@ -17,6 +17,7 @@
 
 import os
 import time
+import shutil
 import itertools
 import typing as tp
 from importlib.metadata import entry_points
@@ -212,3 +213,24 @@ def human_readable_size(size: int, decimal_places: int = 2):
 def backup_path(backup_dir: str) -> str:
     backup_relative_path = time.strftime("%Y-%m-%d-%H-%M-%S")
     return os.path.join(backup_dir, backup_relative_path)
+
+
+def compress_dir(
+    directory: str, output_dir: str, compression_format: str = "gztar"
+) -> None:
+    """
+    Compresses the specified directory and places the archive in the
+    output directory.
+
+    :param directory: The path to the directory to be compressed.
+    :param output_dir: The path to the directory where the compressed
+                       archive will be placed.
+    """
+    # Ensure the output directory exists
+    os.makedirs(output_dir, exist_ok=True)
+
+    # Define the base name for the archive (without extension)
+    archive_base_name = os.path.join(output_dir, os.path.basename(directory))
+
+    # Create a zip archive of the directory
+    shutil.make_archive(archive_base_name, compression_format, directory)