Simple self-update feature

app/update.py

@@ -0,0 +1,79 @@
+# Copyright © 2023 Vulcanize
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http:#www.gnu.org/licenses/>.
+
+import click
+import datetime
+import filecmp
+import os
+from pathlib import Path
+import requests
+import sys
+import stat
+import shutil
+import validators
+from app.util import get_yaml
+
+
+def _download_url(url: str, file_path: Path):
+    r = requests.get(url, stream=True)
+    r.raw.decode_content = True
+    with open(file_path, 'wb') as f:
+        shutil.copyfileobj(r.raw, f)
+
+
+def _error_exit(s: str):
+    print(s)
+    sys.exit(1)
+
+
+# Note at present this probably won't work on non-Unix based OSes like Windows
+@click.command()
+@click.option("--check-only", is_flag=True, default=False, help="only check, don't update")
+@click.pass_context
+def command(ctx, check_only):
+    '''update shiv binary from a distribution url'''
+    # Get the distribution URL from config
+    config_key = 'distribution-url'
+    config_file_path = Path(os.path.expanduser("~/.laconic-so/config.yml"))
+    if not config_file_path.exists():
+        _error_exit(f"Error: Config file: {config_file_path} not found")
+    yaml = get_yaml()
+    config = yaml.load(open(config_file_path, "r"))
+    if "distribution-url" not in config:
+        _error_exit(f"Error: {config_key} not defined in {config_file_path}")
+    distribution_url = config[config_key]
+    # Sanity check the URL
+    if not validators.url(distribution_url):
+        _error_exit(f"ERROR: distribution url: {distribution_url} is not valid")
+    # Figure out the filename for ourselves
+    shiv_binary_path = Path(sys.argv[0])
+    timestamp_filename = f"laconic-so-download-{datetime.datetime.now().strftime('%y%m%d-%H%M%S')}"
+    temp_download_path = shiv_binary_path.parent.joinpath(timestamp_filename)
+    # Download the file to a temp filename
+    if ctx.obj.verbose:
+        print(f"Downloading from: {distribution_url} to {temp_download_path}")
+    _download_url(distribution_url, temp_download_path)
+    # Set the executable bit
+    existing_mode = os.stat(temp_download_path)
+    os.chmod(temp_download_path, existing_mode.st_mode | stat.S_IXUSR)
+    # Switch the new file for the path we ran from
+    # Check if the downloaded file is identical to the existing one
+    same = filecmp.cmp(temp_download_path, shiv_binary_path)
+    if same:
+        if not ctx.obj.quiet:
+            print("Up update available, latest version already installed")
+    if ctx.obj.verbose:
+        print(f"Replacing: {shiv_binary_path} with {temp_download_path}")
+    os.replace(temp_download_path, shiv_binary_path)

cli.py

@@ -22,6 +22,7 @@ from app import build_npms
 from app import deploy
 from app import version
 from app import deployment
+from app import update
 
 CONTEXT_SETTINGS = dict(help_option_names=['-h', '--help'])
 
@@ -48,3 +49,4 @@ cli.add_command(deploy.command, "deploy")  # deploy is an alias for deploy-syste
 cli.add_command(deploy.command, "deploy-system")
 cli.add_command(deployment.command, "deployment")
 cli.add_command(version.command, "version")
+cli.add_command(update.command, "update")

requirements.txt

@@ -7,3 +7,4 @@ PyYAML>=6.0.1
 ruamel.yaml>=0.17.32
 pydantic==1.10.9
 tomli==2.0.1
+validators==0.22.0