Add script to build release binary in LXC container

DEVELOPMENT.md

@@ -77,6 +77,13 @@ pyinstaller -F -n ubup main.py
 Release packages should be build on the oldest Ubuntu version supported by ubup
 to [ensure compatibility](https://pythonhosted.org/PyInstaller/usage.html#making-linux-apps-forward-compatible).
 
+To create a release binary in a LXC container, run:
+
+```bash
+./scripts/build_release.py <version>
+# Replace <version> with the version number (following semver)
+```
+
 ## Contributing
 
 Contributions in form of bug reports, feature proposals or pull requests are highly

scripts/build_release.py

@@ -0,0 +1,65 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+import os
+import subprocess
+
+import click
+
+import container_utils
+
+
+SOURCE_ROOT = os.path.abspath(os.path.dirname(os.path.dirname(__file__)))
+
+UBUNTU_RELEASE = 'xenial'  # 16.04
+RELEASE_ARCH = 'x86_64'
+
+
+def _build_release(release_version: str):
+    container_image = 'ubuntu:{}'.format(UBUNTU_RELEASE)
+    container_name = 'ubup-release-builder-{}'.format(UBUNTU_RELEASE)
+    subprocess.check_call(['lxc', 'launch', '-e', container_image, container_name])
+    try:
+        # Push the source code to the container
+        subprocess.check_call(['lxc', 'file', 'push', '-r', SOURCE_ROOT, container_name + '/root'])
+        container_utils.lxd_wait_for_network(container_name)
+        # Update and upgrade our fresh container
+        subprocess.check_call(['lxc', 'exec', container_name, '--', 'apt-get', 'update'])
+        subprocess.check_call(['lxc', 'exec', container_name, '--', 'apt-get', '-y', 'upgrade'])
+        # Install squashfs (required for snaps to work)
+        subprocess.check_call(['lxc', 'exec', container_name, '--',
+                               'apt-get', '-y', 'install', 'squashfuse'])
+        # Install Python and pip
+        subprocess.check_call(['lxc', 'exec', container_name, '--',
+                               'apt-get', '-y', 'install', 'python3', 'python3-pip'])
+        # Install ubup dependencies as well as pyinstaller
+        subprocess.check_call(['lxc', 'exec', container_name, '--',
+                               'pip3', 'install', 'click', 'ruamel.yaml', 'schema', 'progressbar2', 'pyinstaller'])
+        # Make a release build
+        subprocess.check_call(['lxc', 'exec', container_name, '--', 'bash', '-c',
+                               'cd /root/ubup && pyinstaller -F -n ubup main.py'])
+        # Fetch the release executable
+        os.makedirs(os.path.join(SOURCE_ROOT, 'dist'), exist_ok=True)
+        subprocess.check_call(['lxc', 'file', 'pull', container_name + '/root/ubup/dist/ubup',
+                               os.path.join(SOURCE_ROOT, 'dist', 'ubup-{}-{}-{}'.format(release_version,
+                                                                                        UBUNTU_RELEASE,
+                                                                                        RELEASE_ARCH))])
+
+        # Delete the container
+        subprocess.check_call(['lxc', 'delete', '-f', container_name])
+    except subprocess.CalledProcessError as e:
+        print('An error occurred, trying to destroy container ...')
+        subprocess.check_call(['lxc', 'delete', '-f', container_name])
+        print('Container destroyed.')
+        raise e
+
+
+@click.command()
+@click.argument('release_version')
+def main(release_version: str):
+    container_utils.check_is_lxd_installed()
+    _build_release(release_version)
+
+
+if __name__ == '__main__':
+    main()