Add Drone Discord changelog pipeline and test notification

tools/check.py

@@ -8,6 +8,7 @@ from prefab_identity import check_prefabs
 ROOT=Path(__file__).resolve().parents[1]
 BASE='58D0FB3206B6F859'
 def check():
+ subprocess.run([sys.executable,'-m','unittest','discover','-s',str(ROOT/'tests'),'-p','test_discord_changelog_ci.py'],check=True)
  subprocess.run([sys.executable,str(ROOT/'tests/test_terrain_controller_init.py')],check=True)
  subprocess.run([sys.executable,str(ROOT/'tests/test_terrain_chat_retention.py')],check=True)
  subprocess.run([sys.executable,str(ROOT/'tests/test_empty_server_restart.py')],check=True)

tools/discord_changelog_ci.py

@@ -0,0 +1,136 @@
+#!/usr/bin/env python3
+"""Send the newest changed CHANGELOG.md entry for a Drone main-branch push."""
+import argparse
+import json
+import os
+from pathlib import Path
+import re
+import subprocess
+import sys
+import urllib.error
+import urllib.parse
+import urllib.request
+
+ROOT = Path(__file__).resolve().parents[1]
+CHANGELOG = 'CHANGELOG.md'
+
+
+class ChangelogError(Exception):
+    pass
+
+
+class NoRedirect(urllib.request.HTTPRedirectHandler):
+    def redirect_request(self, req, fp, code, msg, headers, newurl):
+        return None
+
+
+def sections(text):
+    """Entries start at level-two headings; level-three headings stay inside."""
+    headings = list(re.finditer(r'^## ([^\r\n]+)\r?$', text, re.MULTILINE))
+    result = []
+    for index, heading in enumerate(headings):
+        end = headings[index + 1].start() if index + 1 < len(headings) else len(text)
+        title = heading[1].strip()
+        content = text[heading.end():end].strip().replace('\r\n', '\n')
+        if title in [item[0] for item in result]:
+            raise ChangelogError('Changelog entry headings must be unique.')
+        result.append((title, content))
+    return result
+
+
+def latest_changes(before, after):
+    old, new = sections(before), sections(after)
+    if not new or not new[0][1]:
+        raise ChangelogError('CHANGELOG.md needs a nonempty newest ## entry.')
+    latest = new[0]
+    if old and (latest == old[0] or latest[0] in [title for title, _ in old[1:]]):
+        return None  # Unchanged newest entry, or removal/reordering of old entries.
+    message = '**' + latest[0] + '**\n\n' + latest[1]
+    if len(message.encode('utf-16-le')) // 2 > 2000:
+        raise ChangelogError('Newest changelog entry exceeds Discord’s 2000-character limit.')
+    return message
+
+
+def git(repo, *args):
+    result = subprocess.run(['git', *args], cwd=repo, text=True,
+                            stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    if result.returncode:
+        raise ChangelogError('Required Git history is unavailable; no changelog sent.')
+    return result.stdout
+
+
+def commit(value):
+    if not re.fullmatch(r'[0-9a-fA-F]{40}|[0-9a-fA-F]{64}', value or ''):
+        raise ChangelogError('Drone must provide complete before/after commit IDs.')
+    return value.lower()
+
+
+def at_revision(repo, sha):
+    git(repo, 'cat-file', '-e', sha + '^{commit}')
+    if not git(repo, 'ls-tree', '--name-only', sha, '--', CHANGELOG).strip():
+        return ''
+    return git(repo, 'show', sha + ':' + CHANGELOG)
+
+
+def prepare(repo, env):
+    if env.get('DRONE_BUILD_EVENT') != 'push' or env.get('DRONE_COMMIT_BRANCH') != 'main':
+        return None
+    before = commit(env.get('DRONE_COMMIT_BEFORE'))
+    after = commit(env.get('DRONE_COMMIT_SHA'))
+    if git(repo, 'rev-parse', 'HEAD').strip() != after:
+        raise ChangelogError('Checkout does not match the pushed commit; no changelog sent.')
+    previous = ''
+    if set(before) != {'0'}:
+        try:
+            git(repo, 'cat-file', '-e', before + '^{commit}')
+        except ChangelogError:
+            # A force-push may leave the before commit outside the cloned history.
+            git(repo, 'fetch', '--no-tags', 'origin', before)
+        previous = at_revision(repo, before)
+    return latest_changes(previous, at_revision(repo, after))
+
+
+def send(message, webhook):
+    parsed = urllib.parse.urlsplit(webhook)
+    if (parsed.scheme != 'https' or parsed.netloc != 'discord.com'
+            or not re.fullmatch(r'/api/webhooks/[0-9]+/[A-Za-z0-9_-]+', parsed.path)
+            or parsed.query or parsed.fragment):
+        raise ChangelogError('Set the Drone secret discord_webhook_url to a Discord webhook URL.')
+    payload = json.dumps({'content': message, 'allowed_mentions': {'parse': []}}).encode()
+    request = urllib.request.Request(webhook + '?wait=true', data=payload, headers={
+        'Content-Type': 'application/json', 'User-Agent': 'EscapistsReintroduced-Changelog/1.0'})
+    # Never retry automatically: a lost response may still mean Discord accepted it.
+    try:
+        with urllib.request.build_opener(NoRedirect()).open(request, timeout=30) as response:
+            result = json.load(response)
+        if not isinstance(result, dict) or not result.get('id'):
+            raise ValueError('Missing confirmation')
+    except urllib.error.HTTPError as error:
+        raise ChangelogError('Discord returned HTTP ' + str(error.code)
+                             + '; inspect delivery before rerunning.') from None
+    except (urllib.error.URLError, OSError, ValueError):
+        raise ChangelogError('Discord delivery could not be confirmed; inspect Discord before rerunning.') from None
+
+
+def main(argv=None):
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument('--dry-run', action='store_true', help='Print the selected entry without sending it')
+    args = parser.parse_args(argv)
+    try:
+        message = prepare(ROOT, os.environ)
+        if message is None:
+            print('No new changelog entry to send.')
+        elif args.dry_run:
+            print(message)
+        else:
+            send(message, os.environ.get('DISCORD_WEBHOOK_URL', '').strip())
+            print('Discord changelog delivered.')
+    except (ChangelogError, ValueError) as error:
+        # URL parsing errors may contain secrets; only our own messages are safe.
+        print(str(error) if isinstance(error, ChangelogError) else 'Invalid webhook configuration.', file=sys.stderr)
+        return 1
+    return 0
+
+
+if __name__ == '__main__':
+    sys.exit(main())