ci: Bump OTP every two months when possible

Every two months, a scheduler will align the OTP matrix with Debian.

A token with workflow permission is needed.

GH issue: erlware#179
Link: https://packages.debian.org/search?keywords=erlang
Signed-off-by: Ariel Otilibili <[email protected]>

Author: ariel-anieli

.github/workflows/otp-bump.yml

@@ -0,0 +1,38 @@
+name: OTP bump
+
+on:
+  push:
+    branches:
+      - '*'
+
+jobs:
+  otp-bump:
+    name: Bump OTP versions
+    runs-on: ubuntu-latest
+
+    permissions: write-all
+
+    steps:
+    - uses: actions/checkout@master
+      with:
+        submodules: true
+
+    - name: Set up Python
+      uses: actions/setup-python@v5
+      with:
+        python-version: 3.12
+    - name: Setup dependencies
+      run: pip install requests beautifulsoup4
+    - name: Pull OTP versions from Debian
+      run: python3 bump-otp-matrix.py
+    - name: Create Pull Request
+      uses: peter-evans/create-pull-request@v7
+      with:
+        token: ${{ secrets.OTP_BUMP }}
+        delete-branch: true
+        commit-message: 'Bump OTP'
+        branch: 'create-pull-request/otp-bump'
+        title: 'OTP bump'
+        body: |
+          ### OTP bump
+          Aligned versions with [Debian](https://packages.debian.org/search?keywords=erlang).

bump-otp-matrix.py

@@ -0,0 +1,67 @@
+__author__ = "Ariel Otilibili <[email protected]>"
+__copyright__ = "Copyright (c) 2025 Ariel Otilibili"
+__license__ = "MIT "
+
+import json
+import requests
+import re
+
+from bs4 import BeautifulSoup
+
+URL = "https://packages.debian.org/search?keywords=erlang"
+WORKFLOW = ".github/workflows/main.yml"
+
+def get_webpage_in_html(url):
+    response = requests.get(url)
+    return BeautifulSoup(response.content)
+
+
+def get_latest_otp_versions(webpage):
+    # Samples of expected 'li' elements:
+    #
+    # <li class="bullseye"><a class="resultlink" href="/bullseye/erlang">bullseye (oldstable)</a> (interpreters):
+    #         Concurrent, real-time, distributed functional language
+    #
+    #       <br/>1:23.2.6+dfsg-1+deb11u2 [<strong class="pmarker" title="">security</strong>]: all
+    #
+    #
+    #     </li>
+    # <li class="bookworm"><a class="resultlink" href="/bookworm/erlang">bookworm (stable)</a> (interpreters):
+    #         Concurrent, real-time, distributed functional language
+    #
+    #       <br/>1:25.2.3+dfsg-1+deb12u1: all
+    #
+    #
+    #     </li>
+    HEADER = "Concurrent, real-time, distributed functional language"
+    OTP_REGEX = r"1:(\d+)"
+
+    versions = {
+        m.group(1)
+        for p in webpage.find_all("li")
+        if re.search(HEADER, p.text)
+        and not re.search("security", p.text)
+        and (m := re.search(OTP_REGEX, p.text))
+    }
+
+    return sorted(list(versions), reverse=True)
+
+
+def update_otp_versions(versions, workflow):
+    otp_versions = ', '.join(f"'{version}'" for version in versions)
+
+    with open(workflow) as ci:
+        conf = ci.read()
+
+    conf = re.sub("(otp_version: ).*\n", "\\1" + f"[{otp_versions}]" + "\n", conf)
+
+    with open(workflow, "w") as ci:
+        ci.write(conf)
+
+
+if __name__ == "__main__":
+    webpage = get_webpage_in_html(URL)
+    versions = get_latest_otp_versions(webpage)
+    update_otp_versions(versions, WORKFLOW)
+
+    print(json.dumps({'source': URL, 'versions': versions, 'file-changed': WORKFLOW}))