gitlab: convert to shared container for DCO check

This removes the locally maintained DCO checking script in favour of the
shared container image provided by libvirt-ci.git.
Reviewed-by: NAndrea Bolognani <abologna@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

.gitlab-ci.yml

@@ -221,18 +221,15 @@ potfile:
       - libvirt.pot
 
 
-# Check that all commits are signed-off for the DCO. Skip
-# on master branch and -maint branches, since we only need
-# to test developer's personal branches.
-dco:
+# Check that all commits are signed-off for the DCO.
+# Skip on "libvirt" namespace, since we only need to run
+# this test on developer's personal forks from which
+# merge requests are submitted
+check-dco:
   stage: prebuild
-  image: quay.io/libvirt/buildenv-libvirt-fedora-31:latest
-  before_script:
-    - *script_variables
+  image: registry.gitlab.com/libvirt/libvirt-ci/check-dco:master
   script:
-    - ./scripts/require-dco.py
-  only:
-    - branches
+    - /check-dco
   except:
-    - /^v.*-maint$/
-    - master
+    variables:
+      - $CI_PROJECT_NAMESPACE == 'libvirt'

scripts/require-dco.py

-#!/usr/bin/env python3
-
-# require-dco.py: validate all commits are signed off
-#
-# Copyright (C) 2020 Red Hat, Inc.
-#
-# This library is free software; you can redistribute it and/or
-# modify it under the terms of the GNU Lesser General Public
-# License as published by the Free Software Foundation; either
-# version 2.1 of the License, or (at your option) any later version.
-#
-# This library 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
-# Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public
-# License along with this library.  If not, see
-# <http://www.gnu.org/licenses/>.
-
-import os
-import os.path
-import sys
-import subprocess
-
-cwd = os.getcwd()
-reponame = os.path.basename(cwd)
-repourl = "https://gitlab.com/libvirt/%s.git" % reponame
-
-subprocess.check_call(["git", "remote", "add", "dcocheck", repourl])
-subprocess.check_call(["git", "fetch", "dcocheck", "master"],
-                      stdout=subprocess.DEVNULL,
-                      stderr=subprocess.DEVNULL)
-
-ancestor = subprocess.check_output(["git", "merge-base", "dcocheck/master", "HEAD"],
-                                   universal_newlines=True)
-
-ancestor = ancestor.strip()
-
-subprocess.check_call(["git", "remote", "rm", "dcocheck"])
-
-errors = False
-
-print("\nChecking for 'Signed-off-by: NAME <EMAIL>' on all commits since %s...\n" % ancestor)
-
-log = subprocess.check_output(["git", "log", "--format=%H %s", ancestor + "..."],
-                              universal_newlines=True)
-
-if log == "":
-    commits = []
-else:
-    commits = [[c[0:40], c[41:]] for c in log.strip().split("\n")]
-
-for sha, subject in commits:
-
-    msg = subprocess.check_output(["git", "show", "-s", sha],
-                                  universal_newlines=True)
-    lines = msg.strip().split("\n")
-
-    print("🔍 %s %s" % (sha, subject))
-    sob = False
-    for line in lines:
-        if "Signed-off-by:" in line:
-            sob = True
-            if "localhost" in line:
-                print("    ❌ FAIL: bad email in %s" % line)
-                errors = True
-
-    if not sob:
-        print("    ❌ FAIL missing Signed-off-by tag")
-        errors = True
-
-if errors:
-    print("""
-
-❌ ERROR: One or more commits are missing a valid Signed-off-By tag.
-
-
-This project requires all contributors to assert that their contributions
-are provided in compliance with the terms of the Developer's Certificate
-of Origin 1.1 (DCO):
-
-  https://developercertificate.org/
-
-To indicate acceptance of the DCO every commit must have a tag
-
-  Signed-off-by: REAL NAME <EMAIL>
-
-This can be achieved by passing the "-s" flag to the "git commit" command.
-
-To bulk update all commits on current branch "git rebase" can be used:
-
-  git rebase -i master -x 'git commit --amend --no-edit -s'
-
-""")
-
-    sys.exit(1)
-
-sys.exit(0)