diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 6438b33882..bad15c639a 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -421,6 +421,14 @@ coccinelle:
     - util/check-cocci
     - if test "$(git status --porcelain | grep -Ev '\?\?' | wc -l)" -gt "0"; then git status --short; exit 1; fi
 
+danger:
+  <<: *precheck_job
+  needs: []
+  script:
+    - danger-python ci -f
+  only:
+    - merge_requests
+
 flake8:
   <<: *default_triggering_rules
   <<: *base_image
@@ -430,7 +438,7 @@ flake8:
       artifacts: true
   script:
     - *configure
-    - flake8 --max-line-length=80 $(git ls-files '*.py' | grep -v 'ans\.py')
+    - flake8 --max-line-length=80 $(git ls-files '*.py' | grep -vE '(ans\.py|dangerfile\.py)')
   only:
     - merge_requests
 
@@ -444,7 +452,7 @@ pylint:
   script:
     - *configure
     - PYTHONPATH="$PYTHONPATH:$CI_PROJECT_DIR/bin/python"
-    - pylint --rcfile $CI_PROJECT_DIR/.pylintrc $(git ls-files '*.py' | grep -v 'ans\.py')
+    - pylint --rcfile $CI_PROJECT_DIR/.pylintrc $(git ls-files '*.py' | grep -vE '(ans\.py|dangerfile\.py)')
   only:
     - merge_requests
 
diff --git a/dangerfile.py b/dangerfile.py
new file mode 100644
index 0000000000..b017c6aee9
--- /dev/null
+++ b/dangerfile.py
@@ -0,0 +1,194 @@
+############################################################################
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+############################################################################
+
+import re
+
+# Helper functions and variables
+
+def added_lines(target_branch, paths):
+    import subprocess
+    subprocess.check_output(['/usr/bin/git', 'fetch', '--depth', '1', 'origin',
+                             f'{target_branch}:{target_branch}'])
+    diff = subprocess.check_output(['/usr/bin/git', 'diff',
+                                    f'{target_branch}..', '--'] + paths)
+    added_lines = []
+    for line in diff.splitlines():
+        if line.startswith(b'+'):
+            added_lines.append(line)
+    return added_lines
+
+issue_or_mr_id_regex = re.compile(br'\[(GL [#!]|RT #)[0-9]+\]')
+release_notes_regex = re.compile(r'doc/(arm|notes)/notes-.*\.(rst|xml)')
+
+modified_files = danger.git.modified_files
+mr_labels = danger.gitlab.mr.labels
+target_branch = danger.gitlab.mr.target_branch
+
+###############################################################################
+# COMMIT MESSAGES
+###############################################################################
+#
+# - FAIL if any of the following is true for any commit on the MR branch:
+#
+#     * The subject line starts with "fixup!" or "Apply suggestion".
+#
+#     * There is no empty line between the subject line and the log message.
+#
+# - WARN if any of the following is true for any commit on the MR branch:
+#
+#     * The length of the subject line exceeds 72 characters.
+#
+#     * There is no log message present (i.e. commit only has a subject).
+#
+#     * Any line of the log message is longer than 72 characters.  This rule is
+#       not evaluated for lines starting with four spaces, which allows long
+#       lines to be included in the commit log message by prefixing them with
+#       four spaces (useful for pasting compiler warnings, static analyzer
+#       messages, log lines, etc.)
+
+for commit in danger.git.commits:
+    message_lines = commit.message.splitlines()
+    subject = message_lines[0]
+    if subject.startswith('fixup!') or subject.startswith('Apply suggestion'):
+        fail('Fixup commits are still present in this merge request. '
+             'Please squash them before merging.')
+    if len(subject) > 72:
+        warn(
+            f'Subject line for commit {commit.sha} is too long: '
+            f'```{subject}``` ({len(subject)} > 72 characters).'
+        )
+    if len(message_lines) > 1 and message_lines[1]:
+        fail(f'No empty line after subject for commit {commit.sha}.')
+    if len(message_lines) < 3 and not subject.startswith('fixup! '):
+        warn(f'Please write a log message for commit {commit.sha}.')
+    for line in message_lines[2:]:
+        if len(line) > 72 and not line.startswith('    '):
+            warn(
+                f'Line too long in log message for commit {commit.sha}: '
+                f'```{line}``` ({len(line)} > 72 characters).'
+            )
+
+###############################################################################
+# MILESTONE
+###############################################################################
+#
+# FAIL if the merge request is not assigned to any milestone.
+
+if not danger.gitlab.mr.milestone:
+    fail('Please assign this merge request to a milestone.')
+
+###############################################################################
+# VERSION LABELS
+###############################################################################
+#
+# FAIL if any of the following is true for the merge request:
+#
+# * The "Backport" label is set and the number of version labels set is
+#   different than 1.  (For backports, the version label is used for indicating
+#   its target branch.  This is a rather ugly attempt to address a UI
+#   deficiency - the target branch for each MR is not visible on milestone
+#   dashboards.)
+#
+# * Neither the "Backport" label nor any version label is set.  (If the merge
+#   request is not a backport, version labels are used for indicating
+#   backporting preferences.)
+
+backport_label_set = 'Backport' in mr_labels
+version_labels = [l for l in mr_labels if l.startswith('v9.')]
+if backport_label_set and len(version_labels) != 1:
+    fail('The *Backport* label is set for this merge request. '
+         'Please also set exactly one version label (*v9.x*).')
+if not backport_label_set and not version_labels:
+    fail('If this merge request is a backport, set the *Backport* label and '
+         'a single version label (*v9.x*) indicating the target branch. '
+         'If not, set version labels for all targeted backport branches.')
+
+###############################################################################
+# OTHER LABELS
+###############################################################################
+#
+# WARN if any of the following is true for the merge request:
+#
+# * The "Review" label is not set.  (It may be intentional, but rarely is.)
+#
+# * The "Review" label is set, but the "LGTM" label is not set.  (This aims to
+#   remind developers about the need to set the latter on merge requests which
+#   passed review.)
+
+if 'Review' not in mr_labels:
+    warn('This merge request does not have the *Review* label set. '
+         'Please set it if you would like the merge request to be reviewed.')
+elif 'LGTM (Merge OK)' not in mr_labels:
+    warn('This merge request is currently in review. '
+         'It should not be merged until it is marked with the *LGTM* label.')
+
+###############################################################################
+# 'CHANGES' FILE
+###############################################################################
+#
+# FAIL if any of the following is true:
+#
+# * The merge request does not update the CHANGES file, but it does not have
+#   the "No CHANGES" label set.  (This attempts to ensure that the author of
+#   the MR did not forget about adding a CHANGES entry.)
+#
+# * The merge request updates the CHANGES file, but it has the "No CHANGES"
+#   label set.  (This attempts to ensure the the "No CHANGES" label is used in
+#   a sane way.)
+#
+# * The merge request adds a new CHANGES entry that does not contain any
+#   GitLab/RT issue/MR identifiers.
+
+changes_modified = 'CHANGES' in modified_files
+no_changes_label_set = 'No CHANGES' in mr_labels
+if not changes_modified and not no_changes_label_set:
+    fail('This merge request does not modify `CHANGES`. '
+         'Add a `CHANGES` entry or set the *No CHANGES* label.')
+if changes_modified and no_changes_label_set:
+    fail('This merge request modifies `CHANGES`. '
+         'Revert `CHANGES` modifications or unset the *No Changes* label.')
+
+changes_added_lines = added_lines(target_branch, ['CHANGES'])
+identifiers_found = filter(issue_or_mr_id_regex.search, changes_added_lines)
+if changes_added_lines and not any(identifiers_found):
+    fail('No valid issue/MR identifiers found in added `CHANGES` entries.')
+
+###############################################################################
+# RELEASE NOTES
+###############################################################################
+#
+# - FAIL if any of the following is true:
+#
+#     * The merge request does not update release notes and has the "Release
+#       Notes" label set.  (This attempts to point out missing release notes.)
+#
+#     * The merge request updates release notes but does not have the "Release
+#       Notes" label set.  (This ensures that merge requests updating release
+#       notes can be easily found using the "Release Notes" label.)
+#
+# - WARN if this merge request updates release notes, but no GitLab/RT issue/MR
+#   identifiers are found in the lines added to the release notes by this MR.
+
+release_notes_regex = re.compile(r'doc/(arm|notes)/notes-.*\.(rst|xml)')
+release_notes_changed = list(filter(release_notes_regex.match, modified_files))
+release_notes_label_set = 'Release Notes' in mr_labels
+if not release_notes_changed and release_notes_label_set:
+    fail('This merge request has the *Release Notes* label set. '
+         'Add a release note or unset the *Release Notes* label.')
+if release_notes_changed and not release_notes_label_set:
+    fail('This merge request modifies release notes. '
+         'Revert release note modifications or set the *Release Notes* label.')
+
+if release_notes_changed:
+    notes_added_lines = added_lines(target_branch, release_notes_changed)
+    identifiers_found = filter(issue_or_mr_id_regex.search, notes_added_lines)
+    if notes_added_lines and not any(identifiers_found):
+        warn('No valid issue/MR identifiers found in added release notes.')
diff --git a/util/copyrights b/util/copyrights
index 347e19ef83..cc34a7a4ea 100644
--- a/util/copyrights
+++ b/util/copyrights
@@ -1111,6 +1111,7 @@
 ./contrib/scripts/named-bootconf.sh		SH.PORTION	1999,2000,2001,2004,2006,2007,2012,2014,2016,2018,2019,2020
 ./contrib/scripts/nanny.pl			PERL	2000,2001,2004,2007,2012,2014,2016,2018,2019,2020
 ./contrib/scripts/zone-edit.sh.in		SH	2010,2012,2014,2016,2018,2019,2020
+./dangerfile.py					PYTHON	2020
 ./doc/arm/advanced.rst				RST	2020
 ./doc/arm/catz.rst				RST	2020
 ./doc/arm/conf.py				PYTHON	2020