Merge pull request #6160 from guggero/docker-nightly-build

github: add schedule for nightly docker build

.github/workflows/docker.yml

@@ -4,6 +4,9 @@ on:
   push:
     tags:
       - 'v*'
+  schedule:
+    # Every day at midnight (UTC).
+    - cron: '0 0 * * *'
 
 defaults:
   run:
@@ -31,6 +34,10 @@ jobs:
 
       - name: Set env
         run: echo "RELEASE_VERSION=${GITHUB_REF#refs/*/}" >> $GITHUB_ENV
+      
+      - name: Set daily tag
+        if: github.event.schedule == '0 0 * * *'
+        run: echo "RELEASE_VERSION=daily-testing-only" >> $GITHUB_ENV
 
       - name: Build and push
         id: docker_build

docs/release-notes/release-notes-0.15.0.md

@@ -48,6 +48,9 @@
   in review because of unmet contribution guideline
   requirements](https://github.com/lightningnetwork/lnd/pull/6080).
 
+* [A nightly build of the `lnd` docker image is now created
+  automatically](https://github.com/lightningnetwork/lnd/pull/6160).
+
 ## RPC Server
 
 * [Add value to the field