docs_deploy.yml - update to create backup and always be single release (#24781)

* docs_deploy.yml - update to create backup and always be single release

* Add build time variable to make it easier to confirm last successful deploy

.github/workflows/docs_deploy.yml

@@ -79,16 +79,21 @@ jobs:
 
       - name: Deploy
         run: |
-          git clone --single-branch --branch main https://${{ secrets.PX4BUILTBOT_PERSONAL_ACCESS_TOKEN }}@github.com/PX4/docs.px4.io.git
+          git clone --single-branch --branch main --depth 1 https://${{ secrets.PX4BUILTBOT_PERSONAL_ACCESS_TOKEN }}@github.com/PX4/docs.px4.io.git
+          CURRENT_DATETIME=$(date +'%Y%m%d_%H_%M')
+          # make it an orphan branch
+          git checkout --orphan "${CURRENT_DATETIME}_main"
           rm -rf docs.px4.io/${BRANCH_NAME}
           mkdir -p docs.px4.io/${BRANCH_NAME}
           cp -r ~/_book/* docs.px4.io/${BRANCH_NAME}/
           cd docs.px4.io
           git config --global user.name "${{ secrets.PX4BUILDBOT_USER }}"
           git config --global user.email "${{ secrets.PX4BUILDBOT_EMAIL }}"
-          git add ${BRANCH_NAME}
+          git add .
           git commit -a -m "PX4 docs build update (vitepress) `date`"
-          #git add .
-          #git commit --amend -m "PX4 docs build update (vitepress) `date`"
-          #git commit --allow-empty -m "Empty commit to force rebuild"
+          # push branch as backup
+          git push origin "${CURRENT_DATETIME}_main"
+          # Now make main from backup and push updated
+          git branch -D main
+          git checkout -b main
           git push origin main -f

docs/.vitepress/theme/index.js

@@ -37,6 +37,10 @@ export default {
     //Tabs: https://github.com/Red-Asuka/vitepress-plugin-tabs
     app.component("Tab", Tab);
     app.component("Tabs", Tabs);
+    // Global build time variable
+    app.config.globalProperties.$buildTime = JSON.stringify(
+      new Date().toISOString()
+    );
   },
 
   // to support medium zoom: https://github.com/vuejs/vitepress/issues/854

docs/en/index.md

@@ -137,3 +137,5 @@ The PX4 flight stack is hosted under the governance of the [Dronecode Project](h
 <a href="https://www.linuxfoundation.org/projects" style="padding:20px;"><img src="https://mavlink.io/assets/site/logo_linux_foundation.png" alt="Linux Foundation Logo" width="80px" /></a>
 
 <div style="padding:10px">&nbsp;</div>
+
+Doc build time: {{ $buildTime }}