Github CI: Step to use /mnt for docker storage. (#401)

Author: jmontesi

.github/workflows/pre-main.yml

@@ -65,6 +65,20 @@ jobs:
       PFLT_DOCKERCONFIG: '/home/runner/.docker/config'
 
     steps:
+      # Restart docker using /mnt/docker-storage (sdb) instead of /var/lib/docker (sda).
+      # This step needs to be done right after the partner repo's bootstrap scripts, as they
+      # overwrite the docker's daemon.json.
+      - name: Make docker to use /mnt (sdb) for storage
+        run: |
+          df -h
+          lsblk
+          sudo mkdir /mnt/docker-storage
+          sudo jq '.  +={"data-root" : "/mnt/docker-storage"}' < /etc/docker/daemon.json > /tmp/docker-daemon.json
+          sudo cp /tmp/docker-daemon.json /etc/docker/daemon.json
+          cat /etc/docker/daemon.json
+          sudo systemctl restart docker
+          sudo ls -la /mnt/docker-storage
+
       - name: Set up Go 1.21
         uses: actions/setup-go@v5
         with: