To recover from a failure or allow to quickly reset to known state we need to know with what playbook-commit the sever is installed. This commit saves the GIT hash/status when we run the playbook in a file called git_hash.yml. It also backs up that file by copying it to the target machine.

roles/matrix-base/defaults/main.yml

@@ -298,3 +298,7 @@ run_setup: true
 run_self_check: true
 run_start: true
 run_stop: true
+
+# Saves the git hash in a file called git_hash.yml 
+# Set this to false if GIT is not installed on the local system (the system where the ansible command is run on)
+git_save_hash: true

roles/matrix-base/tasks/setup_matrix_base.yml

@@ -19,6 +19,59 @@
     mode: '0660'
   when: "matrix_vars_yml_snapshotting_enabled | bool"
 
+- name: Save current git-repo status on the target to aid with restoring in case of problems
+  block:
+    - name: Get local git hash 
+      delegate_to: 127.0.0.1
+      become: false
+      register: git_describe
+      shell:
+        git describe
+            --always
+            --tags
+            --dirty
+            --long
+            --all
+
+    - set_fact: 
+        git_hash: "{{ git_describe.stdout }}"
+
+    - name: Git hash
+      debug:
+        msg: "Git hash: {{ git_hash }}"
+    
+    - name: Save git hash in git_hash.yml
+      become: false
+      local_action: 
+        copy
+        content="git_hash_last_run{{ ":" }} {{ git_hash }}\n"
+        dest="{{ matrix_vars_yml_snapshotting_src }}/git_hash.yml"
+
+    - name: Copy git_hash.yml file to target
+      copy:
+        src: "{{ matrix_vars_yml_snapshotting_src }}/git_hash.yml"
+        dest: "{{ matrix_base_data_path }}/git_hash.yml"
+        owner: "{{ matrix_user_username }}"
+        group: "{{ matrix_user_groupname }}"
+        mode: '0660'
+
+  rescue:
+    - name: GIT not found error
+      ansible.builtin.debug:
+        msg: >-
+          Couldn't find GIT on the local machine. Continuing without saving the GIT hash.
+          You can disable saving the GIT hash by setting 'git_save_hash: false' in vars.yml
+      when: "git_describe.stderr.find('not found') != -1"
+
+    - name: GIT hash error
+      ansible.builtin.fail:
+        msg: >-
+          Error when trying to get the GIT hash.
+          You can disable saving the GIT hash by setting 'git_save_hash: false' in vars.yml
+      when: "git_describe.stderr.find('not found') == -1"
+
+  when: "matrix_vars_yml_snapshotting_enabled|bool and git_save_hash|bool"
+
 - name: Ensure Matrix network is created in Docker
   community.docker.docker_network:
     name: "{{ matrix_docker_network }}"