diff --git a/docs/roles/_init.md b/docs/roles/_init.md
index 8d4fa92e..a1e37f95 100644
--- a/docs/roles/_init.md
+++ b/docs/roles/_init.md
@@ -27,6 +27,9 @@ bin_directory: "/home/{{ deploy_user }}/.bin"
 # Number of dumps/db to look up for cleanup.
 cleanup_history_depth: 50
 install_php_cachetool: true # set to false if you don't need cachetool, e.g. for a nodejs app
+ce_deploy_version: 1.x
+lock_file: /tmp/ce-deploy-lock
+provision_lock_file: /tmp/ce-provision-lock # must match _init.lock_file in ce-provision
 # AWS ASG variables to allow for the suspension of autoscaling during a code deployment.
 aws_asg:
   name: "" # if the deploy is on an ASG put the name here
diff --git a/docs/roles/database_backup/database_backup-mysql.md b/docs/roles/database_backup/database_backup-mysql.md
index 2766a4f3..f23c9c34 100644
--- a/docs/roles/database_backup/database_backup-mysql.md
+++ b/docs/roles/database_backup/database_backup-mysql.md
@@ -24,6 +24,8 @@ mysql_backup:
   mysqldump_params: "{{ _mysqldump_params }}" # set in _init but you can override here
   # Location on deploy server where the generated MySQL password will be stashed - should be temporary storage
   mysql_password_path: "/tmp/.ce-deploy/{{ project_name }}_{{ build_type }}_{{ build_number }}"
+  # Uncomment to login with MySQL socket instead of TCP/IP (e.g. for MariaDB after secure set-up)
+  #mysql_unix_socket: /run/mysqld/mysqld.sock
   # Number of dumps/db to keep. Note this is independant from the build codebases.
   keep: 10
   # This can be one of the following:
diff --git a/roles/_exit/tasks/main.yml b/roles/_exit/tasks/main.yml
index 0ba2da27..640f3a18 100644
--- a/roles/_exit/tasks/main.yml
+++ b/roles/_exit/tasks/main.yml
@@ -7,3 +7,8 @@
   when:
     - aws_asg.name is defined
     - aws_asg.name | length > 0
+
+- name: Delete the lock file.
+  ansible.builtin.file:
+    path: "{{ lock_file }}"
+    state: absent
diff --git a/roles/_init/README.md b/roles/_init/README.md
index 8d4fa92e..a1e37f95 100644
--- a/roles/_init/README.md
+++ b/roles/_init/README.md
@@ -27,6 +27,9 @@ bin_directory: "/home/{{ deploy_user }}/.bin"
 # Number of dumps/db to look up for cleanup.
 cleanup_history_depth: 50
 install_php_cachetool: true # set to false if you don't need cachetool, e.g. for a nodejs app
+ce_deploy_version: 1.x
+lock_file: /tmp/ce-deploy-lock
+provision_lock_file: /tmp/ce-provision-lock # must match _init.lock_file in ce-provision
 # AWS ASG variables to allow for the suspension of autoscaling during a code deployment.
 aws_asg:
   name: "" # if the deploy is on an ASG put the name here
diff --git a/roles/_init/defaults/main.yml b/roles/_init/defaults/main.yml
index 7f06f695..00c14563 100644
--- a/roles/_init/defaults/main.yml
+++ b/roles/_init/defaults/main.yml
@@ -8,6 +8,9 @@ bin_directory: "/home/{{ deploy_user }}/.bin"
 # Number of dumps/db to look up for cleanup.
 cleanup_history_depth: 50
 install_php_cachetool: true # set to false if you don't need cachetool, e.g. for a nodejs app
+ce_deploy_version: 1.x
+lock_file: /tmp/ce-deploy-lock
+provision_lock_file: /tmp/ce-provision-lock # must match _init.lock_file in ce-provision
 # AWS ASG variables to allow for the suspension of autoscaling during a code deployment.
 aws_asg:
   name: "" # if the deploy is on an ASG put the name here
diff --git a/roles/_init/tasks/main.yml b/roles/_init/tasks/main.yml
index 680ba19f..1b53f4b2 100644
--- a/roles/_init/tasks/main.yml
+++ b/roles/_init/tasks/main.yml
@@ -1,4 +1,35 @@
 ---
+- name: Version check.
+  ansible.builtin.debug:
+    msg: "Using ce-deploy {{ ce_deploy_version }}"
+
+- name: Check for a ce-provision lock file.
+  ansible.builtin.stat:
+    path: "{{ provision_lock_file }}"
+  register: _ce_provision_lock
+
+- name: Abort if ce-provision lock file exists.
+  when: _ce_provision_lock.stat.exists is defined and _ce_provision_lock.stat.exists
+  block:
+    - name: Abort if ce-provision lock file is found.
+      ansible.builtin.debug:
+        msg: "ce-provision lock file discovered, an infrastructure build is in progress! If this is not the case, login to the affected server and delete the file at {{ provision_lock_file }}."
+    - ansible.builtin.meta: end_play
+
+- name: Check OS family.
+  when: ansible_os_family == "Windows"
+  block:
+    - name: Abort if target is a Windows server.
+      ansible.builtin.debug:
+        msg: "ce-deploy currently only supports Linux like operating systems, and works best with Debian Linux."
+    - ansible.builtin.meta: end_play
+
+- name: Set a lock file.
+  ansible.builtin.file:
+    path: "{{ lock_file }}"
+    state: touch
+    mode: 0644
+
 # Ensure default values for common variables.
 - name: Define deploy user.
   ansible.builtin.set_fact:
diff --git a/roles/database_backup/database_backup-mysql/README.md b/roles/database_backup/database_backup-mysql/README.md
index 2766a4f3..f23c9c34 100644
--- a/roles/database_backup/database_backup-mysql/README.md
+++ b/roles/database_backup/database_backup-mysql/README.md
@@ -24,6 +24,8 @@ mysql_backup:
   mysqldump_params: "{{ _mysqldump_params }}" # set in _init but you can override here
   # Location on deploy server where the generated MySQL password will be stashed - should be temporary storage
   mysql_password_path: "/tmp/.ce-deploy/{{ project_name }}_{{ build_type }}_{{ build_number }}"
+  # Uncomment to login with MySQL socket instead of TCP/IP (e.g. for MariaDB after secure set-up)
+  #mysql_unix_socket: /run/mysqld/mysqld.sock
   # Number of dumps/db to keep. Note this is independant from the build codebases.
   keep: 10
   # This can be one of the following: