Add role for adding docker nodes to swarm

roles/swarm/tasks/main.yaml

@@ -0,0 +1,18 @@
+---
+- name: Install Docker
+  ansible.builtin.import_tasks: install.yaml
+
+- name: Configure Docker
+  ansible.builtin.import_tasks: configure.yaml
+
+# This taskfile will set two facts that will be used in subsequent tasks:
+# * _docker_swarm_needs_join: a boolean indicating whether the host needs to be joined to the swarm
+#   or is already joined
+# * _docker_swarm_manager: the inventory hostname of a swarm manager that can be delegated to to
+#   fetch swarm joining info
+- name: Check swarm state ahead of swarm configuration
+  ansible.builtin.import_tasks: check.yaml
+
+- name: Join server to swarm
+  when: _docker_swarm_needs_join
+  ansible.builtin.include_tasks: join.yaml