[EDGEPOD-226] Add installing strongswan to router role

Also fixed ansible-lint failures

Change-Id: I78fbab0a9e2f45ea4f5989c255f09b47ef01bdcc
diff --git a/aether-playbook/roles/router/linux/tasks/ipsec-vpn.yml b/aether-playbook/roles/router/linux/tasks/ipsec-vpn.yml
new file mode 100644
index 0000000..86e7c30
--- /dev/null
+++ b/aether-playbook/roles/router/linux/tasks/ipsec-vpn.yml
@@ -0,0 +1,45 @@
+# Copyright 2020-present Open Networking Foundation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+---
+- name: Run "apt update"
+  apt:
+    update_cache: yes
+  tags: vpn
+
+- name: Install strongSwan
+  apt:
+    name: strongswan
+    state: present
+  tags: vpn
+
+- name: Start strongSwan
+  service:
+    name: strongswan
+    state: started
+    enabled: yes
+  tags: vpn
+
+- name: Create ipsec config and secrets file
+  template:
+    src: "{{ item.src }}"
+    dest: "{{ item.dest }}"
+    owner: root
+    group: root
+    mode: 0640
+  loop:
+    - { src: 'etc/ipsec.secrets.j2', dest: '/etc/ipsec.secrets' }
+    - { src: 'etc/ipsec.conf.j2', dest: '/etc/ipsec.conf' }
+  notify: ipsec restart
+  tags: vpn