[EDGEPOD-226] Add installing strongswan to router role

Also fixed ansible-lint failures

Change-Id: I78fbab0a9e2f45ea4f5989c255f09b47ef01bdcc
diff --git a/aether-playbook/roles/router/linux/templates/etc/ipsec.conf.j2 b/aether-playbook/roles/router/linux/templates/etc/ipsec.conf.j2
new file mode 100644
index 0000000..29acef9
--- /dev/null
+++ b/aether-playbook/roles/router/linux/templates/etc/ipsec.conf.j2
@@ -0,0 +1,42 @@
+# 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.
+
+# basic configuration
+config setup
+    # strictcrlpolicy=yes
+    # uniqueids = no
+
+conn %default
+    ikelifetime=600m # 36,000s
+    keylife=180m # 10,800s
+    rekeymargin=3m
+    keyingtries=3
+    keyexchange=ikev2
+    mobike=no
+    ike=aes256gcm16-sha512-modp2048
+    esp=aes256gcm16-sha512-modp8192
+    authby=psk
+
+conn peer-aether-gcp-vpn-gateway
+    left={{ vpn_local_addr }}
+    leftid={{ vpn_local_id }}
+    leftsubnet={{ vpn_local_subnets }}
+    leftauth=psk
+    right={{ vpn_remote_addr }}
+    rightsubnet={{ vpn_remote_subnets }}
+    rightauth=psk
+    auto=start
+    type=tunnel
+    dpdaction=restart
+    closeaction=restart
diff --git a/aether-playbook/roles/router/linux/templates/etc/ipsec.secrets.j2 b/aether-playbook/roles/router/linux/templates/etc/ipsec.secrets.j2
new file mode 100644
index 0000000..b60cff9
--- /dev/null
+++ b/aether-playbook/roles/router/linux/templates/etc/ipsec.secrets.j2
@@ -0,0 +1,15 @@
+# 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.
+
+{{ vpn_local_addr}} {{ vpn_remote_addr }} : PSK "{{ vpn_psk }}"
\ No newline at end of file