====================
openvpn3-service-aws
====================

---------------------------------------------
OpenVPN 3 Linux - AWS VPC integration service
---------------------------------------------

:Manual section: 8
:Manual group: OpenVPN 3 Linux

SYNOPSIS
========
| ``openvpn3-service-aws`` ``[OPTIONS]``
| ``openvpn3-service-aws`` ``-h`` | ``--help``

DESCRIPTION
===========
The ``openvpn3-service-aws`` is a backend service for OpenVPN 3 Linux,
which enables hosts in VPN subnet to communicate to hosts in VPC subnet.
Upon start, it reads its configuration file and subscribes to
:code:`ROUTE_ADDED` and :code:`ROUTE_REMOVED` signals from
``openvpn3-service-netcfg`` service.  On receiving those signals, service
adds/deletes VPN routes to/from VPC subnet using Amazon EC2 API.

This service is normally started automatically on boot, which is achieved by enabling it
with provided **openvpn3-aws.service** *systemd* unit file.  Alternatively service could
be started manually on the command line.  This process should run as the *@OPENVPN_USERNAME@* user
and will automatically switch to this user account if it has the needed privileges to do so.
Beware that changing this to another user account also requires updating the D-Bus policy
for the ``net.openvpn.v3.aws`` service as well.

CONFIGURATION
=============
To use Amazon EC2 API, service uses temporary security credentials, which are retrieved from
instance metadata.  Credentials are tied to an IAM role, which must be assigned to the EC2
instance where the service is running.

Below is a part of a CloudFormation template, which creates role and instance profile:

::

    "RouteManagerRole": {
      "Type": "AWS::IAM::Role",
      "Properties": {
        "AssumeRolePolicyDocument": {
          "Version": "2012-10-17",
          "Statement": [
            {
              "Effect": "Allow",
              "Principal": {
                "Service": [
                  "ec2.amazonaws.com"
                ]
              },
              "Action": [
                "sts:AssumeRole"
              ]
            }
          ]
        },
        "Policies": [
          {
            "PolicyName": "RouteManagerPolicy",
            "PolicyDocument": {
              "Version": "2012-10-17",
              "Statement": [
                {
                  "Effect": "Allow",
                  "Action": [
                    "ec2:CreateRoute",
                    "ec2:DescribeNetworkInterfaceAttribute",
                    "ec2:DescribeNetworkInterfaces",
                    "ec2:DescribeRouteTables",
                    "ec2:ModifyNetworkInterfaceAttribute",
                    "ec2:ReplaceRoute",
                    "ec2:DeleteRoute"
                  ],
                  "Resource": "*"
                },
                {
                  "Effect": "Allow",
                  "Action": [
                    "ec2messages:GetMessages",
                    "ssm:UpdateInstanceInformation",
                    "ssm:ListInstanceAssociations",
                    "ssm:ListAssociations",
                    "ssmmessages:CreateControlChannel",
                    "ssmmessages:CreateDataChannel",
                    "ssmmessages:OpenControlChannel",
                    "ssmmessages:OpenDataChannel"
                  ],
                  "Resource": "*"
                }
              ]
            }
          }
        ]
      }
    },
    "InstanceProfile": {
      "Type": "AWS::IAM::InstanceProfile",
      "Properties": {
        "Roles": [
          {
            "Ref": "RouteManagerRole"
          }
        ]
      }
    }

An instance profile must be associated with the instance:

::

  "Resources": {
    "EC2Instance": {
      "Type": "AWS::EC2::Instance",
      "Properties": {
        "IamInstanceProfile": {
          "Ref": "InstanceProfile"
        }
      }
    }
  }

In order to retrieve the credentials needed, the ``openvpn3-service-aws``
service requires a role name, which is read from the configuration file
(:code:`/etc/openvpn/openvpn3-aws.json`).  Here is a CloudFormation
snippet which creates this file:

::

  "Metadata": {
    "AWS::CloudFormation::Init": {
      "config": {
        "files": {
          "/etc/openvpn3/openvpn3-aws.json": {
            "content": {
              "Fn::Join": [
                "",
                [
                  "{\n",
                  "\"role\": \"",
                  {
                    "Ref": "RouteManagerRole"
                  },
                  "\"\n",
                  "}\n"
                ]
              ]
            },
            "mode": "000644",
            "owner": "root",
            "group": "root"
           }
        }
      }
    }
  }

Below is an example of configuration file, generated by the script above:

::

  {
    "role": "lev1-RouteManagerRole-1QGQ76R9S4C11"
  }

OPTIONS
=======

-h, --help      Print  usage and help details to the terminal

--version       Prints the version of the program and exists

-c FILE, --config FILE
                Path of configuration file from where role name is read.
                The default is :code:`/etc/openvpn/openvpn3-aws.json`.

--log-level LEVEL
                Sets the default log verbosity for log events generated by
                this service.  The default is :code:`3`.  Valid values are
                :code:`0` to :code:`6`.  Higher log levels results in more
                verbose logs and log level :code:`6` will contain all debug
                log events.

--log-file LOG_DESTINATION
                By default, logging will go via the ``openvpn3-service-logger``
                service.  By providing this argument, logging will also be sent
                to *LOG_DESTINATION*, which can be either a filename or
                :code:`stdout:` where the latter one sends log data to the
                console.

--colour
                This will add colours to log events when logging to file
                or console.  Log events will be coloured based on the log
                level of the event.

--signal-broadcast
                Normally, the ``openvpn3-service-aws`` will attach a
                log stream to the ``openvpn3-service-logger`` service.  By
                providing this option, it will instead broadcast all log events
                to all listeners on the system.

SEE ALSO
========

``openvpn3-linux``\(7)
``openvpn3-service-netcfg``\(8)