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How to expose services on an instance

AMS allows an instance to expose a service to the outer network. For that, it provides a feature called instance services which let you define a port to expose on the instance endpoints. The set of services to expose is defined when the instance is launched. For example, the following command exposes port 22 on the instance’s private endpoint:

amc launch -s tcp:22 bdp7kmahmss3p9i8huu0
Note:

The specified port is exposed only on the IP address assigned to the instance. As the instance is normally not accessible from outside, the LXD node it is running on AMS sets up port forwarding rules on the node and maps the specified port to one in a higher port range (10000 - 110000).

The list of instances (amc ls) will now show the instance and the exposed port 22:

+----------------------+----------------+---------+---------+------+---------------+------------------------+
|          ID          |  APPLICATION   |  TYPE   | STATUS  | NODE |    ADDRESS    |       ENDPOINTS        |
+----------------------+----------------+---------+---------+------+---------------+------------------------+
| bdpaqaqhmss611ruq6kg |      candy     | regular | running | lxd0 | 192.168.100.2 | 192.168.100.2:22/tcp   |
|                      |                |         |         |      |               | 10.103.46.41:10000/tcp |
+----------------------+----------------+---------+---------+------+---------------+------------------------+

As described above, the port 22 is exposed only on the IP address assigned to the instance.
In addition, it was mapped onto port 10000 on the address of the LXD node lxd0.

To help identifying services later on you can give them a name. For the example above we can simply name the service ssh:

amc launch -s ssh:tcp:22 bdp7kmahmss3p9i8huu0

This will help to identify which endpoint is used for which service:

+----------------------+----------------+---------+---------+------+---------------+----------------------------+
|          ID          |  APPLICATION   |  TYPE   | STATUS  | NODE |    ADDRESS    |       ENDPOINTS            |
+----------------------+----------------+---------+---------+------+---------------+----------------------------+
| bdpaqaqhmss611ruq6kg |      candy     | regular | running | lxd0 | 192.168.100.2 | ssh:192.168.100.2:22/tcp   |
|                      |                |         |         |      |               | ssh:10.103.46.41:10000/tcp |
+----------------------+----------------+---------+---------+------+---------------+----------------------------+

If we want to expose the service on the public endpoint of a LXD node, we must slightly change the service definition when the instance is launched:

amc launch -s +tcp:22 bdp7kmahmss3p9i8huu0

Notice the + in front of the port definition. This tells AMS to expose the service on the public endpoint of the LXD node on which the instance is scheduled. The instance list shows the public address of the node on which the instance is running, in the list of endpoints:

+----------------------+----------------+---------+---------+------+---------------+------------------------+
|          ID          |  APPLICATION   |  TYPE   | STATUS  | NODE |    ADDRESS    |       ENDPOINTS        |
+----------------------+----------------+---------+---------+------+---------------+------------------------+
| bdpaqaqhmss611ruq6kg |      candy     | regular | running | lxd0 | 192.168.100.2 | 192.168.100.2:22/tcp   |
|                      |                |         |         |      |               | 147.3.23.6:10000/tcp   |
+----------------------+----------------+---------+---------+------+---------------+------------------------+

Last updated 4 months ago. Help improve this document in the forum.