.. _container-vs-public:

====================================
Assigning a public IP to a container
====================================

This guide will walk you through the steps of assigning a public IP to a container.
This will allow worker node containers to have an IP address that can be used for access from the internet.

.. figure:: public_ip.png
  :alt: Public IP networking
  :figclass: screenshot

Step 1: Reserve a worker node
=============================

See the "reservation of a worker node" section.


Step 2: Create a container
==========================

Here, we connect a container application, running on a worker node, to a public IP. This involves including the container in the "serverpublic" network
when starting the container.

* From the ExPECA home page, click *Container* -> *Containers*

.. figure:: container_run1.png
  :alt: Containers main page
  :figclass: screenshot

* Click *+ Create Container*
* See "Running a basic container" for the steps involved. We will here only focus on the data entered for network connection.
* Under "Networks" tab, bring "serverpublic" to the top
* Under "Miscellaneous" tab, enter environment variables needed for the container.
* Under "Labels" tab, enter a public IP address in the 130.237.11.[113-126]/27 range, as well as the "serverpublic" gateway.
 
.. figure:: container_run2.png
  :alt: Containers networks page
  :figclass: screenshot
.. figure:: container_run3.png
  :alt: Containers miscellaneous page
  :figclass: screenshot
.. figure:: container_run4.png
  :alt: Containers labels page
  :figclass: screenshot

* Click *Create*

.. figure:: container_run5.png
  :alt: Containers main page
  :figclass: screenshot

Note that DNS and default gateway needs to be set for the container. In this case, the container gets this information from 
environment variables in the "miscellaneous" section, but it is up to the container designer for how this should be done.
It can be done either manually through the console, or if they want it done automatically, they can use a container that does such tasks during boot up.
To perform those tasks, the container must have ip commands installed. For an ubuntu container, this means the following line must be included in the Dockerfile:

*RUN apt update && apt install -y openssh-server iproute2*

Then the following commands could be run either manually through the console, or within the container’s entrypoint:

| *# First fix the nameserver on the container*
| *echo nameserver $DNS_IP > /etc/resolv.conf*
| *# Fix the gateway*
| *ip route del default*
| *ip route add default via $GATEWAY_IP*

You should now be able to connect with SSH to your container from the internet.

.. figure:: container_run6.png
  :alt: Container console page
  :figclass: screenshot