EC2 with Docker
Contents
EC2 with Docker¶
Once a Docker image has been created on your local machine, it can easily be run on an EC2 instance and made accessible to public networks.
Table of Contents¶
Launching EC2 instances¶
From the AWS control panel, EC2 instances can quickly be spun up and tared down. It’s pretty easy to accidentally accrue charges, so when creating the instance ensure you only use free tier options.
It is useful in the tags section to create a ‘Name’ tag, since that will appear on billing invoices, so you can quickly identify which service is costing you.
Also make sure that your VPC security group has port 22 exposed for at least your IP address, else you will not be able to connect to the instance. After launching the instance, you will either create or reuse an SSH identity key, i.e. some .pem file. You use this file to authenticate your SSH login.
Connecting via ssh¶
SSH requires your key to have specific permissions so that it cannot accidentally be modified; i.e. run
sudo chmod 400 [key].pem
and then connect to the EC instance with username ec2-user (you can find the IP address under the info tab for your instance on the AWS control panel):
ssh -i [key].pem ec2-user@[public-ip]
The instances can be a little outdated, so it is highly recommended to run
sudo yum update -y
or the equivalent, before doing anything else.
Using Docker containers¶
Amazon provides a special set of integrated tools that can be installed on EC2 instances, such as gimp, libreoffice, or, for our purposes, Docker.
Configuring Docker on EC2¶
To install the docker prerequisites, run
sudo amazon-linux-extras install docker
and set Docker running as a service so that it persists after log-offs
sudo service docker start
Finally, so you don’t have to run every Docker command as sudo, add yourself to the docker group
sudo usermod -a -G docker ec2-user
Note, if you want Docker to persist upon shutdown and restart, you must enable the service with
sudo systemctl enable docker
Running your Docker container¶
Once you have built an image, you can save it as a .tar file for distribution using
docker save -o [filename].tar [image_name]
SCP copy this .tar to the EC2 instance, and then remotely use
docker load -i [filename].tar
to load the image into the Docker image list. You can now run the image using
docker run [image_name]
or disconnected from a shell by including the -d flag. This way, the docker image will still run after log-off (NB this requires Docker to be running as a service). If you are exposing docker ports, ensure they are configured correctly in the VPC. To bind ports use, e.g., -p 8080:8080.
To stop the container, use
docker stop CONTAINER_ID
and remove it with
docker rm CONTAINER_ID