Securing your Docker host is an important part of any successful Docker deployment. With the right best practices, you can ensure that your containers are running securely and without interruption.
Permissions
As a first step to securing your Docker host, it’s crucial to understand what permissions are necessary for each service running on the server. For instance, if you’re using MySQL as a data store for one or more containers then access to that must be limited by creating separate users with just enough privileges needed for them to do their job well.
Another important aspect to consider is your infrastructure’s design. Ensuring that updates are applied without downtime, for example, requires coordination across all of the servers in a cluster so you may need additional help with this task beyond what Docker offers alone. You will also want to make sure that permissions on shared resources are strictly controlled using access control lists (ACLs) or a similar mechanism.
Updates
Lastly, you should consider enabling automatic security updates for your host machine and all of the containers using a tool like Docker Content Trust to ensure that patches are applied as soon as they become available without any user intervention required. This is an important layer of protection against zero-day exploits which can be used to gain unauthorised access to your network.
The following are some additional considerations that may or may not apply to your particular environment:
You want the ability to monitor traffic between containers for suspicious behaviour. One way of accomplishing this is by leveraging 3rd party tools.
Compliance
You need to support a legacy infrastructure. In this case, it may be beneficial to consider using tools that have been designed specifically for the purpose of integrating Docker with non-Docker components such as AWS or OpenStack
Your organisation requires compliance with certain security standards which you must adhere to at all costs. This could mean sacrificing some ease of use for a higher level of security.
Best practices for Docker host security can be implemented in many ways and your organisation may require different considerations depending on the nature of its infrastructure, compliance requirements or other factors as mentioned above. One thing is certain though: it’s essential to plan well ahead before you go live with any new project involving containers since having them up and running isn’t good enough to deliver on your business objectives.