Container linking provides a means for one container to easily communicate with another container on the same host. As we’ve seen in previous examples, most container-to-container communication has occurred through IP addresses. Container linking improves on this by allowing linked containers to communicate with each other by name. In addition to providing basic name resolution, it also provides a means to see what services a linked container is providing. In this recipe, we’ll review how to create container links as well as discuss some of their limitations.
In this recipe, we’ll be demonstrating the configuration on a single Docker host. It is assumed that this host has Docker installed and that Docker is in its default configuration. We’ll be altering name resolution settings on the host, so you’ll need root-level access.