Chapter 1. Introducing Red Hat CodeReady Containers

1.1. About CodeReady Containers

Red Hat CodeReady Containers brings a minimal OpenShift 4 cluster to your local computer. This cluster provides a minimal environment for development and testing purposes. CodeReady Containers is mainly targeted at running on developers' desktops. For other use cases, such as headless or multi-developer setups, use the full OpenShift installer.

Refer to the OpenShift documentation for a full introduction to OpenShift.

CodeReady Containers includes the crc command-line interface (CLI) to interact with the CodeReady Containers virtual machine running the OpenShift cluster.

1.2. Differences from a production OpenShift installation

Red Hat CodeReady Containers is a regular OpenShift installation with the following notable differences:

  • The CodeReady Containers OpenShift cluster is ephemeral and is not intended for production use.
  • It uses a single node which behaves as both a master and worker node.
  • It disables the machine-config and monitoring Operators by default.

    • These disabled Operators cause the corresponding parts of the web console to be non-functional.
    • For the same reason, there is no upgrade path to newer OpenShift versions.
  • The OpenShift instance runs in a virtual machine. This may cause other differences, particularly with external networking.

CodeReady Containers also includes the following non-customizable cluster settings. These settings should not be modified:

  • Use of the *.crc.testing domain.
  • The address range used for internal cluster communication.

    • The cluster uses the 172 address range. This can cause issues when, for example, a proxy is run in the same address space.