Chapter 1. Introducing Red Hat CodeReady Containers
1.1. About CodeReady Containers
Red Hat CodeReady Containers brings a minimal OpenShift Container Platform 4 cluster and Podman container runtime to your local computer. These runtimes provide minimal environments for development and testing purposes. CodeReady Containers is mainly targeted at running on developers' desktops. For other OpenShift Container Platform use cases, such as headless or multi-developer setups, use the full OpenShift installer.
See the OpenShift documentation for a full introduction to OpenShift Container Platform.
CodeReady Containers includes the crc command-line interface (CLI) to interact with the CodeReady Containers instance using the desired container runtime.
1.2. Differences from a production OpenShift installation
The OpenShift preset for Red Hat CodeReady Containers provides a regular OpenShift Container Platform installation with the following notable differences:
- The CodeReady Containers OpenShift cluster is ephemeral and is not intended for production use.
- CodeReady Containers does not have a supported upgrade path to newer OpenShift versions. Upgrading the OpenShift version may cause issues that are difficult to reproduce.
- It uses a single node which behaves as both a control plane and worker node.
- It disables the Cluster Monitoring Operator by default. This disabled Operator causes the corresponding part of the web console to be non-functional.
- The OpenShift cluster runs in a virtual machine known as an instance. This may cause other differences, particularly with external networking.
The OpenShift cluster provided by 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.
