OpenStack Ironic is an OpenStack project that provides bare metal provisioning and management capabilities. It enables users to deploy and manage physical machines (bare metal) as easily and flexibly as virtual machines in an OpenStack environment. Ironic is particularly useful in scenarios where virtualization is not desired or feasible, such as high-performance computing, database clusters, or applications that require direct access to hardware resources.
Here are some key components and concepts of OpenStack Ironic:
- Bare Metal Nodes: In Ironic, physical machines are referred to as “bare metal nodes” or simply “nodes.” These nodes can be any server or computer hardware that supports network booting (PXE) and remote management (e.g., IPMI).
- Ironic Conductor: The Ironic Conductor is responsible for managing and controlling the bare metal nodes. It communicates with the nodes through the IPMI or other supported remote management protocols. Multiple Ironic Conductors can be deployed for scalability and high availability.
- Ironic API: The Ironic API provides a RESTful interface for users to interact with Ironic. It allows users to perform actions such as creating, updating, and deleting nodes, managing node properties, and controlling node power state.
- Drivers: Ironic uses driver modules to interact with different hardware types and manage their specific features and capabilities. There are different types of drivers, including the following:
- Power drivers: Control the power state of nodes (e.g., IPMI).
- Management drivers: Enable remote management of nodes (e.g., IPMI, Redfish).
- Network drivers: Configure network connectivity for nodes (e.g., Neutron, flat, VLAN).
- Storage drivers: Manage storage-related operations on nodes (e.g., disk partitioning).
- Node States: Ironic maintains a state machine for each node, representing its various stages during provisioning and management. Some common node states include available, deployable, active, error, and maintenance. These states reflect the node’s operational status and whether it is ready for provisioning or deployment.
- Deploy Templates: Ironic allows users to define deploy templates, which are configurations that specify how a node should be provisioned. Templates define aspects such as the bootloader, the operating system image, partitioning schemes, and deployment scripts to be executed on the node.
- Integration with other OpenStack projects: Ironic seamlessly integrates with other OpenStack projects. For example, it can leverage Nova for scheduling and managing instances on bare metal nodes, Glance for storing and retrieving images, and Neutron for configuring network connectivity.
- Advanced Features: Ironic offers several advanced features, including:
- RAID configuration: It supports configuring RAID arrays on bare metal nodes.
- Rescue mode: Allows users to access and troubleshoot a node’s file system by booting into a rescue environment.
- Rolling upgrades: Facilitates the upgrade of the Ironic service without causing downtime for the managed nodes.
- Node cleaning: Enables automatic cleaning of nodes, ensuring they are in a known and consistent state before deployment.
Overall, OpenStack Ironic provides a powerful and flexible solution for managing bare metal infrastructure within an OpenStack cloud. It simplifies the provisioning, management, and lifecycle of physical servers, making them as agile and manageable as virtual machines.