Write support for a module

ibek-support connects EPICS modules to generic IOC images. Its module directories hold two different kinds of configuration:

File	Used by	Purpose
<module>.install.yml	ibek-support’s Ansible build tooling	Source version, dependencies, libraries, DBDs and build customizations
<module>.ibek.support.yaml	ibek	Entity models available to IOC instances
Optional patches, protocols, PVI definitions and autosave requests	Build or startup tooling	Supporting assets

Current recipes use ansible.sh <module> in the EPICS build/development container. Older images and instructions may instead use install.sh scripts calling ibek support helpers. ansible.sh belongs to ibek-support, not the ibek Python CLI. Recipe Jinja is evaluated by Ansible, separately from ibek’s runtime Jinja context.

For recipes, dependencies, rebuilding and asset registration, see Build support with Ansible and the recipe reference.

Expose the runtime interface

Start with a small entity model for one useful feature: a port, a controller or a database instance. Declare the inputs in parameters; emit setup commands in pre_init, commands that require a running IOC in post_init, and database loads in databases. Use id parameters and object references when entities need to refer to each other.

The render tutorial gives a complete minimal example. The support YAML reference covers parameter types, ordering, shared values and compound entities; the Jinja reference explains how expressions resolve.

Test definitions locally before rebuilding an image:

ibek ioc generate-schema mymodule.ibek.support.yaml \
    --no-ibek-defs --output ioc.schema.json
IOC=/epics/ioc RUNTIME_DIR=/epics/runtime ibek runtime generate2 config \
    --definitions mymodule.ibek.support.yaml --no-pvi --output generated

Repeat --definitions for each required support file. Explicit definitions replace automatic runtime discovery, so include every module the instance uses. Inspect both st.cmd and ioc.subst; successful rendering does not prove that the driver commands or EPICS macro names are correct. Test the resulting IOC in its developer container as well.

Include support in an image

The generic IOC project selects ibek-support and the modules to build. The Ansible recipes build the modules and register their support YAML under /epics/ibek-defs, with PVI and autosave files in their corresponding locations. ibek ioc generate-schema can then discover the installed definitions and produce the schema published with the image. At startup, ibek reads those same definitions to interpret instance YAML.

For the complete image build/test workflow, follow the generic IOC tutorial and editing a support module. If the change only needs runtime YAML, DB templates or protocols and its compiled support is already in the image, consider a runtime pattern instead.