hla_framework_bd/docs/user/add-new-service.md

Adding a new service

Python setup

Install the uv package manager

CLI (Command-Line Interface)

We have our own cli called agebd.

To use the cli, first clone this repo. Then:

cd cli
uv sync
source .venv/bin/activate
agebd --help

Adding a new service

agebd service add --help

Environments

The services are deployed to 2 environments:

Environment	Network	Host	Deploy path on host
prod	machine	sls-vserv-bd-hla01	/sls/bd/hla/prod/
dev	office	sls-vserv-bd-hla01-dev	/sls/bd/hla/dev/

Process Variables (PVs)

We distinguish between

• prod vs dev PVs
• service specific PVs from a dedicated IOC vs external PVs from other IOCs

PVs - Service Specific

You create them, see (# TODO: docs...)

prod and dev PVs automatically get created.

In your code, you only use the prod name of a PV. The framework will automatically use the dev name/PV when a service runs in the dev environment.

PVs - External

The framework will use the same PV in prod and dev, i.e. there is no dev PV. However, in dev you can only read from the PV, whereas in prod you can also write to it.

PVs - Examples

Environment	Service Specific	External
prod	PV("AGEBD-MYSERVICE:MYPVNAME") read&write	PV("AGEOP-SOME-SERVICE:SOME-PVNAME") read&write
dev	PV("AGEBD-MYSERVICE-DEV:MYPVNAME") read&write	PV("AGEOP-SOME-SERVICE:SOME-PVNAME") readonly

Python

For python services there are 3 environments. The python environment is set through the env variable AGEBD_ENV.

Environment	PVs
AGEBD_ENV=prod	uses prod PVs
AGEBD_ENV=dev	uses dev PVs
AGEBD_ENV=local	uses fake/mock python objects as PVs, no access to real PVs