Rationale

Native development can often mean hardware specific tests or application execution, be it for a specific GPU, a custom MCU or special high performance network card.

Also it's common for teams to share a very powerful build server to be able to compile memory heavy C++ template code and even when using a remote compilation cloud one might still want to use these servers in an hybrid setup.

Support

cmake-re support in this aspects 2 types of selfhosted runner specification :

• CMake RE L1 Digital Twins
• CMake RE L2 On-prem Workers

This page presents how to configure self-hosted runners for CMake RE L1 Digital Twins.

Self-hosted digital twins

In order to use your own runners self-hosted with cmake-re you need to manage the lifetime of the runners yourself, CMake RE does this for you with environment that can be virtualized, containerized, self-hosted runners are not managed in this way.

Requirement: The self-hosted runner shall have an ssh-server and a cmake-re remote rpc server installed. The same procedure as Custom Environments Setup applies for selfhosted runner prerequisites.

Authorized SSH Keys

To launch the cmake-re remote rpc server, cmake-re needs to be authorized, in this regard you will find SSH public keys generated by cmake-re for each environment type in TIPI_HOME_DIR/.ssh/id_rsa_<environment-name>.pub that you can authorize on your self-hosted digital twin.

selfhosted-runnner.json

The file specifying how to connect to the selfhosted runner has the following syntax :

{ 
  "address": "tipi@<hostname>", 
  "port": 22,
  "storage_server": "", 
  "machine_id": "<selfhosted-runner-id>" 
}

The file can be passed to cmake-re in 2 ways :

• Either By setting the environment variable TIPI_SELFHOSTED_RUNNER with the full path to your selfhosted-runner.json file
• Or named <toolchain-name>.json stored aside the <toolchain-name>.cmake to use for the selfhosted runner.

The second option is particularly useful to provide useful default dedicated runners for -DCMAKE_TOOLCHAIN_FILE= toolchains (for example with custom hardware).