Packages

• 1: Usage
• 2: Development

1 - Usage

Overview

After you have set up the .velocitas.json for your project configuration , using packages is pretty straight forward.

Currently, the packages provided by the Velocitas team are the following:

To see how these provided packages are used inside a .velocitas.json you can use the Python template repository as a reference.

Installation

The Velocitas CLI - acting as a package manager for Vehicle App repositories - is installed inside our devcontainer-base-images .
After creation of a devcontainer a postCreateCommand is configured to be executed which runs:

• velocitas init which will initialize all packages referenced in your .velocitas.json. That means, it will download them and run their respective onPostInit programs, if any. (e.g, automated model generation )
• velocitas sync to sync files provided by some packages.

Check the section about our Velocitas CLI to learn more about the background and usage of it.

Velocitas Home Directory

The packages will be downloaded by the Velocitas CLI to ~/.velocitas/packages/<package_name>. More Information: VELOCITAS_HOME .

Next steps

• Lifecycle Management: Development of Packages
• Lifecycle Management: Velocitas CLI

2 - Development

Getting started

First thing you need to do is to create a repository at e.g., https://github.com/my-organisation/my-velocitas-package. The URL needs to be referenced in the .velocitas.json of your Vehicle App repository.

General configuration of Packages

Every Package repository needs a manifest.json at their root. The manifest.json is the package configuration and holds package relevant information and its behaviour.

Here are examples of this configuration:

• devenv-runtimes manifest
• devenv-devcontainer-setup manifest

The manifest of a package describes a list of components. They are a collection of programs or files that serve a similar purpose or are inheritly connected. I.e. they provide a single runtime, a deployment for a runtime or add configuration required for Github Workflows or the devcontainer.

More detailed information and explanation about configuration fields of the manifest.json and package development can be found here .

Configuration of Runtime Packages

If you want to add a new service, adapt runtime.json and manifest.json . In order to use a newly created or updated service, new changes on devenv-runtimes need to be tagged and referenced inside .velocitas.json of the respective package version via a tag or branch name of the repository. When a version is changed in your .velocitas.json you have to initialize it through velocitas init from the terminal so the new package version will be installed. A new service can be started by using velocitas cli command velocitas exec runtime-local <service_id> <args> which can be also configured inside your ./.vscode/tasks.json.

If you plan to develop a Package with the purpose of managing the runtime used together with your Vehicle App the package needs a runtime.json at their root. The runtime.json is the runtime configuration containing all information for the relevant service dependencies with the following three required attributes:

Supported config keys of a service

Runtime configuration helper

{
    "id": "<service_id>",
    "interfaces": [
        "<interface>"
    ],
    "config": [
        {
            "key": "image",
            "value": "<image>:<tag>"
        },
        {
            "key": "port",
            "value": "<port_number>"
        },
        {
            "key": "port-forward",
            "value": "<source_port>:<target_port>"
        },
        {
            "key": "env",
            "value": "<env_key>=<env_value>"
        },
        {
            "key": "mount",
            "value": "<source_path>:<target_path>"
        },
        {
            "key": "arg",
            "value": "<arg>"
        },
        {
            "key": "start-pattern",
            "value": ".*Listening on \\d+\\.\\d+\\.\\d+\\.\\d+:\\d+"
        }
    ]
}

In order to use a newly created or updated service, changes on the respective Package need to be tagged and referenced inside the .velocitas.json of your Vehicle App repository via a tag or branch name of the repository. More info about installation: Usage .

Next steps

• Lifecycle Management: Velocitas CLI