1. Concepts
Overview
The fanr pod provides standardized infrastructure for package management for the Fantom ecosystem:
- standard API for Fantom repositories which are databases of pods
- implementation for file based repositories
- implementation for web based repositories (client and server)
- command line tool for installing pods from repositories
Repos
A repo is a Fantom pod repository. Repos are an abstraction for any database of pods. Repos may store multiple versions of each pod. The Repo API defines the standard interface for working with a repository. Two standard implementations are provided:
- FileRepo: file system based repository
- WebRepo: web based repository which is accessed over a simple HTTP protocol
All repos are identified with a URI - the file: URI scheme maps to FileRepo and http: scheme maps to WebRepo. You can create your own custom repo implementations too. To open a Repo using a given URI:
Repo.makeForUri(`file:/fantom-repo/`)
PodSpec
We model a given pod version with the PodSpec class. A pod spec maps to a specific pod file with a unique version and its pod metadata which includes its summary description and dependencies.
Env
We use the term env to describe the local Fantom environment which is modeled by the Env API. In the fanr architecture we wrap the system Env class with the FanrEnv class. This API is responsible for modeling pod files with the PodSpec API without necessarily having to load pods into memory via the reflection APIs.
Actions
When performing package management tasks we are always working with one repo and one env. The local env is always the environment being used by the fanr tools. The repo is typically configured in "etc/fanr/config.props", although may be overridden using a command line option.
All interactions with a repo or the local env use a dedicated query language that lets us query by pod name, version, or any pod meta-data.
Here are the basic commands we use for working with fanr:
- query: performing queries against repo
- env: performing queries against local env
- publish: upload pods
env => repo - install: download pods
repo => env - uninstall: delete pods from local env
These operations are covered in more detail in the Tool chapter.