hologit

hologit

Hologit is a universal tool for assembling software. It lives inside your project's git repository and enables you to define virtual "holo branches" that can be continuously and efficiently "projected" from a source branch. The projection process handles combining code from remote sources ("compositing") and executing build tools on the result ("lensing") to produce an output file tree.

Compositing offers deeper control over which files are pulled from a remote repository and where they are integrated than git submodules alone, while being more dependable and tracable than language-specific package managers like npm and composer. Instead of copying and moving files around on disk, hologit takes a git-native approach to minimize disk activity by computing new git trees in memory. Computed trees may be written to disk later or used as input to another process without the overhead.

Lensing can execute any existing code or build tool consistently by leveraging habitat and using containers where necessary. However, it also opens the door to a new generation of git-native build tools that do as much of their work as possible in memory, reading and writing to git's object database instead of a working tree on disk.

Quickstart

Create a repository with some simple code

To start this example, we'll use the starter template from Bootstrap's Getting Started guide to create a website:

$ git init holo-example
Initialized empty Git repository in /Users/chris/holo-example/.git/
$ cd holo-example/
$ curl -s https://raw.githubusercontent.com/hologit/examples/basic/index.html > index.html
$ git add index.html
$ git commit -m "Add Bootstrap's starter template as index.html"
[master (root-commit) 82a1a39] Add bootstrap's starter template as index.html
 1 file changed, 22 insertions(+)
 create mode 100644 index.html

Install hologit and initialize repository

Hologit can be installed via npm or habitat:

$ hab pkg install -b jarvus/hologit
» Installing jarvus/hologit
☁ Determining latest version of jarvus/hologit in the 'stable' channel
→ Using jarvus/hologit/0.3.0/20181015020008
★ Install of jarvus/hologit/0.3.0/20181015020008 complete with 0 new packages installed.
» Binlinking git-holo from jarvus/hologit/0.3.0/20181015020008 into /bin
★ Binlinked git-holo from jarvus/hologit/0.3.0/20181015020008 to /bin/git-holo

Define and project a holo branch

$ node ../hologit/bin/cli.js init
initialized config for holo-example

• A static HTML file with bootstrap/jquery CDN links

Merge external code via a holo source

• Pull bootstrap and jquery sources

Assemble the complete source code via a holo lens

• Apply sass compilation and compression via generic lenses

Make use of a projected tree

• Archive tree-ish
• Write to a real branch
• Push to github gh-pages

Advanced Usage

Overlay a project

Build new holo lenses

Roadmap

Reference

TODO

• Have project fetch and read source HEAD if no submodule commit is found
• Refactor source add and source fetch to use common code, leave things in same state