Interface with a Gogs instance from Elixir.

Why? 💡

We needed an easy way to interact with our Gogs (GitHub Backup) Server from our Elixir/Phoenix App. This package is that interface.

Note: We were briefly tempted to write this code inside the Phoenix App that uses it, however we quickly realized that having it separate was better for testability/maintainability. Having a separate module enforces a separation of concerns with a strong "API contract". This way we know this package is well-tested, documented and maintained. And can be used and extended independently of any Elixir/Phoenix app. The Elixir/Phoenix app can treat gogs as a logically separate/independent entity with a clear interface.

What? 📦

A library for interacting with gogs (git) from Elixir apps.

Hopefully this diagram explains how we use the package:

For the complete list of functions, please see the docs: https://hexdocs.pm/gogs 📚

Who? 👤

This library is used by our (Phoenix) GitHub Backup App.
If you find it helpful for your project, please ⭐ on GitHub: github.com/dwyl/gogs

How? 💻

There are a couple of steps to get this working in your project. It should only take 2 mins if you already have your Gogs Server deployed (or access to an existing instance).

If you want to read a step-by-step complete beginner's guide to getting gogs working in a Phoenix App, please see: github.com/dwyl/gogs-demo

Install ⬇️

Install the package from hex.pm, by adding gogs to the list of dependencies in your mix.exs file:

def deps do
  [
    {:gogs, "~> 1.0.2"}
  ]
end

Once you've saved the mix.exs file, run:

mix deps.get

Config ⚙️

If you are writing tests for a function that relies on gogs (and you should!) then you can add the following line to your config/test.exs file:

config :gogs, mock: true

e.g: config/test.exs#L2-L4

Setup 🔧

For gogs to work in your Elixir/Phoenix App, you will need to have a few environment variables defined.

There are 3 required and 2 optional variables. Make sure you read through the next section to determine if you need the optional ones.

Required Environment Variables

See: .env_sample

There are 3 required environment variables:

1. GOGS_URL - the domain where your Gogs Server is deployed, without the protocol, e.g: gogs-server.fly.dev

2. GOGS_ACCESS_TOKEN - the REST API Access Token See: https://github.com/dwyl/gogs-server#connect-via-rest-api-https

3. GOGS_SSH_PRIVATE_KEY_PATH - absolute path to the id_rsa file on your localhost or Phoenix server instance.

@SIMON: this last env var currently not being picked up. So it will just use ~/simon/id_rsa You will need to add your public key to the Gogs instance for this to work on your localhost see: https://github.com/dwyl/gogs-server#add-ssh-key

Optional Environment Variables

GOGS_SSH_PORT

If your Gogs Server is configured with a non-standard SSH port, then you need to define it: GOGS_SSH_PORT
e.g: 10022 for our Gogs Server deployed to Fly.io

You can easily discover the port by either visiting your Gogs Server Config page:
https://your-gogs-server.net/admin/config

e.g: https://gogs-server.fly.dev/admin/config

Or if you don't have admin access to the config page, simply view the ssh clone link on a repo page, e.g: https://gogs-server.fly.dev/nelsonic/public-repo

In our case the GOGS_SSH_PORT e.g: 10022.
If you don't set it, then gogs will assume TCP port 22.

GIT_TEMP_DIR_PATH

If you want to specify a directory where you want to clone git repos to, create a GIT_TEMP_DIR_PATH environment variable. e.g:

export GIT_TEMP_DIR_PATH=tmp

Note: the directory must already exist. (it won't be created if it's not there ...)

Usage

If you just want to read the contents of a file hosted on a Gogs Server, write code similar to this:

org_name = "myorg"
repo_name = "public-repo"
file_name = "README.md"
{:ok, %HTTPoison.Response{ body: response_body}} = 
  Gogs.remote_read_raw(org_name, repo_name,file_name)
# use the response_body (plaintext data)

This is exactly the use-case presented in our demo app: dwyl/gogs-demo#4-create-function

Here's a more real-world scenario in 7 easy steps:

1. Create a New Repo on the Gogs Server

# Define the params for the remote repository:
org_name = "myorg"
repo_name = "repo-name"
private = false # boolean
# Create the repo!
Gogs.remote_repo_create(org_name, repo_name, private)

⚠️ WARNING: there is currently no way to create an Organisation on the Gogs Server via REST API so the org_name must already exists. e.g: https://gogs-server.fly.dev/myorg We will be figuring out a workaround shortly ... #17

2. Clone the Repo

git_repo_url = Gogs.Helpers.remote_url_ssh(org_name, repo_name)
Gogs.clone(git_repo_url)

Provided you have setup the environment variables, and your Elixir/Phoenix App has write access to the filesystem, this should work without any issues. We haven't seen any in practice. But if you get stuck at this step, open an issue

3. Read the Contents of Local (Cloned) File

Once you've cloned the Git Repo from the Gogs Server to the local filesystem of the Elixir/Phoenix App, you can read any file inside it.

org_name = "myorg"
repo_name = "public-repo"
file_name = "README.md"
{:ok, text} == Gogs.local_file_read(org_name, repo_name, file_name)

4. Write to a File

file_name = "README.md"
text = "Your README.md text"
Gogs.local_file_write_text(org_name, repo_name, file_name, text)

This will create a new file if it doesn't already exist.

5. Commit Changes

{:ok, msg} = Gogs.commit(org_name, repo_name, 
  %{message: "your commit message", full_name: "Al Ex", email: "[email protected]"})

6. Push to Gogs Remote

# Push to Gogs Server this one is easy.
Gogs.push(org_name, repo_name)

7. Confirm the File was Update on the Remote repo

# Confirm the README.md was updated on the remote repo:
{:ok, %HTTPoison.Response{ body: response_body}} = 
    Gogs.remote_read_raw(org_name, repo_name, file_name)
"Your README.md text"

Full Function Reference / Docs? 📖

Rather than duplicate all the docs here, please read the complete function reference, on hexdocs: https://hexdocs.pm/gogs/Gogs.html

Tests!

By default, the tests run with "mocks", this means that:

1. Functional tests run faster (0.2 seconds)
2. Tests that require filesystem access will run on GitHub CI.
3. We know that functions are appropriately ["Test Doubled"] so that a downstream Elixir/Phoenix app can run in mock: true and tests will be mocked (and thus fast!)

To alter this setting to run the tests without mocks, simply change the boolean from:

config :gogs, mock: true

To:

config :gogs, mock: false

You should still see the same output as all the functions should be tested.

Test Coverage

When you run the command:

mix c

(an alias for mix coveralls.html)
You will see output similar to the following:

Finished in 0.1 seconds (0.1s async, 0.00s sync)
3 doctests, 27 tests, 0 failures

Randomized with seed 715101
----------------
COV    FILE                                        LINES RELEVANT   MISSED
100.0% lib/git_mock.ex                                55        7        0
100.0% lib/gogs.ex                                   212       41        0
100.0% lib/helpers.ex                                131       17        0
100.0% lib/http.ex                                   119       18        0
100.0% lib/httpoison_mock.ex                         124       20        0
[TOTAL] 100.0%
----------------

If you want to run the tests without mocks (i.e. "end-to-end"), update the line in config/test.exs:

config :gogs, mock: false

When you run end-to-end tests with coverage tracking:

mix c

You should see the same output:

Finished in 5.5 seconds (5.5s async, 0.00s sync)
3 doctests, 27 tests, 0 failures

Randomized with seed 388372
----------------
COV    FILE                                        LINES RELEVANT   MISSED
100.0% lib/git_mock.ex                                55        7        0
100.0% lib/gogs.ex                                   212       41        0
100.0% lib/helpers.ex                                131       17        0
100.0% lib/http.ex                                   119       18        0
100.0% lib/httpoison_mock.ex                         124       20        0
[TOTAL] 100.0%
----------------

The only difference is the time it takes to run the test suite.
The outcome (all tests passing and 100% coverage) should be identical.

If you add a feature to the package, please ensure that the tests pass in both mock: true and mock: false so that we know it works in the real world as well as in the simulated one.

Roadmap

We are aiming to do a 1:1 feature map between GitHub and Gogs so that we can backup our entire organisation, all repos, issues, labels & PRs.

We aren't there yet and we might not be for some time. The order in which we will be working on fleshing out the features is:

1. Git Diff - using the Git module to determine the changes made to a specific file between two Git commits/hashes. This will allow us to visualize the changes made and can therefore derive the contents of a Pull Request without having the PR feature exposed via the Gogs API. See: #27
2. Issues: https://github.com/gogs/docs-api/tree/master/Issues

• Comments - this is the core content of issues. We need to parse all the data and map it to the fields in Gogs.
• Labels - the primary metadata we use to categorize our issues, see: https://github.com/dwyl/labels
• Milestones - used to group issues into batches, e.g. a "sprint" or "feature".

3. Repo Stats: Stars, watchers, forks etc.
4. Your Feature Request Here! Seriously, if you spot a gap in the list of available functions, something you want/need to use Gogs in any a more advanced/custom way, please open an issue so we can discuss!

I'm Stuck! 🤷

As always, if anything is unclear or you are stuck getting this working, please open an issue! github.com/dwyl/gogs/issues we're here to help!

---

⚠️ Disclaimer! ⚠️

This package is provided "as is". We make no guarantee/warranty that it works.
We cannot be held responsible for any undesirable effects of it's usage. e.g: if you use the Gogs.delete/1 it will permanently/irrecoverably delete the repo. Use it with caution!

With the disclaimer out of the way, and your expectations clearly set, here are the facts: We are using this package in "production". We rely on it daily and consider it "mission critical". It works for us an and we have made every effort to document, test & maintain it. If you want to use it, go for it! But please note that we cannot "support" your usage beyond answering questions on GitHub. And unless you have a commercial agreement with [dwyl Ltd.]

If you spot anything that can be improved, please open an issue, we're very happy to discuss!