Git JSON API

A JSON API to serve the contents of JSON files from a Git repo. All files in the repo are expected to be JSON files with a .json extension.

Configuration

Environment Variables

The service uses the following environment variables:

• REPO_URI (required) URI of the Git repository
• SIGNATURE_MAIL (optional) E-mail address used for generated commits
• REPO_TOKEN (optional) Token for accessing private repo
• GIT_JSON_API_VAR_*(optional) A list of variables to be replaced in the content (see "Variable Replacement" for details)

Variable Replacement

The service replaces variables in files when serving and writing. All variables need to be environment variables prefixed with GIT_JSON_API_VAR_. Example:

export GIT_JSON_API_VAR_MY_FANCY_VARIABLE="value"

If a variable occurs in the content it will be replaced by the given value. When writing to the repo values will also be replaced by their variable name.

Example

Content:                          "Hello ${properGreeting}."  
GIT_JSON_API_VAR_PROPER_GREETING: "World"  
Served:                           "Hello World."

API

GET /:version

Returns the contents of the repo at the given version as a single JSON object.

Version can either be a Git commit hash or a reference. The response will contain the Git commit hash in the Git-Commit-Hash header.

The returned object contains the contents of every file in the root of the repo in a property named like the file (without extension). For every directory, it contains another object with the same structure.

If a repo contains file1.json, file2.json, directory/fileA.json and directory/subDirectory/fileB.json, the response would be structured as follows:

// GET <url>/master
{
  "directory" : {
    "fileA": {
      "foo": "bar"
    },
    "subDirectory": {
      "fileB": {
        "foo": "bar"
      }
    }
  },
  "file1": {
    "min": 1,
    "max": 10
  },
  "file2": [
    "item1",
    "item2",
    "item3"
  ]
}

GET /:version/path

Optionally, the previous route can be called with an additional path into the content to retrieve specific data.

// GET <url>/master/directory/fileA
{
  "foo": "bar"
}

PUT /:version/path

The content of a directory or single file can be replaced using a PUT request. The body is expected to contain JSON data for all files and subdirectories or a file. The intended workflow is to query a path using GET /:version/path, make the desired changes to the data and send the whole data back via PUT /:parentVersion/path.

A new Git commit will be created and merged if necessary. The response will contain the hash of the new (merge) commit in the Git-Commit-Hash header. If the merge fails, an error will be returned.

Examples

The body to replace everything inside directory looks like this:

// PUT <url>/master/directory
{
  "files": {
    "fileA": {
      "foo": "bar"
    },
    "subDirectory/fileB": {
        "foo": "bar"
      }
    }
  }
}

The body to replace a single file only looks like this:

// PUT <url>/master/file1
{
  "fileContent" : {
    "min": 10,
    "max": 30
  }
}

Additional properties are:
author: Will be used as commit author.
updateBranch: The branch which should be updated to the new commit (default: "master").

Development Setup

npm install
REPO_URI=<repo-url> npm run watch

Deployment

Heroku/Dokku

The service is designed to be deployed using Dokku and will probably also work with Heroku and other compatible platforms.

Dockerfile

The service contains a Dockerfile to start it directly with Docker.