GitHub to Redshift

This page provides you with instructions on how to extract data from GitHub and load it into Redshift. (If this manual process sounds onerous, check out Stitch, which can do all the heavy lifting for you in just a few clicks.)

What is GitHub?

GitHub is a hosting service for computer code and other resources managed by the Git version control and source code management system. It provides collaboration features such as bug tracking, feature requests, task management, and wikis for hosted projects.

Getting data out of GitHub

GitHub has a REST API that you can use to get information about projects, repositories, pull requests, and just about every other kind of data GitHub stores. For example, to get information about an issue, you would issue the call GET /repos/:owner/:repo/issues/:number.

Sample GitHub data

Here's an example of the kind of response you might see with a query like the one above.

{
  "id": 1,
  "node_id": "MDU6SXNzdWUx",
  "url": "https://api.github.com/repos/octocat/Hello-World/issues/1347",
  "repository_url": "https://api.github.com/repos/octocat/Hello-World",
  "labels_url": "https://api.github.com/repos/octocat/Hello-World/issues/1347/labels{/name}",
  "comments_url": "https://api.github.com/repos/octocat/Hello-World/issues/1347/comments",
  "events_url": "https://api.github.com/repos/octocat/Hello-World/issues/1347/events",
  "html_url": "https://github.com/octocat/Hello-World/issues/1347",
  "number": 1347,
  "state": "open",
  "title": "Found a bug",
  "body": "I'm having a problem with this.",
  "user": {
    "login": "octocat",
    "id": 1,
    "node_id": "MDQ6VXNlcjE=",
    "avatar_url": "https://github.com/images/error/octocat_happy.gif",
    "gravatar_id": "",
    "url": "https://api.github.com/users/octocat",
    "html_url": "https://github.com/octocat",
    "followers_url": "https://api.github.com/users/octocat/followers",
    "following_url": "https://api.github.com/users/octocat/following{/other_user}",
    "gists_url": "https://api.github.com/users/octocat/gists{/gist_id}",
    "starred_url": "https://api.github.com/users/octocat/starred{/owner}{/repo}",
    "subscriptions_url": "https://api.github.com/users/octocat/subscriptions",
    "organizations_url": "https://api.github.com/users/octocat/orgs",
    "repos_url": "https://api.github.com/users/octocat/repos",
    "events_url": "https://api.github.com/users/octocat/events{/privacy}",
    "received_events_url": "https://api.github.com/users/octocat/received_events",
    "type": "User",
    "site_admin": false
  },
  "labels": [
    {
      "id": 208045946,
      "node_id": "MDU6TGFiZWwyMDgwNDU5NDY=",
      "url": "https://api.github.com/repos/octocat/Hello-World/labels/bug",
      "name": "bug",
      "description": "Something isn't working",
      "color": "f29513",
      "default": true
    }
  ],
  "assignee": {
    "login": "octocat",
    "id": 1,
    "node_id": "MDQ6VXNlcjE=",
    "avatar_url": "https://github.com/images/error/octocat_happy.gif",
    "gravatar_id": "",
    "url": "https://api.github.com/users/octocat",
    "html_url": "https://github.com/octocat",
    "followers_url": "https://api.github.com/users/octocat/followers",
    "following_url": "https://api.github.com/users/octocat/following{/other_user}",
    "gists_url": "https://api.github.com/users/octocat/gists{/gist_id}",
    "starred_url": "https://api.github.com/users/octocat/starred{/owner}{/repo}",
    "subscriptions_url": "https://api.github.com/users/octocat/subscriptions",
    "organizations_url": "https://api.github.com/users/octocat/orgs",
    "repos_url": "https://api.github.com/users/octocat/repos",
    "events_url": "https://api.github.com/users/octocat/events{/privacy}",
    "received_events_url": "https://api.github.com/users/octocat/received_events",
    "type": "User",
    "site_admin": false
  },
  "assignees": [
    {
      "login": "octocat",
      "id": 1,
      "node_id": "MDQ6VXNlcjE=",
      "avatar_url": "https://github.com/images/error/octocat_happy.gif",
      "gravatar_id": "",
      "url": "https://api.github.com/users/octocat",
      "html_url": "https://github.com/octocat",
      "followers_url": "https://api.github.com/users/octocat/followers",
      "following_url": "https://api.github.com/users/octocat/following{/other_user}",
      "gists_url": "https://api.github.com/users/octocat/gists{/gist_id}",
      "starred_url": "https://api.github.com/users/octocat/starred{/owner}{/repo}",
      "subscriptions_url": "https://api.github.com/users/octocat/subscriptions",
      "organizations_url": "https://api.github.com/users/octocat/orgs",
      "repos_url": "https://api.github.com/users/octocat/repos",
      "events_url": "https://api.github.com/users/octocat/events{/privacy}",
      "received_events_url": "https://api.github.com/users/octocat/received_events",
      "type": "User",
      "site_admin": false
    }
  ],
  "milestone": {
    "url": "https://api.github.com/repos/octocat/Hello-World/milestones/1",
    "html_url": "https://github.com/octocat/Hello-World/milestones/v1.0",
    "labels_url": "https://api.github.com/repos/octocat/Hello-World/milestones/1/labels",
    "id": 1002604,
    "node_id": "MDk6TWlsZXN0b25lMTAwMjYwNA==",
    "number": 1,
    "state": "open",
    "title": "v1.0",
    "description": "Tracking milestone for version 1.0",
    "creator": {
      "login": "octocat",
      "id": 1,
      "node_id": "MDQ6VXNlcjE=",
      "avatar_url": "https://github.com/images/error/octocat_happy.gif",
      "gravatar_id": "",
      "url": "https://api.github.com/users/octocat",
      "html_url": "https://github.com/octocat",
      "followers_url": "https://api.github.com/users/octocat/followers",
      "following_url": "https://api.github.com/users/octocat/following{/other_user}",
      "gists_url": "https://api.github.com/users/octocat/gists{/gist_id}",
      "starred_url": "https://api.github.com/users/octocat/starred{/owner}{/repo}",
      "subscriptions_url": "https://api.github.com/users/octocat/subscriptions",
      "organizations_url": "https://api.github.com/users/octocat/orgs",
      "repos_url": "https://api.github.com/users/octocat/repos",
      "events_url": "https://api.github.com/users/octocat/events{/privacy}",
      "received_events_url": "https://api.github.com/users/octocat/received_events",
      "type": "User",
      "site_admin": false
    },
    "open_issues": 4,
    "closed_issues": 8,
    "created_at": "2015-04-10T20:09:31Z",
    "updated_at": "2018-03-03T18:58:10Z",
    "closed_at": "2017-02-12T13:22:01Z",
    "due_on": "2016-10-09T23:39:01Z"
  },
  "locked": true,
  "active_lock_reason": "too heated",
  "comments": 0,
  "pull_request": {
    "url": "https://api.github.com/repos/octocat/Hello-World/pulls/1347",
    "html_url": "https://github.com/octocat/Hello-World/pull/1347",
    "diff_url": "https://github.com/octocat/Hello-World/pull/1347.diff",
    "patch_url": "https://github.com/octocat/Hello-World/pull/1347.patch"
  },
  "closed_at": null,
  "created_at": "2015-04-22T13:33:48Z",
  "updated_at": "2015-04-22T13:33:48Z",
  "closed_by": {
    "login": "octocat",
    "id": 1,
    "node_id": "MDQ6VXNlcjE=",
    "avatar_url": "https://github.com/images/error/octocat_happy.gif",
    "gravatar_id": "",
    "url": "https://api.github.com/users/octocat",
    "html_url": "https://github.com/octocat",
    "followers_url": "https://api.github.com/users/octocat/followers",
    "following_url": "https://api.github.com/users/octocat/following{/other_user}",
    "gists_url": "https://api.github.com/users/octocat/gists{/gist_id}",
    "starred_url": "https://api.github.com/users/octocat/starred{/owner}{/repo}",
    "subscriptions_url": "https://api.github.com/users/octocat/subscriptions",
    "organizations_url": "https://api.github.com/users/octocat/orgs",
    "repos_url": "https://api.github.com/users/octocat/repos",
    "events_url": "https://api.github.com/users/octocat/events{/privacy}",
    "received_events_url": "https://api.github.com/users/octocat/received_events",
    "type": "User",
    "site_admin": false
  }
}

Whew!

Loading data into Redshift

Once you have identified all of the columns you will want to insert, you can use the CREATE TABLE statement in Redshift to create a table that can receive all of this data.

With a table built, it may seem like the easiest way to migrate your data (especially if there isn't much of it) is to build INSERT statements to add data to your Redshift table row by row. If you have any experience with SQL, this will be your gut reaction. But beware! Redshift isn't optimized for inserting data one row at a time. If you have a high volume of data to be inserted, you would be better off loading the data into Amazon S3 and then using the COPY command to load it into Redshift.

Keeping GitHub data up to date

Now what? You've built a script that pulls data from the GitHub API and loads it into your data warehouse, but what happens tomorrow when you have new data?

The key is to build your script in such a way that it can identify incremental updates to your data. Thankfully, many of GitHub's API results include fields like created_at that allow you to identify records that are new since your last update (or since the newest record you've copied). Once you've take new data into account, you can set your script up as a cron job or continuous loop to keep pulling down new data as it appears.

Other data warehouse options

Redshift is great, but sometimes you need to optimize for different things when you're choosing a data warehouse. Some folks choose to go with Google BigQuery, PostgreSQL, Snowflake, or Microsoft Azure SQL Data Warehouse, which are RDBMSes that use similar SQL syntax, or Panoply, which works with Redshift instances. Others choose a data lake, like Amazon S3. If you're interested in seeing the relevant steps for loading data into one of these platforms, check out To BigQuery, To Postgres, To Snowflake, To Panoply, To Azure SQL Data Warehouse, and To S3.

Easier and faster alternatives

If all this sounds a bit overwhelming, don’t be alarmed. If you have all the skills necessary to go through this process, chances are building and maintaining a script like this isn’t a very high-leverage use of your time.

Thankfully, products like Stitch were built to move data from GitHub to Redshift automatically. With just a few clicks, Stitch starts extracting your GitHub data via the API, structuring it in a way that's optimized for analysis, and inserting that data into your Redshift data warehouse.