02 January 2017 GitHub, Octokit Robert Muehsig

This blogpost covers a pretty basic GitHub topic: Creating and updating content on GitHub. Of course, there are many ways to do it - e.g. you could do the full Git-ceremony and it would work with all Git hosts, but in my case I just wanted to target the offical GitHub API.

Prerequisite: A GitHub User, Repo and Token

To use this code you will need write access to a GitHub repository and you should have a valid GitHub token.

Code

The most simple way to communicate with the GitHub API is by using the Octokit SDK (from GitHub).

Description: Inside the try-block we try to get the target file, if it is already committed in the repo the API will return the last commit SHA.

With this SHA it is possible to create a new commit to do the actual update.

If the file was not found, we create the file. I’m not a huge fan of this try/catch block, but didn’t found any other way to check if the file is comitted or not (please give me a hint if this is wrong ;))

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Octokit;

namespace CreateOrUpdateGitHubFile
{
    class Program
    {
        static void Main(string[] args)
        {
            Task.Run(async () =>
            {
                var ghClient = new GitHubClient(new ProductHeaderValue("Octokit-Test"));
                ghClient.Credentials = new Credentials("ACCESS-TOKEN");

                // github variables
                var owner = "OWNER";
                var repo = "REPO";
                var branch = "BRANCH";

                var targetFile = "_data/test.txt";

                try
                {
                    // try to get the file (and with the file the last commit sha)
                    var existingFile = await ghClient.Repository.Content.GetAllContentsByRef(owner, repo, targetFile, branch);

                    // update the file
                    var updateChangeSet = await ghClient.Repository.Content.UpdateFile(owner, repo, targetFile,
                       new UpdateFileRequest("API File update", "Hello Universe! " + DateTime.UtcNow, existingFile.First().Sha, branch));
                }
                catch (Octokit.NotFoundException)
                {
                    // if file is not found, create it
                    var createChangeSet = await ghClient.Repository.Content.CreateFile(owner,repo, targetFile, new CreateFileRequest("API File creation", "Hello Universe! " + DateTime.UtcNow, branch));
                }

                
                
            }).Wait();
        }
    }
}

The demo code is also available on GitHub.

Hope this helps.


Written by Robert Muehsig

Software Developer - from Dresden, Germany, now living & working in Switzerland. Microsoft MVP & Web Geek.
Other Projects: KnowYourStack.com |ExpensiveMeeting | EinKofferVollerReisen.de


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