Usage example of creating a repo and pushing several files inside a single commit (for just 1 file, the contents api is easier to use)

go-github_usage.go

package main

import (
	"context"
	"errors"
	"time"

	"github.com/google/go-github/github"
	"golang.org/x/oauth2"
)

// getGitHubClient generates a new github client using the given context
func getGitHubClient(ctx context.Context) (client *github.Client, err error) {
	token, err := os.Getenv("GITHUB_AUTH_TOKEN")
	if err != nil {
		return
	}
	if token == "" {
		return nil, errors.New("Empty github token. Please verify your AWS_PROFILE variable")
	}
	ts := oauth2.StaticTokenSource(&oauth2.Token{AccessToken: token})
	tc := oauth2.NewClient(ctx, ts)
	client = github.NewClient(tc)
	return
}

// createGithubRepo creates a new github repository
func createGithubRepo(repoOwner, repoName, description string, tags []string, private bool) error {
	ctx := context.Background()
	client, err := getGitHubClient(ctx)
	if err != nil {
		return err
	}

	disable := false
	enable := true
	r := &github.Repository{Name: &repoName, Private: &private, Description: &description, HasWiki: &disable, HasProjects: &disable, HasPages: &disable, AutoInit: &enable}
	_, _, err = client.Repositories.Create(ctx, repoOwner, r)
	if err != nil {
		return err
	}
	_, _, err = client.Repositories.ReplaceAllTopics(ctx, repoOwner, repoName, tags)
	return err
}

// pushGithubRepo generates a new commit with the content of the templates
// prepared for the repository
func pushGithubRepo(repoOwner, repoName, commitMsg string, data map[string][]byte) error {
	ctx := context.Background()
	client, err := getGitHubClient(ctx)
	if err != nil {
		return err
	}

	// Get the ref object for the master branch
	ref, _, err := client.Git.GetRef(ctx, repoOwner, repoName, "refs/heads/master")
	if err != nil {
		return err
	}

	// Create a tree with what to commit
	authName := "my-login"
	authEmail := "my-email@example.com"
	date := time.Now()
	author := &github.CommitAuthor{Date: &date, Name: &authName, Email: &authEmail}
	entries := []github.TreeEntry{}
	for file, content := range data {
		    entries = append(entries, github.TreeEntry{Path: github.String(file), Type: github.String("blob"), Content: github.String(string(content)), Mode: github.String("100644")})
	}

	tree, _, err := client.Git.CreateTree(ctx, repoOwner, repoName, *ref.Object.SHA, entries)
	if err != nil {
		return err
	}

	// Get the parent commit to attach the commit to
	parent, _, err := client.Repositories.GetCommit(ctx, repoOwner, repoName, *ref.Object.SHA)
	if err != nil {
		return err
	}
	parent.Commit.SHA = parent.SHA

	// Create the commit in the tree
	commit := &github.Commit{Author: author, Message: github.String(commitMsg), Tree: tree, Parents: []github.Commit{*parent.Commit}}
	newCommit, _, err := client.Git.CreateCommit(ctx, repoOwner, repoName, commit)
	if err != nil {
		return err
	}

	// Attach the commit to the master branch
	ref.Object.SHA = newCommit.SHA
	_, _, err = client.Git.UpdateRef(ctx, repoOwner, repoName, ref, false)

	return err
}