main.go

package main

import (
	"github.com/google/go-github/github"
	// "github.com/xoebus/statham"
	"golang.org/x/oauth2"
	"io"
	"net/http"
	"os"
)

import log "github.com/palette-software/go-log-targets"

// This mapping thing is a workaround an issue in the google/go-github package
// https://github.com/google/go-github/issues/246
// When that is solved this can be much more simple
func connect(token string) *github.Client {
	githubTransport := &oauth2.Transport{
		Source: oauth2.StaticTokenSource(
			&oauth2.Token{AccessToken: token},
		),
	}
	// defaultTransport := &http.Transport{}
	// mappedTransport := statham.NewTransport(defaultTransport, statham.Mapping{
	// "api.github.com": githubTransport,
	// })
	httpClient := &http.Client{Transport: githubTransport}
	return github.NewClient(httpClient)
}

func main() {
	log.AddTarget(os.Stdout, log.LevelInfo)
	if len(os.Args) < 4 {
		log.Error("Usage: ", os.Args[0], " <owner> <repository> <access token> [release tag]")
		os.Exit(1)
	}
	owner := os.Args[1]
	repo := os.Args[2]
	token := os.Args[3]

	client := connect(token)

	var release *github.RepositoryRelease
	var err error

	if len(os.Args) > 4 {
		tag := os.Args[4]
		release, _, err = client.Repositories.GetReleaseByTag(owner, repo, tag)
	} else {
		// Get the latest release
		release, _, err = client.Repositories.GetLatestRelease(owner, repo)
	}

	if err != nil {
		log.Error("Error while getting latest release: ", err)
		os.Exit(1)
	}

	// Get assets for the release
	var opt github.ListOptions
	assets, _, err := client.Repositories.ListReleaseAssets(owner, repo, *(release.ID), &opt)

	// Download each asset
	for _, asset := range assets {

		// Create file on file system
		outFile, err := os.Create(*(asset.Name))
		if err != nil {
			log.Error("Error creating file: ", asset.Name, err)
			continue
		}
		defer outFile.Close()

		// Download the asset
		content, redirectURL, err := client.Repositories.DownloadReleaseAsset(owner, repo, *(asset.ID))
		if err != nil {
			log.Error("Error while downlaoding asset: ", asset.Name, err)
			continue
		}

		if redirectURL != "" {
			// We are going to overwrite the contents acquired before, but as per the documentation the
			// content must be nil. So we are free to overwrite it
			response, err := http.Get(redirectURL)
			if err != nil {
				log.Error("Failed to download redirected content from URL:", redirectURL)
				continue
			}
			content = response.Body
		}

		// Do not move this deferred call before the redirect URL check, since content might be
		// changed in there!
		defer content.Close()

		// Write contents to file
		_, err = io.Copy(outFile, content)
		if err != nil {
			log.Error("Error while writing file: ", asset.Name, err)
		}
	}
}