Add a Github label to all issues in a repository based on an existing label

main.go

package main

import (
	"context"
	"fmt"
	"github.com/google/go-github/v27/github"
	flag "github.com/spf13/pflag"
	"golang.org/x/oauth2"
	"log"
	"net/url"
	"os"
)

func main() {
	var owner string
	var repository string
	var newLabel string
	var existingLabel string
	flag.StringVarP(&owner, "owner", "o", "kpettijohn", "Git repo owner")
	flag.StringVarP(&repository, "repo", "r", "issue-tests", "Git repo name")
	flag.StringVarP(&newLabel, "new-label", "n", "proj/prometheus", "Label to add to all issues on a given repo")
	flag.StringVarP(&existingLabel, "existing-label", "e", "Prometheus", "Existing label")
	flag.Parse()

	baseURL, err := url.Parse("https://enterprise.org.com/api/v3/")
	if err != nil {
		log.Fatalf("Error: %s", err)

	}
	uploadURL, err := url.Parse("https://enterprise.org.com/api/v3/")
	if err != nil {
		log.Fatalf("Error: %s", err)

	}

	ctx := context.Background()
	ts := oauth2.StaticTokenSource(
		&oauth2.Token{AccessToken: os.Getenv("GITHUB_TOKEN")},
	)
	tc := oauth2.NewClient(ctx, ts)

	client := github.NewClient(tc)
	client.BaseURL = baseURL
	client.UploadURL = uploadURL

	repos, _, err := client.Repositories.Get(ctx, owner, repository)
	if err != nil {
		log.Fatalf("Error: %s", err)

	}

	issueListopetions := &github.IssueListByRepoOptions{
		State:  "all",
		Labels: []string{existingLabel},
	}
	issues, _, err := client.Issues.ListByRepo(ctx, owner, repository, issueListopetions)
	if err != nil {
		log.Fatalf("Error: %s", err)

	}
	for _, issue := range issues {
		log.Printf("Adding label (%s) to issue #%d on %s/%s...", newLabel, *issue.Number, owner, repository)
		_, resp, err := client.Issues.AddLabelsToIssue(ctx, owner, repository, *issue.Number, []string{newLabel})
		if err != nil {
			log.Fatalf("Error: %s", err)
		}
		log.Println(resp.Response.Status)
	}
}