Add new DRY_RUN parameter that prevents writing to gitea

This is so that the script can be tested more easily without introducing
changes in the destination Gitea instance.

README.md

@@ -53,9 +53,10 @@ services:
           - GITHUB_USERNAME=github-user
           - GITEA_URL=https://your-gitea.url
           - GITEA_TOKEN=please-exchange-with-token
-          #- GITHUB_TOKEN=please-exchange-with-token # Optional, set to mirror private repos
-          #- MIRROR_PRIVATE_REPOSITORIES=true # Optional, set to mirror private repos
+          # - GITHUB_TOKEN=please-exchange-with-token # Optional, set to mirror private repos
+          # - MIRROR_PRIVATE_REPOSITORIES=true # Optional, set to mirror private repos
           # - DELAY=3600 # Optional, set to change the delay between checks (in seconds)
+          # - DRY_RUN=true # Optional, set to only log what would be done
         container_name: mirror-to-gitea
 ```
 ## Building from Source
@@ -99,6 +100,7 @@ In your Docker Compose file, replace `jaedle/mirror-to-gitea:latest` with `build
 - `GITHUB_TOKEN`: [GitHub personal access token](https://docs.github.com/en/free-pro-team@latest/github/authenticating-to-github/creating-a-personal-access-token). **Attention: if this is set, the token will be transmitted to your specified Gitea instance!**
 - `MIRROR_PRIVATE_REPOSITORIES`: If set to `true`, your private GitHub repositories will also be mirrored to gitea. The `GITHUB_TOKEN` parameter must be set for this to work.
 - `DELAY`: How often to check for new repositories in seconds. Default is 3600 (1 hour).
+- `DRY_RUN`: If set to `true` or `1`, the script will only log what would be done, but not actually create any mirror.
 
 ## Things to do
 

src/index.js

@@ -80,13 +80,17 @@ function mirrorOnGitea(repository, gitea, giteaUser, githubToken) {
 
 }
 
-async function mirror(repository, gitea, giteaUser, githubToken) {
+async function mirror(repository, gitea, giteaUser, githubToken, dryRun) {
   if (await isAlreadyMirroredOnGitea(repository.name,
     gitea,
     giteaUser)) {
     console.log('Repository is already mirrored; doing nothing: ', repository.name);
     return;
   }
+  if (dryRun) {
+    console.log('DRY RUN: Would mirror repository to gitea: ', repository);
+    return;
+  }
   console.log('Mirroring repository to gitea: ', repository.name);
   await mirrorOnGitea(repository, gitea, giteaUser, githubToken);
 }
@@ -117,6 +121,7 @@ async function main() {
     return;
   }
 
+  const dryRun = ['1', 'true'].includes(process.env.DRY_RUN);
 
   const githubRepositories = await getGithubRepositories(githubUsername, githubToken, mirrorPrivateRepositories);
   console.log(`Found ${githubRepositories.length} repositories on github`);
@@ -130,7 +135,7 @@ async function main() {
   const queue = new PQueue({ concurrency: 4 });
   await queue.addAll(githubRepositories.map(repository => {
     return async () => {
-      await mirror(repository, gitea, giteaUser, githubToken);
+      await mirror(repository, gitea, giteaUser, githubToken, dryRun);
     };
   }));
 }