如何获取Heroku部署后运行时修改的.json文件内容？

Hey there! I’ve run into this exact issue before—let’s walk through why this happens and how to get those updated files.

Why You Can’t Pull Runtime Files via Git #

Heroku’s dynos use an ephemeral filesystem, which means any files created or modified while your app runs are temporary. They’ll be erased if your dyno restarts (this happens automatically during deployments, scaling, or routine maintenance). Additionally, your Heroku Git repository only tracks the code you originally deployed—it doesn’t sync runtime changes back to the repo.

Solutions to Get Your Updated .json Files #

1. Copy Individual Files Directly with Heroku CLI

The simplest way to grab a single file is using the heroku ps:copy command. Run this in your local terminal:

heroku ps:copy path/to/your/file.json -a your-app-name

Replace path/to/your/file.json with the actual file path in your app, and your-app-name with your Heroku app’s name. This will copy the runtime-updated file straight to your local current directory.

2. Download a Snapshot of the Dyno Filesystem

If you need multiple runtime-modified files, you can package them into an archive and pull it locally:

1. Open a bash session in your running dyno:

   heroku run bash -a your-app-name
   

2. Once inside, create a compressed archive of your target files:

   tar -czf runtime-files.tar.gz path/to/your/json/files/
   

3. Exit the bash session with exit, then copy the archive to your local machine:

   heroku ps:copy runtime-files.tar.gz -a your-app-name
   

4. Extract the archive locally to access your files:

   tar -xzf runtime-files.tar.gz
   

3. Long-Term Fix: Use Persistent Storage

While the above methods work for one-off retrievals, storing persistent data in local .json files isn’t a sustainable practice on Heroku. Instead, switch to a persistent storage solution like:

• Heroku Postgres: A managed relational database for structured data.
• Heroku Redis: For key-value data or caching needs.
• Object Storage Add-ons: Heroku offers official add-ons for cloud object storage, where you can store .json files permanently without worrying about dyno resets.

This way, your data stays intact across dyno restarts, and you can access it from anywhere without manual file copies.

内容的提问来源于stack exchange，提问作者o purp