Using SSH

Table of Contents

You can use SSH to inspect how your app is operating, transfer files via SCP, or interact directly with your bound services. More information about one-off tasks.

You can get a shell via the cf ssh command, which lets you securely log in to an application instance where you can perform debugging, environment inspection, and other tasks.

Application debugging tips

Configure your shell: If you’re trying to debug your app, you’ll need to configure your session to match your application’s environment by running /tmp/lifecycle/shell.

Interact with services: You can interact directly with the services bound to your application via port forwarding (described under “Configure Your SSH Tunnel”). This allows you to access those services using native clients on your local machine. The Service Connect plugin makes this even easier.

Connect to a crashing app: You may be trying to determine why your application keeps crashing, but it doesn’t stay up long enough for an SSH session. This happens because Cloud Foundry detects when an application fails the “health check” (typically by connecting to a TCP port), then recreates the container and runs the start command again. To determine why your start command is failing, you can override the start command and the health check with:

cf push -u process -c "sleep 600" ... [your other push options]

This overrides the port health check with the process check, and sets the start command to just sleep. That will give you 10 minutes to cf ssh and inspect your container.

How to disable SSH access

SSH access is enabled by default. Space Developers can disable SSH access to individual applications, and Space Managers can disable SSH access to all apps running within a space. See Enabling and Disabling SSH Access for the commands.

You should disable SSH access for production applications to ensure you can audit changes to those applications.

SSH version information

Application containers use the SSH-2.0 protocol. The SSH service uses the Cloud Foundry SSH implementation. For more on how Cloud Foundry implements SSH, refer to Cloud Foundry’s documentation on Understanding Application SSH.

Troubleshooting SSH issues

If you are having trouble connecting to your application via SSH, please refer to this knowledge base article.