App SSH Overview
This topic introduces SSH configuration for apps in your Cloud Foundry Application Runtime deployment.
If you need to troubleshoot an instance of an app, you can gain SSH access to the app using the SSH proxy and daemon.
For example, one of your app instances may be unresponsive, or the log output from the app may be inconsistent or incomplete. You can SSH into the individual VM that runs the problem instance to troubleshoot.
Note: If you have mutual TLS between Gorouter and app containers, app containers accept incoming communication only from the Gorouter. This disables
Operators, space managers, and space developers can configure SSH access for Cloud Foundry, spaces, and apps as described in this table:
|User Role||Scope of SSH Permissions Control||How They Define SSH Permissions|
|Operator||Entire deployment||Configure the deployment to allow or prohibit SSH access (one-time). For more information, see Configuring SSH Access for Cloud Foundry.|
|Space Manager||Space||cf CLI allow-space-ssh and disallow-space-ssh commands|
|Space Developer||App||cf CLI enable-ssh and disable-ssh commands|
An app is SSH-accessible only if operators, space managers, and space developers all grant SSH access at their respective levels. For example, the image below shows a deployment where:
- An operator allowed SSH access at the deployment level.
- A space manager allowed SSH access for apps running in spaces “A” and “B” but not “C.”
- A space developer enabled SSH access for apps that include “Foo,” “Bar,” and “Baz.”
As a result, apps “Foo,” “Bar,” and “Baz” accept SSH requests.
Space managers and space developers can configure SSH access from the command line. The Cloud Foundry Command Line Interface (cf CLI) also includes commands to return the value of the SSH access setting. See the Accessing Apps with Diego SSH topic to use and configure SSH at both the app level and the space level.
Cloud Foundry deployments control SSH access to apps at the Cloud Foundry level. Additionally, Cloud Foundry supports load balancing of SSH sessions. The Configuring SSH Access topic describes how to set SSH access for your deployment.
The SSH system components include the SSH proxy and daemon, and the system also supports authentication, and load balancing of incoming SSH traffic. The Application SSH Components and Processes topic provides a conceptual overview.Create a pull request or raise an issue on the source for this page in GitHub