Chapter 23. Executing Remote Commands
You can use the CLI to execute remote commands in a container. This allows you to run general Linux commands for routine operations in the container.
23.2. Basic Usage
Support for remote container command execution is built into the CLI:
$ oc exec <pod> [-c <container>] <command> [<arg_1> ... <arg_n>]
$ oc exec mypod date Thu Apr 9 02:21:53 UTC 2015
Clients initiate the execution of a remote command in a container by issuing a request to the Kubernetes API server:
In the above URL:
<node_name>is the FQDN of the node.
<namespace>is the namespace of the target pod.
<pod>is the name of the target pod.
<container>is the name of the target container.
<command>is the desired command to be executed.
Additionally, the client can add parameters to the request to indicate if:
- the client should send input to the remote container’s command (stdin).
- the client’s terminal is a TTY.
- the remote container’s command should send output from stdout to the client.
- the remote container’s command should send output from stderr to the client.
After sending an
exec request to the API server, the client upgrades the connection to one that supports multiplexed streams; the current implementation uses SPDY.
The client creates one stream each for stdin, stdout, and stderr. To distinguish among the streams, the client sets the
streamType header on the stream to one of
The client closes all streams, the upgraded connection, and the underlying connection when it is finished with the remote command execution request.