command

Command that will always run when the system starts. If not set, the default command (CMD) of the image is performed.

Usage:

command: ['COMMAND_GOES_HERE', "arg1", "arg2", ...],
// Old style (still supported but not recommended)
command: 'COMMAND_GOES_HERE',
Examples:

In a node.js application it would be interesting to run npm start to start the web server.

command: ['npm', 'start'],

In turn, in rails, we would start with rackup config.ru.

command: ['bundle', 'exec', 'rackup', 'config.ru', '--port', '$HTTP_PORT'],