Elastic Container Instance:Set startup command and arguments

How it works

To override the default startup settings defined in the image, such as the working directory, startup command, and arguments, you can configure the following parameters:

• Working directory

  When you build an image, you can use the WORKDIR instruction to specify the container's working directory. Commands executed at container startup run in this directory. For more information, see WORKDIR.

  When you create an ECI instance, you can override the WORKDIR instruction by setting the container's working directory (WorkingDir).

  Note

  • If the image does not specify a WORKDIR and you do not set a working directory when creating the ECI instance, the working directory defaults to the root directory (/).

  • If the specified working directory does not exist, the system automatically creates it.

• Startup command and arguments

  When you build an image, you can use the ENTRYPOINT and CMD instructions to specify the command and arguments to execute when the container starts. For more information, see ENTRYPOINT and CMD.

  When you create an ECI instance, you can override the ENTRYPOINT and CMD instructions by setting the container's startup command (Command) and arguments (Arg). The following rules determine how these overrides take effect:

  Important

  The startup command must be a command supported by the container image. Otherwise, the container fails to start.

  Image ENTRYPOINT	Image CMD	Container Command	Container Arg	Executed command	Description
  mkdir	/data/backup	Not set	Not set	mkdir /data/backup	If the container's Command and Arg are not set, the image's ENTRYPOINT and CMD are executed.
  mkdir	/data/backup	cd	Not set	cd	If the container's Command is set but Arg is not, only the container's Command is executed. The image's ENTRYPOINT and CMD are ignored.
  mkdir	/data/backup	Not set	/opt/backup	mkdir /opt/backup	If the container's Arg is set but Command is not, the image's ENTRYPOINT is executed with the container's Arg.
  mkdir	/data/backup	cd	/opt/backup	cd /opt/backup	If the container's Command and Arg are both set, only the container's Command and Arg are executed. The image's ENTRYPOINT and CMD are ignored.

Configuration