*** Use the supported plugin now *** The Docker plugin is a XL Deploy plugin that adds capability for deploying applications to a Docker machines or Docker Swarm Clusters.
You can use a $$ (double-dollar sign) when your configuration needs a literal dollar sign. This also prevents Compose from interpolating a value, so a $$ allows you to refer to environment variables that you don’t want processed by Compose.
From the doc: https://docs.docker.com/compose/compose-file/#variable-substitution Both $VARIABLE and ${VARIABLE} syntax are supported.
You can use a $$ (double-dollar sign) when your configuration needs a literal dollar sign. This also prevents Compose from interpolating a value, so a $$ allows you to refer to environment variables that you don’t want processed by Compose.