
host.docker.internal - localhost to a container is just itself rather than your host machine.localhost but for the default host.docker.internal is the way


You only pay for what you use — charges start when a request is sent to the container or when it is manually started. Charges stop after the container instance goes to sleep, which can happen automatically after a timeout. This makes it easy to scale to zero, and allows you to get high utilization even with bursty traffic.

host.docker.internalhost.docker.internalARG FOO
RUN echo $FOO=> [build 3/8] RUN echo BAR"image_vars": {
"FOO": "BAR"
}