How to inspect a container's IP, obtain it and add it to /etc/hosts file with a local domain name resolution

Question

I am working on Linux Ubuntu with docker containers and I want the following added to the last line of /etc/hosts in a new line:

IP_from_docker_container hostname_assigned 172.20.1.2 docker.dev.example.com

I have been trying commands such as: echo, printf, aux, sed, tee

This is what i unsuccessfully tried:

echo "\n" | docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' CONTAINER | echo "       docker.dev.whip-around.com" | sudo tee -a /etc/hosts

Command to get container's IP works fine. I put it here as a reference only:

 docker inspect -f '{{range.NetworkSettings.Networks}}{{.IPAddress}}{{end}}' CONTAINER_NAME

Answer 1

>> appends to a file, so you can try this:

echo `docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' CONT_NAME` example.com >> /etc/hosts