How can you make the Docker container use the host machine's '/etc/hosts' file?

Question

I want to make it so that the Docker container I spin up use the same /etc/hosts settings as on the host machine I run from. Is there a way to do this?

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Answer 1

If trusted users start your containers, you could use a shell function to easily "copy" the /etc/hosts entries that you need:

add_host_opt() { awk "/\\<${1}\\>/ {print \"--add-host $1:\" \$1}" /etc/hosts; }

You can then do:

docker run $(add_host_opt host.name) ubuntu cat /etc/hosts

That way you do not have to hard-code the IP addresses.