rootless: add an entry to /etc/hosts when using slirp4netns

[giuseppe]

Closes: #3405

Signed-off-by: Giuseppe Scrivano [email protected]

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[TomSweeneyRedHat]

Changes LGTM, just wondering if we should also add a trailing comment to the line too, something like "# used by rootless Podman" or "# used by slirp4netns" or perhaps just "# slirp4netns"

[rhatdan]

@giuseppe Yes please add a comment. Is there a possibility for a conflict here? If the hostname was added twice? What happens?

[giuseppe]

@giuseppe Yes please add a comment. Is there a possibility for a conflict here? If the hostname was added twice? What happens?

comment added. In that case the resolver will use all the specified addresses.

# printf "192.168.10.1 foo\n192.168.10.2 foo\n192.168.10.3 foo\n" >> /etc/hosts
# python -c 'import socket; print(socket.gethostbyname_ex("foo"))'
('foo', [], ['192.168.10.1', '192.168.10.2', '192.168.10.3'])

[rhatdan]

/lgtm