Extra hosts (`extra_hosts` in compose-file, or `--hosts` in services) adds
custom host/ip mappings to the container's `/etc/hosts`.
The current implementation used a `map[string]string{}` as intermediate
storage, and sorted the results alphabetically when converting to a service-spec.
As a result, duplicate hosts were removed, and order of host/ip mappings was not
preserved (in case the compose-file used a list instead of a map).
According to the **host.conf(5)** man page (http://man7.org/linux/man-pages/man5/host.conf.5.html)
multi Valid values are on and off. If set to on, the resolver
library will return all valid addresses for a host that
appears in the /etc/hosts file, instead of only the first.
This is off by default, as it may cause a substantial
performance loss at sites with large hosts files.
Multiple entries for a host are allowed, and even required for some situations,
for example, to add mappings for IPv4 and IPv6 addreses for a host, as illustrated
by the example hosts file in the **hosts(5)** man page (http://man7.org/linux/man-pages/man5/hosts.5.html):
# The following lines are desirable for IPv4 capable hosts
127.0.0.1 localhost
# 127.0.1.1 is often used for the FQDN of the machine
127.0.1.1 thishost.mydomain.org thishost
192.168.1.10 foo.mydomain.org foo
192.168.1.13 bar.mydomain.org bar
146.82.138.7 master.debian.org master
209.237.226.90 www.opensource.org
# The following lines are desirable for IPv6 capable hosts
::1 localhost ip6-localhost ip6-loopback
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
This patch changes the intermediate storage format to use a `[]string`, and only
sorts entries if the input format in the compose file is a mapping. If the input
format is a list, the original sort-order is preserved.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Upstream-commit: dbdf8f6468
Component: cli
docker/cli
This repository is the home of the cli used in the Docker CE and Docker EE products.
Development
docker/cli is developed using Docker.
Build a linux binary:
$ make -f docker.Makefile binary
Build binaries for all supported platforms:
$ make -f docker.Makefile cross
Run all linting:
$ make -f docker.Makefile lint
List all the available targets:
$ make help
In-container development environment
Start an interactive development environment:
$ make -f docker.Makefile shell
In the development environment you can run many tasks, including build binaries:
$ make binary
Legal
Brought to you courtesy of our legal counsel. For more context, please see the NOTICE document in this repo.
Use and transfer of Docker may be subject to certain restrictions by the United States and other governments.
It is your responsibility to ensure that your use and/or transfer does not violate applicable laws.
For more information, please see https://www.bis.doc.gov
Licensing
docker/cli is licensed under the Apache License, Version 2.0. See LICENSE for the full license text.