https://github.com/hausgold/libnss-mac-mdns
Enable NSS hostent lookups for .mac domains
https://github.com/hausgold/libnss-mac-mdns
avahi dns hostent macos mdns name-service-switch nss oss
Last synced: 6 months ago
JSON representation
Enable NSS hostent lookups for .mac domains
- Host: GitHub
- URL: https://github.com/hausgold/libnss-mac-mdns
- Owner: hausgold
- License: mit
- Created: 2017-12-14T15:51:26.000Z (almost 8 years ago)
- Default Branch: master
- Last Pushed: 2024-03-11T07:08:12.000Z (over 1 year ago)
- Last Synced: 2024-03-12T07:49:53.002Z (over 1 year ago)
- Topics: avahi, dns, hostent, macos, mdns, name-service-switch, nss, oss
- Language: C
- Size: 96.7 KB
- Stars: 2
- Watchers: 13
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
- Code of conduct: CODE_OF_CONDUCT.md
Awesome Lists containing this project
README
[](https://github.com/hausgold/libnss-mac-mdns/actions/workflows/test.yml)
This project is dedicated to enable containers on a Docker subnetwork to lookup
macOS compatible mDNS domain names by the low level Name Service Switch (NSS).
So when a request from the host system is routed into the Docker subnetwork,
with a domain like `app.local.mac` and the compatibility jump host was able to
resolve the correct mDNS domain (`app.local`) everything is fine. But when the
subnetwork internal applications start using the macOS compatibility domain
(`.mac` suffix), things get messy. The lookup is doomed to fail, because nobody
responds to the `.mac` suffix domain. Thats where this plugin jumps into. We
allow domain resolution with the `.mac` suffix in place by using the Avahi
client, just like a jump host.
- [Requirements](#requirements)
- [Usecase](#usecase)
- [Getting started](#getting-started)
- [Usage](#usage)
- [Testing](#testing)
- [Contributing](#contributing)
- [Credits](#credits)
## Requirements
* [GNU Make](https://www.gnu.org/software/make/) (>=4.2.1)
* [GCC](http://gcc.gnu.org/) (>=7.2.1)
* [glibc](http://www.gnu.org/software/libc) (>=2.26)
* [glib2](https://wiki.gnome.org/Projects/GLib) (>=2.54.2)
## Usecase
## Getting started
First you need to clone this repository from Github:
```bash
# Clone the repository
$ git clone https://github.com/hausgold/libnss-mac-mdns.git
# Go in the repository directory
$ cd libnss-mac-mdns
```
We assume you have prepared the requirements in advance. The only thing
which is left, is to build, install and use the NSS plugin:
```bash
# Build the NSS plugin from source
$ make build
# Install the NSS plugin into your system
$ sudo make install
```
After the successful installation of the plugin you can configure it. Just edit
your `/etc/nsswitch.conf` file with system permissions and change the `hosts`
configuration like this:
```
hosts: [..all your stuff..] mac_mdns
```
Just make sure that `mac_mdns` is before `dns`.
## Usage
We assume you have a running mDNS stack on every Docker container you use,
and/or on your host system is an Avahi mDNS server running. Just make sure
your mDNS stack is working properly and can resolve domains like `app.local`.
When you installed and configured the libnss-mac-mdns library, you can start
resolving `.mac` suffixed domains.
```bash
# Lookup a regular mDNS domain
$ getent hosts app.local
# => 172.17.0.17
# Lookup the macOS compatibility domain
$ getent hosts app.local.mac
# => 172.17.0.17
```
As you can see here, we just allow both resolutions, without touching the mDNS
configuration at all.
## Testing
So if you like to start developing, just make your changes, and run `make test`
and you should be able to validate your changes. The only requirement to make
this work, is the configuration on the `/etc/nsswitch.conf` file, just like
described above. (hard requirement for the tests)
## Contributing
Bug reports and pull requests are welcome on GitHub at
https://github.com/hausgold/libnss-mac-mdns.
## Credits
This project was heavily inspired by [Danielle Madeley excellent docker-nss
library](https://github.com/danni/docker-nss). We also had a deeper look at
the following projects to get our thing going:
* https://github.com/lathiat/nss-mdns
* https://github.com/ryandoyle/nss-etcd
* https://github.com/goneri/libnss-openvpn
* https://github.com/resin-io-modules/libnss-openvpn-rs (We started with Rust)