godns/README.md
2017-05-18 18:28:23 +08:00

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GODNS
====
A simple and fast dns cache server written by go.
Similar to [dnsmasq](http://www.thekelleys.org.uk/dnsmasq/doc.html), but supports some difference features:
* Keep hosts records in redis and the local file /etc/hosts
* Auto-Reloads when hosts configuration is changed. (Yes, dnsmasq needs to be reloaded)
## Installation & Running
1. Install
$ go get github.com/kenshinx/godns
2. Build
$ cd $GOPATH/src/github.com/kenshinx/godns
$ go build -o godns
3. Running
$ sudo ./godns -c godns.conf
4. Test
$ dig www.github.com @127.0.0.1
More details about how to install and running godns can reference my [blog (Chinese)](http://blog.kenshinx.me/blog/compile-godns/)
## Use godns
$ sudo vi /etc/resolv.conf
nameserver #the ip of godns running
## Configuration
All the configuration in `godns.conf` is a TOML format config file.
More about Toml :[https://github.com/mojombo/toml](https://github.com/mojombo/toml)
#### resolv.conf
Upstream server can be configured by changing file from somewhere other than "/etc/resolv.conf"
```
[resolv]
resolv-file = "/etc/resolv.conf"
```
If multiple `namerservers` are set in resolv.conf, the upsteam server will try in a top to bottom order
#### cache
Only the local memory storage backend is currently implemented. The redis backend is in the todo list
```
[cache]
backend = "memory"
expire = 600 # default expire time 10 minutes
maxcount = 100000
```
#### hosts
Force resolve domain to assigned ip, support two types hosts configuration:
* locale hosts file
* remote redis hosts
__hosts file__
can be assigned at godns.conf,default : `/etc/hosts`
```
[hosts]
host-file = "/etc/hosts"
```
Hosts file format is described in [linux man pages](http://man7.org/linux/man-pages/man5/hosts.5.html).
More than that , `*.` wildcard is supported additional.
__redis hosts__
This is a special requirment in our system. Must maintain a global hosts configuration,
and support update the host records from other remote server.
Therefore, while "redis-hosts" be enabled, will query the redis db when each dns request is reached.
The hosts record is organized with redis hash map. and the key of the map is configured.
```
[hosts]
redis-key = "godns:hosts"
```
_Insert hosts records into redis_
```
redis > hset godns:hosts www.test.com 1.1.1.1
```
Compared with file-backend records, redis-backend hosts support multiple A entries.
```
redis > hset godns:hosts www.test.com 1.1.1.1,2.2.2.2
```
## Benchmark
__Debug close__
```
$ go test -bench=.
testing: warning: no tests to run
PASS
BenchmarkDig-8 50000 57945 ns/op
ok _/usr/home/keqiang/godns 3.259s
```
The result : 15342 queries/per second
The test environment:
CentOS release 6.4
* CPU:
Intel Xeon 2.40GHZ
4 cores
* MEM:
46G
## Web console
Joke: A web console for godns
[https://github.com/kenshinx/joke](https://github.com/kenshinx/joke)
screenshot
![joke](https://raw.github.com/kenshinx/joke/master/screenshot/joke.png)
## Deployment
Deployment in productive supervisord highly recommended.
```
[program:godns]
command=/usr/local/bin/godns -c /etc/godns.conf
autostart=true
autorestart=true
user=root
stdout_logfile_maxbytes = 50MB
stdoiut_logfile_backups = 20
stdout_logfile = /var/log/godns.log
```
## TODO
* The redis cache backend
* Update ttl
## LICENSE
godns is under the MIT license. See the LICENSE file for details.