This commit is contained in:
DoTheEvolution 2020-05-06 02:27:22 +02:00
parent 19da529c64
commit be6530bf6d
1 changed files with 115 additions and 37 deletions

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@ -15,15 +15,14 @@ Lightweight DHCP and DNS server.
```
/etc/
└── dnsmasq.conf
├── dnsmasq.conf
├── hosts
└── resolve.conf
```
# Installation
* Install dnsmasq from your linux official repos.
* configuration
* enable and start the service</br>
`sudo systemctl enable --now dnsmasq`
* Install dnsmasq from your linux official repos
# Configuration
@ -33,59 +32,138 @@ Configuration file location: /etc/dnsmasq.conf
`dnsmasq.conf`
```bash
# dont use resolv.conf as it gets changed by DHCP
resolv-file=/etc/resolv.conf.dnsmasq
# DNS --------------------------------------------------------------------------
# DHCP netmask
# CLients get 255.255.255.0 as netmask
dhcp-option=1,255.255.255.0
# Never forward plain names (without a dot or domain part)
domain-needed
# Never forward addresses in the non-routed address spaces.
bogus-priv
# default gateway
# clients get 192.168.1.251 as gateway
dhcp-option=3,192.168.1.69
# If you don't want dnsmasq to read /etc/resolv.conf
no-resolv
no-poll
# dns
# clients get 192.168.1.69 as DNS (this is the IP of the Pi itself)
dhcp-option=6,192.168.1.69
# DHCP and DNS interface and address
interface=enp0s25
listen-address=::1,127.0.0.1
# Upstream Google and Cloudflare nameservers
server=8.8.8.8
server=1.1.1.1
#you can assign fixed ip adresses to hosts based on mac address
dhcp-host=ma:ca:dr:e:ss:00,mycomp192.168.1.1,12h
# DNS wildcard -----------------------------------------------------------------
# wildcard dns entry sending domain and all its subdomains to an ip
address=/blabla.org/192.168.1.2
# subdomain override
address=/plex.blabla.org/192.168.1.3
# all hosts not identified by mac get a dynamic ip out of this range:
dhcp-range=192.168.1.120,192.168.1.200,12h
# DHCP -------------------------------------------------------------------------
dhcp-range=192.168.1.51,192.168.1.199,255.255.255.0,480h
# gateway
dhcp-option=3,192.168.1.1
dhcp-authoritative
#dhcp-leasefile=/var/lib/misc/dnsmasq.leases
```
# resolv.conf
Edit /etc/resolv.conf to send all requests to dnsmasq, then prevent c
Contains DNS nameservers to be used by this linux machine.</br>
Since dnsmasq, a DNS server, is running right on this machine,
the entries should point to localhost.
* `nameserver 127.0.0.1`
Bit of an issue is that this file is often dynamically generated and changed
by various system services like systemd or dhcpcd.
To prevent this,
it will be flagged as immutable, which prevents all possible changes to it
unless the attribute is removed.
Then make it immutable to prevent other services from making changes to it
Edit /`etc/resolv.conf` and set localhost as the dns nameserver.
`resolv.conf`
```
nameserver ::1
nameserver 127.0.0.1
```
Make it immutable to prevent any changes to it.
* `chattr +i /etc/resolv.conf`
Check if the content is what was set.
* `cat /etc/resolv.conf`
If it was changed by dhcpcd, edit `/etc/dhcpcd.conf`
and add `nohook resolv.conf` at the end.</br>
Restart the machine, disable the immutability, edit it again,
add immutability, and check.
* `sudo chattr -i /etc/resolv.conf`
* `sudo nano /etc/resolv.conf`
* `sudo chattr +i /etc/resolv.conf`
* `cat /etc/resolv.conf`
# /etc/hosts
dnsmasq reads all the DNS hosts and names from the /etc/hosts file,
so add your DNS hosts IP addresses and name pairs as shown.
dnsmasq reads `/etc/hosts` for IP hostname pairs entries.
This is where you can add hostnames you wish to route to local servers.
127.0.0.1 dnsmasq
192.168.56.10 dnsmasq
192.168.56.1 gateway
192.168.56.100 maas-controller
192.168.56.20 nagios
192.168.56.25 webserver1
Unfortunately no wildcard support.
But as seen in the `dnsmasq.conf` there is a wildcard section solving this,
so blabla stuff here is redundant.
`hosts`
```
127.0.0.1 docker-host
192.168.1.2 docker-host
192.168.1.1 gateway
192.168.1.2 blabla.org
192.168.1.2 nextcloud.blabla.org
192.168.1.2 book.blabla.org
192.168.1.2 passwd.blabla.org
192.168.1.2 grafana.blabla.org
```
# Start the services
`sudo systemctl enable --now dnsmasq`
# Test it
##### DHCP
Set some machine to use DHCP for its network setting.
It should just work.
You can check on the dnsmasq host file `/var/lib/misc/dnsmasq.leases`
for the active leases.
##### DNS
* `nslookup google.com`
* `nslookup gateway`
* `nslookup docker-host`
* `nslookup blabla.org`
* `nslookup whateverandom.blabla.org`
* `nslookup plex.blabla.org`
# Update
* [watchtower](https://github.com/DoTheEvo/selfhosted-apps-docker/tree/master/watchtower)
updates the image automaticly
During host linux packages update.
* manual image update</br>
`docker-compose pull`</br>
`docker-compose up -d`</br>
`docker image prune`
# Backup and restore
##### Backup
Using [BorgBackup setup](https://github.com/DoTheEvo/selfhosted-apps-docker/tree/master/borg_backup)
that makes daily snapshot of the entire /etc directory
which contains the config files.
##### restore
Replace the config files with the one from backup