Custom Dns

Specifying custom DNS servers

Configure Docker’s DNS so all LogZilla containers use the desired resolvers.

1. Create or edit /etc/docker/daemon.json on the host.

2. Add DNS settings (JSON):

   json
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   {
   "dns": ["1.2.3.4", "5.6.7.8"],
   "dns-search": ["example.com"]
   }
   

   Notes:

   • Replace the IPs and domain with values for the environment.
   • Keep the file valid JSON; merge with existing keys if present.
   • Restarting Docker will interrupt running containers. Plan a short maintenance window.

3. Restart Docker:

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sudo systemctl restart docker

Custom host mappings (without changing DNS)

When DNS reverse lookups are unavailable or specific overrides are needed, configure static host mappings for LogZilla containers using /etc/logzilla/hosts.in (loaded into container /etc/hosts).

1. Create or edit /etc/logzilla/hosts.in on the host. Format matches /etc/hosts (multiple names per line allowed):

   text
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   1.2.3.4 foo.bar.baz
   2.3.4.5 baz.lab.com
   10.11.12.13 somedevice somedevice.foo.com
   

2. Restart affected container(s) to apply the mapping. For syslog:

   bash
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   logzilla restart -c syslog
   

3. Verify inside the container that the entry exists:

bash
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docker exec -ti lz_syslog cat /etc/hosts

The hosts.in file is read by LogZilla during container (re)creation and populates container extra_hosts. Update the file and restart relevant containers whenever mappings change.