[Kea-users] DHCP4 not starting or writing log file

[Tomek Mrugalski]

On 07.08.2018 12:58, McBride Lawrence wrote:
> I checked the formatting of the conf file – ARRGH! It was all over the
> place so I have started again using a more friendly editor (ATOM)
You can also use on-line validators, such as this:
http://jsonviewer.stack.hu/ to verify your config is a valid JSON.

Having said that, unless you did something very weird with the config,
Kea should be able to tell exactly what's wrong.

As mentioned before, the very early stages of Kea startup (before it's
able to read and apply its config) can be controlled with a variable.
You can start Kea this way:

# KEA_LOGGER_DESTINATION=stdout kea-dhcp4 -d -c your-config.json

The KEA_LOGGER_DESTINATION could be a file, but for me the most
convenient way is to tell Kea to print on standard output, so I see
everything on the console. Also, you may want to add -d which will print
debug messages. If there's too many of them, try to run without -d first.

The important parts should be logged on ERROR level, so you should see
them anyway, but sometimes there may be some subtle hints in the debug
messages.

> I also installed kea via RPM – v1.0 only available in CentOs
> repositories though. I could get it to start using the basic config
> but as soon as I tried to edit it for MySQL rather than memfile it
> came up with errors when I tried to run it.
Kea 1.0 it's VERY old. Support for MySQL was very basic back then. IIRC
1.0 allowed to only store leases, not host reservations. Also, 1.0 is
not supported anymore for years. It was released in 2015. It's unlikely
anyone would be able to help you. Tons of essential features are missing
there: host reservations in MySQL, client classification, no hooks. Just
to give you an impression how much has changed since 1.0, the changelog
has over
2000 lines.

This package was most likely compiled without MySQL support.

If I may suggest something, compiling recent Kea is much easier on
Ubuntu. If you want to get a quick look, setting up a modern Ubuntu,
such as 18.04, would be the fastest way to get going quick.

If you need to use CentOS, I think you should look at this page:
https://kea.isc.org/wiki/SystemNotesCentoOS7

This installation guide was written for CentOS7 + Kea 1.2, but hopefully
it's still adequate for 1.4. If it doesn't, take a look at Section
14.4.8 of Kea User's Guide:
https://kea.isc.org/docs/kea-guide.html#hooks-radius

It's about installing Kea 1.4 with RADIUS hook on CentOS 7.4. You can
skip the step about installing Radius, skip --with-freeradius and use
--with-mysql instead.

On a related note, it would be great if someone who installed Kea 1.4 on
CentOS could share its installation steps.

Hope that helps a bit.

Tomek