Fix #166 : DNS Support

[rdujardin]

Hello,

I created a new DNS application, with its own menu and its two new objects Zone and Record. It handles DNS and Reverse DNS. It's essentially things added, but there are some modifications in IPAM too, in order to handle reverse DNS : I added an optional PTR field to IPAddress, and several optional fields to Prefix : ttl, soa_name, soa_contact, soa_serial, soa_refresh, soa_retry, soa_expire and soa_minimum, and I added a function to_bind() for reverse DNS exporting, and some triggers to update serials automatically.

It seems my fork isn't passing the build test, but when I forked the develop branch wasn't either, and I checked that errors didn't come from my code. So if you merge, no problem is expected as develop branch is now passing.

I have described my work in the issue #166 , and here is the doc page I wrote for the application :

Zones

A zone corresponds to a zone file in a DNS server, it stores the SOA (Start Of Authority) record and other records that are stored as Record objects.

Zone objects handle only forward DNS, reverse DNS is handled by Prefixes (in IPAM section), which also store a SOA record.

Netbox provides two views in the DNS menu to get the exports in BIND format, which is compatible with every DNS server, directly or by import. Those
exports are also accessible as JSON through the REST API. One of these views is the export of all the forward zones in the database,
the second is the export of all the reverse zones.

The reverse zones are correctly merged and/or divided to meet the requirements of a DNS server (for instance, IPv4 reverse zones must be /16 or /24), and
not to duplicate records (for instance if you have in database the prefixes 192.168.0.0/16 and 192.168.1.0/24, only the biggest will be exported) ; however,
only IP addresses which are in an active prefix will be taken into account. Obviously, reverse DNS is supported for both IPv4 and IPv6.

The SOA Serial field is not editable : it's automatically created and managed by Netbox. Each time a zone (forward or reverse) is exported,
if there are changes since the last export or if it's the first export, the serial will be incremented. It's in the following format :
YYYYMMDDNN with Y the year, M the month, D the day and N a two-digit counter.

As zones and their BIND exports are readable through the REST API, it is possible to write some external script to automatically update
your DNS server configuration from Netbox's database.

---

Record

Each Record object represents a DNS record, i.e. a link between a hostname and a resource, which can be either an IP address or a text value,
for instance another name if the record is of CNAME type.

Records must be linked to an existing zone, and hold either an IP address link or a text value. The "Address" field points to an IP address
in database, but if you want to put an IP in your record but not in your database (if you don't own the IP for instance), it's possible
by putting the IP as text value instead.

You can create, edit or import records with IPs not existing yet in the database. They will be automatically created (but not the prefixes !).
However, the zones must be created first, they won't be so automatically.

Reverse DNS is not supported by Record objects, but by the "PTR" field in IP addresses. If this field is modified and not empty, a corresponding
A/AAAA record is automatically created if the corresponding zone is found in the database. Be careful, if there was A/AAAA records
for the old PTR value, they are not deleted.

[ventris]

Nice work

[jeremystretch]

Hey, so, this is clearly a lot of work and I appreciate that. But I wish you had synced with me before you started. I had no idea you were working on this; DNS support hasn't even been added to the roadmap yet. I'm afraid I don't have time at the moment to review the data model and address all the conflicts presented here.

I'm going to put this on hold until we figure out a spot for it, which won't be until after custom fields have been implemented, at the earliest. I'd love to get this implemented in NetBox, but the roadmap takes priority.

[rdujardin]

Hello.

I understand, I have posted some messages on the issue but I didn't told you directly, it's my bad.

I have merged with current develop branch and solved the conflicts, it will be less work for you to check this if you want to get it integrated into Netbox.

Thank you for the answer.

[rdujardin]

Hello.

I added a few commits to :

• allow A/AAAA autocreating when PTR is given a FQDN, which means that if you have a zone "foo.net", both PTR "something.foo.net" and "something.foo.net." will be taken into account
• fix a bug with A/AAAA autocreating when adding a new IP address (there was a bug because the record was saved before the address, which caused a problem as the record has a foreign key on the ip address)

And I merged with current develop branch. :)

[rdujardin]

I added a char field 'extra_conf' (max length 500) to store extra config data about a zone (or a reverse zone). For instance, in NSD, zones can have a parameter 'notify' which indicates the IP of the slave DNS server to notify. These parameters can be textually added in this field since it supports '\n'.

[visbits]

Once this is merged, netbox is rapidly becoming the best dcim tool ive seen.

[csfreak]

Now that custom fields, has been merged to develop, can we get this on the roadmap?

[rdujardin]

I added some fixes that I don't have pushed here yet, and I need to do a bit of code cleaning again. Please don't merge now, in a few days it will be ready. :)

[marc-us]

Please merge this into master. It is a necessary feature.

[angystardust]

@rdujardin does it support TXT records?

[viennaa]

@rdujardin Is it likely that you commit your changes from August?

[sts]

@rdujardin Can you provide some screenshots of the current version?

[jeremystretch]

I'm going to close out this PR as it has stagnated. I'd still like to add DNS support to NetBox in the future, but there are several more pressing features (such as a writeable API) that I want to implement first.

[kztime]

@rdujardin Hi! What did you decide in the end? I also need this feature and me too working on it.

[DanSheps]

@kztime

I'm going to close out this PR as it has stagnated. I'd still like to add DNS support to NetBox in the future, but there are several more pressing features (such as a writeable API) that I want to implement first.

It is still roadmapped for the future, as per the above, but right now I believe there are still more pressing issues.