DNS as code - Tools for managing DNS across multiple providers
In the vein of infrastructure as code octoDNS provides a set of tools & patterns that make it easy to manage your DNS records across multiple providers. The resulting config can live in a repository and be deployed just like the rest of your code, maintaining a clear history and using your existing review & workflow.
The architecture is pluggable and the tooling is flexible to make it applicable to a wide variety of use-cases. Effort has been made to make adding new providers as easy as possible. In the simple case that involves writing of a single
class and a couple hundred lines of code, most of which is translating between the provider's schema and octoDNS's. More on some of the ways we use it and how to go about extending it below and in the /docs directory.
Table of Contents
- Getting started
- Automatic PTR generation
- Compatibility and Compliance
- Custom Sources and Providers
- Other Uses
- Getting help
- Related Projects and Resources
Running through the following commands will install the latest release of octoDNS and set up a place for your config files to live. To determine if provider specific requirements are necessary see the providers table below.
$ mkdir dns $ cd dns $ python -m venv env ... $ source env/bin/activate # provider-specific-requiremnts would be things like: octodns-route53 octodns-azure $ pip install octodns <provider-specific-requirements> $ mkdir config
Installing a specific commit SHA
If you'd like to install a version that has not yet been released in a repetable/safe manner you can do the following. In general octoDNS is fairly stable in between releases thanks to the plan and apply process, but care should be taken regardless.
$ pip install -e git+https://firstname.lastname@example.org/octodns/octodns.git@<SHA>#egg=octodns
We start by creating a config file to tell octoDNS about our providers and the zone(s) we want it to manage. Below we're setting up a
YamlProvider to source records from our config files and both a
DynProvider to serve as the targets for those records. You can have any number of zones set up and any number of sources of data and targets for records for each. You can also have multiple config files, that make use of separate accounts and each manage a distinct set of zones. A good example of this this might be
./config/production.yaml. We'll focus on a
Dynamic Zone Config
octoDNS supports dynamically building the list of zones it will work with when source providers support it. The most common use of this would be with
YamlProvider and a single dynamic entry to in effect use the files that exist in the provider's directory as the source of truth. Other providers may support the
list_zones method and be available to populate zones dynamically as well. This can be especially useful when using
octodns-dump to create an initial setup from an existing provider.
An example config would look something like:
--- providers: config: class: octodns.provider.yaml.YamlProvider directory: ./config default_ttl: 3600 enforce_order: True ns: class: octodns_ns1.Ns1Provider api_key: env/NS1_API_KEY route53: class: octodns_route53.Route53Provider access_key_id: env/AWS_ACCESS_KEY_ID secret_access_key: env/AWS_SECRET_ACCESS_KEY zones: # This is a dynamic zone config. The source(s), here `config`, will be # queried for a list of zone names and each will dynamically be set up to # match the dynamic entry. '*': sources: - config targets: - ns1 - route53
Static Zone Config
In cases where finer grained control is desired and the configuration of individual zones varies
zones can be an explicit list with each configured zone listed along with it's specific setup. As exemplified below
alias zones can be useful when two zones are exact copies of each other, with the same configuration and records. YAML anchors are also helpful to avoid duplication where zones share config, but not records.
--- manager: include_meta: True max_workers: 2 providers: config: class: octodns.provider.yaml.YamlProvider directory: ./config default_ttl: 3600 enforce_order: True ns: class: octodns_ns1.Ns1Provider api_key: env/NS1_API_KEY route53: class: octodns_route53.Route53Provider access_key_id: env/AWS_ACCESS_KEY_ID secret_access_key: env/AWS_SECRET_ACCESS_KEY zones: example.com.: &dual_target sources: - config targets: - ns1 - route53 # these have the same setup as example.com., but will have their own files # in the configuration directory for records. third.tv.: *dual_target fourth.tv.: *dual_target example.net.: # example.net. is an exact copy of example.com., there will not be an # example.net.yaml file in the config directory as `alias` includes # duplicating the records of the aliased zone along with its config. alias: example.com. other.com.: lenient: True sources: - config targets: - ns1
General Configuration Concepts
class is a special key that tells octoDNS what python class should be loaded. Any other keys will be passed as configuration values to that provider. In general any sensitive or frequently rotated values should come from environmental variables. When octoDNS sees a value that starts with
env/ it will look for that value in the process's environment and pass the result along.
Further information can be found in the
docstring of each source and provider class.
include_meta key in the
manager section of the config controls the creation of a TXT record at the root of a zone that is managed by octoDNS. If set to
True, octoDNS will create a TXT record for the root of the zone with the value
provider=<target-provider>. If not specified, the default value for
max_workers key in the
manager section of the config enables threading to parallelize the planning portion of the sync.
Quick Example Record
Now that we have something to tell octoDNS about our providers & zones we need to tell it about our records. We'll keep it simple for now and just create a single
A record at the top-level of the domain.
--- '': ttl: 60 type: A values: - 126.96.36.199 - 188.8.131.52
Further information can be found in Records Documentation.
We're ready to do a dry-run with our new setup to see what changes it would make. Since we're pretending here we'll act like there are no existing records for
example.com. in our accounts on either provider.
$ octodns-sync --config-file=./config/production.yaml ... ******************************************************************************** * example.com. ******************************************************************************** * route53 (Route53Provider) * Create <ARecord A 60, example.com., [u'184.108.40.206', '220.127.116.11']> * Summary: Creates=1, Updates=0, Deletes=0, Existing Records=0 * dyn (DynProvider) * Create <ARecord A 60, example.com., [u'18.104.22.168', '22.214.171.124']> * Summary: Creates=1, Updates=0, Deletes=0, Existing Records=0 ******************************************************************************** ...
There will be other logging information presented on the screen, but successful runs of sync will always end with a summary like the above for any providers & zones with changes. If there are no changes a message saying so will be printed instead. Above we're creating a new zone in both providers so they show the same change, but that doesn't always have to be the case. If to start one of them had a different state you would see the changes octoDNS intends to make to sync them up.
WARNING: octoDNS assumes ownership of any domain you point it to. When you tell it to act it will do whatever is necessary to try and match up states including deleting any unexpected records. Be careful when playing around with octoDNS. It's best to experiment with a fake zone or one without any data that matters until you're comfortable with the system.
Now it's time to tell octoDNS to make things happen. We'll invoke it again with the same options and add a
--doit on the end to tell it this time we actually want it to try and make the specified changes.
$ octodns-sync --config-file=./config/production.yaml --doit ...
The output here would be the same as before with a few more log lines at the end as it makes the actual changes. After which the config in Route53 and Dyn should match what's in the yaml file.
In the above case we manually ran octoDNS from the command line. That works and it's better than heading into the provider GUIs and making changes by clicking around, but octoDNS is designed to be run as part of a deploy process. The implementation details are well beyond the scope of this README, but here is an example of the workflow we use at GitHub. It follows the way GitHub itself is branch deployed.
The first step is to create a PR with your changes.
Assuming the code tests and config validation statuses are green the next step is to do a noop deploy and verify that the changes octoDNS plans to make are the ones you expect.
After that comes a set of reviews. One from a teammate who should have full context on what you're trying to accomplish and visibility in to the changes you're making to do it. The other is from a member of the team here at GitHub that owns DNS, mostly as a sanity check and to make sure that best practices are being followed. As much of that as possible is baked into
After the reviews it's time to branch deploy the change.
If that goes smoothly, you again see the expected changes, and verify them with
octodns-report you're good to hit the merge button. If there are problems you can quickly do a
.deploy dns/main to go back to the previous state.
Bootstrapping config files
Very few situations will involve starting with a blank slate which is why there's tooling built in to pull existing data out of providers into a matching config file.
$ octodns-dump --config-file=config/production.yaml --output-dir=tmp/ example.com. route53 2017-03-15T13:33:34 INFO Manager __init__: config_file=tmp/production.yaml 2017-03-15T13:33:34 INFO Manager dump: zone=example.com., sources=('route53',) 2017-03-15T13:33:36 INFO Route53Provider[route53] populate: found 64 records 2017-03-15T13:33:36 INFO YamlProvider[dump] plan: desired=example.com. 2017-03-15T13:33:36 INFO YamlProvider[dump] plan: Creates=64, Updates=0, Deletes=0, Existing Records=0 2017-03-15T13:33:36 INFO YamlProvider[dump] apply: making changes
The above command pulled the existing data out of Route53 and placed the results into
tmp/example.com.yaml. That file can be inspected and moved into
config/ to become the new source. If things are working as designed a subsequent noop sync should show zero changes.
Note that a Dynamic Zone Config and be really powerful in combination with
octodns-dump allowing you to quickly create a set of octoDNS zone files for all the zones configured in your sources.
$ octodns-dump --config-file=config/production.yaml --output-dir=tmp/ '*' route53 ...
It is important to review any
WARNING log lines printed out during an
octodns-dump invocation as it will give you information about records that aren't supported fully or at all by octoDNS and thus won't be exact matches or included in the dumps. Generally records that cannot be converted are either of a type that octoDNS does not support or those that include "dynamic" functionality that doesn't match octoDNS's behaviors.
The table below lists the providers octoDNS supports. They are maintained in their own repositories and released as independent modules.
Updating to use extracted providers
- Include the extracted module in your python environment, e.g. if using Route53 that would require adding the
octodns_route53module to your requirements.txt, setup.py, or similar.
- Update the
classvalue for your provider to the new path, e.g. again for Route53 that would be replacing
The module required and provider class path for extracted providers can be found in the table above.
Similar to providers, but can only serve to populate records into a zone, cannot be synced to.
|EnvVarSource||TXT||No||read-only environment variable injection|
|AxfrSource||A, AAAA, CAA, CNAME, LOC, MX, NS, PTR, SPF, SRV, TXT||No||read-only|
|ZoneFileSource||A, AAAA, CAA, CNAME, MX, NS, PTR, SPF, SRV, TXT||No||read-only|
|TinyDnsFileSource||A, CNAME, MX, NS, PTR||No||read-only|
- ALIAS support varies a lot from provider to provider care should be taken to verify that your needs are met in detail.
- Dyn's UI doesn't allow editing or view of TTL, but the API accepts and stores the value provided, this value does not appear to be used when served
- Dnsimple's uses the configured TTL when serving things through the ALIAS, there's also a secondary TXT record created alongside the ALIAS that octoDNS ignores
- octoDNS itself supports non-ASCII character sets, but in testing Cloudflare is the only provider where that is currently functional end-to-end. Others have failures either in the client libraries or API calls
|AcmeMangingProcessor||Useful when processes external to octoDNS are managing acme challenge DNS records, e.g. LetsEncrypt|
|AutoArpa||See Automatic PTR generation below|
|ExcludeRootNsChanges||Filter that errors or warns on planned root/APEX NS records changes.|
|IgnoreRootNsFilter||Filter that INGORES root/APEX NS records and prevents octoDNS from trying to manage them (where supported.)|
|MetaProcessor||Adds a special meta record with timing, UUID, providers, and/or version to aid in debugging and monitoring.|
|NameAllowlistFilter||Filter that ONLY manages records that match specified naming patterns, all others will be ignored|
|NameRejectlistFilter||Filter that INGORES records that match specified naming patterns, all others will be managed|
|OwnershipProcessor||Processor that implements ownership in octoDNS so that it can manage only the records in a zone in sources and will ignore all others.|
|SpfDnsLookupProcessor||Processor that checks SPF values for violations of DNS query limits|
|TtlRestrictionFilter||Processor that restricts the allow TTL values to a specified range or list of specific values|
|TypeAllowlistFilter||Filter that ONLY manages records of specified types, all others will be ignored|
|TypeRejectlistFilter||Filter that INGORES records of specified types, all others will be managed|
|octodns-spf||SPF Value Management for octoDNS|
Automatic PTR generation
octoDNS supports automatically generating PTR records from the
AAAA records it manages. For more information see the auto-arpa documentation.
Compatibility and Compliance
lenient mostly focuses on the details of
Records and standards compliance. When set to
true octoDNS will allow allow non-compliant configurations & values where possible. For example CNAME values that don't end with a
., label length restrictions, and invalid geo codes on
dynamic records. When in lenient mode octoDNS will log validation problems at
WARNING and try and continue with the configuration or source data as it exists. See Lenience for more information on the concept and how it can be configured.
strict_supports is a
Provider level parameter that comes into play when a provider has been asked to create a record that it is unable to support. The simplest case of this would be record type, e.g.
SSHFP not being supported by
AzureProvider. If such a record is passed to an
AzureProvider as a target the provider will take action based on the
true it will throw an exception saying that it's unable to create the record, when set to
false it will log at
WARNING with information about what it's unable to do and how it is attempting to working around it. Other examples of things that cannot be supported would be
dynamic records on a provider that only supports simple or the lack of support for specific geos in a provider, e.g. Route53Provider does not support
It is worth noting that these errors will happen during the plan phase of things so that problems will be visible without having to make changes.
This concept is currently a work in progress and only partially implemented. While work is on-going
strict_supports will default to
false. Once the work is considered complete & ready the default will change to
true as it's a much safer and less surprising default as what you configure is what you'll get unless an error is throw telling you why it cannot be done. You will then have the choice to explicitly request that things continue with work-arounds with
strict_supports set to
false. In the meantime it is encouraged that you manually configure the parameter to
true in your provider configs.
strict_supports parameter is available on all providers and can be configured in YAML as follows:
providers: someprovider: class: whatever.TheProvider ... strict_supports: true
Custom Sources and Providers
You can check out the source and provider directory to see what's currently supported. Sources act as a source of record information. AxfrSource and TinyDnsFileSource are currently the only OSS sources, though we have several others internally that are specific to our environment. These include something to pull host data from gPanel and a similar provider that sources information about our network gear to create both
PTR records for their interfaces. Things that might make good OSS sources might include an
ElbSource that pulls information about AWS Elastic Load Balancers and dynamically creates
CNAMEs for them, or
Ec2Source that pulls instance information so that records can be created for hosts similar to how our
Most of the things included in octoDNS are providers, the obvious difference being that they can serve as both sources and targets of data. We'd really like to see this list grow over time so if you use an unsupported provider then PRs are welcome. The existing providers should serve as reasonable examples. Those that have no GeoDNS support are relatively straightforward. Unfortunately most of the APIs involved to do GeoDNS style traffic management are complex and somewhat inconsistent so adding support for that function would be nice, but is optional and best done in a separate pass.
class key in the providers config section can be used to point to arbitrary classes in the python path so internal or 3rd party providers can easily be included with no coordination beyond getting them into PYTHONPATH, most likely installed into the virtualenv with octoDNS.
For examples of building third-party sources and providers, see Related Projects & Resources.
Syncing between providers
While the primary use-case is to sync a set of yaml config files up to one or more DNS providers, octoDNS has been built in such a way that you can easily source and target things arbitrarily. As a quick example the config below would sync
githubtest.net. from Route53 to Dyn.
--- providers: route53: class: octodns.provider.route53.Route53Provider access_key_id: env/AWS_ACCESS_KEY_ID secret_access_key: env/AWS_SECRET_ACCESS_KEY dyn: class: octodns.provider.dyn.DynProvider customer: env/DYN_CUSTOMER username: env/DYN_USERNAME password: env/DYN_PASSWORD zones: githubtest.net.: sources: - route53 targets: - dyn
Internally we use custom sources to create records based on dynamic data that changes frequently without direct human intervention. An example of that might look something like the following. For hosts this mechanism is janitorial, run periodically, making sure the correct records exist as long as the host is alive and ensuring they are removed after the host is destroyed. The host provisioning and destruction processes do the actual work to create and destroy the records.
--- providers: gpanel-site: class: github.octodns.source.gpanel.GPanelProvider host: 'gpanel.site.github.foo' token: env/GPANEL_SITE_TOKEN powerdns-site: class: octodns.provider.powerdns.PowerDnsProvider host: 'internal-dns.site.github.foo' api_key: env/POWERDNS_SITE_API_KEY zones: hosts.site.github.foo.: sources: - gpanel-site targets: - powerdns-site
Please see our contributing document if you would like to participate!
Related Projects and Resources
- GitHub Action: octoDNS-Sync
- Sample Implementations. See how others are using it
- Custom Sources & Providers.
octodns/octodns-ddns: A simple Dynamic DNS source.
doddo/octodns-lexicon: Use Lexicon providers as octoDNS providers.
asyncon/octoblox: Infoblox provider.
sukiyaki/octodns-netbox: NetBox source.
jcollie/octodns-netbox-dns: NetBox-DNS Plugin provider.
kompetenzbolzen/octodns-custom-provider: zonefile provider & phpIPAM source.
Financial-Times/octodns-fastly: An octoDNS source for Fastly.
- Article: Visualising DNS records with Neo4j + code
- Video: FOSDEM 2019 - DNS as code with octodns
- GitHub Blog: Enabling DNS split authority with octoDNS
- Tutorial: How To Deploy and Manage Your DNS using octoDNS on Ubuntu 18.04
- Cloudflare Blog: Improving the Resiliency of Our Infrastructure DNS Zone
If you know of any other resources, please do let us know!
octoDNS is licensed under the MIT license.
The MIT license grant is not for GitHub's trademarks, which include the logo designs. GitHub reserves all trademark and copyright rights in and to all GitHub trademarks. GitHub's logos include, for instance, the stylized designs that include "logo" in the file title in the following folder: https://github.com/octodns/octodns/tree/main/docs/logos/
GitHub® and its stylized versions and the Invertocat mark are GitHub's Trademarks or registered Trademarks. When using GitHub's logos, be sure to follow the GitHub logo guidelines.
octoDNS was designed and authored by Ross McFarland and Joe Williams. See https://github.com/octodns/octodns/graphs/contributors for a complete list of people who've contributed.