PowerDNS-API-Proxy

Description

The proxy can be used between a PowerDNS API and a client.

There is the possibility to define multiple tokens. Each token is represented by an environment. A environment can get access to one or more zones. Within a zone, the token can be limited to one or more records.

Usage

Container

Containers are available under Packages.

docker run -v config:/config -e PROXY_CONFIG_PATH=/config/config.yaml -e LOG_LEVEL=WARNING --name powerdns-api-proxy ghcr.io/akquinet/powerdns-api-proxy:latest

Authentication

The token is expected in the header X-API-Key as with the PowerDNS API.

If the token is missing a HTTP 401 is returned.

RBAC

If a resource is not allowed, then a HTTP 403 comes back.

An overview of the allowed resources of a token can be seen with a GET on <url>/info/allowed.

Configuration

The configuration takes place in YAML format.

Base

The Upstream PowerDNS API must be maintained at the top level.

pdns_api_url: "https://powerdns-api.example.com"
pdns_api_token: "blablub"
pdns_api_verify_ssl: True
environments:
  ...

Environment

An environment needs a name and a SHA512 token hash. The hash is then compared with the hashed value from the API client request.

...
environments:
  - name: "Test1"
    token_sha512: "1954a12ef0bf45b3a1797437509037f178af846d880115d57668a8aaa05732deedcbbd02bfa296b4f4e043b437b733fd6131933cfdc0fb50c4cf7f9f2bdaa836"
    zones:
      ...

A token / hash pair can be created with the following commands:

token=$(tr -dc A-Za-z0-9 </dev/urandom | head -c 40 ; echo '')
token_hash=$(echo -n "$token" | sha512sum | cut -f 1 -d " ")
echo "Token: $token\nHash: $token_hash"

Zones

Under an environment zones can be defined.

These are specified in a list.

...
environments:
    - name: "Test1"
      description: "Test Environment"
      zones:
        - name: "example.com"

Simply specifying the zone without any further settings allows write permissions within the zone. Within a zone there are always read permissions.

Records

Under a zone records can be defined.

Thus the token has only write permissions on the records which are specified in the list.

...
environments:
    - name: "Test1"
      ...
      zones:
       - name: "example.com"
         records:
           - "test.example.com"

Regex

Additionally to the records list a regex_records list can be defined. In this list regex can be to define, which records are allowed.

...
environments:
    - name: "Test1"
      ...
      zones:
       - name: "example.com"
         regex_records:
           - "_acme-challenge.service-.*.example.com"

Services

Under a zone services can be defined.

ACME

The ACME service allows, if only single records are specified, to create an ACME challenge for them.

...
environments:
    - name: "Test1"
      zones:
        - name: "example.com"
          records:
            - "test.example.com"
          services:
            acme: true

Admin

Under a zone admin rights can be defined. With this it is possible to create and delete the zone.

...
environments:
    - name: "Test1"
      zones:
        - name: "example.com"
          admin: true

Subzones

Under a zone the option subzones: true can be set.

With this it is possible that the token also gets rights on all subzones which are under the zone.

...
environments:
    - name: "Test1"
      zones:
        - name: "example.com"
          subzones: true

Regex

Under a zone the option regex: true can be set.

That allows use regex in the zone name.

In this example all zones which end with .example.com are allowed.

...
environments:
  - name: "Test1"
    zones:
     - name: ".*\\.example.com"
       regex: true

Global read

Global read permissions can be defined under an environment.

For this the Environment must have the option global_read: true.

This allows the token to read all zones in the PowerDNS.

...
environments:
    - name: "Test1"
      global_read_only: true

Global search

Global search rights can be defined under an environment.

For this, the environment must have the global_search: true option.

This makes it possible to use the /search-data endpoint. https://doc.powerdns.com/authoritative/http-api/search.html

...
environments:
    - name: "Test1"
      global_search: true

Metrics of the proxy

The proxy exposes metrics on the /metrics endpoint. With the metrics_enabled option set to false, the metrics can be disabled.

The metrics_require_auth option can be used to disable the need for authentication for the /metrics endpoint.

...
metrics_enabled: false # default is true
metrics_require_auth: false # default is true

Give an environment access to the metrics

When the metrics_proxy option is set to true, the environment has access to the /metrics endpoint of the proxy.

...
environments:
    - name: "Test1"
      metrics_proxy: true

When metrics_require_auth is enabled, basic auth needs to be used.

• username: name of the environment
• password: token

Metrics

The prometheus-fastapi-instrumentator is used for the default metrics.

Additionally http requests per environment are counted.

API Docs

The API documentation can be viewed at <url>/docs.

It can be deactivated with the api_docs_enabled option.

api_docs_enabled: false # default is true

Index

The index page can be deactivated with the index_enabled option and customized with index_html.

index_enabled: false # default is true
index_html: "<html><body><h1>PowerDNS API Proxy</h1></body></html>"

Development

Install requirements

virtualenv .venv && source .venv/bin/activate
make setup

Run tests

make unit
make test

Start a webserver with docker

On saving python files, FastAPI will reload automatically.

make run-docker-debug

Environment variables

PROXY_CONFIG_PATH=./config.yml
LOG_LEVEL=DEBUG