Cathead

Cathead is a utility to monitor SSL certificates for expiry and retrieve new certificates when expiry is near.

This project is borne out of frustration with using cron and certmonger and various other bits of bash to monitor and renew certificates.

Warning

This project is under active development so expect changes to APIs and configurations.

Running

1. Clone repo :

   git clone https://github.com/takac/cathead

2. Install requirements and cathead into a virtual env. :

   virtualenv .venv pip install -r requirements.txt pip install .

3. Construct a config file specifying which certs to track and how to refresh them. See the example_config.py file.

   The certs section contains the details of the certificates to monitor and which driver should be used. The common name and other cert details should also be specified here.

   driver

   Name of the driver to use. Use the name value from the driver.

   key

   Path to the key. This key will be regenerated at every refresh.

   cert

   Path to the cert.

   common_name

   Common name of the certificate.

   on_refresh_success

   Callback action to execute on successful refresh of cert. Use the name value of an action defined in the actions section.

   on_refresh_failure

   Callback action to execute on failure to refresh the cert. Use the name value of an action defined in the actions section.

   The drivers section specifies how new certs are obtained, the only 2 drivers currently supported are Anchor (currently named ECA, due to be changed), and self signed certs.

   name

   Name of the driver used to associate with certificates.

   driver

   Python class of the driver. e.g. cathead.drivers.selfsign.SelfSignDriver.

   All other keys in the driver are passed into the driver class at construction. e.g. SelfSignDriver(**drivers['selfsign'])

   The actions section contains actions to perform on different events. So far the possible events are:

   • Successful refresh of a certificate
   • Failure to refresh a certificate

   Actions can either by system calls or python calls.

   name

   Name of the action, used to associate with a certificate event callback.

   type

   The type of action, either 'system' for a system call (e.g. reboot) or 'python' which allows executing a python callable.

   module

   Use this when using type of python to select which module the callable is in.

   command

   Specify the command or callable to be run.

   args

   Specify the arguments to the command or callable. This should be a list.

4. Run cathead with your requirements file. :

   cathead example_config.py

Note

For the self signing driver you will need to generate a key to sign the certs with. This can be done using :

openssl genrsa 2048 > ca.key

Naming

The name comes from the anchor support as this project can be used in conjunction with Anchor an an ephemeral PKI service.