Product configurations can be automated with orchestration management systems such as Puppet, Chef, Salt, Ansible, etc. Most of these orchestration systems provide their own templating engine for templating configuration files. The problem with this model is that for each orchestration system a separate set of templates need to be created for the same product. Switching between different orchestration systems & maintaining different sets of templates files are very costly. Furthermore, instance configuration will have complex requirements. In the case of a Cartridge instance, there are numerous run-time factors that you need to take into account for the correct configuration to take place. Some of these factors include clustering and database information, the role of the Cartridge type in the clustering context and even the role of the Cartridge on the product specific distributed setup (such as that of WSO2 API Manager).
WSO2 Configurator solves these problems by implementing a generic templating solution, which can work with any orchestration system, and also tackle the cumbersome task of configuring products and instances that have complex requirements. Thereby, you can use the Configurator to seamlessly automate the configuration process that needs to be carried out when configuring Private PaaS and its cartridges.
WSO2 Configurator is a Python module written using the Jinja2 template engine, which can configure a product using a set of key/value pairs. As shown in the above diagram configuration parameters can be either provided by using a set of environment variables or using the
module.ini file inside the template module. The template module includes the template files, any other files that need to be copied to the product distribution, such as patches, and the module.ini file.
WSO2 Private PaaS Cartridges releases template modules for all the WSO2 products.
The Configurator operates on a set of configuration templates, which are referred to as a
Template Module. A Template Module should be of the following folder structure and should contain the files and templates, which are needed to configure the specific Cartridge.
files folder contains the static files, which do not require any template processing. For example,
mysql-connector-java-5.1.36.jar file should go inside the
templates folder contains the configurable template files. For example, if clustering can be configured in a particular template module for a Carbon product, the
axis2.xml file should be included in the templates folder as a templated file,
axis2.xml.template. The template file content for the clustering related area can look as follows:
The Configurator uses the following templating language: Jinja Templating
module.ini file contains the configurable options for the specific template module. For example, for the above mentioned clustering enabled
axis2.xml.template file, the following can be the likely entries of the
READ_FROM_ENVIRONMENT is set to
true, then the Configurator will override any values specified in the
module.ini file with values from the environment variables.
CARBON_HOME is the path to the product, which has to be configured using the specified templates.
Running the Configurator
The Configurator is hosted on the Private PaaS Cartridge Repository. When running the configurator you have to point to the location of the template module. It will look for the
module.ini file, read the configuration values, process the templates inside
templates folder, and copy the processed templates and the files inside
files folder to the
CARBON_HOME. For details steps on running the configurator, see Running the Configurator with a Template Module.