Evary container folder must contain PARAMS.md which describes the container environment parameters.
Example:
| parameter | default |
|---|---|
| Parameter group | |
| DIRECT_PARAMETER_A | $INDIRECT_PARAMETER_A |
| DIRECT_PARAMETER_B | $INDIRECT_PARAMETER_B |
| DIRECT_parameter_aaa | /foo/bar |
| INDIRECT_PARAMETER_A | FQDN host name from /etc/hosts |
| INDIRECT_PARAMETER_B |
Parameters are grouped into logical groups, such as Config, Analytics, etc. Each group is dedicated to TF component (Config), other component (RabbitMQ), functional block (Keystone authentication). Groups are placed in alphabetical order within the table. Group names are bold.
If your container use an existing parameter which is used by any other container, find its PARAMS.md and use the same group for the parameter.
If you add a new unique parameter look in other PARAMS.md to find an appropriate group. If such group does not exist, create a new one.
Direct parameters are used in entrypoints in various ways related to their meaning, but indirect parameters are used as default values for other parameters only. Direct parameters are related to entrypoint logic whereas indirect parameters are intended to simplify setting of direct parameters.
Typical example of an indirect parameter is CONTROLLER_NODES which is not directly related to any container service but may be used to set both config and analytics nodes.
Direct parameters precede indirect ones within a group. Each subgroup is sorted alphabetically, case sensitive. Names of indirect parameters are italic.
Default values refer to other parameters with $ prefix.
Default value may be a text describing what the value is instead of particular direct value.