Skip to content

Latest commit

 

History

History
187 lines (131 loc) · 6.65 KB

add-new-config-option.rst

File metadata and controls

187 lines (131 loc) · 6.65 KB
Raw

Add new configuration option

This document is a guide for Modules developers that wish to introduce a new configuration option for the :command:`module` command.

Core code

Introducing new configuration option means declaring it then using it (get its value then branch code in :file:`modulecmd.tcl` script to adapt :command:`module` command behavior.

  1. First declare configuration option in g_config_defs definition array

    New configuration option name should be short yet understandable. If composed of multiple words, they should be joined by _ character. Option value could be superseded by an environment variable, using same name than config, upper-cased and prefixed by MODULES_.

    Entry in g_config_defs definition array uses option name as key then a list as value composed with:

    • Superseding environment variable
    • Default value
    • Is configuration lockable to default value (0 or 1)
    • Value kind (i for integer, s for string, b for boolean, l for colon-separated list, o for other)
    • Valid value list (empty list if no validation list)
    • Internal value representation (optional)
    • Specific procedure to call to initialize option value (optional)
    • Valid value list kind (empty string, intbe or eltlist)

  2. Update the Tcl code that compose the :file:`modulecmd.tcl` script to adapt behavior depending on the value defined (by default or superseded) for the configuration option. Use the getConf helper procedure to fetch configuration option value. This part highly depends on the kind of configuration option introduced.

Installation scripts

If the default value of the configuration option may be selected at installation time, an installation option should be added on the :file:`configure` script.

  1. Define installation option argument in :file:`configure` script, add it to the internal help message of this shell script, define an internal <optionname> variable that is set to the default installation option value, then updated when install option argument is set.

  2. Define the <optionname> variable in :file:`Makefile.inc.in` set to the @<optionname>@ mark, that will be replaced by chosen value for option when :file:`configure` script will generate :file:`Makefile.inc`. Define the install_<optionname> variable in :file:`site.exp.in` to get value set for option within testsuite. Update translate-in-script rule in :file:`Makefile` to add translation of the @<optionname>@ mark into selected value.

  3. Set the @<optionname>@ mark as the default value for configuration option in g_config_defs definition array in Tcl core code

    When the make installation step is performed the :file:`modulecmd.tcl` script file is generated with the @<optionname>@ mark replaced by selected default value.

Initialization scripts

New configuration option should be referred in the shell completion scripts as argument for the :subcmd:`config` sub-command.

Files that should be edited to add reference to the new option:

Example commit: :ghcommit:`abfef4ed`

Documentation

Man pages and other user documentation have to be updated to describe the introduced option.

Files that should be edited:

  • :file:`doc/source/module.rst` (module manpage)
    • add configuration option description with mconfig anchor under :subcmd:`config` sub-command section
    • add environment variable description with envvar anchor under ENVIRONMENT section
  • :file:`doc/source/changes.rst`
    • add configuration option under Modules configuration options section of current Modules major version
    • add environment variable under Environment section of current Modules major version
  • :file:`INSTALL.rst`
    • add configuration and related environment variable and installation option in the table under Configuration options section

Example commits:

In case an installation option has been added, it should be covered by documentation

Testsuite

Non-regression testsuite must be adapted first to ensure existing tests still pass then to add specific tests to check the behavior of the added configuration option and ensure overall code coverage does not drop.

  1. First, clear the run test environment from predefined configuration value, set over the associated environment variable.

    If default value for option could be set at installation time, it may be important to take this chosen default value into account, thanks to the install_<optionname> Tcl variable set in :file:`site.exp`.

  2. Add new configuration option to the list of options tested over the :subcmd:`config` sub-command.

  3. Craft specific tests to validate the correct behavior of the configuration when not set, set with valid or invalid values.

    • File to edit: depends on what is impacted by the new configuration option, if some tests already exist for concerned behavior (existing testsuite file to update) or not (new testfile to create).
    • Example commit: :ghcommit:`122039e5`

  4. Optionally if a new installation option has been introduced, it may be interesting to adapt CI configuration to test a value different than the default one