Load environment variables in config file

[m@…]

Hi,

We're deploying trac in a containerized environment and it would be useful to pass parts of the configuration file as environment variables, specifically the db string / db credentials.

I've found prior art doing this:

• ​https://github.com/marina-lab/docker-trac/blob/master/patches/001_read_env_vars.patch
• ​https://github.com/marina-lab/docker-trac/blob/7f4d3196c5b080d74d99cafe57e19472c300604d/config.py.patch

( with information about why the change here: ​https://github.com/marina-lab/docker-trac/commit/054a2d820856abc8d7b78a727a4c706f9917332d#diff-7f3552a4131e0f60dfffa919511f1660ab995c4c9c92ef10591c9003033fbfb5).

The attached patch allows for embedding eg %(DATABASE_URL)s in the config file using configparser's machinery.

[Jun Omae]

I don't absolutely think you've tried the patch to Trac 1.6.x.

• First parameter of the UnicodeConfigParser is not a dict
• The UnicodeConfigParser explicitly disables the interpolation feature in order to prevent errors when a user set %(...) in trac.ini unintently.

class UnicodeConfigParser(ConfigParser):
    """A Unicode-aware version of ConfigParser. Arguments are encoded to
    UTF-8 and return values are decoded from UTF-8.
    """

    # All of the methods of ConfigParser are overridden except
    # `getboolean`, `getint`, `getfloat`, `defaults`, `read`, `readfp`,
    # `optionxform` and `write`. `getboolean`, `getint` and `getfloat`
    # call `get`, so it isn't necessary to reimplement them.
    # The base class `RawConfigParser` doesn't inherit from `object`
    # so we can't use `super`.

    def __init__(self, ignorecase_option=True, **kwargs):
        self._ignorecase_option = ignorecase_option
        kwargs.setdefault('interpolation', None)
        ConfigParser.__init__(self, **kwargs)

[Jun Omae]

We're deploying trac in a containerized environment and it would be useful to pass parts of the configuration file as environment variables, specifically the db string / db credentials.

BTW, I don't think storing DB credentials to environment variables is secure….

[m@…]

Looking further into this, in git commit 5e93df6be0742b4d039544580da12efa695792fb / [10565], the option was added to interpolate a subset of params based on the params= argument,

this was undone in git commit 4485bc76dc29e038ad3aef5fa2bbace27b1735c3 / 4485bc76dc29e038ad3aef5fa2bbace27b1735c3 referring to ticket #10640

git commit 3e0aa1338100bdf1b3b757f57b033906071f3207 / [17483] for unknown reasons removes interpolation

[m@…]

Sorry, 4485bc76dc29e038ad3aef5fa2bbace27b1735c3 → [10641]

[m@…]

Updated patch

[Jun Omae]

params parameter of Configuration.__init__ seems to be no longer used. So, I don't think the interpolation for %(envname)s works, introduced in [10565] (#9674).

P.S. Please stop changing the milestone.

[Jun Omae]

params parameter of Configuration.__init__ seems to be no longer used. So, I don't think the interpolation for %(envname)s works, introduced in [10565] (#9674).

The changes have been reverted in [10640-10641].

Closing as a duplicate of #9674.

[m@…]

Closing as a duplicate of #9674.

While the behaviour of this ticket/patch does overlap #9674, what's being asked here is much more exhaustive than what's being asked in that ticket, asking for ALL environment variables being parameterized as opposed to a single computed envname.