Feat/dynaconf

This MR moves us from standard yaml configs to using dynaconf.

Description

There are multiple neat features that could be implemented with Dynaconf, but for this MR I wanted to keep things as simple as possible, so I've done this with as few changes as I could.

The way the configurations are used is not changed, the only changes are:

1. Webservice config files moved to a 'config' directory
2. Configs loaded by config/__init__.py
3. Changed the config loading code to import configs from the module
4. Configs are loaded from multiple places, in this order: config/S.yaml, config/.secret.S.yaml, ~/.config/pycalibration/S.yaml, DYNACONF_S_* env vars (where S is the service name, e.g. webservice or serve_overview

How Has This Been Tested?

Checked that the configs, when accessed as a dictionary, are identical between the original and dynaconf version

Relevant Documents (optional)

• todo

Types of changes

• New feature (non-breaking change which adds functionality)
• Docs (changes to the documentation)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I added tests where appropriate.

Reviewers

@calibration there are a few other changes I need to do, main one being to make the command line arguments work again (currently passing a config path does nothing), but apart from that this is ready for review

Closes https://git.xfel.eu/gitlab/calibration/planning/issues/22

added Waiting for review label

added 9 commits

• 80432219...50be018c - 5 commits from branch master
• 49356934 - Add dynaconf to requirements
• 82972858 - Add ".secrets.*" to gitignore
• 27bce9c1 - Use Dynaconf for mdc config
• 51309a0d - Use Dynaconf for webservice configuration

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added 4 commits

• bd927b97 - Add user level path to settings files list
• 506d651f - Add configuration section to readme
• 4c54d2b1 - Adjust env var prefix
• 46ee7729 - Add env var section to docs

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added 4 commits

• 8d6f33f0 - Remove old global config statement
• 5d67a1aa - Add init file to allow for relative import
• 2042dfa1 - Use absolute paths for configs in config dir
• 923d6600 - Fix `config-file` arguments

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marked the checklist item todo as completed

marked the checklist item I have updated the documentation accordingly. as completed

added 2 commits

• aa4fe7c9 - Use absolute paths for configs in config dir
• 03e0b5b7 - Fix `config-file` arguments

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added 3 commits

• f92c6577 - Fix conf file flag for update mdc
• 8e10d0f3 - Enable recursive merge
• 75f1f915 - Use absolute path for user config files

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added 3 commits

• f92c6577 - Fix conf file flag for update mdc
• 8e10d0f3 - Enable recursive merge
• 75f1f915 - Use absolute path for user config files

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added 1 commit

• bfd68ad8 - Misc fixes for checks

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added 1 commit

• 54461d7d - Misc fixes for checks

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added 1 commit

• b6ec78d5 - Use absolute paths for all configs

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added 2 commits

• 0f58dcaa - Add notes for fields meant to be secrets
• ad9049c4 - Make all paths absolute

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