* [FEATURE] File Secret Loading
* add a validator for secrets
* run the secrets validator before the main config validator
* only allow a secret to be defined in one of: config, env, file env
* remove LF if found in file
* update configuration before main config validation
* fix unit tests
* implement secret testing
* refactor the secrets validator
* make check os agnostic
* update docs
* add warning when user attempts to use ENV instead of ENV file
* discourage ENV in docs
* update config template
* oxford comma
* apply suggestions from code review
* rename Validate to ValidateConfiguration
* add k8s example
* add deprecation notice in docs and warning
* style changes
* implement SMTP notifier startup check
* check dial, starttls, auth, mail from, rcpt to, reset, and quit
* log the error on failure
* implement mock
* misc optimizations, adjustments, and refactoring
* implement validate_skip config option
* fix comments to end with period
* fix suites that used smtp notifier without a smtp container
* add docs
* add file notifier startup check
* move file mode into const.go
* disable gosec linting on insecureskipverify since it's intended, warned, and discouraged
* minor PR commentary adjustment
* apply suggestions from code review
Co-Authored-By: Amir Zarrinkafsh <nightah@me.com>
* [FEATURE] Customizable Email Subject
* allow users to optionally change email subject
* this is so they can more easily communicate the source of the email
* Update docs/configuration/notifier/smtp.md
Co-Authored-By: Amir Zarrinkafsh <nightah@me.com>
Co-authored-by: Clément Michaud <clement.michaud34@gmail.com>
Co-authored-by: Amir Zarrinkafsh <nightah@me.com>
