fix!: Correctly construct OIDC endpoints

[sbernauer]

Description

Related to stackabletech/nifi-operator#716, but also will fix stuff in all other tools using OIDC (at least Superset and Trino)

Implementations

• fix: Construction of OIDC endpoint when rootPath has no trailing slash nifi-operator#718
• fix: Construction of OIDC endpoint when rootPath has a trailing slash trino-operator#673
• fix: Construction of OIDC endpoint when rootPath has a trailing slash druid-operator#656
• fix: Construction of OIDC endpoint when rootPath has a trailing slash airflow-operator#547
• fix: Construction of OIDC endpoint when rootPath has a trailing slash superset-operator#569

Definition of Done Checklist

• Not all of these items are applicable to all PRs, the author should update this template to only leave the boxes in that are relevant
• Please make sure all these things are done and tick the boxes

# Author
- [ ] Changes are OpenShift compatible
- [ ] CRD changes approved
- [ ] Integration tests passed (for non trivial changes)

# Reviewer
- [ ] Code contains useful comments
- [ ] (Integration-)Test cases added
- [ ] Documentation added or updated
- [ ] Changelog updated
- [ ] Cargo.toml only contains references to git tags (not specific commits or branches)

# Acceptance
- [ ] Feature Tracker has been updated
- [ ] Proper release label has been added

[Techassi]

LGTM, mostly minor comments.

[Techassi]

Also, we should maybe think about default to an empty string instead.

operator-rs/crates/stackable-operator/src/commons/authentication/oidc.rs

Lines 52 to 54 in 4a8d377

	/// Root HTTP path of the identity provider. Defaults to `/`.
	#[serde(default = "default_root_path")]
	root_path: String,

[sbernauer]

Also, we should maybe think about default to an empty string instead.

Even when you change the default to an empty string it currently still returns https://my.keycloak.server/. I personally fine the / a bit more intuitive default (regardless if we strip trailing slashes anyway)

[Techassi]

Two very minor comments.

[sbernauer]

Release notes

All the affected operators are listed below in the description.

• Nifi Operator
• Trino Operator
• Druid Operator
• Airflow Operator
• Superset Operator

Snippet:

Operators have been fixed to work correctly with OpenID Connect rootPaths with and without trailing slashes.