It appears that adding a contextPath cookie via https://micronaut-projects.github.io/micronaut-openapi/latest/guide/#serverFilter or https://micronaut-projects.github.io/micronaut-openapi/latest/guide/#urlParameter is only applying the contextPath to fetching the OpenAPI3 spec YAML file.

Retrieval of the various res/** resources (e.g. res/swagger-ui.css, res/swagger-ui-bundle.js, etc.) are still being fetched from the root path / instead of the contextPath specified.

For an app behind a reverse-proxy this causes rendering of SwaggerUI to fail and give a blank page.

• Operating System: MacOS Sonoma 14.5 (though this issue is not platform-specific)
• Micronaut platform: 4.5.0 (though has been observed in any prior release used)
• JDK: 17
• Kotlin: 1.9.23 (though has been observed in any prior release used)

An nginx server configured with a simple reverse-proxy is required to reproduce the issue.

The example-reverse-proxy.conf file in this repository contains a sample configuration for nginx.

On MacOS the shortest path to running the reverse-proxy is installing nginx via Homebrew:

brew install nginx

Find the nginx.conf file:

nginx -t

Drop the contents of example-reverse-proxy.conf into the nginx.conf file.

brew services start nginx

Adjust the app.swagger-context-path property in application.yml according to the scenario being tested (outlined below).

Perform the Gradle build.

Execute the ./gradlew run command in the application directory.

Ensure the app.swagger-context-path property in application.yml is an empty string.

Start the app.

Go to localhost:8080/docs/swagger-ui in a browser; SwaggerUI renders properly.

Ensure the app.swagger-context-path property in application.yml is set to /dev/example.

Start the app.

Go to localhost:8080/docs/swagger-ui in a browser; SwaggerUI does not render properly.

An error page is displayed with message:

Fetch error
Not Found /dev/example/docs/swagger/micronaut-openapi-context-path-issue-1.0.0.yml

^^^the contextPath cookie value is prepended to the OpenAPI3 spec YAML file path, but not to the res/** resources mapped to /docs/swagger-ui-res/**.

The contextPath cookie is present in DevTools for the interactions with the /docs/swagger-ui-res/** endpoints.

Ensure the app.swagger-context-path property in application.yml is set to /dev/example.

Ensure the reverse-proxy is running.

Start the app.

Go to localhost:8081/dev/example/docs/swagger-ui in a browser; SwaggerUI does not render properly.

A blank page is displayed.

The contextPath cookie is present in DevTools for the interactions with the /docs/swagger-ui-res/** endpoints.

However, the URL used for these resources does not include the contextPath cookie value.

For example, in DevTools it is observed that the URL for the swagger-ui-bundle.js resource is http://localhost:8081/docs/swagger-ui-res/swagger-ui-bundle.js instead of http://localhost:8081/dev/example/docs/swagger-ui-res/swagger-ui-bundle.js.