The ui directory contains static files and templates used in the web UI. For easier distribution, they are statically compiled into the binary using the vfsgen library.

During development it is more convenient to always use the files on disk to directly see changes without recompiling. To make this work, remove the builtinassets build tag in the flags entry in .promu.yml, and then make build. (or build Prometheus using go build ./cmd/prometheus-webhook-dingtalk).

This will serve all files from your local filesystem. This is for development purposes only.