@Idez, which version of Traefik you used?
I'm currently testing with version Traefik version 2.0.0 on Windows and I am not seeing the effect of the api insecure setting, here's the simple configuration I used to test:
traefik.toml
[entrypoints]
[entrypoints.web]
address = ":80"
[providers]
[providers.file]
filename = "routers.toml"
watch = true
[api]
insecure = false
[log]
level = "debug"
filepath = "traefik.log"
format = "common"
[accesslog]
filepath = "access.log"
format = "common"
routers.toml
[http]
[http.routers]
[http.routers.dashboard]
rule = "host(`localhost`)"
entrypoints = ["web"]
service = "api@internal"
The /api/entrypoints path can still be requested with success on "http://locahost/api/entrypoints".
[{"address":":80","transport":{"lifeCycle":{"graceTimeOut":10000000000},"respondingTimeouts":{"idleTimeout":180000000000}},"forwardedHeaders":{},"name":"web"}]