fake azure device code login webserver

this was written for my job so that i could have an emulation of running kubelogin.exe in a -login devicecode context.

must run with the --disable-instance-discovery flag.

how it works

long story short: i forced gemini to check the requests being made to the webserver when i ran kubelogin.exe against the ip.

webserver

it is important to note that kubelogin.exe requires that authority hosts be https, therefore, for this, we rely on caddy to make a reverse-proxy.

we start a webserver on localhost:3001 as http and then start a reverse proxy which serves it on localhost:3000 as https.

requests

gemini accepts functionally all requests, but appropriately fulfills json's in the format they are required to be by kubelogin.exe.

it correctly implements the device_code standard, and serves back a token that expires in one hour. the access_token field is a random JWT.

how to run

please only execute the server through npm as such:

> npm run fake-azure

this will run a powershell script that also starts the reverse-proxy caddy server and kills it when you SIGINT.

usage example

> kubelogin.exe get-token --login devicecode `
∙   --server-id sid `
∙   --client-id cid `
∙   --tenant-id custom `
∙   --authority-host https://127.0.0.1:3000/ `
∙   --disable-instance-discovery
To sign in, use a web browser to open the page https://127.0.0.1:3000/device.
{"kind":"ExecCredential","apiVersion":"client.authentication.k8s.io/v1beta1","spec":{"interactive":false},"status":{"expirationTimestamp":"2026-01-07T03:47:48Z","token":"eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJyZWFsIjoiZGF0YSIsImlhdCI6MTc2Nzc1NDA2OH0.duIHauMrsHh4Fj2MtRZ-Ya1tU4mwR4PZrWAypTdUt4g"}}