loki-reverse-proxy

Reverse proxy for Loki API with proper Grafana API token authentication.

Under the hood it use Grafana /api/auth/keys API to validate the token and then dispatch the request to Loki.

Caution

When succesfully authenticated, by default tokens are cached for 5 minutes

Getting started

$ git clone https://github.com/MyUnisoft/loki-reverse-proxy.git
$ cd loki-reverse-proxy
$ npm ci
$ npm run build

Environment Variables

To configure the project you have to register (set) environment variables on your system. These variables can be set in a .env file (that file must be created at the root of the project).

GRAFANA_URL=""
LOKI_URL=""

SERVER_HOST=xxx.domain.com
SERVER_PORT=4000

# SSL/TLS Configuration
SERVER_SSL_ENABLED=false
SERVER_SSL_CERT=/absolute/path/to/file.crt
SERVER_SSL_KEY=/absolute/path/to/file.key

# Enable if behind a proxy like NGINX or Haproxy
TRUST_PROXY=false

# Automatically forward pino (logger) logs to LOKI_URL
SELF_MONITORING=false

Let's go baby 🔥

$ npm start

Env

Here is the full Zod schema for envs:

const envSchema = z.object({
  GRAFANA_URL: z.string().url().trim(),
  LOKI_URL: z.string().url().trim(),
  TOKEN_CACHE_MS: z.coerce.number().optional().default(1_000 * 60 * 5),
  SERVER_PORT: z.coerce.number().optional().default(0),
  SERVER_HOST: z.string().optional(),
  SERVER_SSL_ENABLED: zBoolean("false"),
  SERVER_SSL_CERT: z.string().optional(),
  SERVER_SSL_KEY: z.string().optional(),
  SERVER_SSL_CA: z.string().optional(),
  TRUST_PROXY: zBoolean("false"),
  SELF_MONITORING: zBoolean("false")
});

Where zBoolean is defined as

function zBoolean(defaultValue?: "false" | "true") {
  const zEnum = z.enum(["true", "false"]).transform((value) => value === "true");

  return defaultValue ? zEnum.optional().default(defaultValue) : zEnum;
}

API

/health

Return proxy uptime

{
  "uptime": 10
}

Roadmap

• Find a way to also proxy Grafana API (currently that's not possible with the same root prefix).

Contributors ✨

Thanks goes to these wonderful people (emoji key):

Thomas.G 💻 🐛 🛡️ 📖

PierreDemailly 👀

License

MIT