GraphQL Proxy

A lightweight, configurable GraphQL proxy server that supports operation-based routing and load balancing.

Features

• Operation-based routing (query/mutation/subscription)
• Operation name-based routing
• Weighted load balancing
• Local metrics tracking
• Configurable timeouts and connection settings
• JSON/Text logging with configurable output
• Support for both GET and POST requests
• GraphQL operation validation
• Header forwarding

Installation

go install github.com/abdullah2993/graphql-proxy/cmd/gqlproxy@latest

Usage

1. Create a config file (default: config.yaml):

server:
  read_timeout: 30s
  write_timeout: 30s
  idle_timeout: 90s
  max_idle_conns: 100
  max_idle_conns_host: 10
  handshake_timeout: 10s
  response_timeout: 30s

logging:
  level: info
  format: json
  output: stdout

upstreams:
  - url: "http://graphql1:8080/graphql"
    capabilities:
      - query
      - mutation
    operation_names:
      - getUserProfile
      - updateUserProfile
    weight: 2

2. Run the proxy:

gqlproxy -addr :8080 -config config.yaml

Configuration

Server Settings

• read_timeout: Maximum duration for reading the entire request
• write_timeout: Maximum duration for writing the response
• idle_timeout: Maximum duration to wait for the next request
• max_idle_conns: Maximum number of idle connections
• max_idle_conns_host: Maximum idle connections per host
• handshake_timeout: Maximum duration for TLS handshake
• response_timeout: Maximum duration for upstream response

Logging Settings

• level: Log level (debug, info, warn, error)
• format: Log format (json, text)
• output: Log output (stdout, stderr, or file path)

Upstream Settings

• url: GraphQL server endpoint
• capabilities: List of supported operations (query, mutation, subscription)
• operation_names: List of operation names this server can handle (optional)
• weight: Load balancing weight (higher number = more traffic)

API

The proxy accepts GraphQL requests via:

POST

• Content-Type: application/json

{
  "query": "query { ... }",
  "variables": {},
  "operationName": "optional"
}

• Content-Type: application/graphql

query {
  ...
}

GET

/graphql?query=query{...}&variables={}&operationName=optional

Load Balancing

The proxy uses weighted random selection to distribute requests among eligible upstream servers. A server is considered eligible if it:

1. Supports the operation type (query/mutation/subscription)
2. Can handle the specific operation name (if configured)