Proxy Endpoints

Proxy endpoints forward requests to an internal service and return its responses. Portway adds token authentication, environment headers and URL rewriting.

Configuration ​

Each endpoint is defined in its own entity.json:

{
  "Url": "http://internal-service:8080/api/resource",
  "Methods": ["GET", "POST", "PUT", "DELETE"],
  "AllowedEnvironments": ["dev", "test", "prod"]
}

The target host must be listed in allowedHosts of environments/network-access-policy.json (Network access policy). Backends with NTLM authentication (e.g. Exact Globe+, Exact Synergy) require a domain service account (Deploying on Windows Server).

Fallback URLs, retries, response transforms, delete patterns and method translation: Entity configuration.

Request forwarding ​

Forwarded unchanged:

• HTTP method
• Query string, including OData options
• Request body and content type
• Request headers, except hop-by-hop headers, Host, Content-Length and X-Forwarded-*

The X-Forwarded-For header is set from the verified client connection. The client's Authorization header is forwarded unless the environment sets its own.

Environment headers from environments/{env}/settings.json and the endpoint's HttpMethodAppendHeaders are added to every forwarded request and replace client headers of the same name:

# Added by Portway from environment settings
ServerName: PROD-APP-SERVER
DatabaseName: production
Origin: Portway

OData on proxy endpoints ​

OData options, $expand included, are forwarded as written and never parsed. Portway processes $expand only on SQL Table and View endpoints.

The SupportsOData flag documents $select, $top and $filter on the endpoint's GET operation. Without it, the operation documents that query parameters are forwarded unchanged.

{
  "Url": "http://localhost:8020/services/Exact.Entity.REST.EG/Account",
  "Methods": ["GET"],
  "SupportsOData": true
}

URL rewriting ​

Internal URLs in responses are rewritten to gateway paths.

Internal service response:

{
  "_links": {
    "self": "http://internal-service:8080/api/users/123",
    "orders": "http://internal-service:8080/api/users/123/orders"
  }
}

Response returned to the caller:

{
  "_links": {
    "self": "/api/prod/UserService/123",
    "orders": "/api/prod/UserService/123/orders"
  }
}

Caching ​

GET responses are cached for Caching:DefaultCacheDurationSeconds (default 300). The cache key includes the URL, query string, Authorization header and selected tenant values. POST, PUT, DELETE and PATCH bypass the cache and invalidate cached GET responses for the endpoint.

Troubleshooting ​