• Introduction
• Quickstart
• Configure
  • Meta config
  • Routing rules
  • API groups
  • Service discovery
  • HTTP server
  • HTTP clients
  • Open tracing
  • Access log
  • Proxy headers
• Plugins
  • Authentication
    • OAuth 2 with JWT access token
    • OAuth 2 with opaque token introspection
  • Request transformation
  • CORS
  • Brute-force protection
  • ACP authorizer
• How to
  • Read routing rules from Consul
  • Read secrets from Vault
  • Inject OAuth2 subject into request
  • Configure SSL/TLS for ingress traffic with private key in Vault secret
  • Configure SSL/TLS for ingress traffic with private key in environment variable or file

Introduction

Pyron is a lightweight, developers, and DevOps friendly API Gateway with advanced authentication and authorization capabilities. It's build using Scala on top of the Vertx.io framework enabling high performance and non-blocking execution. Plugin based architecture allows further extensions of capabilities and features as well as seamless integrations. Native support of the HashiCorp Consul service catalog enables Pyron to bridge the traditional network with service discovery based routing. Support for declarative configuration model allows Pyron to be easily integrated into the CI/CD process.

Supported functionality

Deployment

Pyron can be deployed and run as:

• Standalone JVM process
• Docker Container
• Kubernetes service deployed using Helm

Routing and Proxy

Pyron provides many tools to publish and manage your API endpoints:

• L7 Routing - API calls can be routed to different targets based on the URI path patterns
• URI Rewrite - ability to drop a prefix or modify the URI before the request is proxied to the upstream service
• TCP/IP Proxy Headers - Support for X-Forwarded-For, X-TrueClient-IP, Proxy VIA headers
• Load Balancing - Client-side load balancing support
• Static up-stream service discovery - ability to configure a static set of upstream services to be used in load balancing pool
• Catalog based up-stream service discovery - ability to utilize Consul service catalog to discover instances of the up-stream services
• Static TLS support - ability to enable TLS based on provided certificate and key, ability to configure desired ciphers and TLS versions
• Vault based TLS support - ability to use Vault as a source for the TLS certificates

Request/response Transformation

Cloudentity Pyron can normalize your API by transforming and managing requests to the services it protects.

• HTTP Request Header transformation - ability to inject/modify headers
• HTTP Request path parameter transformation - ability to inject/modify path parameters
• HTTP Request body transformation - ability to modify the request body (currently only available for JSON based payload)
• Cross-Domain Support - CORS headers publishing and support

Logging & Monitoring

• Correlation ID integration - Injection as well as utilization of the external correlation id to relate transactions for full tracing
• Open Tracing support - provides visibility into cross-service communication and instrumentation, enabling the distributed tracing.
• Rich Access Logs - the ability to stream logs to file, socket or Kafka

Authentication

As an enforcement point, Pyron integrates with a wide range of protocols and tools to ensure the request is not only authorized but also secure in the context of a wide range of risk and business rules.

• JWT OAuth Access Token based - authenticate and authorize the request using OAuth Token
• Opaque OAuth Access Token based - authenticate and authorize the request using Opaque OAuth Token with Introspection
• Fallback Authentication - the ability to chain multiple authentication methods together and define the fallback scenarios Request authentication.

Configuration

Pyron offers support for declarative configuration model out of the box with support for various sources of configuration.

• File-based Declarative configuration - the ability to load configuration from JSON/YAML based configuration files
• Consul & Vault based declarative configuration - the ability to load configuration from Consul Key-Value Store as well as secrets and certificates from Vault
• HTTP based declarative configuration - the ability to load configuration from an external HTTP endpoint

Integration with Microservices

• API Request retries - ability to configure failure conditions and count of the API request retries strategy
• Request failover - the ability to failover the request to next health instance of the upstream microservice
• Circuit Breaker support - support for the circuit breaker pattern, works in concert with request retries and request failover
• OpenAPI Specification publishing and transformation - ability to transform and published the OpenAPI specs provided by the upstream services

API Security

Cloudentity Pyron also provides broad API protection with many standard features.

• Brute Force Protection (in-memory implementation) - Ability to protect APIs against brute force attacks or perform simple rate spike arrests - in-memory implementation
• Brute Force Protection (IMDG based) - Enterprise Feature - Ability to protect APIs against brute force attacks or make simple rate spike arrests - implementation using IMDG enabling shared state between all instances of the API Gateway.

Extensibility

Pyron also allows for custom plugins, which can be used to integrate legacy or proprietary systems as part of the standard data flow and enforcement. This could include custom callouts, complex business logic, or custom protocol/security management.

• Plugins - ability to add third-party plugins in Java or Scala
• Plugins Reload - ability to add plugins in runtime

Quickstart

NOTE
You need docker and docker-compose installed with access to docker.artifactory.syntegrity.com artifactory.
Please contact Cloudentity team to get artifactory access.

This section walks you through the steps required to expose an API using Pyron. We will expose http://example.com API at /example path.

Checkout this repository, go into install directory in your terminal and execute docker-compose up -d.

Configure routing rule

Set content of /configs/rules.json to:

{
  "rules": [
    {
      "default": {
        "targetHost": "example.com",
        "targetPort": 80
      },
      "endpoints": [
        {
          "method": "GET",
          "pathPattern": "/example",
          "rewritePath": "/"
        }
      ]
    }
  ]
}

After saving rules.json, wait 5 seconds for Pyron to automatically reload the routing rules.

Verify

Executing curl -v localhost:8080/example should return 200 status code with body of example.com web page.

NOTE
Pyron's alive endpoint is at /alive path. curl -v localhost:8080/alive should return 200 status code.

Environment variables

You can configure Pyron using environment variables defined in install/configs/.pyron_env file. After changing a variable, recreate Pyron container using docker-compose up -d command.

Configure

• Meta config
• Routing rules
  • Method and path pattern
  • Path prefix
  • Rewrite path
  • Rewrite method
  • Response timeout
  • Retry
  • Preserve Host header
  • Request body handling (buffer/stream/drop)
  • Request body size limit
• API groups
• Service discovery
  • Consul service discovery
  • Configuration-based service discovery
  • Self-registration in Consul
• HTTP server
• HTTP clients
  • Default retries and timeout
  • Circuit breaker
• Open tracing
• Access log
  • Authentication context and request headers in access log
• Proxy headers

Meta config

At startup Pyron needs meta-config.json file describing where to read configuration from.

{
  "scanPeriod": 5000,
  "stores": [
    {
      "type": "classpath",
      "format": "json",
      "config": {
        "path": "config.json"
      }
    },
    {
      "type": "file",
      "format": "json",
      "config": {
        "path": "rules.json"
      }
    }
  ]
}

Above meta-config.json defines two configuration stores: config.json from JAR classpath and rules.json from the file system.

config.json defines minimal configuration required to run Pyron. Routing rules are provided in rules.json.

You will find meta-config.json in install/configs folder.

Learn how to read configuration from Consul and secrets from Vault.

Routing rules

A rule defines routing to a target endpoint. Rules are grouped in blocks that share common attributes in the default object. If an endpoint attribute is missing then it is taken from default.

{
  "rules": [
    {
      "default": {
        "targetHost": "example.com",
        "targetPort": 80
      },
      "endpoints": [
        ...
      ]
    }
  ]
}

Attribute	Description
targetHost	host of target service (upstream)
targetPort	port of target service

Method and path pattern

{
  "rules": [
    {
      "default": {
        "targetHost": "example.com",
        "targetPort": 80
      },
      "endpoints": [
        {
          "method": "POST",
          "pathPattern": "/user"
        }
      ]
    }
  ]
}

Attribute	Description
method	HTTP method
pathPattern	regular expression extended with support of path-param placeholders, e.g. /user/{id}

Example: client's call POST /user is proxied to target POST /user.

Path prefix

Expose multiple endpoints using the same path prefix.

{
  "rules": [
    {
      "default": {
        "targetHost": "example.com",
        "targetPort": 80,
        "pathPrefix": "/example",
        "dropPrefix": true
      },
      "endpoints": [
        {
          "method": "POST",
          "pathPattern": "/user"
        },
        {
          "method": "GET",
          "pathPattern": "/user/{id}"
        }
      ]
    }
  ]
}

Attribute	Description
pathPrefix	prefix appended to pathPattern (optional)
dropPrefix	drop path prefix when calling target service (default true)

By default, the prefix is dropped when calling target service. To preserve the prefix set dropPrefix to false.

Example: client's call POST /example/user is proxied to target POST /user.

Rewrite path

{
  "rules": [
    {
      "default": {
        "targetHost": "example.com",
        "targetPort": 80
      },
      "endpoints": [
        {
          "method": "GET",
          "pathPattern": "/user/{id}",
          "rewritePath": "/entities/user/{id}"
        }
      ]
    }
  ]
}

Attribute	Description
rewritePath	path that Pyron calls target service at (optional, pathPattern used if this not set)

Example: client's call GET /user/123 is proxied to target GET /entities/user/123

Rewrite method

{
  "rules": [
    {
      "default": {
        "targetHost": "example.com",
        "targetPort": 80
      },
      "endpoints": [
        {
              "method": "POST",
              "rewriteMethod": "PUT",
              "pathPattern": "/user"
            }
      ]
    }
  ]
}

Attribute	Description
rewriteMethod	method that Pyron calls target service with (optional, method used if this not set)

Example: client's call POST /user is proxied to target PUT /user.

Response timeout

{
  "rules": [
    {
      "default": {
        "targetHost": "example.com",
        "targetPort": 80
      },
      "endpoints": [
        {
          "method": "POST",
          "pathPattern": "/user",
          "call": {
            "responseTimeout": 3000
          }
        }
      ]
    }
  ]
}

Attribute	Description
call.responseTimeout	target service response timeout in milliseconds

Retry

{
  "rules": [
    {
      "default": {
        "targetHost": "example.com",
        "targetPort": 80
      },
      "endpoints": [
        {
          "method": "POST",
          "pathPattern": "/user",
          "call": {
            "retries": 1,
            "failureHttpCodes": [500],
            "retryFailedResponse": true,
            "retryOnException": true
          }
        }
      ]
    }
  ]
}

Attribute	Description
call.retries	maximum number of retries
call.failureHttpCodes	response codes that Pyron retries if returned by target service
call.retryFailedResponse	retry call if target service returned code in failureHttpCodes (default true)
call.retryOnException	retry call on HTTP client exception, e.g. response timeout (default true)

Preserve Host header

{
  "rules": [
    {
      "default": {
        "targetHost": "example.com",
        "targetPort": 80
      },
      "endpoints": [
        {
          "method": "POST",
          "pathPattern": "/user",
          "preserveHostHeader": true
        }
      ]
    }
  ]
}

Attribute	Description
preserveHostHeader	should send to target service Host header received from the client (default false)

By default, Pyron sends target host in Host header to target service, set preserveHostHeader to true to send Host header sent by the client instead.

Request body handling (buffer/stream/drop)

{
  "rules": [
    {
      "default": {
        "targetHost": "example.com",
        "targetPort": 80
      },
      "endpoints": [
        {
          "method": "POST",
          "pathPattern": "/user",
          "requestBody": "buffer"
        }
      ]
    }
  ]
}

Attribute	Description
requestBody	body handling strategy (buffer, stream or drop, default buffer)

• buffer - load entire body into memory, required by some plugins (e.g. transform-request)
• stream - stream the body directly to target service (after applying request plugins)
• drop - ignore the body, do not transfer it to target service (Content-Length header of target request is set to 0)

Request body size limit

{
  "rules": [
    {
      "default": {
        "targetHost": "example.com",
        "targetPort": 80
      },
      "endpoints": [
        {
          "method": "POST",
          "pathPattern": "/user",
          "requestBodyMaxSize": 100
        }
      ]
    }
  ]
}

Attribute	Description
requestBodyMaxSize	max number of kilobytes transferred to target service (optional)

NOTE
If maximum body size is reached then Pyron responds to the client with 413 status code.

If the request body is using chunked Transfer-Encoding (content length is not known upfront) and requestBody is stream then the body streaming to target service stops when requestBodyMaxSize kilobytes has been streamed. Otherwise no data is sent to target service if requestBodyMaxSize limit would be reached.

Set DEFAULT_REQUEST_BODY_MAX_SIZE env variable with default requestBodyMaxSize for all routing rules.

API Groups

API Groups allow separating routing rule sets. You can define a set of rules and expose it on a domain and/or base-path. An incoming request is initially matched against domain and base-path and then dispatched to appropriate set for further processing.

{
  "apiGroups": {
    "example": {
      "_group": {
        "domains": ["demo.com"],
        "basePath": "/apis"
      },
      "_rules": [
        {
          "default": {
            "targetHost": "example.com",
            "targetPort": 8080
          },
          "endpoints": [
            {
              "method": "GET",
              "pathPattern": "/user"
            }
          ]
        }
      ]
    }
  }
}

Attribute	Description
_group.domains	Host headers Pyron matches the API group for
_group.basePath	base path Pyron matches the API group at (optional)

Note _ (underscore) in _rules and _group.

API Groups configuration details.

Service discovery

Pyron Gateway provides support for service discovery utilizing Consul client or configuration object.

{
  "rules": [
    {
      "default": {
        "targetService": "example-service"
      },
      "endpoints": [
        ...
      ]
    }
  ]
}

Attribute	Description
targetService	service-name of target nodes from service-discovery

Pyron calls nodes with targetService service-name using a round-robin load balancer.

Below you will find instructions on how to enable service discovery providers.

Consul service discovery

Add sd-provider/consul to MODULES environment variable, i.e. MODULES=["sd-provider/consul"].

Env variable	Description
CONSUL_HOST	host
CONSUL_PORT	port (default 8500)
CONSUL_SSL	SSL enabled (default false)
CONSUL_ACL_TOKEN	ACL token (optional)
CONSUL_DC	data center (optional)
CONSUL_TIMEOUT	connection timeout (optional)
CONSUL_SD_SCAN_PERIOD	nodes refresh period in milliseconds (default 2000)

Note: nodes registered in Consul need to have http-endpoint tag and ssl tag if exposed over SSL.

Configuration-based service discovery

Add sd-provider/static to MODULES environment variable, i.e. MODULES=["sd-provider/static"].

Add sd-records configuration attribute (e.g. in system.json file).

{
  "sd-records": [
    {
      "name": "example-service",
      "location": {
        "host": "example.com",
        "port": 80,
        "ssl": false,
        "root": "/v1"
      }
    }
  ]
}

Attribute	Description
name	service-name of target node
location.host	host of target node
location.port	port of target node
location.ssl	SSL of target node
location.root	root path of target node (optional)

Self-registration in Consul

Pyron node can register itself in Consul for service discovery.

Add sd-registrar/consul to MODULES environment variable, i.e. MODULES=["sd-registrar/consul"].

Env variable	Description
CONSUL_HOST	host
CONSUL_PORT	port (default 8500)
CONSUL_SSL	SSL enabled (default false)
CONSUL_ACL_TOKEN	ACL token (optional)
CONSUL_DC	data center (optional)
CONSUL_TIMEOUT	connection timeout (optional)
REGISTER_SD_SERVICE_NAME	Pyron service name
REGISTER_SD_HOST	host of Pyron node
REGISTER_SD_PORT	port of Pyron node
REGISTER_SD_SSL	ssl of Pyron node (default false)
REGISTER_SD_HEALTHCHECK_HOST	host of Pyron health-check (default SELF_SD_SERVICE_NAME)
REGISTER_SD_HEALTHCHECK_PORT	port of Pyron health-check (default SELF_SD_HEALTHCHECK_PORT)
REGISTER_SD_HEALTHCHECK_PATH	path of Pyron health-check (default /alive)
REGISTER_SD_HEALTHCHECK_INTERVAL	health-check interval (default 3s)
REGISTER_SD_DEREGISTER_AFTER	node de-register period when health-check fails (default 600s)
REGISTER_SD_TAGS	extra node tags (default [])

HTTP server

Pyron uses Vertx HTTP server implementation. Use environment variables to configure io.vertx.core.http.HttpServerOptions.

Environment variables map to HttpServerOptions (see docs) attributes in following way:

• All variable names start with HTTP_SERVER_ prefix,
• HttpServerOptions attribute name is capitalized and camel-case is replaced with underscore _.
• If an attribute has object value then it's sub-attribute env names are prefixed with HTTP_SERVER_{parent-env-name}__ (note double underscore).

Examples:

Name	HttpServerOptions attribute
HTTP_SERVER_PORT	port
HTTP_SERVER_ACCEPT_BACKLOG	acceptBacklog
HTTP_SERVER_PEM_TRUST_OPTIONS__CERT_PATHS	pemTrustOptions.certPaths

In order to set HttpServerOptions attribute with collection value use JSON syntax, e.g. HTTP_SERVER_PEM_TRUST_OPTIONS__CERT_PATHS=["/etc/ssl/cert.pem"].

HTTP clients

Pyron uses Vertx implementation of HTTP clients. Use environment variables to configure default io.vertx.core.http.HttpClientOptions.

Environment variables map to HttpClientOptions (see docs) attributes the same way they map to HttpServerOptions.

Name	HttpClientOptions attribute
HTTP_CLIENT_MAX_POOL_SIZE	maxPoolSize
HTTP_CLIENT_KEEP_ALIVE	keepAlive
HTTP_CLIENT_TRUST_ALL	trustAll

You can configure HTTP client for each target service separately (note that default attributes from environment variables are ignored in this case):

{
  "smart-http-target-clients": {
    "example-service": {
      "http": {
        "maxPoolSize": 50
      }
    }
  }
}

Default retries and timeout

{
  "smart-http-target-clients": {
    "example-service": {
      "responseTimeout": 3000,
      "retries": 5,
      "failureHttpCodes": [500]
    }
  }
}

Target client retry and timeout default attributes are overridden by values set in routing rule.

Circuit breaker

Configure io.vertx.circuitbreaker.CircuitBreakerOptions in circuitBreaker object to enable circuit breaker functionality per target service.

{
  "smart-http-target-clients": {
    "example-service": {
      "circuitBreaker": {
        "maxFailures": 3
      }
    }
  }
}

Open tracing

Add tracing/jaeger to MODULES environment variable, i.e. MODULES=["tracing/jaeger"].

Env variable	Description
TRACING_SERVICE_NAME	Pyron name in Jaeger
JAEGER_AGENT_HOST	Jaeger agent host (optional)
JAEGER_AGENT_PORT	Jaeger agent port (optional)
JAEGER_SAMPLER_MANAGER_HOST_PORT	Jaeger sampler host:port (optional)
TRACING_FORMAT	tracing format: cloudentity, jaeger, zipkin (default cloudentity)

cloudentity tracing format allows configuration of span context key and baggage item prefix:

Env variable	Description
TRACING_TRACE_ID	span context key (default x-trace-id)
TRACING_BAGGAGE_PREFIX	baggage item prefix (default x-ctx-)

Access log

{
  "timestamp": "2018-04-06T15:14:33.929Z",
  "trueClientIp": "192.168.0.13",
  "remoteClient": "192.168.0.127",
  "http": {
    "httpVersion": "HTTP/1.1",
    "method": "GET",
    "uri": "/service-a/user/123",
    "status": "200"
  },
  "gateway": {
    "method": "GET",
    "path": "/user/{userId}",
    "pathPrefix": "/service-a",
    "aborted": false,
    "targetService": "service-a"
  },
  "request": {
    "headers": {
      "Host": ["example.com"]
    }
  },
  "authnCtx": {
      "method": "oauth2",
      "user":"4b1b17f8-a934-458f-3c08-cc01d9f9b917",
      "uid":"admin@cloudentity.com"
    }
  },
  "timeMs": "3"
}

Attribute	Description
timestamp	request time in ISO 8601 format
trueClientIp	IP address of original client, either X-Real-IP header or first IP from X-Forwarded-For or remote address
remoteIp	IP of the direct client
authnCtx	authentication context
httpVersion	HTTP version
method	HTTP method
uri	URI without host
status	HTTP status code
gateway.method	method of matching rule
gateway.path	path pattern of matching rule
gateway.pathPrefix	path prefix of matching rule
gateway.aborted	true if Pyron aborted the call without proxying to target service; false otherwise
gateway.interrupted	true if the call was interrupted by the client; false otherwise
gateway.failed	true if an exception occurred on target call or plugin application; not set otherwise
gateway.targetService	target service of matching rule
request.headers	request headers
timeMs	time from receiving the request body till writing full response body

Authentication context and request headers in the access log

Env variable	Description	Example
ACCESS_LOG_SLF4J_DISABLED	disable SLF4J access logging (default false)	true
ACCESS_LOG_AUTHN_CTX	authentication context set in access log (optional)	{"method":"authnMethod","user":"sub","uid":"email"}
ACCESS_LOG_REQUEST_HEADERS_ALL	log all headers flag (default false)	true
ACCESS_LOG_REQUEST_HEADERS_WHITELIST	log selected headers (optional)	["Host","User-Agent"]
ACCESS_LOG_REQUEST_HEADERS_MASK_WHOLE	mask whole logged header (optional)	["Authorization"]
ACCESS_LOG_REQUEST_HEADERS_MASK_PARTIAL	mask logged header partially (optional)	["Token"]

Proxy headers

Pyron applies following request headers modification (unless disabled):

• Add remote-address.host to X-Forwarded-For headers
• Add remote-address.protocol to X-Forwarded-Proto headers
• If Host header is set then add it to X-Forwarded-Host headers
• If True Client IP header is missing then set it to first X-Forwarded-For value
• Set True Client IP header to upstream service

Env variable	Description
PROXY_HEADERS_ENABLED	enable proxy headers (default true)
INPUT_TRUE_CLIENT_IP_HEADER	True Client IP header name (default X-Real-IP)
OUTPUT_TRUE_CLIENT_IP_HEADER	Outgoing True Client IP header name (default X-Real-IP)

Plugins

Plugins extend request-response flow, e.g. can enforce authorization rules, modify request or response, enhance access or audit logs, etc.

• Authentication
• Request transformation
• CORS
• ACP authorizer

Read about plugins application in routing rules.

How to

• Read routing rules from Consul
• Read secrets from Vault
• Inject OAuth2 subject into request
• Configure SSL/TLS for ingress traffic with private key in Vault secret
• Configure SSL/TLS for ingress traffic with private key in environment variable or file