Spring Cloud Zuul RateLimit

Table of Contents

• Overview
• Usage
• Available implementations
• Common application properties
• Further Customization
  • Key Generator
  • Error Handling
  • Event Handling
• Contributing
  • Code of Conduct
  • Acknowledgement
• Footnote

Overview

Module to enable rate limit per service in Netflix Zuul.

There are five built-in rate limit approaches:

• Authenticated User

  • Uses the authenticated username or 'anonymous'

• Request Origin

  • Uses the user origin request

• URL

  • Uses the request path of the downstream service

• URL Pattern

  • Uses the request Ant path pattern to the downstream service

• ROLE

  • Uses the authenticated user roles

• Request method

  • Uses the HTTP request method

• Request header

  • Uses the HTTP request header

• Global configuration per service:

  • This one does not validate the request Origin, Authenticated User or URI

  • To use this approach just don’t set param 'type'

Note	It is possible to combine Authenticated User, Request Origin, URL, ROLE and Request Method just adding multiple values to the list

Usage

Note	Latest version:

Note	If you are using Spring Boot version 1.5.x you MUST use Spring Cloud Zuul RateLimit version 1.7.x. Please take a look at the Maven Central and pick the latest artifact in this version line.

Add the dependency on pom.xml

<dependency>
    <groupId>com.marcosbarbero.cloud</groupId>
    <artifactId>spring-cloud-zuul-ratelimit</artifactId>
    <version>${latest-version}</version>
</dependency>

Add the following dependency accordingly to the chosen data storage:

• Redis

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>

• Consul

<dependency>
   <groupId>org.springframework.cloud</groupId>
   <artifactId>spring-cloud-starter-consul</artifactId>
</dependency>

• Spring Data JPA

<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>

This implementation also requires a database table, bellow here you can find a sample script:

CREATE TABLE rate (
  rate_key VARCHAR(255) NOT NULL,
  remaining BIGINT,
  remaining_quota BIGINT,
  reset BIGINT,
  expiration TIMESTAMP,
  PRIMARY KEY(rate_key)
);

• Bucket4j JCache

<dependency>
     <groupId>com.github.vladimir-bukhtoyarov</groupId>
     <artifactId>bucket4j-core</artifactId>
</dependency>
<dependency>
     <groupId>com.github.vladimir-bukhtoyarov</groupId>
     <artifactId>bucket4j-jcache</artifactId>
</dependency>
<dependency>
     <groupId>javax.cache</groupId>
     <artifactId>cache-api</artifactId>
</dependency>

• Bucket4j Hazelcast (depends on Bucket4j JCache)

<dependency>
     <groupId>com.github.vladimir-bukhtoyarov</groupId>
     <artifactId>bucket4j-hazelcast</artifactId>
</dependency>
<dependency>
     <groupId>com.hazelcast</groupId>
     <artifactId>hazelcast</artifactId>
</dependency>

• Bucket4j Infinispan (depends on Bucket4j JCache)

<dependency>
     <groupId>com.github.vladimir-bukhtoyarov</groupId>
     <artifactId>bucket4j-infinispan</artifactId>
</dependency>
<dependency>
     <groupId>org.infinispan</groupId>
     <artifactId>infinispan-core</artifactId>
</dependency>

• Bucket4j Ignite (depends on Bucket4j JCache)

<dependency>
     <groupId>com.github.vladimir-bukhtoyarov</groupId>
     <artifactId>bucket4j-ignite</artifactId>
</dependency>
<dependency>
     <groupId>org.apache.ignite</groupId>
     <artifactId>ignite-core</artifactId>
</dependency>

Sample YAML configuration

zuul:
  ratelimit:
    key-prefix: your-prefix
    enabled: true
    repository: REDIS
    behind-proxy: true
    add-response-headers: true
    deny-request:
      response-status-code: 404 #default value is 403 (FORBIDDEN)
      origins:
        - 200.187.10.25
        - somedomain.com
    default-policy-list: #optional - will apply unless specific policy exists
      - limit: 10 #optional - request number limit per refresh interval window
        quota: 1000 #optional - request time limit per refresh interval window (in seconds)
        refresh-interval: 60 #default value (in seconds)
        type: #optional
          - user
          - origin
          - url
          - http_method
    policy-list:
      myServiceId:
        - limit: 10 #optional - request number limit per refresh interval window
          quota: 1000 #optional - request time limit per refresh interval window (in seconds)
          refresh-interval: 60 #default value (in seconds)
          type: #optional
            - user
            - origin
            - url
        - type: #optional value for each type
            - user=anonymous
            - origin=somemachine.com
            - url=/api #url prefix
            - role=user
            - http_method=get #case insensitive
            - http_header=customHeader
        - type:
            - url_pattern=/api/*/payment

Sample Properties configuration

zuul.ratelimit.enabled=true
zuul.ratelimit.key-prefix=your-prefix
zuul.ratelimit.repository=REDIS
zuul.ratelimit.behind-proxy=true
zuul.ratelimit.add-response-headers=true

zuul.ratelimit.deny-request.response-status-code=404
zuul.ratelimit.deny-request.origins[0]=200.187.10.25
zuul.ratelimit.deny-request.origins[1]=somedomain.com

zuul.ratelimit.default-policy-list[0].limit=10
zuul.ratelimit.default-policy-list[0].quota=1000
zuul.ratelimit.default-policy-list[0].refresh-interval=60

# Adding multiple rate limit type
zuul.ratelimit.default-policy-list[0].type[0]=user
zuul.ratelimit.default-policy-list[0].type[1]=origin
zuul.ratelimit.default-policy-list[0].type[2]=url
zuul.ratelimit.default-policy-list[0].type[3]=http_method

# Adding the first rate limit policy to "myServiceId"
zuul.ratelimit.policy-list.myServiceId[0].limit=10
zuul.ratelimit.policy-list.myServiceId[0].quota=1000
zuul.ratelimit.policy-list.myServiceId[0].refresh-interval=60
zuul.ratelimit.policy-list.myServiceId[0].type[0]=user
zuul.ratelimit.policy-list.myServiceId[0].type[1]=origin
zuul.ratelimit.policy-list.myServiceId[0].type[2]=url

# Adding the second rate limit policy to "myServiceId"
zuul.ratelimit.policy-list.myServiceId[1].type[0]=user=anonymous
zuul.ratelimit.policy-list.myServiceId[1].type[1]=origin=somemachine.com
zuul.ratelimit.policy-list.myServiceId[1].type[2]=url_pattern=/api/*/payment
zuul.ratelimit.policy-list.myServiceId[1].type[3]=role=user
zuul.ratelimit.policy-list.myServiceId[1].type[4]=http_method=get
zuul.ratelimit.policy-list.myServiceId[1].type[5]=http_header=customHeader

Both 'quota' and 'refresh-interval', can be expressed with Spring Boot’s duration formats:

• A regular long representation (using seconds as the default unit)

• The standard ISO-8601 format used by java.time.Duration (e.g. PT30M means 30 minutes)

• A more readable format where the value and the unit are coupled (e.g. 10s means 10 seconds)

Available implementations

There are eight implementations provided:

Implementation	Data Storage
ConsulRateLimiter	Consul
RedisRateLimiter	Redis
SpringDataRateLimiter	Spring Data
Bucket4jJCacheRateLimiter	Bucket4j
Bucket4jHazelcastRateLimiter
Bucket4jIgniteRateLimiter
Bucket4jInfinispanRateLimiter

Bucket4j implementations require the relevant bean with @Qualifier("RateLimit"):

• JCache - javax.cache.Cache

• Hazelcast - com.hazelcast.map.IMap

• Ignite - org.apache.ignite.IgniteCache

• Infinispan - org.infinispan.functional.ReadWriteMap

Common application properties

Property namespace: zuul.ratelimit

Property name	Values	Default Value
enabled	true/false	false
behind-proxy	true/false	false
response-headers	NONE, STANDARD, VERBOSE	VERBOSE
key-prefix	String	${spring.application.name:rate-limit-application}
repository	CONSUL, REDIS, JPA, BUCKET4J_JCACHE, BUCKET4J_HAZELCAST, BUCKET4J_INFINISPAN, BUCKET4J_IGNITE	-
deny-request	DenyRequest	-
default-policy-list	List of Policy	-
policy-list	Map of Lists of Policy	-
postFilterOrder	int	FilterConstants.SEND_RESPONSE_FILTER_ORDER - 10
preFilterOrder	int	FilterConstants.FORM_BODY_WRAPPER_FILTER_ORDER

Deny Request properties

Property name	Values	Default Value
origins	list of origins to have the access denied	-
response-status-code	the http status code to be returned on a denied request	403 (FORBIDDEN)

Policy properties:

Property name	Values	Default Value
limit	number of requests	-
quota	time of requests	-
refresh-interval	seconds	60
type	[ORIGIN, USER, URL, URL_PATTERN, ROLE, HTTP_METHOD, HTTP_HEADER]	[]
breakOnMatch	true/false	false

Further Customization

This section details how to add custom implementations

Key Generator

If the application needs to control the key strategy beyond the options offered by the type property then it can be done just by creating a custom RateLimitKeyGenerator bean^[1] implementation adding further qualifiers or something entirely different:

  @Bean
  public RateLimitKeyGenerator ratelimitKeyGenerator(RateLimitProperties properties, RateLimitUtils rateLimitUtils) {
      return new DefaultRateLimitKeyGenerator(properties, rateLimitUtils) {
          @Override
          public String key(HttpServletRequest request, Route route, RateLimitProperties.Policy policy) {
              return super.key(request, route, policy) + ":" + request.getMethod();
          }
      };
  }

Error Handling

This framework uses 3rd party applications to control the rate limit access and these libraries are out of control of this framework. If one of the 3rd party applications fails, the framework will handle this failure in the DefaultRateLimiterErrorHandler class which will log the error upon failure.

If there is a need to handle the errors differently, it can be achieved by defining a custom RateLimiterErrorHandler bean^[2], e.g:

  @Bean
  public RateLimiterErrorHandler rateLimitErrorHandler() {
    return new DefaultRateLimiterErrorHandler() {
        @Override
        public void handleSaveError(String key, Exception e) {
            // custom code
        }

        @Override
        public void handleFetchError(String key, Exception e) {
            // custom code
        }

        @Override
        public void handleError(String msg, Exception e) {
            // custom code
        }
    }
  }

Event Handling

If the application needs to be notified when a rate limit access was exceeded then it can be done by listening to RateLimitExceededEvent event:

    @EventListener
    public void observe(RateLimitExceededEvent event) {
        // custom code
    }

Contributing

Spring Cloud Zuul Rate Limit is released under the non-restrictive Apache 2.0 license, and follows a very standard Github development process, using Github tracker for issues and merging pull requests into master. If you want to contribute even something trivial please do not hesitate, but follow the guidelines below.

Code of Conduct

This project adheres to the Contributor Covenant code of conduct. By participating, you are expected to uphold this code. Please report unacceptable behavior to [email protected].

Acknowledgement

Footnote

Any doubt open an issue. Any fix send me a Pull Request.

---

1. By declaring a new RateLimitKeyGenerator, you replace the DefaultRateLimitKeyGenerator.

2. By declaring a new RateLimitErrorHandler, you replace the DefaultRateLimitErrorHandler.