Spring Cloud Zuul RateLimit

Table of Contents

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

Overview

Module to enable rate limit per service in Netflix Zuul.

There are four 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

• 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 and URL just adding multiple values to the list

Usage

Note	Latest version:

Add the dependency on pom.xml

<dependency>
    <groupId>com.marcosbarbero.cloud</groupId>
    <artifactId>spring-cloud-zuul-ratelimit</artifactId>
    <version>LATEST</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>

• 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>

• InMemory

For InMemory implementation there’s no need to add any extra dependency other than com.marcosbarbero.cloud:spring-cloud-zuul-ratelimit

Sample configuration

zuul:
  ratelimit:
    key-prefix: your-prefix
    enabled: true
    repository: REDIS
    behind-proxy: true
    default-policy: #deprecated - please use "default-policy-list"
      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
    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
    policies: #deprecated - please use "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
    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

Available implementations

There are eight implementations provided:

Implementation	Data Storage
InMemoryRateLimiter	ConcurrentHashMap
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.core.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
key-prefix	String	${spring.application.name:rate-limit-application}
repository	CONSUL, REDIS, JPA, BUCKET4J_JCACHE, BUCKET4J_HAZELCAST, BUCKET4J_INFINISPAN, BUCKET4J_IGNITE, IN_MEMORY	IN_MEMORY
default-policy	Policy	-
policies	Map of Policy	-
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

Policy properties:

Property name	Values	Default Value
limit	number of calls	-
quota	time of calls	-
refresh-interval	seconds	60
type	[ORIGIN, USER, URL]	[]

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 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 some 3rd party applications to store and control the rate limit access, as it does not has control over those applications and they can fail once a while the framework itself handles the failure in the class DefaultRateLimiterErrorHandler just by adding some error logs.

If there is a need to handle the errors differently, it can be achieved just by defining a custom RateLimiterErrorHandler bean, 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
        }
    }
  }

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.

Adding Project Lombok Agent

This project uses Project Lombok to generate getters and setters etc. Compiling from the command line this shouldn’t cause any problems, but in an IDE you need to add an agent to the JVM. Full instructions can be found in the Lombok website. The sign that you need to do this is a lot of compiler errors to do with missing methods and fields.

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 marcos.hgb@gmail.com.

Acknowledgement

Footnote

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