Spring Cloud Gateway

Spencer Gibb - @spencerbgibb (Original) Ryan Baxter @ryanjbaxterStephane Maldini - @smaldini

Younjin Jeong - @YZCerberos

yjeong@pivotal.io

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Spencer Gibb

Spring Cloud Gateway

Spring Cloud Gateway

Run on Spring Framework 5+

Spring Cloud Gateway

Run on Spring Boot 2+&

Feature a cloud-native pattern

Spring Cloud Gateway

That cloud-native pattern isAPI Gateway

What is an API Gateway ?

http://microservices.io/patterns/apigateway.html

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Routing

Security

Monitoring

Canary-ing

Monolith Strangling

Resiliency

Gateway Types

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Appliance

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SAAS

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Web Server

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Mesh

Proxy Pattern

Sidecar Pattern

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Developer Oriented

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Zuul 1

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Zuul 1Zuul 2

https://medium.com/netflix-techblog/zuul-2-the-netflix-journey-to-asynchronous-non-blocking-

systems-45947377fb5c

https://www.youtube.com/watch?v=2oXqbLhMS_A

Spring Cloud Gateway

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Built on…

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Project Reactor

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Project Reactor

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Non-Blocking

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Inside the Gateway

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Inside the Gateway

Predicates

PathHostDate/TimeMethodHeadersQuery ParamsCookiesRead Body….

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Inside the Gateway

Pre-Filters

HeadersPathRate LimitingCookiesHystrixModify Body…

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Inside the Gateway

Global Filters

Netty RouterWeb SocketsLoad BalancerMetrics…

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Inside the Gateway

Post Filters

Set statusHeadersCookies…

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spring:

cloud:

gateway:

- id: foo_route

uri: lb://foo

predicates:

- Host=**.foo.org

- Path=/headers

- Method=GET

- Header=X-Request-Id, \d+

- Query=foo, ba.

- Query=baz

- Cookie=chocolate, ch.p

- After=1900-01-20T17:42:47.789-07:00[America/Denver]

filters:

- AddRequestHeader=X-Request-Foo, Bar

- AddResponseHeader=X-Response-Foo, Bar

- Hystrix=foo

- SecureHeaders

- RewritePath=/foo/(?<segment>.*), /$\{segment}

Route Configuration: YAML

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spring:

cloud:

gateway:

- id: foo_route

uri: lb://foo

predicates:

- Host=**.foo.org

- Path=/headers

- Method=GET

- Header=X-Request-Id, \d+

- Query=foo, ba.

- Query=baz

- Cookie=chocolate, ch.p

- After=1900-01-20T17:42:47.789-07:00[America/Denver]

filters:

- AddRequestHeader=X-Request-Foo, Bar

- AddResponseHeader=X-Response-Foo, Bar

- Hystrix=foo

- SecureHeaders

- RewritePath=/foo/(?<segment>.*), /$\{segment}

Route Configuration: YAML

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Route Configuration: Java@Bean

public RouteLocator customRouteLocator(RouteLocatorBuilder builder,

ThrottleGatewayFilterFactory throttle) {

return builder.routes()

.route(r -> r.host("**.abc.org").and().path("/image/png")

.filters(f -> f.addResponseHeader("X-TestHeader", "foobar"))

.uri("http://httpbin.org:80")

)

.route(r -> r.path("/image/webp")

.filters(f -> f.addResponseHeader("X-AnotherHeader", "baz"))

.uri("http://httpbin.org:80")

)

.route(r -> r.order(-1)

.host("**.throttle.org").and().path("/get")

.filters(f -> f.filter(throttle.apply(1, 1, 10,

TimeUnit.SECONDS)))

.uri("http://httpbin.org:80")

)

.build();

}

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Custom Filters

public class SetStatusWebFilterFactory implements GatewayFilterFactory {

@Override

public GatewayFilter apply(Config config) {

final HttpStatus status = parse(config.status);

return (exchange, chain) -> chain.filter(exchange)

.doOnComplete(() -> setResponseStatus(exchange, status));

}

}

Demo

Design Ideas

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Embedded

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Embedded

Sample Use Case

When latency is essential> no added network hops

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Embedded

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Embedded

Sample Use Case

Fine-grained access control for pay-per-use service or fragile backing service

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Facade

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Facade

Sample Use Cases

Prevent direct access to apps

Polyglot compatible

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Facade

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Facade

Sample Use Cases

Cross-cutting concerns

Present common API to clients

Shield clients from app refactoring (monolith → microservices)

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Cross-Cutting + App-Specific

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Cross-Cutting + App-Specific

Sample Use Case

Delegate cross-cutting concerns to a separate common gateway (and a separate dev team!)

What Else Do We Have For Free ?

Remember ?

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Spring Security

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Micrometer Support

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Micrometer Support

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Zipkin Support

https://github.com/spring-cloud/spring-cloud-gateway

https://github.com/spring-cloud-samples/spring-cloud-gateway-sample

http://slides.com/spencer/spring-cloud-gateway

https://github.com/ryanjbaxter/gateway-s1p-2018

Spencer Gibb - @spencerbgibb

Ryan Baxter @ryanjbaxter

Stephane Maldini - @smaldini

Questions?