--- title: "How to Proxy External Services in Apache APISIX Ingress Controller - API7.ai" description: "The methods of proxying external services in APISIX Ingress Controller are introduced." url: "https://api7.ai/blog/proxy-services-in-apisix-ingress-controller" --- [Blog](https://api7.ai/blog) [Products](https://api7.ai/category/products)[Technology](https://api7.ai/category/technology)[Ecosystem](https://api7.ai/category/ecosystem)[Case Study](https://api7.ai/category/usercase)[Team & Community](https://api7.ai/category/community) Search ⌘ + K [Blog](https://api7.ai/blog) Products # How to Proxy External Services in Apache APISIX Ingress Controller Yeqi Peng January 13, 2023 [Products](https://api7.ai/category/products) In this tutorial, we will introduce how to configure external services in ApisixUpstream resources. This is useful when your service depends on a third-party service or a service from another K8s cluster. It also provides a way to manage your ApisixRoute with shared ExternalName services, without modifying a large number of ApisixRoutes when the referenced service name is updated. ## Prerequisites - an available Kubernetes cluster - an available APISIX and APISIX Ingress Controller installation We assume that your APISIX is installed in the `apisix` namespace. ## Introduction APISIX Ingress supports configuring external services as backends, both for K8s ExternalName services and direct domains. In this case, we don't configure the `backends` field in the ApisixRoute resource. Instead, we will use the `upstreams` field to refer to an ApisixUpstream resource with the `externalNodes` field configured. For example: ``` # httpbin-route.yaml apiVersion: apisix.apache.org/v2 kind: ApisixRoute metadata: name: httpbin-route spec: http: - name: rule1 match: hosts: - local.httpbin.org paths: - /* # backends: # We won't use the `backends` field # - serviceName: httpbin # servicePort: 80 upstreams: - name: httpbin-upstream ``` This configuration tells the ingress controller not to resolve upstream hosts through the K8s services but to use the configuration defined in the referenced ApisixUpstream. The referenced ApisixUpstream *MUST* have the `externalNodes` field configured. For example: ``` # httpbin-upstream.yaml apiVersion: apisix.apache.org/v2 kind: ApisixUpstream metadata: name: httpbin-upstream spec: externalNodes: - type: Domain name: httpbin.org ``` In this yaml example, we configured `httpbin.org` as the backend. The type `Domain` indicates that this is a third-party service, and any domain name is supported here. If you want to use an external name service in the K8s cluster, the type should be `Service` and the name should be the service name. By configuring ApisixUpstream with the type `Service`, the ingress controller will automatically keep track of the content of the ExternalName service and its changes. ## External Domain Upstream ``` apiVersion: apisix.apache.org/v2 kind: ApisixRoute metadata: name: httpbin-route spec: http: - name: rule1 match: hosts: - local.httpbin.org paths: - /* upstreams: - name: httpbin-upstream --- apiVersion: apisix.apache.org/v2 kind: ApisixUpstream metadata: name: httpbin-upstream spec: externalNodes: - type: Domain name: httpbin.org ``` After applying the above configuration, we can try to access `httpbin.org` directly through APISIX. ``` kubectl exec -it -n apisix APISIX_POD_NAME -- curl -i -H "Host: local.httpbin.org" http://127.0.0.1:9080/get ``` If everything works, you will see the result like this: ``` HTTP/1.1 200 OK Content-Type: application/json Content-Length: 321 Connection: keep-alive Date: Thu, 15 Dec 2022 10:47:30 GMT Access-Control-Allow-Origin: * Access-Control-Allow-Credentials: true Server: APISIX/3.0.0 { "args": {}, "headers": { "Accept": "*/*", "Host": "local.httpbin.org", "User-Agent": "curl/7.29.0", "X-Amzn-Trace-Id": "Root=xxxxx", "X-Forwarded-Host": "local.httpbin.org" }, "origin": "127.0.0.1, xxxxxxxxx", "url": "http://local.httpbin.org/get" } ``` The header `Server: APISIX/3.0.0` indicates that the request has been sent from APISIX. And the response contains `X-Amzn-Trace-Id` indicating that the request was handled by the online httpbin service. ## External Name Service Upstream Let's deploy a simple httpbin app in the namespace `test` as the backend for the external name service we will create later. ``` kubectl create ns test kubectl -n test run httpbin --image-pull-policy IfNotPresent --image=kennethreitz/httpbin --port 80 kubectl -n test expose pod/httpbin --port 80 ``` Then use the following configuration to create an ExternalName service in the `apisix` namespace. ``` apiVersion: v1 kind: Service metadata: name: ext-httpbin spec: type: ExternalName externalName: httpbin.test.svc ``` Now we can create an ExternalName service ApisixRoute and ApisixUpstream. ``` apiVersion: apisix.apache.org/v2 kind: ApisixRoute metadata: name: ext-route spec: http: - name: rule1 match: hosts: - ext.httpbin.org paths: - /* upstreams: - name: ext-upstream --- apiVersion: apisix.apache.org/v2 kind: ApisixUpstream metadata: name: ext-upstream spec: externalNodes: - type: Service name: ext-httpbin ``` Once the configurations are synced, try to access it with the following command. The only argument that changes is the header we pass. ``` kubectl exec -it -n apisix APISIX_POD_NAME -- curl -i -H "Host: ext.httpbin.org" http://127.0.0.1:9080/get ``` The output should be like: ``` HTTP/1.1 200 OK Content-Type: application/json Content-Length: 234 Connection: keep-alive Date: Thu, 15 Dec 2022 10:54:21 GMT Access-Control-Allow-Origin: * Access-Control-Allow-Credentials: true Server: APISIX/3.0.0 { "args": {}, "headers": { "Accept": "*/*", "Host": "ext.httpbin.org", "User-Agent": "curl/7.29.0", "X-Forwarded-Host": "ext.httpbin.org" }, "origin": "127.0.0.1", "url": "http://ext.httpbin.org/get" } ``` We can see the response is similar to the previous one, but some fields don't exist. That's because the request was sent to our local httpbin service rather than the online one. ## Domain In External Name Service The external name service can also hold any domain name outside the K8s cluster. Let's update the external service configuration we applied in the previous section. ``` apiVersion: v1 kind: Service metadata: name: ext-httpbin spec: type: ExternalName externalName: httpbin.org ``` Try reaccessing it, and the output should contain multiple `origin` and an `X-Amzn-Trace-Id` header, which means we are accessing the online `httpbin.org` service. ## Conclusion In this tutorial, we extend the functional boundaries of the APISIX Ingress Controller by proxying requests to external services. It allows users to easily integrate third-party services, such as [authentication](https://api7.ai/blog/api-gateway-authentication) services or cross-cluster services. For more information about API gateway, please visit our [blogs](https://api7.ai/blog) or [contact us](https://api7.ai/contact). Tags: [APISIX Ingress Controller](https://api7.ai/tags/apisix-ingress-controller) [Kubernetes](https://api7.ai/tags/kubernetes) Share article link Share Related Posts [![How to Use Gateway API in APISIX Ingress Controller](https://static.api7.ai/uploads/2024/09/06/jTbR13pX_Gateway%20API.png)](https://api7.ai/blog/how-to-use-gateway-api-in-apisix-ingress-controller) ## [How to Use Gateway API in APISIX Ingress Controller](https://api7.ai/blog/how-to-use-gateway-api-in-apisix-ingress-controller) [![Why Is APISIX Ingress Controller a Better Choice Compared with Traefik?](https://static.api7.ai/uploads/2024/09/06/ldwwEzTf_APISIX%20Ingress%20Controller-3.png)](https://api7.ai/blog/apisix-ingress-better-than-traefik) ## [Why Is APISIX Ingress Controller a Better Choice Compared with Traefik?](https://api7.ai/blog/apisix-ingress-better-than-traefik) Table of Contents - [Prerequisites](#prerequisites) - [Introduction](#introduction) - [External Domain Upstream](#external-domain-upstream) - [External Name Service Upstream](#external-name-service-upstream) - [Domain In External Name Service](#domain-in-external-name-service) - [Conclusion](#conclusion) ## Related Posts [![Why Is APISIX Ingress Controller a Better Choice than Emissary-ingress?](https://static.api7.ai/uploads/2024/12/24/CLpj341F_apisix-ingress-controller-vs-emissary.png)](https://api7.ai/blog/apisix-ingress-vs-emissary-ingress) Products March 17, 2023 #### [Why Is APISIX Ingress Controller a Better Choice than Emissary-ingress?](https://api7.ai/blog/apisix-ingress-vs-emissary-ingress) This article compares the performance of APISIX Ingress Controller and Emissary-ingress from multiple dimensions such as scalability and service discovery integration. 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