Usage of Ingress controller

In this article, we will use ingress controller CRDs (CustomResourceDefinition) to define routing rules against the admin api of Apache APISIX.

Scenes

Configure a simple routing rule through the ingress controller CRDs. After synchronizing to the gateway, the data traffic is accessed to the back-end service through Apache APISIX. Then, we gradually add or remove plug-ins to the routing to achieve functional expansion.

As shown below.

A simple example

Define the simplest route to direct traffic to the back-end service, the back-end service is named httpserver.

As shown below.(The ip list in nodes is an example, no specific meaning)

Now we define with CRDs as follows.

1. Define Upstream with ApisixUpstream

apiVersion: apisix.apache.org/v1
kind: ApisixUpstream
metadata:
  name: foo
spec:
  ports:
  - port: 8080
    loadbalancer:
      type: chash
      hashOn: header
      key: hello

2. Define Service with ApisixService

apiVersion: apisix.apache.org/v1
kind: ApisixService
metadata:
  name: foo
spec:
  upstream: foo
  port: 8080

3. Define Route with ApisixRoute

apiVersion: apisix.apache.org/v1
kind: ApisixRoute
metadata:
  name: foo-route
spec:
  rules:
  - host: test.apisix.apache.org
    http:
      paths:
      - backend:
          serviceName: foo
          servicePort: 8080
        path: /hello*

Tips: When defining ApisixUpstream, there is no need to define a specific pod ip list, the ingress controller will do service discovery based on namespace/name/port composite index.

List the way to define the above rules using Admin API to facilitate comparison and understanding.

# 1. Define upstream: foo-upstream id=1 (the ip list in nodes is an example, no specific meaning)
curl -XPUT http://127.0.0.1:9080/apisix/admin/upstreams/1 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -d '
{
    "nodes": {
        "10.244.143.48:8080": 100,
        "10.244.102.43:8080": 100,
        "10.244.102.63:8080": 100
    },
    "desc": "foo-upstream",
    "type": "roundrobin"
}
'
# 2. Define service: foo-service, id=2, binding upstream: foo-upstream
curl -XPUT http://127.0.0.1:9080/apisix/admin/services/2 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -d '
{
    "desc": "foo-service",
    "upstream_id": 1
}
'

# 3. Define route: foo-route， id=3， binding service: foo-service

curl -XPUT http://127.0.0.1:9080/apisix/admin/routes/3 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -d '
{
    "desc": "foo-route",
    "uri": "/hello*",
    "host": "test.apisix.apache.org",
    "service_id": "2"
}'

Add a plugin

Next, take the proxy-rewrite plugin as an example.

Add plug-ins through admin api to achieve the purpose of rewriting upstream uri.

e.g. test.apisix.apache.org/hello -> test-rewrite.apisix.apache.org/copy/hello

With CRDs, use ApisixService as example.

apiVersion: apisix.apache.org/v1
kind: ApisixService
metadata:
  name: foo
spec:
  upstream: foo
  port: 8080
  plugins:
  - enable: true
    name: proxy-rewrite
    config:
    regex_uri:
    - '^/(.*)'
    - '/copy/$1'
    scheme: http
    host: test-rewrite.apisix.apache.org

For facilitating understanding, show the way with Admin API as below.

curl http://127.0.0.1:9080/apisix/admin/services/2 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
    "desc": "foo-service",
    "upstream_id": "1",
    "plugins": {
        "proxy-rewrite": {
            "regex_uri": ["^/(.*)", "/copy/$1"],
            "scheme": "http",
            "host": "test-rewrite.apisix.apache.org"
        }
    }
}'

It can be found that the way of defining plugins is almost the same, except that the format is changed from json to yaml.

By defining the plug-in in CRDs, you can disable the plug-in by setting enable: false without deleting it. Keep the original configuration for easy opening next time.

Tips: ApisixRoute and ApisixService both support plugins definition.