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  2. Kong系列 - 05 - 使用入门

Kong系列 - 05 - 使用入门

由 走远了吗. 提交于 2019-12-19 01:04:32

Kong的核心实体概念。

  • client：指下游客户端。
  • service：指上游服务。
  • route：定义匹配客户端请求的规则，每个路由都与一个服务相关联，而服务可能有多个与之相关联的路由。
  • plugin：它是在代理生命周期中运行的业务逻辑，插件可以生效于全局或者特定的路由和服务。
  • consumer：消费者表示服务的消费者或者使用者，可能是一个用户，也可能是一个应用。

Kong是一个API网关，其核心能力是代理客户端对上游服务的访问，下面举例说明Kong是如何进行代理服务的。

我们先部署一个echo服务。该服务没有对Kubernetes外暴露端口。如果想从Kubernetes集群之外访问该服务就需要通过Kong网关代理。

vi echo-server-service.yaml
apiVersion: v1
kind: Service
metadata:
  labels:
    app: echo
  name: echo
spec:
  ports:
  - port: 8080
    name: high
    protocol: TCP
    targetPort: 8080
  - port: 80
    name: low
    protocol: TCP
    targetPort: 8080
  selector:
    app: echo
---
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: echo
  name: echo
spec:
  replicas: 1
  selector:
    matchLabels:
      app: echo
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: echo
    spec:
      containers:
      - image: e2eteam/echoserver:2.2
        name: echo
        ports:
        - containerPort: 8080
        env:
          - name: NODE_NAME
            valueFrom:
              fieldRef:
                fieldPath: spec.nodeName
          - name: POD_NAME
            valueFrom:
              fieldRef:
                fieldPath: metadata.name
          - name: POD_NAMESPACE
            valueFrom:
              fieldRef:
                fieldPath: metadata.namespace
          - name: POD_IP
            valueFrom:
              fieldRef:
                fieldPath: status.podIP
        resources: {}

为了让Kong感知k8s的echo服务，需要在Kong中创建一个Kong的服务echo-service，该Kong服务指向k8s的echo服务。

curl -X POST \
  --url http://192.168.1.55:32444/services/ \
  --data 'name=echo-service' \
  --data 'url=http://echo:8080' \
  -s | python -m json.tool
{
    "client_certificate": null,
    "connect_timeout": 60000,
    "created_at": 1576504925,
    "host": "echo",
    "id": "f15edf62-cb68-4279-a41f-7f5273ccd001",
    "name": "echo-service",
    "path": null,
    "port": 8080,
    "protocol": "http",
    "read_timeout": 60000,
    "retries": 5,
    "tags": null,
    "updated_at": 1576504925,
    "write_timeout": 60000
}

查询服务services列表，可以看出刚才创建的服务echo-service。

curl -X GET \
  --url http://192.168.1.55:32444/services/ \
  -s | python -m json.tool
{
    "data": [
        {
            "client_certificate": null,
            "connect_timeout": 60000,
            "created_at": 1576504925,
            "host": "echo",
            "id": "f15edf62-cb68-4279-a41f-7f5273ccd001",
            "name": "echo-service",
            "path": null,
            "port": 8080,
            "protocol": "http",
            "read_timeout": 60000,
            "retries": 5,
            "tags": null,
            "updated_at": 1576504925,
            "write_timeout": 60000
        }
    ],
    "next": null
}

为了让Kong知道客户端的哪些请求是访问echo服务的，需要为echo服务添加一条路由。每个服务是可以有多个路由与之对应。以下的路由规则为路径前缀为/foo的请求，将被转发到echo服务。

curl -X POST \
  --url http://192.168.1.55:32444/services/echo-service/routes \
  --data 'name=echo-service-route' \
  --data 'paths[]=/foo' \
  -s | python -m json.tool
{
    "created_at": 1576505187,
    "destinations": null,
    "headers": null,
    "hosts": null,
    "https_redirect_status_code": 426,
    "id": "d152f741-9ed1-47d2-98bc-f8c438075e2e",
    "methods": null,
    "name": "echo-service-route",
    "paths": [
        "/foo"
    ],
    "preserve_host": false,
    "protocols": [
        "http",
        "https"
    ],
    "regex_priority": 0,
    "service": {
        "id": "f15edf62-cb68-4279-a41f-7f5273ccd001"
    },
    "snis": null,
    "sources": null,
    "strip_path": true,
    "tags": null,
    "updated_at": 1576505187
}

测试一下，可以看出根据路由规则能够访问echo服务。

curl -iX GET --url http://192.168.1.55:32080/foo
HTTP/1.1 200 OK
Content-Type: text/plain; charset=UTF-8
Transfer-Encoding: chunked
Connection: keep-alive
Date: Mon, 16 Dec 2019 14:09:21 GMT
Server: echoserver
X-Kong-Upstream-Latency: 5
X-Kong-Proxy-Latency: 65
Via: kong/1.3.0


Hostname: echo-75cf96d976-pwbg7

Pod Information:
        node name:      k8s-node2
        pod name:       echo-75cf96d976-pwbg7
        pod namespace:  default
        pod IP: 10.244.2.12

Server values:
        server_version=nginx: 1.14.2 - lua: 10015

Request Information:
        client_address=10.244.2.11
        method=GET
        real path=/
        query=
        request_version=1.1
        request_scheme=http
        request_uri=http://echo:8080/

Request Headers:
        accept=*/*
        connection=keep-alive
        host=echo:8080
        user-agent=curl/7.29.0
        x-forwarded-for=10.244.0.0
        x-forwarded-host=192.168.1.55
        x-forwarded-port=8000
        x-forwarded-proto=http
        x-real-ip=10.244.0.0

Request Body:
        -no body in request-

Kong通过插件扩展其网关能力，Kong的一个很大的优势就是有功能丰富的开源插件，并且能方便地自定义插件。

key-auth插件是一个身份验证插件，在添加此插件之前，对服务的所有请求都会被直接转发到上游服务，如果添加并配置此插件后，只有正确密钥的请求才会被转发到上游服务，否则将被拒绝。以下API给echo-service应用了key-auth插件，意味所有对echo-service的请求都会被key-auth插件处理。

curl -X POST \
  --url http://192.168.1.55:32444/services/echo-service/plugins \
  --data 'name=key-auth' \
  -s | python -m json.tool
{
    "config": {
        "anonymous": null,
        "hide_credentials": false,
        "key_in_body": false,
        "key_names": [
            "apikey"
        ],
        "run_on_preflight": true
    },
    "consumer": null,
    "created_at": 1576674272,
    "enabled": true,
    "id": "0d8231dd-e820-45b4-bc78-f8b9758346fa",
    "name": "key-auth",
    "protocols": [
        "grpc",
        "grpcs",
        "http",
        "https"
    ],
    "route": null,
    "run_on": "first",
    "service": {
        "id": "f15edf62-cb68-4279-a41f-7f5273ccd001"
    },
    "tags": null
}

此时请求echo-service，由于没有携带key，key-auth插件拒绝请求。

curl -iX GET --url http://192.168.1.55:32080/foo
HTTP/1.1 401 Unauthorized
Date: Wed, 18 Dec 2019 13:08:18 GMT
Content-Type: application/json; charset=utf-8
Connection: keep-alive
WWW-Authenticate: Key realm="kong"
Content-Length: 41
Server: kong/1.3.0

{"message":"No API key found in request"}

创建一个消费者consumer。

curl -X POST \
  --url http://192.168.1.55:32444/consumers \
  --data 'username=twingao' \
  -s | python -m json.tool
{
    "created_at": 1576674684,
    "custom_id": null,
    "id": "5b6be948-00bb-4479-a012-67d73824c2fe",
    "tags": null,
    "username": "twingao"
}

为消费者twingao配置一个key。

curl -X POST \
  --url http://192.168.1.55:32444/consumers/twingao/key-auth \
  --data 'key=123456' \
  -s | python -m json.tool
{
    "consumer": {
        "id": "5b6be948-00bb-4479-a012-67d73824c2fe"
    },
    "created_at": 1576674825,
    "id": "0c815096-4cda-4056-824a-dff6eb799384",
    "key": "123456"
}

此时访问echo-service，携带上请求头apikey: 123456，key-auth身份验证成功，会放行请求；如果携带的apikey不正确，则不会放行请求。

curl -iX GET --url http://192.168.1.55:32080/foo --header 'apikey: 123456'
HTTP/1.1 200 OK
Content-Type: text/plain; charset=UTF-8
Transfer-Encoding: chunked
Connection: keep-alive
Date: Wed, 18 Dec 2019 13:19:22 GMT
Server: echoserver
X-Kong-Upstream-Latency: 7
X-Kong-Proxy-Latency: 66
Via: kong/1.3.0



Hostname: echo-75cf96d976-pwbg7

Pod Information:
        node name:      k8s-node2
        pod name:       echo-75cf96d976-pwbg7
        pod namespace:  default
        pod IP: 10.244.2.14

Server values:
        server_version=nginx: 1.14.2 - lua: 10015

Request Information:
        client_address=10.244.2.13
        method=GET
        real path=/
        query=
        request_version=1.1
        request_scheme=http
        request_uri=http://echo:8080/

Request Headers:
        accept=*/*
        apikey=123456
        connection=keep-alive
        host=echo:8080
        user-agent=curl/7.29.0
        x-consumer-id=5b6be948-00bb-4479-a012-67d73824c2fe
        x-consumer-username=twingao
        x-forwarded-for=10.244.0.0
        x-forwarded-host=192.168.1.55
        x-forwarded-port=8000
        x-forwarded-proto=http
        x-real-ip=10.244.0.0

Request Body:
        -no body in request-

curl -iX GET --url http://192.168.1.55:32080/foo --header 'apikey: 123'
HTTP/1.1 401 Unauthorized
Date: Wed, 18 Dec 2019 13:19:57 GMT
Content-Type: application/json; charset=utf-8
Connection: keep-alive
Content-Length: 48
Server: kong/1.3.0

{"message":"Invalid authentication credentials"}

 

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