Ambassador系列-04-服务配置Mapping

Ambassador设计旨在让Kubernetes服务的开发者可以轻松灵活地配置流量如何路由到该服务，其核心是Mapping资源，支持7层的HTTP，GRPC和Websocket，也可以通过TCPMapping支持4层的TCP连接。Ambassador必须定义一个或多个Mapping才能访问上游服务。

Mapping通过不同的配置选项实现不同的路由规则，下面进行说明。

增加Request Headers

Ambassador可以给上游服务的http请求中添加请求头header。

vi echo-server-mapping.yaml
---
apiVersion: getambassador.io/v1
kind: Mapping
metadata:
  name: echo-server-mapping
spec:
  prefix: /foo
  add_request_headers:
    x-test-proto: "%PROTOCOL%"
    x-test-ip: "%DOWNSTREAM_REMOTE_ADDRESS_WITHOUT_PORT%"
    x-test-static: This is a test header
    x-test-static-2:
      value: This the test header #same as above  x-test-static header
  service: echo:8080

kubectl apply -f echo-server-mapping.yaml

curl -i http://192.168.1.50:38080/foo
HTTP/1.1 200 OK
date: Sat, 07 Dec 2019 07:25:09 GMT
content-type: text/plain
server: envoy
x-envoy-upstream-service-time: 1
lua-scripts-enabled: Processed
transfer-encoding: chunked


Hostname: echo-5599595fd9-2vfnt

Pod Information:
        node name:      k8s-node1
        pod name:       echo-5599595fd9-2vfnt
        pod namespace:  default
        pod IP: 10.244.1.7

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

Request Information:
        client_address=10.244.1.9
        method=GET
        real path=/
        query=
        request_version=1.1
        request_scheme=http
        request_uri=http://192.168.1.50:8080/

Request Headers:
        accept=*/*
        content-length=0
        host=192.168.1.50:38080
        user-agent=curl/7.29.0
        x-envoy-expected-rq-timeout-ms=3000
        x-envoy-internal=true
        x-envoy-original-path=/foo
        x-forwarded-for=10.244.0.0
        x-forwarded-proto=http
        x-request-id=6075a013-5d50-48ec-9f56-4f2d0dca7bdc
        x-test-ip=10.244.0.0
        x-test-proto=HTTP/1.1
        x-test-static=This is a test header
        x-test-static-2=This the test header

Request Body:
        -no body in request-

增加Response Headers

vi echo-server-mapping.yaml
---
apiVersion: getambassador.io/v1
kind: Mapping
metadata:
  name: echo-server-mapping
spec:
  prefix: /foo
  add_response_headers:
    x-test-static: This is a test header
  service: echo:8080

kubectl apply -f echo-server-mapping.yaml

curl -i http://192.168.1.50:38080/foo
HTTP/1.1 200 OK
date: Sat, 07 Dec 2019 07:28:36 GMT
content-type: text/plain
server: envoy
x-envoy-upstream-service-time: 1
x-test-static: This is a test header
lua-scripts-enabled: Processed
transfer-encoding: chunked


Hostname: echo-5599595fd9-2vfnt

Pod Information:
        node name:      k8s-node1
        pod name:       echo-5599595fd9-2vfnt
        pod namespace:  default
        pod IP: 10.244.1.7

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

Request Information:
        client_address=10.244.1.9
        method=GET
        real path=/
        query=
        request_version=1.1
        request_scheme=http
        request_uri=http://192.168.1.50:8080/

Request Headers:
        accept=*/*
        content-length=0
        host=192.168.1.50:38080
        user-agent=curl/7.29.0
        x-envoy-expected-rq-timeout-ms=3000
        x-envoy-internal=true
        x-envoy-original-path=/foo
        x-forwarded-for=10.244.0.0
        x-forwarded-proto=http
        x-request-id=45500d8e-5e76-49b8-9c75-6726f6cb47d6

Request Body:
        -no body in request-

删除Request Headers

---
apiVersion: getambassador.io/v1
kind: Mapping
metadata:
  name: echo-server-mapping
spec:
  prefix: /foo
  remove_request_headers:
  - authorization
  service: echo:8080

删除Response Headers

---
apiVersion: getambassador.io/v1
kind: Mapping
metadata:
  name: echo-server-mapping
spec:
  prefix: /foo
  remove_response_headers:
  - x-envoy-upstream-service-time
  service: echo:8080

使用host或者host_regex路由

Ambassador支持按照host或者host正则表达式进行路由分发。

vi echo-server-mapping.yaml
---
apiVersion: getambassador.io/v1
kind: Mapping
metadata:
  name: echo-server-mapping
spec:
  prefix: /foo
  host: example-echo.com
  service: echo:8080

kubectl apply -f echo-server-mapping.yaml

curl -i -H "Host: example-echo.com" http://192.168.1.50:38080/foo
HTTP/1.1 200 OK
date: Sat, 07 Dec 2019 07:41:21 GMT
content-type: text/plain
server: envoy
x-envoy-upstream-service-time: 5
lua-scripts-enabled: Processed
transfer-encoding: chunked


Hostname: echo-5599595fd9-2vfnt

Pod Information:
        node name:      k8s-node1
        pod name:       echo-5599595fd9-2vfnt
        pod namespace:  default
        pod IP: 10.244.1.7

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

Request Information:
        client_address=10.244.2.7
        method=GET
        real path=/
        query=
        request_version=1.1
        request_scheme=http
        request_uri=http://example-echo.com:8080/

Request Headers:
        accept=*/*
        content-length=0
        host=example-echo.com
        user-agent=curl/7.29.0
        x-envoy-expected-rq-timeout-ms=3000
        x-envoy-internal=true
        x-envoy-original-path=/foo
        x-forwarded-for=10.244.0.0
        x-forwarded-proto=http
        x-request-id=dd4601b5-5d6f-4b15-bb9b-36cd69aac8b1

Request Body:
        -no body in request-

host改写host_rewrite

有些上游服务区分主机host，Ambassador分发到上游服务时可以改写host请求头。

vi echo-server-mapping.yaml
---
apiVersion: getambassador.io/v1
kind: Mapping
metadata:
  name: echo-server-mapping
spec:
  prefix: /foo
  host_rewrite: example-echo.com
  service: echo:8080

kubectl apply -f echo-server-mapping.yaml

curl -i http://192.168.1.50:38080/foo
HTTP/1.1 200 OK
date: Sat, 07 Dec 2019 07:54:48 GMT
content-type: text/plain
server: envoy
x-envoy-upstream-service-time: 11
lua-scripts-enabled: Processed
transfer-encoding: chunked


Hostname: echo-5599595fd9-ffxpn

Pod Information:
        node name:      k8s-node2
        pod name:       echo-5599595fd9-ffxpn
        pod namespace:  default
        pod IP: 10.244.2.6

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

Request Information:
        client_address=10.244.2.7
        method=GET
        real path=/
        query=
        request_version=1.1
        request_scheme=http
        request_uri=http://example-echo.com:8080/

Request Headers:
        accept=*/*
        content-length=0
        host=example-echo.com
        user-agent=curl/7.29.0
        x-envoy-expected-rq-timeout-ms=3000
        x-envoy-internal=true
        x-envoy-original-path=/foo
        x-forwarded-for=10.244.0.0
        x-forwarded-proto=http
        x-request-id=aa8a6982-bf11-4650-b6f3-17d830a402fd

Request Body:
        -no body in request-

使用路径前缀prefix或者prefix_regex路由

---
apiVersion: getambassador.io/v1
kind: Mapping
metadata:
  name: echo-server-mapping
spec:
  prefix: /
  service: echo:8080

重定向

主机重定向Host Redirect。请求http://$AMBASSADOR_URL/redirect时会返回301，重定向到http://www.baidu.com/redirect。

vi redirect-mapping.yaml
---
apiVersion: getambassador.io/v1
kind: Mapping
metadata:
  name: redirect-mapping
spec:
  prefix: /redirect
  service: www.baidu.com
  host_redirect: true

kubectl apply -f redirect-mapping.yaml

curl -i -L http://192.168.1.50:38080/redirect
HTTP/1.1 301 Moved Permanently
location: http://www.baidu.com/redirect
lua-scripts-enabled: Processed
date: Sat, 07 Dec 2019 11:41:01 GMT
server: envoy
content-length: 0

HTTP/1.1 302 Found
Cache-Control: max-age=86400
Connection: Keep-Alive
Content-Length: 222
Content-Type: text/html; charset=iso-8859-1
Date: Sat, 07 Dec 2019 11:41:01 GMT
Expires: Sun, 08 Dec 2019 11:41:01 GMT
Location: https://www.baidu.com/search/error.html
Server: Apache

HTTP/1.1 200 OK
Accept-Ranges: bytes
Cache-Control: max-age=86400
Connection: Keep-Alive
Content-Length: 15852
Content-Type: text/html
Date: Sat, 07 Dec 2019 11:41:02 GMT
Etag: "3dec-57b3a9a43af80"
Expires: Sun, 08 Dec 2019 11:41:02 GMT
Last-Modified: Thu, 22 Nov 2018 06:01:50 GMT
P3p: CP=" OTI DSP COR IVA OUR IND COM "
Server: Apache
Set-Cookie: BAIDUID=8291E8A91272E7E222C7C17DF16BFE66:FG=1; expires=Sun, 06-Dec-20 11:41:02 GMT; max-age=31536000; path=/; domain=.baidu.com; version=1
Vary: Accept-Encoding,User-Agent

<!DOCTYPE html>
<!--STATUS OK-->
<html>
<head>
    <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
    <meta http-equiv="content-type" content="text/html;charset=utf-8">
    <meta content="always" name="referrer">
    <script src="https://ss1.bdstatic.com/5eN1bjq8AAUYm2zgoY3K/r/www/nocache/imgdata/seErrorRec.js"></script>
    <title>页面不存在_百度搜索</title>
......

主机和路径重定向Host Redirect+Path Redirect，请求http://$AMBASSADOR_URL/redirect时会返回301，重定向到http://www.baidu.com/ip。

vi redirect-mapping.yaml
---
apiVersion: getambassador.io/v1
kind: Mapping
metadata:
  name: redirect-mapping
spec:
  prefix: /redirect
  service: www.baidu.com
  host_redirect: true
  path_redirect: /ip

kubectl apply -f redirect-mapping.yaml

curl -i -L http://192.168.1.50:38080/redirect
HTTP/1.1 301 Moved Permanently
location: http://www.baidu.com/ip
lua-scripts-enabled: Processed
date: Sat, 07 Dec 2019 11:51:35 GMT
server: envoy
content-length: 0

HTTP/1.1 302 Found
Cache-Control: max-age=86400
Connection: Keep-Alive
Content-Length: 222
Content-Type: text/html; charset=iso-8859-1
Date: Sat, 07 Dec 2019 11:51:36 GMT
Expires: Sun, 08 Dec 2019 11:51:36 GMT
Location: https://www.baidu.com/search/error.html
Server: Apache

HTTP/1.1 200 OK
Accept-Ranges: bytes
Cache-Control: max-age=86400
Connection: Keep-Alive
Content-Length: 15852
Content-Type: text/html
Date: Sat, 07 Dec 2019 11:51:36 GMT
Etag: "3dec-57b3a9a43af80"
Expires: Sun, 08 Dec 2019 11:51:36 GMT
Last-Modified: Thu, 22 Nov 2018 06:01:50 GMT
P3p: CP=" OTI DSP COR IVA OUR IND COM "
Server: Apache
Set-Cookie: BAIDUID=E2C2E199B52AE9299C1446F31FC46288:FG=1; expires=Sun, 06-Dec-20 11:51:36 GMT; max-age=31536000; path=/; domain=.baidu.com; version=1
Vary: Accept-Encoding,User-Agent

<!DOCTYPE html>
<!--STATUS OK-->
<html>
<head>
    <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
    <meta http-equiv="content-type" content="text/html;charset=utf-8">
    <meta content="always" name="referrer">
    <script src="https://ss1.bdstatic.com/5eN1bjq8AAUYm2zgoY3K/r/www/nocache/imgdata/seErrorRec.js"></script>
    <title>页面不存在_百度搜索</title>
......

重写Rewrites

不指定rewrite，默认方式，访问http://$AMBASSADOR_URL/prefix/status/200时，重写为http://httpbin/status/200。

---
apiVersion: getambassador.io/v1
kind: Mapping
metadata:
  name: httpbin2-mapping
spec:
  prefix: /prefix
  service: httpbin

指定rewrite，访问http://$AMBASSADOR_URL/prefix/status/200时，重写为http://httpbin/status/200。

vi httpbin2-mapping.yaml
---
apiVersion: getambassador.io/v1
kind: Mapping
metadata:
  name: httpbin2-mapping
spec:
  prefix: /prefix
  service: httpbin

kubectl apply -f httpbin2-mapping.yaml

curl -i http://192.168.1.50:38080/httpstatus/200
HTTP/1.1 200 OK
server: envoy
date: Sat, 07 Dec 2019 12:06:57 GMT
content-type: text/html; charset=utf-8
access-control-allow-origin: *
access-control-allow-credentials: true
content-length: 0
x-envoy-upstream-service-time: 6
lua-scripts-enabled: Processed

rewrite为空字符串，访问http://$AMBASSADOR_URL/status/200时，重写为http://httpbin/status/200。

vi httpbin2-mapping.yaml
---
apiVersion: getambassador.io/v1
kind: Mapping
metadata:
  name: httpbin2-mapping
spec:
  prefix: /status
  service: httpbin
  rewrite: ""

kubectl apply -f httpbin2-mapping.yaml

curl -i http://192.168.1.50:38080/status/200
HTTP/1.1 200 OK
server: envoy
date: Sat, 07 Dec 2019 12:10:09 GMT
content-type: text/html; charset=utf-8
access-control-allow-origin: *
access-control-allow-credentials: true
content-length: 0
x-envoy-upstream-service-time: 11
lua-scripts-enabled: Processed

自动重试Automatic Retries

retry_on：(必填)指定重试失败请求的条件，支持的值列表为以下值之一：
    5xx
    gateway-error
    connect-failure
    retriable-4xx
    refused-stream
    retriable-status-codes
num_retries：(缺省值1) 重试次数
per_try_timeout：(缺省值为全局的请求超时时间)每次重试的超时时间。

Ambassador系列文章

Ambassador系列-01-介绍、安装和使用

Ambassador系列-02-Module模块

Ambassador系列-03-服务配置和服务发现

Ambassador系列-04-服务配置Mapping

Ambassador系列-05-负载均衡

Ambassador系列-06-金丝雀发布、断路器、CORS和流量镜像

Ambassador系列-07-TCP映射TCPMapping

Ambassador系列-08-TLS配置-HTTPS重定向和TLS终结

Ambassador系列-09-AuthService认证服务

Ambassador系列-10-RateLimitService限速服务

Ambassador系列-11-Helm安装Ambassador Edge Stack 1.1.0