高性能API网关Kong介绍

本文关键词：高性能、API网关、Kong、微服务
0.Introduction to Kong

API网关是随着微服务（Microservice）概念兴起的一种架构模式。原本一个庞大的单体应用（All in one）业务系统被拆分成许多微服务（Microservice）系统进行独立的维护和部署，服务拆分带来的变化是API的规模成倍增长，API的管理难度也在日益增加，使用API网关发布和管理API逐渐成为一种趋势。一般来说，API网关是运行于外部请求与内部服务之间的一个流量入口，实现对外部请求的协议转换、鉴权、流控、参数校验、监控等通用功能。

本文即将介绍的Kong，是一个开源的API gateway和微服务管理的工具，基于Nginx和lua-nginx-module（特殊的OpenResty），Kong具有可插拔的架构，使其功能强大且灵活。
2.Key Concepts
Service: Kong的一个实体对象，表示了外部的上游API或者微服务
Route: Kong的一个实体对象，表示了一种将下游请求映射到上游服务的路由
Consumer: Kong的一个实体对象，表示使用API的开发者或者机器，在使用Kong时，一个Consumer仅与Kong交互。
Plugin：插件用于是Kong内部将请求转发给上游API前后执行的一系列动作，Kong在其插件库中提供了非常强大的插件
Credential: A certificate object represents a public certificate/private key pair for an SSL certificate.
SNI: An SNI object represents a many-to-one mapping of hostnames to a certificate. That is, a certificate object can have many hostnames associated with it
Upstream: 上游服务，指代Kong背后的API或者服务，也是客户端请求转发的目的端，The upstream object represents a virtual hostname and can be used to loadbalance incoming requests over multiple services (targets).
Target: A target is an ip address/hostname with a port that identifies an instance of a backend service. Every upstream can have many targets, and the targets can be dynamically added. Changes are effectuated on the fly.
Admin API -用于管理Kong配置，端点，使用者，插件等的RESTful API端点
下图展示了Kong和其他传统架构的区别，可以帮助我们理解为什么有Kong：

大概有鉴权、监控、日志、安全审计、ACL、缓存、限流、serverless等等。
3.Setup
官方文档提供了多种环境下详细的安装说明。我们这里使用docker进行安装（docker安装过程略）：

1.create docker network

$ docker network create kong-net

2.run PostgreSQL database

$ docker run -d --name kong-database \

        --network=kong-net \
        -p 5432:5432 \
        -e "POSTGRES_USER=kong" \
        -e "POSTGRES_DB=kong" \
        postgres:9.6

3.prepare database

$ docker run --rm \

--network=kong-net \
-e "KONG_DATABASE=postgres" \
-e "KONG_PG_HOST=kong-database" \
-e "KONG_CASSANDRA_CONTACT_POINTS=kong-database" \
kong:latest kong migrations bootstrap

Unable to find image 'kong:latest' locally
latest: Pulling from library/kong
59265c40e257: Pull complete
6389eff8e6ff: Pull complete
f58488256be6: Pull complete
Digest: sha256:f7ed033bb9955da0fcefa034d07fee324cad6d01c12ebf54268dfe825ba2e92c
Status: Downloaded newer image for kong:latest
bootstrapping database...
migrating core on database 'kong'...
core migrated up to: 000_base (executed)
core migrated up to: 001_14_to_15 (executed)
core migrated up to: 002_15_to_1 (executed)
migrating oauth2 on database 'kong'...
oauth2 migrated up to: 000_base_oauth2 (executed)
oauth2 migrated up to: 001_14_to_15 (executed)
oauth2 migrated up to: 002_15_to_10 (executed)
migrating acl on database 'kong'...
acl migrated up to: 000_base_acl (executed)
acl migrated up to: 001_14_to_15 (executed)
migrating jwt on database 'kong'...
jwt migrated up to: 000_base_jwt (executed)
jwt migrated up to: 001_14_to_15 (executed)
migrating basic-auth on database 'kong'...
basic-auth migrated up to: 000_base_basic_auth (executed)
basic-auth migrated up to: 001_14_to_15 (executed)
migrating key-auth on database 'kong'...
key-auth migrated up to: 000_base_key_auth (executed)
key-auth migrated up to: 001_14_to_15 (executed)
migrating rate-limiting on database 'kong'...
rate-limiting migrated up to: 000_base_rate_limiting (executed)
rate-limiting migrated up to: 001_14_to_15 (executed)
rate-limiting migrated up to: 002_15_to_10 (executed)
migrating hmac-auth on database 'kong'...
hmac-auth migrated up to: 000_base_hmac_auth (executed)
hmac-auth migrated up to: 001_14_to_15 (executed)
migrating response-ratelimiting on database 'kong'...
response-ratelimiting migrated up to: 000_base_response_rate_limiting (executed)
response-ratelimiting migrated up to: 001_14_to_15 (executed)
response-ratelimiting migrated up to: 002_15_to_10 (executed)
22 migrations processed
22 executed
database is up-to-date

4.start Kong

$ docker run -d --name kong \

--network=kong-net \
-e "KONG_DATABASE=postgres" \
-e "KONG_PG_HOST=kong-database" \
-e "KONG_CASSANDRA_CONTACT_POINTS=kong-database" \
-e "KONG_PROXY_ACCESS_LOG=/dev/stdout" \
-e "KONG_ADMIN_ACCESS_LOG=/dev/stdout" \
-e "KONG_PROXY_ERROR_LOG=/dev/stderr" \
-e "KONG_ADMIN_ERROR_LOG=/dev/stderr" \
-e "KONG_ADMIN_LISTEN=0.0.0.0:8001, 0.0.0.0:8444 ssl" \
-p 8000:8000 \
-p 8443:8443 \
-p 8001:8001 \
-p 8444:8444 \
kong:latest

999a5cf1db1a8c23ca870933b73407d7ae5f0fd2d9a895a78627a9c27e08045c

$ docker container ls
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
999a5cf1db1a kong:latest "/docker-entrypoint.…" 8 seconds ago Up 7 seconds 0.0.0.0:8000-8001->8000-8001/tcp, 0.0.0.0:8443-8444->8443-8444/tcp kong
ecb50c2f7307 postgres:9.6 "docker-entrypoint.s…" About an hour ago Up About an hour 0.0.0.0:5432->5432/tcp
容器启动完毕后，尝试curl -i http://localhost:8001/，得到如下：
{

"plugins": {
    "enabled_in_cluster": [ ], 
    "available_on_server": {
        "response-transformer": true, 
        "oauth2": true, 
        "acl": true, 
        "correlation-id": true, 
        "pre-function": true, 
        "jwt": true, 
        "cors": true, 
        "ip-restriction": true, 
        "basic-auth": true, 
        "key-auth": true, 
        "rate-limiting": true, 
        "request-transformer": true, 
        "http-log": true, 
        "file-log": true, 
        "hmac-auth": true, 
        "ldap-auth": true, 
        "datadog": true, 
        "tcp-log": true, 
        "zipkin": true, 
        "post-function": true, 
        "request-size-limiting": true, 
        "bot-detection": true, 
        "syslog": true, 
        "loggly": true, 
        "azure-functions": true, 
        "udp-log": true, 
        "response-ratelimiting": true, 
        "aws-lambda": true, 
        "statsd": true, 
        "prometheus": true, 
        "request-termination": true
    }
}, 
"tagline": "Welcome to kong", 
"configuration": {
    "plugins": [
        "bundled"
    ], 
    "admin_ssl_enabled": true, 
    "lua_ssl_verify_depth": 1, 
    "trusted_ips": { }, 
    "prefix": "/usr/local/kong", 
    "loaded_plugins": {
        "response-transformer": true, 
        "request-termination": true, 
        "prometheus": true, 
        "ip-restriction": true, 
        "pre-function": true, 
        "jwt": true, 
        "cors": true, 
        "statsd": true, 
        "basic-auth": true, 
        "key-auth": true, 
        "ldap-auth": true, 
        "aws-lambda": true, 
        "http-log": true, 
        "response-ratelimiting": true, 
        "hmac-auth": true, 
        "request-size-limiting": true, 
        "datadog": true, 
        "tcp-log": true, 
        "zipkin": true, 
        "post-function": true, 
        "bot-detection": true, 
        "acl": true, 
        "loggly": true, 
        "syslog": true, 
        "azure-functions": true, 
        "udp-log": true, 
        "file-log": true, 
        "request-transformer": true, 
        "correlation-id": true, 
        "rate-limiting": true, 
        "oauth2": true
    }, 
    "cassandra_username": "kong", 
    "ssl_cert_key": "/usr/local/kong/ssl/kong-default.key", 
    "admin_ssl_cert_key": "/usr/local/kong/ssl/admin-kong-default.key", 
    "dns_resolver": { }, 
    "pg_user": "kong", 
    "mem_cache_size": "128m", 
    "ssl_ciphers": "ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256", 
    "nginx_admin_directives": { }, 
    "nginx_http_directives": [
        {
            "value": "prometheus_metrics 5m", 
            "name": "lua_shared_dict"
        }
    ], 
    "pg_host": "kong-database", 
    "nginx_acc_logs": "/usr/local/kong/logs/access.log", 
    "proxy_listen": [
        "0.0.0.0:8000", 
        "0.0.0.0:8443 ssl"
    ], 
    "client_ssl_cert_default": "/usr/local/kong/ssl/kong-default.crt", 
    "ssl_cert_key_default": "/usr/local/kong/ssl/kong-default.key", 
    "db_update_frequency": 5, 
    "db_update_propagation": 0, 
    "stream_listen": [
        "off"
    ], 
    "nginx_err_logs": "/usr/local/kong/logs/error.log", 
    "cassandra_port": 9042, 
    "dns_order": [
        "LAST", 
        "SRV", 
        "A", 
        "CNAME"
    ], 
    "dns_error_ttl": 1, 
    "headers": [
        "server_tokens", 
        "latency_tokens"
    ], 
    "cassandra_lb_policy": "RequestRoundRobin", 
    "nginx_optimizations": true, 
    "pg_timeout": 5000, 
    "database": "postgres", 
    "pg_database": "kong", 
    "nginx_worker_processes": "auto", 
    "lua_package_cpath": "", 
    "admin_acc_logs": "/usr/local/kong/logs/admin_access.log", 
    "lua_package_path": "./?.lua;./?/init.lua;", 
    "nginx_pid": "/usr/local/kong/pids/nginx.pid", 
    "upstream_keepalive": 60, 
    "client_ssl": false, 
    "admin_access_log": "/dev/stdout", 
    "cassandra_data_centers": [
        "dc1:2", 
        "dc2:3"
    ], 
    "cassandra_ssl": false, 
    "proxy_listeners": [
        {
            "transparent": false, 
            "ssl": false, 
            "ip": "0.0.0.0", 
            "proxy_protocol": false, 
            "port": 8000, 
            "http2": false, 
            "listener": "0.0.0.0:8000"
        }, 
        {
            "transparent": false, 
            "ssl": true, 
            "ip": "0.0.0.0", 
            "proxy_protocol": false, 
            "port": 8443, 
            "http2": false, 
            "listener": "0.0.0.0:8443 ssl"
        }
    ], 
    "proxy_ssl_enabled": true, 
    "client_max_body_size": "0", 
    "proxy_error_log": "/dev/stderr", 
    "enabled_headers": {
        "latency_tokens": true, 
        "X-Kong-Proxy-Latency": true, 
        "Via": true, 
        "server_tokens": true, 
        "Server": true, 
        "X-Kong-Upstream-Latency": true, 
        "X-Kong-Upstream-Status": false
    }, 
    "dns_stale_ttl": 4, 
    "lua_socket_pool_size": 30, 
    "db_resurrect_ttl": 30, 
    "origins": { }, 
    "cassandra_consistency": "ONE", 
    "db_cache_ttl": 0, 
    "admin_error_log": "/dev/stderr", 
    "pg_ssl_verify": false, 
    "dns_not_found_ttl": 30, 
    "pg_ssl": false, 
    "nginx_daemon": "off", 
    "nginx_kong_stream_conf": "/usr/local/kong/nginx-kong-stream.conf", 
    "cassandra_repl_strategy": "SimpleStrategy", 
    "error_default_type": "text/plain", 
    "dns_no_sync": false, 
    "nginx_proxy_directives": { }, 
    "proxy_access_log": "/dev/stdout", 
    "nginx_kong_conf": "/usr/local/kong/nginx-kong.conf", 
    "cassandra_schema_consensus_timeout": 10000, 
    "dns_hostsfile": "/etc/hosts", 
    "admin_listeners": [
        {
            "transparent": false, 
            "ssl": false, 
            "ip": "0.0.0.0", 
            "proxy_protocol": false, 
            "port": 8001, 
            "http2": false, 
            "listener": "0.0.0.0:8001"
        }, 
        {
            "transparent": false, 
            "ssl": true, 
            "ip": "0.0.0.0", 
            "proxy_protocol": false, 
            "port": 8444, 
            "http2": false, 
            "listener": "0.0.0.0:8444 ssl"
        }
    ], 
    "ssl_cipher_suite": "modern", 
    "ssl_cert": "/usr/local/kong/ssl/kong-default.crt", 
    "cassandra_timeout": 5000, 
    "admin_ssl_cert_key_default": "/usr/local/kong/ssl/admin-kong-default.key", 
    "cassandra_ssl_verify": false, 
    "cassandra_contact_points": [
        "kong-database"
    ], 
    "real_ip_header": "X-Real-IP", 
    "real_ip_recursive": "off", 
    "cassandra_repl_factor": 1, 
    "client_ssl_cert_key_default": "/usr/local/kong/ssl/kong-default.key", 
    "admin_ssl_cert": "/usr/local/kong/ssl/admin-kong-default.crt", 
    "anonymous_reports": true, 
    "log_level": "notice", 
    "kong_env": "/usr/local/kong/.kong_env", 
    "pg_port": 5432, 
    "admin_ssl_cert_default": "/usr/local/kong/ssl/admin-kong-default.crt", 
    "client_body_buffer_size": "8k", 
    "ssl_preread_enabled": true, 
    "ssl_cert_csr_default": "/usr/local/kong/ssl/kong-default.csr", 
    "stream_listeners": { }, 
    "cassandra_keyspace": "kong", 
    "ssl_cert_default": "/usr/local/kong/ssl/kong-default.crt", 
    "nginx_conf": "/usr/local/kong/nginx.conf", 
    "admin_listen": [
        "0.0.0.0:8001", 
        "0.0.0.0:8444 ssl"
    ]
}, 
"version": "1.0.3", 
"node_id": "3ccef799-3037-4a8f-8ccd-2e60326b4444", 
"lua_version": "LuaJIT 2.1.0-beta3", 
"prng_seeds": {
    "pid: 36": 229762112224, 
    "pid: 37": 131951181922, 
    "pid: 1": 136391662351
}, 
"timers": {
    "pending": 5, 
    "running": 0
}, 
"hostname": "999a5cf1db1a"

}
上面几个端口，分别是：
:8000 on which Kong listens for incoming HTTP traffic from your clients, and forwards it to your upstream services.
:8443 on which Kong listens for incoming HTTPS traffic. This port has a similar behavior as the :8000 port, except that it expects HTTPS traffic only. This port can be disabled via the configuration file.
:8001 on which the Admin API used to configure Kong listens.
:8444 on which the Admin API listens for HTTPS traffic.
4.API Management
在本地配置Kong完毕后，我们来感受一下Kong强大的特性。首先我们有一个简单的API服务，之前已经写好的一个flavors的增删改查，以flavors的查询为例，我们将GET /flavors/detail添加到Kong中。
我们的API server地址是http://127.0.0.1:8080/flavors...，于是我们有：
route path: /flavors/detail
service host: http://127.0.0.1:8080
4.1 Add a service
curl -i -X POST \
--url http://localhost:8001/services/ \ --data 'name=example-flavors'\ --data 'url=http://127.0.0.1:8080/flavors...'
得到的响应：
HTTP/1.1 201 Created
Date: Wed, 27 Feb 2019 06:08:25 GMT
Content-Type: application/json; charset=utf-8
Connection: keep-alive
Access-Control-Allow-Origin: *
Server: kong/1.0.3
Content-Length: 273

{ "host": "127.0.0.1", "created_at": 1551247705, "connect_timeout": 60000, "id": "abba6d52-b239-4b8f-ad11-1e7389d4cf71", "protocol": "http", "name": "example-flavors", "read_timeout": 60000, "port": 8080, "path": "/flavors/detail", "updated_at": 1551247705, "retries": 5, "write_timeout": 60000 }
4.2 List current services
curl -i -X GET \
--url http://localhost:8001/services/
得到的响应：
HTTP/1.1 200 OK
Date: Wed, 27 Feb 2019 06:11:07 GMT
Content-Type: application/json; charset=utf-8
Connection: keep-alive
Access-Control-Allow-Origin: *
Server: kong/1.0.3
Content-Length: 296

{ "next": null, "data": [ { "host": "127.0.0.1", "created_at": 1551247705, "connect_timeout": 60000, "id": "abba6d52-b239-4b8f-ad11-1e7389d4cf71", "protocol": "http", "name": "example-flavors", "read_timeout": 60000, "port": 8080, "path": "/flavors/detail", "updated_at": 1551247705, "retries": 5, "write_timeout": 60000 } ] }
可以看到目前就我们前面添加的一个。
4.3 Add a route to service
有了服务之后，我们为服务填一个转发路由：
curl -i -X POST \
--url http://localhost:8001/service... \ --data 'hosts[]=hb.ctyun.com' \ --data 'paths[]=/flavors/detail' \ --data 'name=flavor-detail'
得到的响应是：
HTTP/1.1 201 Created
Date: Wed, 27 Feb 2019 06:24:00 GMT
Content-Type: application/json; charset=utf-8
Connection: keep-alive
Access-Control-Allow-Origin: *
Server: kong/1.0.3
Content-Length: 377

{ "created_at": 1551248640, "methods": null, "id": "11dbb4a1-7452-4d40-a45a-de3f3cad5275", "service": { "id": "abba6d52-b239-4b8f-ad11-1e7389d4cf71" }, "name": "flavor-detail", "hosts": [ "hb.ctyun.com" ], "updated_at": 1551248640, "preserve_host": false, "regex_priority": 0, "paths": [ "/flavors/detail" ], "sources": null, "destinations": null, "snis": null, "protocols": [ "http", "https" ], "strip_path": true }
原先获取flavors列表，我们是通过：
curl -X GET http://localhost:8080/flavors...
而我们现在可以直接通过Kong进行访问，注意，我们必须修改Header，添加指定的Host信息：
curl -X GET http://localhost:8000/flavors... -H 'Host:hb.ctyun.com'
结果遇到了报错，提示：
172.18.0.1 - - [27/Feb/2019:06:43:17 +0000] "GET /flavors/detail HTTP/1.1" 502 69 "-" "curl/7.54.0"
2019/02/27 06:43:17 [error] 36#0: *35879 connect() failed (111: Connection refused) while connecting to upstream, client: 172.18.0.1, server: kong, request: "GET /flavors/detail HTTP/1.1", upstream: "http://127.0.0.1:8080/flavors/detail", host: "hb.ctyun.com"
可以看到能够按照路由规则进行转发，但是由于网络问题（kong部署在了docker容器中），所以没有办法进行访问。
我们重新创建service、route，并使用kennethreitz/httpbin来验证：

运行一个容器，将本地的8080的请求转发到容器的80端口

docker run -d --name simple-web-server \

--network kong-net \
-p 8080:80 kennethreitz/httpbin

创建名为demo的service

curl -i -X POST \
--url http://localhost:8001/services/ \
--data 'name=demo'\
--data 'url=http://simple-web-server/get'

HTTP/1.1 201 Created
Date: Wed, 27 Feb 2019 07:51:45 GMT
Content-Type: application/json; charset=utf-8
Connection: keep-alive
Access-Control-Allow-Origin: *
Server: kong/1.0.3
Content-Length: 256

{

"host": "simple-web-server", 
"created_at": 1551253905, 
"connect_timeout": 60000, 
"id": "978de8a6-6767-4741-baca-a25c9a131f9d", 
"protocol": "http", 
"name": "demo", 
"read_timeout": 60000, 
"port": 80, 
"path": "/get", 
"updated_at": 1551253905, 
"retries": 5, 
"write_timeout": 60000

}

为service demo配置route规则

curl -i -X POST \
--url http://localhost:8001/service... \
--data 'hosts[]=api.ctyun.com' \
--data 'paths[]=/get' \
--data 'name=demo-get'

HTTP/1.1 201 Created
Date: Wed, 27 Feb 2019 07:52:40 GMT
Content-Type: application/json; charset=utf-8
Connection: keep-alive
Access-Control-Allow-Origin: *
Server: kong/1.0.3
Content-Length: 361

{

"created_at": 1551253960, 
"methods": null, 
"id": "06d6754e-a4ae-4be6-9b87-b64ccfe6c920", 
"service": {
    "id": "978de8a6-6767-4741-baca-a25c9a131f9d"
}, 
"name": "demo-get", 
"hosts": [
    "api.ctyun.com"
], 
"updated_at": 1551253960, 
"preserve_host": false, 
"regex_priority": 0, 
"paths": [
    "/get"
], 
"sources": null, 
"destinations": null, 
"snis": null, 
"protocols": [
    "http", 
    "https"
], 
"strip_path": true

}
然后我们尝试通过访问kong，转发到httpbin：
curl -i -X GET http://localhost:8000/get -H 'Host:api.ctyun.com'

HTTP/1.1 200 OK
Content-Type: application/json
Content-Length: 266
Connection: keep-alive
Server: gunicorn/19.9.0
Date: Wed, 27 Feb 2019 07:56:50 GMT
Access-Control-Allow-Origin: *
Access-Control-Allow-Credentials: true
X-Kong-Upstream-Latency: 9
X-Kong-Proxy-Latency: 84
Via: kong/1.0.3

{
"args": {},
"headers": {

"Accept": "*/*",
"Connection": "keep-alive",
"Host": "simple-web-server",
"User-Agent": "curl/7.54.0",
"X-Forwarded-Host": "api.ctyun.com"

},
"origin": "172.18.0.1",
"url": "http://api.ctyun.com/get"
}
至此，我们已经可以通过来源host、route将请求换发到指定的目标host，并且得到了返回值，这就算完成了基本API转发流程。
4.4 Plugins
Kong提供了非常丰富的插件，都可以在Kong Hub找得到。这里我们简单为我们的服务配置一个Key Authentication的plugin。
在服务demo上启用key-auth的插件：
curl -X POST http://localhost:8001/service... \

--data "name=key-auth" 

{

"created_at": 1551256029, 
"config": {
    "key_names": [
        "apikey"
    ], 
    "run_on_preflight": true, 
    "anonymous": null, 
    "hide_credentials": false, 
    "key_in_body": false
}, 
"id": "4eaa000f-0fa2-4b3e-8c13-2db4c6b7ce49", 
"service": {
    "id": "978de8a6-6767-4741-baca-a25c9a131f9d"
}, 
"enabled": true, 
"run_on": "first", 
"consumer": null, 
"route": null, 
"name": "key-auth"

}
也可以在具体的route上启用插件，比如：
curl -X POST http://<host>:8001/routes/{route_id}/plugins \
--data "name=key-auth"
我们这里就不再赘述了。
开启插件后，再次访问前面的simple-web-server，则有：
curl -i -X GET http://localhost:8000/get -H 'Host:api.ctyun.com'
HTTP/1.1 401 Unauthorized
Date: Wed, 27 Feb 2019 08:27:13 GMT
Content-Type: application/json; charset=utf-8
Connection: keep-alive
WWW-Authenticate: Key realm="kong"
Content-Length: 41
Server: kong/1.0.3

{"message":"No API key found in request"}
此时插件key-auth已经开启了，开启之后怎么用呢？要想使用鉴权插件，离不开Consumer。如何创建Consumer并使用指定的插件，我们放到4.5 Add Consumers中尽心更详细的介绍。
4.5 Add Consumers
添加一个consumer，username和custom_id指定任一即可：
curl -i -X POST \
--url http://localhost:8001/consumers/ \ --data "username=<USERNAME>" \ --data "custom_id=<CUSTOM_ID>"
如：
curl -i -X POST \
--url http://localhost:8001/consumers/ \
--data "username=elbarco"

HTTP/1.1 201 Created
Date: Wed, 27 Feb 2019 08:47:50 GMT
Content-Type: application/json; charset=utf-8
Connection: keep-alive
Access-Control-Allow-Origin: *
Server: kong/1.0.3
Content-Length: 107

{

"custom_id": null, 
"created_at": 1551257270, 
"username": "elbarco", 
"id": "738627ae-57e9-4b20-9d1d-fb12998d5296"

}
为用户提供一个key：
curl -i -X POST \
--url http://localhost:8001/consume... \
--data 'key=hola-elbarco'

HTTP/1.1 201 Created
Date: Wed, 27 Feb 2019 09:12:12 GMT
Content-Type: application/json; charset=utf-8
Connection: keep-alive
Access-Control-Allow-Origin: *
Server: kong/1.0.3
Content-Length: 147

{

"key": "hola-elbarco", 
"created_at": 1551258732, 
"consumer": {
    "id": "738627ae-57e9-4b20-9d1d-fb12998d5296"
}, 
"id": "b9cb021d-cb37-4841-b172-40ff2dcacb5e"

}
此时，我们就可以带着鉴权访问前面的simple-web-server了，有两种方式：
curl http://kong:8000/{proxy path}?apikey=<some_key>

curl http://kong:8000/{proxy path} \

-H 'apikey: <some_key>'

我们这里任选一种即可：
curl -i -X GET http://localhost:8000/get -H 'Host:api.ctyun.com' -H 'apikey:hola-elbarco'

HTTP/1.1 200 OK
Content-Type: application/json
Content-Length: 398
Connection: keep-alive
Server: gunicorn/19.9.0
Date: Wed, 27 Feb 2019 09:19:31 GMT
Access-Control-Allow-Origin: *
Access-Control-Allow-Credentials: true
X-Kong-Upstream-Latency: 68
X-Kong-Proxy-Latency: 26
Via: kong/1.0.3

{
"args": {},
"headers": {

"Accept": "*/*",
"Apikey": "hola-elbarco",
"Connection": "keep-alive",
"Host": "simple-web-server",
"User-Agent": "curl/7.54.0",
"X-Consumer-Id": "738627ae-57e9-4b20-9d1d-fb12998d5296",
"X-Consumer-Username": "elbarco",
"X-Forwarded-Host": "api.ctyun.com"

},
"origin": "172.18.0.1",
"url": "http://api.ctyun.com/get"
}
4.6 Rate limiting
额外的，我们再看一下限流插件：Rate Limiting。
5.Advanced Features
5.1 Load balancing
Loadbalancing reference
6.Kong Dashboard (From community)
Kong的商业版中，提供了一个可视化界面工具，叫做Kong Manager，功能很是强大，比如：

试用需要申请，我们转而在社区中寻求替代工具，于是在Github上搜到了Kong Dashboard，提供了使用npm和docker安装两种方式，这里采用docker的方式安装一下，看看效果：

Start Kong Dashboard

docker run --rm -p 9090:8080 pgbi/kong-dashboard start --kong-url http://locahost:8001

Start Kong Dashboard on a custom port

docker run --rm -p [port]:8080 pgbi/kong-dashboard start --kong-url http://kong:8001

Start Kong Dashboard with basic auth

docker run --rm -p 8080:8080 pgbi/kong-dashboard start \ --kong-url http://kong:8001 --basic-auth user1=password1 user2=password2

See full list of start options

docker run --rm -p 8080:8080 pgbi/kong-dashboard start --help
docker run --rm --name kong-dashboard -p 9090:808i0 pgbi/kong-dashboard start --kong-url http://locahost:8001
docker run --rm --network kong-net --name kong-dashboard -p 9090:8080 pgbi/kong-dashboard start --kong-url http://kong:8001
Connecting to Kong on http://kong:8001 ...
This version of Kong dashboard doesn't support Kong v0.15 and higher.
受限于Kong的版本：
docker container exec 999a5cf1db1a kong version
1.0.3
我们没办法接入kong-dashboard，后面再进行调研吧。
7.Summary
kong的模型比较清晰，从service、route、plugin到upstream、consumer，通用性比较强，因为插件的存在，功能扩展性也很高。从我们的实际业务触发，也可以参考借鉴这种模型方式，先从核心功能出发。
8.Reference
[1].An Introduction to Kong
[2].Kong Admin API