前端代理
为了了解 Envoy 作为前端代理的优势，我们发布了一个 docker compose 沙箱，它部署了一个前端 Envoy 和几个服务（简单的 aiohttp 应用程序），并与运行中的服务 Envoy 位于同一位置。
这三个容器将部署在名为 envoymesh 的虚拟网络中。
以下是一张显示 docker compose 部署的示意图
所有传入的请求都通过前端 Envoy 路由，前端 Envoy 充当位于 envoymesh 网络边缘的反向代理。端口 8080、8443 和 8001 由 docker compose 公开（参见 docker-compose.yaml）以处理 HTTP、HTTPS 对服务的调用以及对 /admin 的请求。
此外，请注意，前端 Envoy 路由到服务容器的所有流量实际上都被路由到服务 Envoy（在 envoy.yaml 中设置的路由）。
反过来，服务 Envoy 通过循环地址将请求路由到 aiohttp 应用程序（在 service-envoy.yaml 中设置的路由）。这种设置说明了与您的服务一起运行服务 Envoy 的优势：所有请求都由服务 Envoy 处理，并有效地路由到您的服务。
步骤 1：启动所有容器
更改到 examples/front-proxy 目录。
$ pwd
envoy/examples/front-proxy
$ docker compose pull
$ docker compose up --build -d
$ docker compose ps
Name Command State Ports
---------------------------------------------------------------------------------------------------------------------------------------------------------
front-proxy_front-envoy_1 /docker-entrypoint.sh /bin ... Up 10000/tcp, 0.0.0.0:8080->8080/tcp, 0.0.0.0:8001->8001/tcp, 0.0.0.0:8443->8443/tcp
front-proxy_service1_1 python3 /code/service.py ... Up (healthy)
front-proxy_service2_1 python3 /code/service.py ... Up (healthy)
步骤 2：测试 Envoy 的路由功能
您现在可以通过 front-envoy 向两个服务发送请求。
对于 service1
$ curl -v localhost:8080/service/1
* Trying ::1...
* TCP_NODELAY set
* Connected to localhost (::1) port 8080 (#0)
> GET /service/1 HTTP/1.1
> Host: localhost:8080
> User-Agent: curl/7.64.1
> Accept: */*
>
< HTTP/1.1 200 OK
< content-type: text/html; charset=utf-8
< content-length: 92
< server: envoy
< date: Mon, 06 Jul 2020 06:20:00 GMT
< x-envoy-upstream-service-time: 2
<
Hello from behind Envoy (service 1)! hostname: 36418bc3c824 resolvedhostname: 192.168.160.4
对于 service2
$ curl -v localhost:8080/service/2
* Trying ::1...
* TCP_NODELAY set
* Connected to localhost (::1) port 8080 (#0)
> GET /service/2 HTTP/1.1
> Host: localhost:8080
> User-Agent: curl/7.64.1
> Accept: */*
>
< HTTP/1.1 200 OK
< content-type: text/html; charset=utf-8
< content-length: 92
< server: envoy
< date: Mon, 06 Jul 2020 06:23:13 GMT
< x-envoy-upstream-service-time: 2
<
Hello from behind Envoy (service 2)! hostname: ea6165ee4fee resolvedhostname: 192.168.160.2
请注意，每个请求虽然发送到前端 Envoy，但都正确地路由到各自的应用程序。
我们还可以使用 HTTPS 调用前端 Envoy 后面的服务。例如，调用 service1
$ curl https://127.0.0.1:8443/service/1 -k -v
* Trying ::1...
* TCP_NODELAY set
* Connected to localhost (::1) port 8443 (#0)
* ALPN, offering h2
* ALPN, offering http/1.1
* successfully set certificate verify locations:
* CAfile: /etc/ssl/cert.pem
CApath: none
* TLSv1.2 (OUT), TLS handshake, Client hello (1):
* TLSv1.2 (IN), TLS handshake, Server hello (2):
* TLSv1.2 (IN), TLS handshake, Certificate (11):
* TLSv1.2 (IN), TLS handshake, Server key exchange (12):
* TLSv1.2 (IN), TLS handshake, Server finished (14):
* TLSv1.2 (OUT), TLS handshake, Client key exchange (16):
* TLSv1.2 (OUT), TLS change cipher, Change cipher spec (1):
* TLSv1.2 (OUT), TLS handshake, Finished (20):
* TLSv1.2 (IN), TLS change cipher, Change cipher spec (1):
* TLSv1.2 (IN), TLS handshake, Finished (20):
* SSL connection using TLSv1.2 / ECDHE-RSA-CHACHA20-POLY1305
* ALPN, server did not agree to a protocol
* Server certificate:
* subject: CN=front-envoy
* start date: Jul 5 15:18:44 2020 GMT
* expire date: Jul 5 15:18:44 2021 GMT
* issuer: CN=front-envoy
* SSL certificate verify result: self signed certificate (18), continuing anyway.
> GET /service/1 HTTP/1.1
> Host: localhost:8443
> User-Agent: curl/7.64.1
> Accept: */*
>
< HTTP/1.1 200 OK
< content-type: text/html; charset=utf-8
< content-length: 92
< server: envoy
< date: Mon, 06 Jul 2020 06:17:14 GMT
< x-envoy-upstream-service-time: 3
<
Hello from behind Envoy (service 1)! hostname: 36418bc3c824 resolvedhostname: 192.168.160.4
步骤 3：测试 Envoy 的负载均衡功能
现在，让我们扩展 service1 节点以展示 Envoy 的负载均衡能力
$ docker compose scale service1=3
Creating and starting example_service1_2 ... done
Creating and starting example_service1_3 ... done
现在，如果我们多次向 service1 发送请求，前端 Envoy 将通过对三个 service1 机器进行循环轮询来负载均衡请求
$ curl -v localhost:8080/service/1
* Trying ::1...
* TCP_NODELAY set
* Connected to localhost (::1) port 8080 (#0)
> GET /service/1 HTTP/1.1
> Host: localhost:8080
> User-Agent: curl/7.64.1
> Accept: */*
>
< HTTP/1.1 200 OK
< content-type: text/html; charset=utf-8
< content-length: 92
< server: envoy
< date: Mon, 06 Jul 2020 06:21:47 GMT
< x-envoy-upstream-service-time: 6
<
Hello from behind Envoy (service 1)! hostname: 3dc787578c23 resolvedhostname: 192.168.160.6
$ curl -v localhost:8080/service/1
* Trying 192.168.99.100...
* Connected to 192.168.99.100 (192.168.99.100) port 8080 (#0)
> GET /service/1 HTTP/1.1
> Host: 192.168.99.100:8080
> User-Agent: curl/7.54.0
> Accept: */*
>
< HTTP/1.1 200 OK
< content-type: text/html; charset=utf-8
< content-length: 89
< x-envoy-upstream-service-time: 1
< server: envoy
< date: Fri, 26 Aug 2018 19:40:22 GMT
<
Hello from behind Envoy (service 1)! hostname: 3a93ece62129 resolvedhostname: 192.168.160.5
$ curl -v localhost:8080/service/1
* Trying 192.168.99.100...
* Connected to 192.168.99.100 (192.168.99.100) port 8080 (#0)
> GET /service/1 HTTP/1.1
> Host: 192.168.99.100:8080
> User-Agent: curl/7.43.0
> Accept: */*
>
< HTTP/1.1 200 OK
< content-type: text/html; charset=utf-8
< content-length: 89
< x-envoy-upstream-service-time: 1
< server: envoy
< date: Fri, 26 Aug 2018 19:40:24 GMT
< x-envoy-protocol-version: HTTP/1.1
<
Hello from behind Envoy (service 1)! hostname: 36418bc3c824 resolvedhostname: 192.168.160.4
步骤 4：进入容器并使用 curl 调用服务
除了从您的主机使用 curl 外，您还可以进入容器本身并在其中使用 curl。要进入容器，您可以使用 docker compose exec <container_name> /bin/bash。例如，我们可以进入 front-envoy 容器，并在其中使用 curl 调用本地服务
$ docker compose exec front-envoy /bin/bash
root@81288499f9d7:/# curl localhost:8080/service/1
Hello from behind Envoy (service 1)! hostname: 85ac151715c6 resolvedhostname: 172.19.0.3
root@81288499f9d7:/# curl localhost:8080/service/1
Hello from behind Envoy (service 1)! hostname: 20da22cfc955 resolvedhostname: 172.19.0.5
root@81288499f9d7:/# curl localhost:8080/service/1
Hello from behind Envoy (service 1)! hostname: f26027f1ce28 resolvedhostname: 172.19.0.6
root@81288499f9d7:/# curl localhost:8080/service/2
Hello from behind Envoy (service 2)! hostname: 92f4a3737bbc resolvedhostname: 172.19.0.2
步骤 5：进入容器并使用 curl 调用管理界面
Envoy 运行时也会将一个 admin 附加到您想要的端口。
在示例配置中，管理界面绑定到端口 8001。
我们可以使用 curl 调用它以获取有用的信息
/server_info 提供有关您正在运行的 Envoy 版本的信息。
/stats 提供有关 Envoy 服务器的统计信息。
在示例中，我们可以进入 front-envoy 容器以查询管理界面
$ docker compose exec front-envoy /bin/bash
root@e654c2c83277:/# curl localhost:8001/server_info
{
"version": "093e2ffe046313242144d0431f1bb5cf18d82544/1.15.0-dev/Clean/RELEASE/BoringSSL",
"state": "LIVE",
"hot_restart_version": "11.104",
"command_line_options": {
"base_id": "0",
"use_dynamic_base_id": false,
"base_id_path": "",
"concurrency": 8,
"config_path": "/etc/envoy.yaml",
"config_yaml": "",
"allow_unknown_static_fields": false,
"reject_unknown_dynamic_fields": false,
"ignore_unknown_dynamic_fields": false,
"admin_address_path": "",
"local_address_ip_version": "v4",
"log_level": "info",
"component_log_level": "",
"log_format": "[%Y-%m-%d %T.%e][%t][%l][%n] [%g:%#] %v",
"log_format_escaped": false,
"log_path": "",
"service_cluster": "front-proxy",
"service_node": "",
"service_zone": "",
"drain_strategy": "Gradual",
"mode": "Serve",
"disable_hot_restart": false,
"enable_mutex_tracing": false,
"restart_epoch": 0,
"cpuset_threads": false,
"disabled_extensions": [],
"bootstrap_version": 0,
"hidden_envoy_deprecated_max_stats": "0",
"hidden_envoy_deprecated_max_obj_name_len": "0",
"file_flush_interval": "10s",
"drain_time": "600s",
"parent_shutdown_time": "900s"
},
"uptime_current_epoch": "188s",
"uptime_all_epochs": "188s"
}
root@e654c2c83277:/# curl localhost:8001/stats
cluster.service1.external.upstream_rq_200: 7
...
cluster.service1.membership_change: 2
cluster.service1.membership_total: 3
...
cluster.service1.upstream_cx_http2_total: 3
...
cluster.service1.upstream_rq_total: 7
...
cluster.service2.external.upstream_rq_200: 2
...
cluster.service2.membership_change: 1
cluster.service2.membership_total: 1
...
cluster.service2.upstream_cx_http2_total: 1
...
cluster.service2.upstream_rq_total: 2
...
请注意，我们可以获取上游集群的成员数量、它们完成的请求数量、有关 http 入口的信息以及大量其他有用的统计信息。
另见
- Envoy 管理界面快速入门指南
Envoy 管理界面快速入门指南。