acs/proxy

自定义代理镜像，通过FROM dockercloud/haproxy的方式继承自镜像dockercloud/haproxy，动态感知容器的状态，做到后端容器负载均衡代理和服务发现。特点是将HAProxy负载均衡软件的所有配置都参数化了，方便用户自定义自己的需求和配置。该镜像的主要用于aliyun容器服务的默认路由服务不能满足用户的场景，方便用户对HAProxy进行自定义配置。

动态负载均衡代理和服务发现的原理

• 镜像acs/proxy通过容器自身环境变量确定负载均衡的全局(GLOBAL)和默认(DEFAULT)的配置
• 镜像acs/proxy侦听集群中的事件，例如容器状态的变化，发生变化后重新获取集群中相关容器的信息，确定最新的负载均衡配置
• 镜像acs/proxy根据最新的负载均衡配置去重新加载（reload）该配置，使得该配置生效。

如何确定负载均衡的后端容器

• 根据acs/proxy的环境变量ADDITIONAL_SERVICES来确定范围
  • ADDITIONAL_SERVICES: "*" # 范围为整个集群
  • ADDITIONAL_SERVICES: "project_name1:service_name1,project_name2:service_name2" # 范围为当前应用和指定应用的指定服务
  • ADDITIONAL_SERVICES 不设置或者为空 # 范围为当前应用的容器
• 根据每个容器的标签来确定是否加入acs/proxy的后端。
  • aliyun.proxy.VIRTUAL_HOST: "www.toolchainx.com" # 加入后端，且域名为www.toolchainx.com
  • aliyun.proxy.required: "true" # 加入后端，且作为默认的后端

如何在前端绑定SLB

• 使用自定义SLB标签，例如：aliyun.lb.port_80: 'tcp://proxy:80'

示例模板

lb:
  image: registry.aliyuncs.com/acs/proxy:0.5
  ports:
   - '80:80'
  restart: always
  labels:
    aliyun.addon: "proxy"
    aliyun.global: "true"
    aliyun.lb.port_80: tcp://proxy:80
  environment:
    ADDITIONAL_SERVICES: "*"
web:
  image: registry.aliyuncs.com/acs-sample/wordpress:4.5
  ports:
    - '80'
  environment:
    WORDPRESS_AUTH_KEY: changeme
    WORDPRESS_SECURE_AUTH_KEY: changeme
    WORDPRESS_LOGGED_IN_KEY: changeme
    WORDPRESS_NONCE_KEY: changeme
    WORDPRESS_AUTH_SALT: changeme
    WORDPRESS_SECURE_AUTH_SALT: changeme
    WORDPRESS_LOGGED_IN_SALT: changeme
    WORDPRESS_NONCE_SALT: changeme
    WORDPRESS_NONCE_AA: changeme
  restart: always
  links:
    - 'db:mysql'
  labels:
    aliyun.logs: /var/log
    aliyun.probe.url: http://container/license.txt
    aliyun.probe.initial_delay_seconds: '10'
    aliyun.proxy.VIRTUAL_HOST: www.toolchainx.com
    aliyun.scale: '3'
db:
  image: registry.aliyuncs.com/acs-sample/mysql:5.7
  environment:
    MYSQL_ROOT_PASSWORD: password
  restart: always
  labels:
    aliyun.logs: /var/log/mysql

配置说明

通过acs/proxy镜像的环境变量设置全局（GLOBAL）和默认（DEFAULT）的配置

Settings in this part is immutable, you have to redeploy HAProxy service to make the changes take effects

Environment Variable	Default	Description
ADDITIONAL_SERVICES		list of additional services to balance (es: prj1:web,prj2:sql). Discovery will be based on `com.docker.compose.[project
BALANCE	roundrobin	load balancing algorithm to use. Possible values include: roundrobin, static-rr, source, leastconn. See:HAProxy:balance
CA_CERT_FILE		the path of a ca-cert file. This allows you to mount your ca-cert file directly from a volume instead of from envvar. If set, CA_CERT envvar will be ignored. Possible value: /cacerts/cert0.pem
CA_CERT		CA cert for haproxy to verify the client. Use the same format as DEFAULT_SSL_CERT
CERT_FOLDER		the path of certificates. This allows you to mount your certificate files directly from a volume instead of from envvars. If set, DEFAULT_SSL_CERT and SSL_CERT from linked services are ignored. Possible value:/certs/
DEFAULT_SSL_CERT		Default ssl cert, a pem file content with private key followed by public certificate, '\n'(two chars) as the line separator. should be formatted as one line - see SSL Termination
EXTRA_BIND_SETTINGS		comma-separated string(<port>:<setting>) of extra settings, and each part will be appended to the related port bind section in the configuration file. To escape comma, use \,. Possible value: 443:accept-proxy, 80:name http
EXTRA_DEFAULT_SETTINGS		comma-separated string of extra settings, and each part will be appended to DEFAULT section in the configuration file. To escape comma, use \,
EXTRA_FRONTEND_SETTINGS_<PORT>		comma-separated string of extra settings, and each part will be appended frontend section with the port number specified in the name of the envvar. To escape comma, use \,. E.g. EXTRA_FRONTEND_SETTINGS_80=balance source, maxconn 2000
EXTRA_GLOBAL_SETTINGS		comma-separated string of extra settings, and each part will be appended to GLOBAL section in the configuration file. To escape comma, use \,. Possible value: tune.ssl.cachesize 20000, tune.ssl.default-dh-param 2048
EXTRA_ROUTE_SETTINGS		a string which is append to the each backend route after the health check, can be over written in the linked services. Possible value: "send-proxy"
EXTRA_SSL_CERTS		list of extra certificate names separated by comma, eg. CERT1, CERT2, CERT3. You also need to specify each certificate as separate env variables like so: CERT1="<cert-body1>", CERT2="<cert-body2>", CERT3="<cert-body3>"
HEALTH_CHECK	check	set health check on each backend route, possible value: "check inter 2000 rise 2 fall 3". See:HAProxy:check
HTTP_BASIC_AUTH		a comma-separated list of credentials(<user>:<pass>) for HTTP basic auth, which applies to all the backend routes. To escape comma, use \,. Attention: DO NOT rely on this for authentication in production
MAXCONN	4096	sets the maximum per-process number of concurrent connections.
MODE	http	mode of load balancing for HAProxy. Possible values include: http, tcp, health
MONITOR_PORT		the port number where monitor_uri should be added to. Use together with MONTIOR_URI. Possible value: 80
MONITOR_URI		the exact URI which we want to intercept to return HAProxy's health status instead of forwarding the request.See: http://cbonte.github.io/haproxy-dconv/configuration-1.5.html#4-monitor-uri. Possible value: /ping
OPTION	redispatch	comma-separated list of HAProxy option entries to the default section.
RSYSLOG_DESTINATION	127.0.0.1	the rsyslog destination to where HAProxy logs are sent
SKIP_FORWARDED_PROTO		If set to any value, HAProxy will not add an X-Forwarded- headers. This can be used when combining HAProxy with another load balancer
SSL_BIND_CIPHERS		explicitly set which SSL ciphers will be used for the SSL server. This sets the HAProxy ssl-default-bind-ciphers configuration setting.
SSL_BIND_OPTIONS	no-sslv3	explicitly set which SSL bind options will be used for the SSL server. This sets the HAProxy ssl-default-bind-options configuration setting. The default will allow only TLSv1.0+ to be used on the SSL server.
STATS_AUTH	stats:stats	username and password required to access the Haproxy stats.
STATS_PORT	1936	port for the HAProxy stats section. If this port is published, stats can be accessed at http://<host-ip>:<STATS_PORT>/
TIMEOUT	connect 5000, client 50000, server 50000	comma-separated list of HAProxy timeout entries to the default section.

被代理的后端服务通过相应服务镜像的标签（LABEL）进行某一后端服务的配置###

即通过将标签（LABEL）写到后端服务的镜像上面来配置
Settings here can overwrite the settings in HAProxy, which are only applied to the linked services. If run in Docker Cloud, when the service redeploys, joins or leaves HAProxy service, HAProxy service will automatically update itself to apply the changes

Labels	Description
aliyun.proxy.APPSESSION	sticky session option, possible value JSESSIONID len 52 timeout 3h. See:HAProxy:appsession
aliyun.proxy.BALANCE	load balancing algorithm to use. Possible values include: roundrobin, static-rr, source, leastconn. See:HAProxy:balance
aliyun.proxy.COOKIE	sticky session option. Possible value SRV insert indirect nocache. See:HAProxy:cookie
aliyun.proxy.DEFAULT_SSL_CERT	similar to SSL_CERT, but stores the pem file at /certs/cert0.pem as the default ssl certs. If multiple DEFAULT_SSL_CERT are specified in linked services and HAProxy, the behavior is undefined
aliyun.proxy.EXCLUDE_PORTS	comma separated port numbers(e.g. 3306, 3307). By default, HAProxy will add all the ports exposed by the application services to the backend routes. You can exclude the ports that you don't want to be routed, like database port
aliyun.proxy.EXTRA_ROUTE_SETTINGS	a string which is append to the each backend route after the health check,possible value: "send-proxy"
aliyun.proxy.EXTRA_SETTINGS	comma-separated string of extra settings, and each part will be appended to either related backend section or listen session in the configuration file. To escape comma, use \,. Possible value: balance source
aliyun.proxy.FORCE_SSL	if set(any value) together with ssl termination enabled. HAProxy will redirect HTTP request to HTTPS request.
aliyun.proxy.GZIP_COMPRESSION_TYPE	enable gzip compression. The value of this envvar is a list of MIME types that will be compressed, possible value: text/html text/plain text/css
aliyun.proxy.HEALTH_CHECK	set health check on each backend route, possible value: "check inter 2000 rise 2 fall 3". See:HAProxy:check
aliyun.proxy.HSTS_MAX_AGE	enable HSTS. It is an integer representing the max age of HSTS in seconds, possible value: 31536000
aliyun.proxy.HTTP_CHECK	enable HTTP protocol to check on the servers health, possible value: "OPTIONS * HTTP/1.1\r\nHost:\ www". See:HAProxy:httpchk
aliyun.proxy.OPTION	comma-separated list of HAProxy option entries. option specified here will be added to related backend or listen part, and overwrite the OPTION settings in the HAProxy container
aliyun.proxy.SSL_CERT	ssl cert, a pem file with private key followed by public certificate, '\n'(two chars) as the line separator
aliyun.proxy.TCP_PORTS	comma separated ports(e.g. 9000, 9001, 2222/ssl). The port listed in TCP_PORTS will be load-balanced in TCP mode. Port ends with /ssl indicates that port needs SSL termination.
aliyun.proxy.VIRTUAL_HOST_WEIGHT	an integer of the weight of an virtual host, used together with VIRTUAL_HOST, default:0. It affects the order of acl rules of the virtual hosts. The higher weight one virtual host has, the more priority that acl rules applies.
aliyun.proxy.VIRTUAL_HOST	specify virtual host and virtual path. Format: [scheme://]domain[:port][/path], .... wildcard * can be used in domain and path part

Check the HAProxy configuration manual for more information on the above.

Virtual host and virtual path

Both virtual host and virtual path can be specified in environment variable VIRTUAL_HOST, which is a set of comma separated urls with the format of [scheme://]domain[:port][/path].

Item	Default	Description
scheme	http	possible values: http, https, wss
domain		virtual host. * can be used as the wildcard
port	80/433	port number of the virtual host. When the scheme is https wss, the default port will be to 443
/path		virtual path, starts with /. * can be used as the wildcard

examples of matching

Virtual host	Match	Not match
http://domain.com	domain.com	www.domain.com
domain.com	domain.com	www.domain.com
domain.com:90	domain.com:90	domain.com
https://domain.com	https://domain.com	domain.com
https://domain.com:444	https://domain.com:444	https://domain.com
*.domain.com	www.domain.com	domain.com
*domain.com	www.domain.com, domain.com, anotherdomain.com	www.abc.com
www.e\*e.com	www.domain.com, www.exxe.com	www.axxa.com
www.domain.\*	www.domain.com, www.domain.org	domain.com
*	any website with HTTP
https://*	any website with HTTPS
*/path	domain.com/path, domain.org/path?u=user	domain.com/path/
*/path/	domain.com/path/, domain.org/path/?u=user	domain.com/path, domain.com/path/abc
*/path/*	domain.com/path/, domain.org/path/abc	domain.com/abc/path/
*/*/path/*	domain.com/path/, domain.org/abc/path/, domain.net/abc/path/123	domain.com/path
*/*.js	domain.com/abc.js, domain.org/path/abc.js	domain.com/abc.css
*/*.do/	domain.com/abc.do/, domain.org/path/abc.do/	domain.com/abc.do
*/path/*.php	domain.com/path/abc.php	domain/abc.php, domain.com/root/abc.php
*.domain.com/*.jpg	www.domain.com/abc.jpg, abc.domain.com/123.jpg	domain.com/abc.jpg
*/path, */path/	domain.com/path, domain.org/path/
domain.com:90, https://domain.com	domain.com:90, https://domain.com

Note:

1. The sequence of the acl rules generated based on VIRTUAL_HOST are random. In HAProxy, when an acl rule with a wide scope(e.g. *.domain.com) is put before a rule with narrow scope(e.g. web.domain.com), the narrow rule will never be reached. As a result, if the virtual hosts you set have overlapping scopes, you need to use VIRTUAL_HOST_WEIGHT to manually set the order of acl rules, namely, giving the narrow virtual host a higher weight than the wide one.
2. Every service that has the same VIRTUAL_HOST environment variable setting will be considered and merged into one single service. It may be useful for some testing scenario.

SSL termination

acs/proxy supports ssl termination on multiple certificates. For each application that you want ssl terminates, simply set SSL_CERT and VIRTUAL_HOST. HAProxy, then, reads the certificate from the link environment and sets the ssl termination up.

Attention: there was a bug that if an environment variable value contains "=", which is common in the SSL_CERT, docker skips that environment variable. As a result, multiple ssl termination only works on docker 1.7.0 or higher.

SSL termination is enabled when:

1. at least one SSL certificate is set, and
2. either VIRTUAL_HOST is not set, or it is set with "https" as the scheme.

To set SSL certificate, you can either:

1. set DEFAULT_SSL_CERT in acs/proxy, or
2. set aliyun.proxy.SSL_CERT and/or DEFAULT_SSL_CERT in the application services linked to HAProxy

The difference between aliyun.proxy.SSL_CERT and DEFAULT_SSL_CERT is that, the multiple certificates specified by SSL_CERT are stored in as cert1.pem, cert2.pem, ..., whereas the one specified by DEFAULT_SSL_CERT is always stored as cert0.pem. In that case, HAProxy will use cert0.pem as the default certificate when there is no SNI match. However, when multiple DEFAULT_SSL_CERTIFICATE is provided, only one of the certificates can be stored as cert0.pem, others are discarded.

PEM Files

The certificate specified in acs/proxy or in the linked application services is a pem file, containing a private key followed by a public certificate(private key must be put before the public certificate and any extra Authority certificates, order matters). You can run the following script to generate a self-signed certificate:

openssl req -x509 -newkey rsa:2048 -keyout key.pem -out ca.pem -days 1080 -nodes -subj '/CN=*/O=My Company Name LTD./C=US'
cp key.pem cert.pem
cat ca.pem >> cert.pem

Once you have the pem file, you can run this command to convert the file correctly to one line:

awk 1 ORS='\\n' cert.pem

Copy the output and set it as the value of aliyun.proxy.SSL_CERT or DEFAULT_SSL_CERT.

Affinity and session stickiness

There are three method to setup affinity and sticky session:

1. set aliyun.proxy.BALANCE=source in your application service. When setting source method of balance, HAProxy will hash the client IP address and make sure that the same IP always goes to the same server.
2. set aliyun.proxy.APPSESSION=<value>. use application session to determine which server a client should connect to. Possible value of <value> could be JSESSIONID len 52 timeout 3h
3. set aliyun.proxy.COOKIE=<value>. use application cookie to determine which server a client should connect to. Possible value of <value> could be SRV insert indirect nocache

Check HAProxy:appsession and HAProxy:cookie for more information.

TCP load balancing

By default, acs/proxy runs in http mode. If you want a linked service to run in a tcp mode, you can specify the environment variable TCP_PORTS, which is a comma separated ports(e.g. 9000, 9001).

For example, if you run:

docker --name app-1 --expose 9000 --expose 9001 -e TCP_PORTS="9000, 9001" your_app
docker --name app-2 --expose 9000 --expose 9001 -e TCP_PORTS="9000, 9001" your_app
docker run --link app-1:app-1 --link app-2:app-2 -p 9000:9000, 9001:9001 acs/proxy

Then, haproxy balances the load between app-1 and app-2 in both port 9000 and 9001 respectively.

Moreover, If you have more exposed ports than TCP_PORTS, the rest of the ports will be balancing using http mode.

For example, if you run:

docker --name app-1 --expose 80 --expose 22 -e TCP_PORTS=22 your_app
docker --name app-2 --expose 80 --expose 22 -e TCP_PORTS=22 your_app
docker run --link app-1:app-2 --link app-2:app-2 -p 80:80 -p 22:22 acs/proxy

Then, haproxy balances in http mode at port 80 and balances in tcp on port at port 22.

In this way, you can do the load balancing both in tcp and in http at the same time.

In TCP_PORTS, if you set port that ends with '/ssl', for example 2222/ssl, HAProxy will set ssl termination on port 2222.

Note:

1. You are able to set VIRTUAL_HOST and TCP_PORTS at the same them, giving more control on http mode.
2. Be careful that, the load balancing on tcp port is applied to all the services. If you link two(or more) different services using the same TCP_PORTS, acs/proxy considers them coming from the same service.

WebSocket support

---

There are two ways to enable the support of websocket:

1. As websocket starts using HTTP protocol, you can use virtual host to specify the scheme using ws or wss. For example, `-e VIRTUAL_HOST="ws://ws.domain.com, wss://wss.domain.com"
2. Websocket itself is a TCP connection, you can also try the TCP load balancing mentioned in the previous section.

Use case scenarios

My webapp container exposes port 8080(or any other port), and I want the proxy to listen in port 80

Use the following:

docker run -d --expose 80 --name webapp dockercloud/hello-world
docker run -d --link webapp:webapp -p 80:80 acs/proxy

My webapp container exposes port 80 and database ports 8083/8086, and I want the proxy to listen in port 80 without my database ports added to haproxy

docker run -d -e EXCLUDE_PORTS=8803,8806 --expose 80 --expose 8033 --expose 8086 --name webapp dockercloud/hello-world
docker run -d --link webapp:webapp -p 80:80 acs/proxy

My webapp container exposes port 8080(or any other port), and I want the proxy to listen in port 8080

Use the following:

docker run -d --expose 8080 --name webapp your_app
docker run -d --link webapp:webapp -p 8080:80 acs/proxy

#### I want the proxy to terminate SSL connections and forward plain HTTP requests to my webapp to port 8080(or any port)

Use the following:

docker run -d -e SSL_CERT="YOUR_CERT_TEXT" --name webapp dockercloud/hello-world
docker run -d --link webapp:webapp -p 443:443 -p 80:80 acs/proxy

or

docker run -d --link webapp:webapp -p 443:443 -p 80:80 -e DEFAULT_SSL_CERT="YOUR_CERT_TEXT" acs/proxy

The certificate in YOUR_CERT_TEXT is a combination of private key followed by public certificate. Remember to put \n between each line of the certificate. A way to do this, assuming that your certificate is stored in ~/cert.pem, is running the following:

docker run -d --link webapp:webapp -p 443:443 -p 80:80 -e DEFAULT_SSL_CERT="$(awk 1 ORS='\\n' ~/cert.pem)" acs/proxy

I want the proxy to terminate SSL connections and redirect HTTP requests to HTTPS

Use the following:

docker run -d -e FORCE_SSL=yes -e SSL_CERT="YOUR_CERT_TEXT" --name webapp dockercloud/hello-world
docker run -d --link webapp:webapp -p 443:443 acs/proxy

I want to load my SSL certificate from volume instead of passing it through environment variable

You can use CERT_FOLDER envvar to specify which folder the certificates are mounted in the container, using the following:

docker run -d --name webapp dockercloud/hello-world
docker run -d --link webapp:webapp -e CERT_FOLDER="/certs/" -v $(pwd)/cert1.pem:/certs/cert1.pem -p 443:443 acs/proxy

I want to set up virtual host routing by domain

Virtual hosts can be configured by the proxy reading linked container environment variables (VIRTUAL_HOST). Here is an example:

docker run -d -e VIRTUAL_HOST="www.webapp1.com, www.webapp1.org" --name webapp1 dockercloud/hello-world
docker run -d -e VIRTUAL_HOST=www.webapp2.com --name webapp2 your/webapp2
docker run -d --link webapp1:webapp1 --link webapp2:webapp2 -p 80:80 acs/proxy

In the example above, when you access http://www.webapp1.com or http://www.webapp1.org, it will show the service running in container webapp1, and http://www.webapp2.com will go to container webapp2.

If you use the following:

docker run -d -e VIRTUAL_HOST=www.webapp1.com --name webapp1 dockercloud/hello-world
docker run -d -e VIRTUAL_HOST=www.webapp2.com --name webapp2-1 dockercloud/hello-world
docker run -d -e VIRTUAL_HOST=www.webapp2.com --name webapp2-2 dockercloud/hello-world
docker run -d --link webapp1:webapp1 --link webapp2-1:webapp2-1 --link webapp2-2:webapp2-2 -p 80:80 acs/proxy

When you access http://www.webapp1.com, it will show the service running in container webapp1, and http://www.webapp2.com will go to both containers webapp2-1 and webapp2-2 using round robin (or whatever is configured in BALANCE).

I want all my *.node.io domains point to my service

docker run -d -e VIRTUAL_HOST="*.node.io" --name webapp dockercloud/hello-world
docker run -d --link webapp:webapp -p 80:80 acs/proxy

I want web.domain.com go to one service and *.domain.com go to another service

docker run -d -e VIRTUAL_HOST="web.domain.com" -e VIRTUAL_HOST_WEIGHT=1 --name webapp dockercloud/hello-world
docker run -d -e VIRTUAL_HOST="*.domain.com" -e VIRTUAL_HOST_WEIGHT=0 --name app dockercloud/hello-world
docker run -d --link webapp:webapp --link app:app -p 80:80 acs/proxy

I want all the requests to path /path point to my service

docker run -d -e VIRTUAL_HOST="*/path, */path/*" --name webapp dockercloud/hello-world
docker run -d --link webapp:webapp -p 80:80 acs/proxy

I want all the static html request point to my service

docker run -d -e VIRTUAL_HOST="*/*.htm, */*.html" --name webapp dockercloud/hello-world
docker run -d --link webapp:webapp -p 80:80 acs/proxy

I want to see stats of HAProxy

docker run -d --link webapp:webapp -e STATS_AUTH="auth:auth" -e STATS_PORT=1936 -p 80:80 -p 1936:1936 acs/proxy

I want to send all my logs to papertrailapp

Replace <subdomain> and <port> with your the values matching your papertrailapp account:

docker run -d --name web1 dockercloud/hello-world
docker run -d --name web2 dockercloud/hello-world
docker run -it --env RSYSLOG_DESTINATION='<subdomain>.papertrailapp.com:<port>' -p 80:80 --link web1:web1 --link web2:web2 acs/proxy

Topologies using virtual hosts

阿里云容器服务代理拓扑图

                                                           |---- container_a1
                                    |----- service_a ----- |---- container_a2
                                    |   (virtual host a)   |---- container_a3
internet --- SLB ----- acs/proxy--- |
                                    |                      |---- container_b1
                                    |----- service_b ----- |---- container_b2
                                        (virtual host b)   |---- container_b3

Manually reload haproxy

In most cases, acs/proxy will configure itself automatically when the linked services change, you don't need to reload it manually. But for some reason, if you have to do so, here is how:

• docker exec <haproxy_id> /reload.sh, if you are on the node where acs/proxy deploys