From 385708f221db656341093ea99600fb520bc04e0c Mon Sep 17 00:00:00 2001 From: Maria Bermudez Date: Thu, 17 Jan 2019 11:23:12 -0800 Subject: [PATCH] remove outdated ambassador pattern #7845 --- .../thirdparty/ambassador_pattern_linking.md | 179 ------------------ 1 file changed, 179 deletions(-) delete mode 100644 config/thirdparty/ambassador_pattern_linking.md diff --git a/config/thirdparty/ambassador_pattern_linking.md b/config/thirdparty/ambassador_pattern_linking.md deleted file mode 100644 index 91fd169722..0000000000 --- a/config/thirdparty/ambassador_pattern_linking.md +++ /dev/null @@ -1,179 +0,0 @@ ---- -description: Using the Ambassador pattern to abstract (network) services -keywords: Examples, Usage, links, docker, documentation, examples, names, name, container naming -redirect_from: -- /engine/articles/ambassador_pattern_linking/ -- /engine/admin/ambassador_pattern_linking/ -title: (Obsolete) Link via an ambassador container -noratings: true ---- - -This content is out of date. Docker now includes better ways to -manage multiple services together, as well as a mix of containerized and -uncontainerized services. Consider using one or more of the following: - -- [User-defined networks](/engine/userguide/networking.md#user-defined-networks) - allow you to connect services together, including managing DNS resolution - among them. - -- [Overlay networks](/engine/userguide/networking/overlay-security-model.md) - allow containers running on different Docker hosts to communicate in a - seamless, encapsulated way. - -- [Configs](/engine/swarm/configs.md) allow you to plug configuration details - into swarm service containers at runtime instead of baking configuration - details into your Docker images. This allows you to change configuration - details, such as IP addresses to reach services external to Docker, on the fly. - -- [Stacks](https://docs.docker.com/get-started/part5/) allow you to group - multiple swarm services together, including defining networks, storage, and - dependency relationships among the services. - -Consider using one or more of the above solutions rather than the content below. - -## Obsolete: Ambassador linking model - -Rather than hardcoding network links between a service consumer and -provider, Docker encourages service portability, for example instead of: - - (consumer) --> (redis) - -Requiring you to restart the `consumer` to attach it to a different -`redis` service, you can add ambassadors: - - (consumer) --> (redis-ambassador) --> (redis) - -Or - - (consumer) --> (redis-ambassador) ---network---> (redis-ambassador) --> (redis) - -When you need to rewire your consumer to talk to a different Redis -server, you can just restart the `redis-ambassador` container that the -consumer is connected to. - -This pattern also allows you to transparently move the Redis server to a -different docker host from the consumer. - -Using the `svendowideit/ambassador` container, the link wiring is -controlled entirely from the `docker run` parameters. - -### Two host example - -Start actual Redis server on one Docker host - - big-server $ docker run -d --name redis crosbymichael/redis - -Then add an ambassador linked to the Redis server, mapping a port to the -outside world - - big-server $ docker run -d --link redis:redis --name redis_ambassador -p 6379:6379 svendowideit/ambassador - -On the other host, you can set up another ambassador setting environment -variables for each remote port we want to proxy to the `big-server` - - client-server $ docker run -d --name redis_ambassador --expose 6379 -e REDIS_PORT_6379_TCP=tcp://192.168.1.52:6379 svendowideit/ambassador - -Then on the `client-server` host, you can use a Redis client container -to talk to the remote Redis server, just by linking to the local Redis -ambassador. - - client-server $ docker run -i -t --rm --link redis_ambassador:redis relateiq/redis-cli - redis 172.17.0.160:6379> ping - PONG - -### How it works - -The following example shows what the `svendowideit/ambassador` container -does automatically (with a tiny amount of `sed`) - -On the Docker host (192.168.1.52) that Redis runs on: - - # start actual redis server - $ docker run -d --name redis crosbymichael/redis - - # get a redis-cli image for connection testing - $ docker pull relateiq/redis-cli - - # test the redis server by talking to it directly - $ docker run -t -i --rm --link redis:redis relateiq/redis-cli - redis 172.17.0.136:6379> ping - PONG - ^D - - # add redis ambassador - $ docker run -t -i --link redis:redis --name redis_ambassador -p 6379:6379 alpine:3.2 sh - -In the `redis_ambassador` container, you can see the linked Redis -containers `env`: - - / # env - REDIS_PORT=tcp://172.17.0.136:6379 - REDIS_PORT_6379_TCP_ADDR=172.17.0.136 - REDIS_NAME=/redis_ambassador/redis - HOSTNAME=19d7adf4705e - SHLVL=1 - HOME=/root - REDIS_PORT_6379_TCP_PORT=6379 - REDIS_PORT_6379_TCP_PROTO=tcp - REDIS_PORT_6379_TCP=tcp://172.17.0.136:6379 - TERM=xterm - PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin - PWD=/ - / # exit - -This environment is used by the ambassador `socat` script to expose Redis -to the world (via the `-p 6379:6379` port mapping): - - $ docker container rm redis_ambassador - $ CMD="apk update && apk add socat && sh" - $ docker run -t -i --link redis:redis --name redis_ambassador -p 6379:6379 alpine:3.2 sh -c "$CMD" - [...] - / # socat -t 100000000 TCP4-LISTEN:6379,fork,reuseaddr TCP4:172.17.0.136:6379 - -Now ping the Redis server via the ambassador: - -Now go to a different server: - - $ CMD="apk update && apk add socat && sh" - $ docker run -t -i --expose 6379 --name redis_ambassador alpine:3.2 sh -c "$CMD" - [...] - / # socat -t 100000000 TCP4-LISTEN:6379,fork,reuseaddr TCP4:192.168.1.52:6379 - -And get the `redis-cli` image so we can talk over the ambassador bridge. - - $ docker pull relateiq/redis-cli - $ docker run -i -t --rm --link redis_ambassador:redis relateiq/redis-cli - redis 172.17.0.160:6379> ping - PONG - -### The svendowideit/ambassador Dockerfile - -The `svendowideit/ambassador` image is based on the `alpine:3.2` image with -`socat` installed. When you start the container, it uses a small `sed` -script to parse out the (possibly multiple) link environment variables -to set up the port forwarding. On the remote host, you need to set the -variable using the `-e` command line option. - - --expose 1234 -e REDIS_PORT_1234_TCP=tcp://192.168.1.52:6379 - -Will forward the local `1234` port to the remote IP and port, in this -case `192.168.1.52:6379`. - - # - # do - # docker build -t svendowideit/ambassador . - # then to run it (on the host that has the real backend on it) - # docker run -t -i -link redis:redis -name redis_ambassador -p 6379:6379 svendowideit/ambassador - # on the remote host, you can set up another ambassador - # docker run -t -i -name redis_ambassador -expose 6379 -e REDIS_PORT_6379_TCP=tcp://192.168.1.52:6379 svendowideit/ambassador sh - # you can read more about this process at https://docs.docker.com/articles/ambassador_pattern_linking/ - - # use alpine because its a minimal image with a package manager. - # prettymuch all that is needed is a container that has a functioning env and socat (or equivalent) - FROM alpine:3.2 - - RUN apk update && \ - apk add socat && \ - rm -r /var/cache/ - - CMD env | grep _TCP= | (sed 's/.*_PORT_\([0-9]*\)_TCP=tcp:\/\/\(.*\):\(.*\)/socat -t 100000000 TCP4-LISTEN:\1,fork,reuseaddr TCP4:\2:\3 \&/' && echo wait) | sh