zhaijack commented on a change in pull request #342: Issue 338: add first draft Docker image including community suggestions URL: https://github.com/apache/bookkeeper/pull/342#discussion_r131287387
########## File path: docker/README.md ########## @@ -0,0 +1,174 @@ + +# What is Apache Bookkeeper? + +Apache ZooKeeper is a software project of the Apache Software Foundation, providing a replicated log service which can be used to build replicated state machines. A log contains a sequence of events which can be applied to a state machine. BookKeeper guarantees that each replica state machine will see all the same entries, in the same order. + +> [Apache Bookkeeper](http://bookkeeper.apache.org/) + + +# How to use this image + +Bookkeeper needs [Zookeeper](https://zookeeper.apache.org/) in order to preserve its state and publish its bookies (bookkepeer servers). The client only need to connect to a Zookkeeper server in the ensamble in order to obtain the list of Bookkeeper servers. + +## TL;DR + +If you just want to see things working, you can play with Makefile hosted in this project and check its targets for a fairly complex set up example: +``` +git clone https://github.com/apache/bookkeeper +cd bookkeeper/docker +make run-demo +``` +While, if you don't have access to a X environment, e.g. on default MacOS, It has to run the last command manually in 6 terminals respectively. +``` +make run-zk +make run-bk BOOKIE=1 +make run-bk BOOKIE=2 +make run-bk BOOKIE=3 +make run-dice +make run-dice +``` +This will do all the following steps and start up a working ensemble with two dice applications. + +## Step by step + +The simplest way to let Bookkeeper servers publish themselves with a name, which could be resolved consistently across container runs, is through creation of a [docker network](https://docs.docker.com/engine/reference/commandline/network_create/): +``` +docker network create "my-bookkeeper-network" +``` +Then we can start a Zookeeper (from [Zookeeper official image](https://hub.docker.com/_/zookeeper/)) server in standalone mode on that network: +``` +docker run -d \ + --network "my-bookkeeper-network" \ + --name "my-zookeeper" \ + --hostname "my-zookeeper" \ + zookeeper +``` +And initialize the metadata store that bookies will use to store information: +``` +docker run -it --rm \ + --network "my-bookkeeper-network" \ + --env ZK_URL=my-zookeeper:2181 \ + bookkeeper \ + bookkeeper shell metaformat +``` +Now we can start our Bookkeeper ensemble (e.g. with three bookies): +``` +docker run -it\ + --network "my-bookkeeper-network" \ + --env ZK_URL=my-zookeeper:2181 \ + --name "bookie1" \ + --hostname "bookie1" \ + bookkeeper +``` +And so on for "bookie2" and "bookie3". We have now our fully functional ensemble, ready to accept clients. + +In order to play with our freshly created ensemble, you can use the simple application taken from [Bookkeeper Tutorial](http://bookkeeper.apache.org/docs/master/bookkeeperTutorial.html) and packaged in a [docker image](https://github.com/caiok/bookkeeper-tutorial) for convenience. + +This application check if it can be leader, if yes start to roll a dice and book this rolls on bookkeeper, otherwise it will start to follow the leader rolls. If leader stops, follower will try to become leader and so on. + +Start a dice application (you can run it several times to view the behavior in a concurrent environment): +``` +docker run -it --rm \ + --network "my-bookkeeper-network" \ + --env ZK_URL=my-zookkeeper:2181 \ + caiok/bookkeeper-tutorial +``` + +## Configuration + +Bookkeeper configuration is located in `/opt/bookkeeper/conf` in the docker container, it is a copy of [these files](https://github.com/apache/bookkeeper/tree/master/bookkeeper-server/conf) in bookkeeper repo. + +There are 2 ways to set bookkeeper configuration: + +1, Apply setted (e.g. docker -e kk=vv) environment variables into configuration files. Environment variable names is in format "BK_originalName", in which "originalName" is the key in config files. + +2, If you are able to handle your local volumes, use `docker --volume` command to bind-mount your local configure volumes to `/opt/bookkeeper/conf`. + +Example showing how to use your own configuration files: +``` +$ docker run --name bookie1 -d \ + -v $(local_configure_dir):/opt/bookkeeper/conf/ \ < == use 2nd approach, mount dir contains config_files + -e BK_bookiePort=3181 \ < == use 1st approach, set bookiePort + -e BK_zkServers=zk-server1:2181,zk-server2:2181 \ < == use 1st approach, set zookeeper servers + -e BK_journalPreAllocSizeMB=32 \ < == use 1st approach, set journalPreAllocSizeMB in [bk_server.conf](https://github.com/apache/bookkeeper/blob/master/bookkeeper-server/conf/bk_server.conf) + bookkeeper +``` + +### Override rules for bookkeeper configuration +If you have applied several ways to set the same config target, e.g. the environment variable names contained in [these files](https://github.com/apache/bookkeeper/tree/master/bookkeeper-server/conf) and conf_file in /opt/bookkeeper/conf/. + +Then the override rules is as this: + +Environment variable names contained in [these files](https://github.com/apache/bookkeeper/tree/master/bookkeeper-server/conf), e.g. `zkServers` + + Override + +Values in /opt/bookkeeper/conf/conf_files. + +Take above example, if in docker instance you have bind-mount your config file as /opt/bookkeeper/conf/bk_server.conf, and in it contains key-value pair: `zkServers=zk-server3:2181`, then the value that take effect finally is `zkServers=zk-server1:2181,zk-server2:2181` + +Because + +`-e zkServers=zk-server1:2181,zk-server2:2181` will override key-value pair: `zkServers=zk-server3:2181`, which contained in /opt/bookkeeper/conf/bk_server.conf. + + +### Environment variable names that mostly used for your configuration. + +#### `BK_bookiePort` + +This variable allows you to specify the port on which Bookkeeper should listen for incoming connections. + +This will override `bookiePort` in [bk_server.conf](https://github.com/apache/bookkeeper/blob/master/bookkeeper-server/conf/bk_server.conf). + +Default value is "3181". + +#### `BK_zkServers` + +This variable allows you to specify a list of machines of the Zookeeper ensemble. Each entry has the form of `host:port`. Entries are separated with a comma. + +This will override `zkServers` in [bk_server.conf](https://github.com/apache/bookkeeper/blob/master/bookkeeper-server/conf/bk_server.conf). + +Default value is "127.0.0.1:2181" + +#### `BK_zkLedgersRootPath` + +This variable allows you to specify the root directory bookkeeper will use on Zookeeper to store ledgers metadata. + +This will override `zkLedgersRootPath ` in [bk_server.conf](https://github.com/apache/bookkeeper/blob/master/bookkeeper-server/conf/bk_server.conf). + +Default value is "/bookkeeper/ledgers" + +#### `BK_CLUSTER_NAME` + +This variable allows you to specify the root directory bookkeeper will use on Zookeeper. + +Default value is "/bookkeeper" Review comment: Thanks. will change it. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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