Captain -- Simplest service discovery in the universe

Captain is yet another service discovery implementation based on redis. Captain sacrifices a little high availability for simplicity and performance. In most cases, we don't have tens of thousands of machines, the possibility of machine crashing is very low, high availability is not so abviously important. But the market only provides zookeeper/etcd/consul, they are complex, at least much complexer compared with captain.

Why Agent

Php has no stabilized multithread support. So agent is provided to communite with php client using ramdisk file.

Architecture

RAM Structure

Usage

install redis
install java8
install maven

#create ramdisk
hdiutil attach -nomount ram://163840
newfs_hfs /dev/disk2
mkdir -p /tmp/ramdisk/captain
mount -t hfs /dev/disk2 /tmp/ramdisk/captain
cd /tmp/ramdisk/captain
dd if=/dev/zero of=agent bs=12608007 count=1

git clone github.com/pyloque/captain-java.git
git clone github.com/pyloque/captain-agent.git

cd captain-java
mvn package
mvn install

cd captain-agent
mvn package
java -jar target/captain-agent.jar
java -jar target/captain-agent.jar ${configfile}  # custom config file

open browser
http://localhost:6790/agent/

Configuration

Default Config File is ${user.home}/.captain/captain.agent.ini

[bind]
port=6790

[server]
origins=localhost:6789

[watch]
interval=1000
keepalive=5

[shm]
file=/tmp/ramdisk/captain/agent  # ramdisk file location

API

1. watch service /api/service/watch?name=service1&name=service2
2. watch kv /api/kv/watch?key=key1&key=key2
3. get service /api/service/get?name=service1
4. get kv /api/kv/get?key=key1

Screenshot

Notice

Agent will not support service registration.