run hazelcast based on docker locally - hazelcast

Question

I want to run Hazelcast for POC for future use based on docker in the aws instances.
I use the next configuration to run in on my laptop for some investigation:
docker run -e JAVA_OPTS="-Dhazelcast.local.publicAddress=192.168.1.227:5701" -itd -p 5701:5701 hazelcast/hazelcast
docker run -e JAVA_OPTS="-Dhazelcast.local.publicAddress=192.168.1.227:5702" -itd -p 5702:5701 hazelcast/hazelcast
It starts ok, but once try to open it in the browser I got next warnings:
docker logs -ft a91ed298117a
2020-02-02T16:30:41.846203500Z ########################################
2020-02-02T16:30:41.846284000Z # JAVA_OPTS=-Dhazelcast.mancenter.enabled=false -Djava.net.preferIPv4Stack=true -Djava.util.logging.config.file=/opt/hazelcast/logging.properties -XX:MaxRAMPercentage=80.0 -Dhazelcast.local.publicAddress=192.168.1.227:5702
2020-02-02T16:30:41.846346700Z # CLASSPATH=/opt/hazelcast/*:/opt/hazelcast/lib/*
2020-02-02T16:30:41.846374200Z # starting now....
2020-02-02T16:30:41.846424700Z ########################################
2020-02-02T16:30:41.846467100Z + exec java -server -Dhazelcast.mancenter.enabled=false -Djava.net.preferIPv4Stack=true -Djava.util.logging.config.file=/opt/hazelcast/logging.properties -XX:MaxRAMPercentage=80.0 -Dhazelcast.local.publicAddress=192.168.1.227:5702 com.hazelcast.core.server.StartServer
Members {size:2, ver:2} [
2020-02-02T16:30:52.360102700Z Member [192.168.1.227]:5701 - e152d11b-df3e-4c29-a363-188842fc624c
2020-02-02T16:30:52.360128200Z Member [192.168.1.227]:5702 - e7811c67-34ef-4ec5-9687-1945d7c36b69 this
2020-02-02T16:30:52.360159400Z ]
2020-02-02T16:30:52.360183200Z
2020-02-02T16:30:53.384531200Z Feb 02, 2020 4:30:53 PM com.hazelcast.core.LifecycleService
2020-02-02T16:30:53.384586000Z INFO: [192.168.1.227]:5702 [dev] [3.12.6] [192.168.1.227]:5702 is STARTED
2020-02-02T16:31:00.582731400Z Feb 02, 2020 4:31:00 PM com.hazelcast.nio.tcp.TcpIpConnection
2020-02-02T16:31:00.582871900Z WARNING: [192.168.1.227]:5702 [dev] [3.12.6] Connection[id=2, /172.17.0.3:5701->/172.17.0.1:60574, qualifier=null, endpoint=null, alive=false, type=NONE] closed. Reason: Exception in Connection[id=2, /172.17.0.3:5701->/172.17.0.1:60574, qualifier=null, endpoint=null, alive=true, type=NONE], thread=hz._hzInstance_1_dev.IO.thread-in-1
2020-02-02T16:31:00.582909200Z java.lang.IllegalStateException: REST API is not enabled.
2020-02-02T16:31:00.583013000Z at com.hazelcast.nio.tcp.UnifiedProtocolDecoder.onRead(UnifiedProtocolDecoder.java:96)
2020-02-02T16:31:00.583049600Z at com.hazelcast.internal.networking.nio.NioInboundPipeline.process(NioInboundPipeline.java:135)
2020-02-02T16:31:00.583077900Z at com.hazelcast.internal.networking.nio.NioThread.processSelectionKey(NioThread.java:369)
2020-02-02T16:31:00.583122400Z at com.hazelcast.internal.networking.nio.NioThread.processSelectionKeys(NioThread.java:354)
2020-02-02T16:31:00.583189100Z at com.hazelcast.internal.networking.nio.NioThread.selectLoop(NioThread.java:280)
2020-02-02T16:31:00.583220000Z at com.hazelcast.internal.networking.nio.NioThread.run(NioThread.java:235)
2020-02-02T16:31:00.583249400Z
2020-02-02T16:31:00.604505300Z Feb 02, 2020 4:31:00 PM com.hazelcast.nio.tcp.TcpIpConnection
Could you please help me to understand where I goes wrong?

Answer 1

The Hazelcast REST API is not enabled by default and that is why you get the exception in the logs. Also, keep in mind, that it does not make much sense to open Hazelcast in the browser, since it does not serve any HTTP webpage.
Saying that, you successfully run Hazelcast cluster in Docker. Now if you want to play with it, the simplest way is to either enable REST API or to use your language of choice and connect with Hazelcast client.
1. REST API
To start Hazelcast with REST API enabled, you need to add -Dhazelcast.rest.enabled=true to your JAVA_OPTS. So in your case, you can run the following commands:
docker run -e JAVA_OPTS="-Dhazelcast.local.publicAddress=192.168.1.227:5701 -Dhazelcast.rest.enabled=true" -itd -p 5701:5701 hazelcast/hazelcast:3.12.6
docker run -e JAVA_OPTS="-Dhazelcast.local.publicAddress=192.168.1.227:5702 -Dhazelcast.rest.enabled=true" -itd -p 5702:5701 hazelcast/hazelcast:3.12.6
Then, you can use Hazelcast REST API, for example to add and read the value form the map:
$ curl -X POST 192.168.1.227:5701/hazelcast/rest/maps/mapName/foo -d "bar"
$ curl 192.168.1.227:5701/hazelcast/rest/maps/mapName/foo
bar
2. Hazelcast Client
There are Hazelcast Clients in most programming languages. You only need to specify 192.168.1.227:5701 and 192.168.1.227:5702 as the address of your Hazelcast cluster. For example, in Python it would look like this.
import hazelcast
config = hazelcast.ClientConfig()
config.network_config.addresses.append("192.168.1.227:5701")
config.network_config.addresses.append("192.168.1.227:5702")
client = hazelcast.HazelcastClient(config)
my_map = client.get_map("map")
my_map.put("key", "value")
client.shutdown()
Then, you can run it with:
pip install hazelcast-python-client && python client.py