$ docker run --network="dockerjenkinssuite_default"  csanchez/jenkins-swarm-slave -username admin -password admin -executors 1 -master http://172.18.0.2:8080
Running java -jar /usr/share/jenkins/swarm-client-3.4.jar -fsroot /home/jenkins-slave -username admin -password admin -executors 1 -master http://172.18.0.2:8080
May 10, 2017 8:23:43 PM hudson.plugins.swarm.Client main
INFO: Client.main invoked with: [-fsroot /home/jenkins-slave -username admin -password admin -executors 1 -master http://172.18.0.2:8080]
May 10, 2017 8:23:46 PM hudson.plugins.swarm.Client run
INFO: Discovering Jenkins master
Exception in thread "main" java.lang.NullPointerException
    at hudson.plugins.swarm.SwarmClient.createHttpClient(SwarmClient.java:333)
    at hudson.plugins.swarm.SwarmClient.discoverFromMasterUrl(SwarmClient.java:213)
    at hudson.plugins.swarm.Client.run(Client.java:114)
    at hudson.plugins.swarm.Client.main(Client.java:87)

$ docker run -it --network="dockerjenkinssuite_default" --rm nicolaka/netshoot
/ # curl http://admin:admin@172.18.0.2:8080/api/xml
<hudson _class='hudson.model.Hudson'><assignedLabel></assignedLabel><mode>NORMAL</mode><nodeDescription>the master Jenkins node</nodeDescription><nodeName></nodeName><numExecutors>2</numExecutors><job _class='org.jenkinsci.plugins.workflow.job.WorkflowJob'><name>Monthly Statistics Ingest</name><url>http://10.30.0.152/job/Monthly%20Statistics%20Ingest/</url><color>notbuilt</color></job><overallLoad></overallLoad><primaryView _class='hudson.model.AllView'><name>all</name><url>http://10.30.0.152/</url></primaryView><quietingDown>false</quietingDown><slaveAgentPort>50000</slaveAgentPort><unlabeledLoad _class='jenkins.model.UnlabeledLoadStatistics'></unlabeledLoad><useCrumbs>true</useCrumbs><useSecurity>true</useSecurity><view _class='hudson.model.AllView'><name>all</name><url>http://10.30.0.152/</url></view></hudson>