I follow tutorial. But I'am stuck at maven building. It give connection time out. I use proxy. I did necessary changes for <proxies> element in conf/settings.xml didn't work. export proxy_https=<my_proxy_host:port> didn't work. my codes are below.
[root@hadooptest iot-truck-streaming]# /usr/maven/apache-maven-3.5.0/bin/mvn clean package -DskipTests
[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Build Order:
[INFO]
[INFO] transport-domain
[INFO] stream-simulator
[INFO] storm-streaming
[INFO] storm-demo-webapp
[INFO] storm-kafka-0.8-plus
[INFO] Storm Demo Parent Project
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building transport-domain 1.0.0-SNAPSHOT
[INFO] ------------------------------------------------------------------------
Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-clean-plugin/2.5/maven-clean-plu...
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary:
[INFO]
[INFO] transport-domain ................................... FAILURE [ 0.788 s]
[INFO] stream-simulator ................................... SKIPPED
[INFO] storm-streaming .................................... SKIPPED
[INFO] storm-demo-webapp .................................. SKIPPED
[INFO] storm-kafka-0.8-plus ............................... SKIPPED
[INFO] Storm Demo Parent Project .......................... SKIPPED
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 0.925 s
[INFO] Finished at: 2017-10-20T13:46:51+03:00
[INFO] Final Memory: 19M/483M
[INFO] ------------------------------------------------------------------------
[ERROR] Plugin org.apache.maven.plugins:maven-clean-plugin:2.5 or one of its dependencies could not be resolved: Failed to read artifact descriptor for org.apache.maven.plugins:maven-clean-plugin:jar:2.5: Could not transfer artifact org.apache.maven.plugins:maven-clean-plugin:pom:2.5 from/to central (https://repo.maven.apache.org/maven2): sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/PluginResolutionException