Kurento tutorial does not run - amazon-web-services

Question

I am trying to run the Kurento "WebRTC Magic Mirror" tutorial from the Linux Mint terminal, but get these errors.
mvn compile exec:java -Dkms.url=ws://(MY aws ip):8888/kurento
Warning: JAVA_HOME environment variable is not set.
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building Kurento Java Tutorial - Magic Mirror 6.7.1
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-enforcer-plugin:1.4.1:enforce (enforce-java-version) # kurento-magic-mirror ---
[INFO]
[INFO] --- maven-enforcer-plugin:1.4.1:enforce (enforce-maven-version) # kurento-magic-mirror ---
[INFO]
[INFO] --- maven-enforcer-plugin:1.4.1:enforce (enforce-bytecode-version) # kurento-magic-mirror ---
[INFO]
[INFO] --- maven-enforcer-plugin:1.4.1:enforce (enforce-ban-duplicate-classes) # kurento-magic-mirror ---
[WARNING] Rule 0: org.apache.maven.plugins.enforcer.BanDuplicateClasses failed with message:
Duplicate classes found:
Found in:
org.slf4j:jcl-over-slf4j:jar:1.7.21:compile
commons-logging:commons-logging:jar:1.1.3:compile
Duplicate classes:
org/apache/commons/logging/impl/SimpleLog$1.class
org/apache/commons/logging/LogConfigurationException.class
org/apache/commons/logging/Log.class
org/apache/commons/logging/impl/NoOpLog.class
org/apache/commons/logging/impl/SimpleLog.class
org/apache/commons/logging/LogFactory.class
[INFO]
[INFO] --- maven-enforcer-plugin:1.4.1:enforce (enforce-ban-circular-dependencies) # kurento-magic-mirror ---
[INFO]
[INFO] --- buildnumber-maven-plugin:1.4:create-timestamp (get-build-timestamp) # kurento-magic-mirror ---
[INFO]
[INFO] --- buildnumber-maven-plugin:1.4:create (get-scm-revision) # kurento-magic-mirror ---
[INFO] Executing: /bin/sh -c cd '/home/jonado/kurento-tutorial-java/kurento-magic-mirror' && 'git' 'rev-parse' '--verify' 'HEAD'
[INFO] Working directory: /home/jonado/kurento-tutorial-java/kurento-magic-mirror
[INFO] Storing buildNumber: a54263bde3275fc6e49db51be17268040df4e53d at timestamp: 1530780937453
[WARNING] Cannot get the branch information from the git repository:
Detecting the current branch failed: fatal: ref HEAD is not a symbolic ref
[INFO] Executing: /bin/sh -c cd '/home/jonado/kurento-tutorial-java/kurento-magic-mirror' && 'git' 'rev-parse' '--verify' 'HEAD'
[INFO] Working directory: /home/jonado/kurento-tutorial-java/kurento-magic-mirror
[INFO] Storing buildScmBranch: UNKNOWN
[INFO]
[INFO] --- maven-resources-plugin:2.7:resources (default-resources) # kurento-magic-mirror ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 14 resources
[INFO] Copying 2 resources
[INFO]
[INFO] --- maven-compiler-plugin:3.3:compile (default-compile) # kurento-magic-mirror ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 3 source files to /home/jonado/kurento-tutorial-java/kurento-magic-mirror/target/classes
[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR :
[INFO] -------------------------------------------------------------
[ERROR] No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK?
[INFO] 1 error
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2.688 s
[INFO] Finished at: 2018-07-05T11:55:37+03:00
[INFO] Final Memory: 29M/599M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.3:compile (default-compile) on project kurento-magic-mirror: Compilation failure
[ERROR] No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK?
[ERROR] -> [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/MojoFailureException
I have installed Kurento Media server on AWS as written in the documentation (part 4.1): https://media.readthedocs.org/pdf/doc-kurento/stable/doc-kurento.pdf , and after that just followed the instructions to run the tutorial.
The first warning message says:
JAVA_HOME environment variable is not set.
As Media Server is located on AWS, isn't it suppose to be already installed? If not, how can I install it?
Also, I wanted to configure STUN server, however I don't know where to find WebRtcEndpoint.conf.ini file, as Kurento Media Server is located on AWS. So, where is it possible to find WebRtcEndpoint.conf.ini file?
And the main question: what should I change/install/update in order to successfully run the tutorial?

Answer 1

You need to install the Java JDK to run any of the Java demos on your computer. The Java demo is separate from the Kurento Media Server, it uses the Java Kurento Client libraries to send/receive messages from the Kurento Media Server.
And in regards to WebRtcEndpoint.conf.ini, that is located on the AWS server where you deployed Kurento Media Server. You will need to edit the file (/etc/kurento/modules/kurento/WebRtcEndpoint.conf.ini) and restart Kurento for the changes to take effect. Related Kurento Config docs