Scalatra app on Openshift - setting Jetty IP - jetty

Question

I'm trying to deploy a minimal Scalatra application on Openshift with DIY cartridge. I've managed to get SBT working, but when it comes to container:start, I get the error:
FAILED SelectChannelConnector#0.0.0.0:8080: java.net.SocketException: Permission denied
Apparently, embedded Jetty tries to open socket at 0.0.0.0, which is prohibited by Openshift (you can only open ports at $OPENSHIFT_INTERNAL_IP). How can I tell Jetty exactly which IP I need it to listen?

Answer 1

Yes you are right about $OPENSHIFT_INTERNAL_IP. So edit ${jetty.home}/etc/jetty.xml and set jetty.host in the connector section as follows:
…..
<Set name="connectors">
<Array type="org.mortbay.jetty.Connector">
<Item>
<New class="org.mortbay.jetty.nio.SelectChannelConnector">
<Set name="host"><SystemProperty name="jetty.host" />$OPENSHIFT_INTERNAL_IP</Set>
<Set name="port"><SystemProperty name="jetty.port" default="8080"/></Set>
...
</New>
</Item>
</Array>
</Set>
hth

Answer 2

I've never used Openshift, so I'm groping a bit here.
Do you have a jetty.host set?
You may need to set up a jetty.xml file and set it in there. See http://docs.codehaus.org/display/JETTY/Newbie+Guide+to+Jetty for how to set the host. You can tell the xsbt web plugin about jetty.xml by setting your project up like this:
https://github.com/JamesEarlDouglas/xsbt-web-plugin/wiki/Settings
Alternately, you may be able to pass the parameter to Jetty during startup. That'd look like this: -Djetty.host="yourhostname"

Answer 3

To get running with jetty 9.2.13.v20150730 on the Openshift with DIY cartridge you have to run with Java8 setting it to run on the $OPENSHIFT_INTERNAL_IP as follows. First ssh onto the host and download a jdk8 with
cd $OPENSHIFT_DATA_DIR
wget --no-check-certificate --no-cookies --header "Cookie: oraclelicense=accept-securebackup-cookie" http://download.oracle.com/otn-pub/java/jdk/8u5-b13/jdk-8u5-linux-x64.tar.gz
tar -zxf jdk-8u5-linux-x64.tar.gz
export PATH=$OPENSHIFT_DATA_DIR/jdk1.8.0_05/bin:$PATH
export JAVA_HOME="$OPENSHIFT_DATA_DIR/jdk/jdk1.8.0_05"
java -version
Then in your .openshift\action_hooks\start ensure you have the same exported variables with something like:
# see http://stackoverflow.com/a/23895161/329496 to install jdk1.8 no DIY cartridge
export JAVA_HOME="$OPENSHIFT_DATA_DIR/jdk/jdk1.8.0_05"
export PATH=$OPENSHIFT_DATA_DIR/jdk1.8.0_05/bin:$PATH
nohup java -cp ${OPENSHIFT_REPO_DIR}target/dependency/jetty-runner.jar org.eclipse.jetty.runner.Runner --host ${OPENSHIFT_DIY_IP} --port ${OPENSHIFT_DIY_PORT} ${OPENSHIFT_REPO_DIR}/target/thinbus-srp-spring-demo.war > ${OPENSHIFT_LOG_DIR}server.log 2>&1 &
(Note that jdk-8u20-linux-x64.tar.gz has also been reported to work so you may want to check for the latest available.)
That setup does not need a jetty.xml as it sets the --host and --port to bind to the correct interface and run the built war file. What it does require is that jetty-runner.jar is copied out of the ivy cache into the target folder. With maven to do that you add something like:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<version>2.3</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>copy</goal>
</goals>
<configuration>
<artifactItems>
<artifactItem>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-runner</artifactId>
<version>${jetty.version}</version>
<destFileName>jetty-runner.jar</destFileName>
</artifactItem>
</artifactItems>
</configuration>
</execution>
</executions>
</plugin>
Google suggest that the SBT equivalent is simply retrieveManaged := true. You can ssh to the host and run find to figure out where the jetty-runner.jar dependency has been copied to and update the start command appropriately.