Scalatra app on Openshift - setting Jetty IP

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

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.

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

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