fabric8/tomcat-6 repository overview

⁠Apache Tomcat 6.0.45

A simple docker build for installing a vanilla Tomcat 6.0.45 below /opt/tomcat. It comes out of the box and is intended for use for integration testing.

During startup a directory specified by the environment variable DEPLOY_DIR (/deployments by default) is checked for .war files. If there are any, they are linked into the webapps/ directory for automatic deployment. This plays nicely with the docker-maven-plugin⁠ and its 'assembly' mode which can automatically create Docker data container with Maven artifacts exposed from a directory /deployments.

⁠Agent Bond

For this image Agent Bond⁠ is enabled. Agent Bond exports metrics from Jolokia⁠ and jmx_exporter⁠.

The agent is installed as /opt/agent-bond/agent-bond.jar and enables the following agents by default:

• Jolokia⁠ : version undefined and port 8778
• jmx_exporter⁠: version undefined and port 9779

You can influence the behaviour of agent-bond-opts by setting various environment variables:

⁠Agent-Bond Options

Agent bond itself can be influenced with the following environment variables:

• AB_OFF : If set disables activation of agent-bond (i.e. echos an empty value). By default, agent-bond is enabled.
• AB_ENABLED : Comma separated list of sub-agents enabled. Currently allowed values are jolokia and jmx_exporter. By default both are enabled.

⁠Jolokia configuration

• AB_JOLOKIA_CONFIG : If set uses this file (including path) as Jolokia JVM agent properties (as described in Jolokia's reference manual⁠). By default this is /opt/jolokia/jolokia.properties.
• AB_JOLOKIA_HOST : Host address to bind to (Default: 0.0.0.0)
• AB_JOLOKIA_PORT : Port to use (Default: 8778)
• AB_JOLOKIA_USER : User for authentication. By default authentication is switched off.
• AB_JOLOKIA_HTTPS : Switch on secure communication with https. By default self signed server certificates are generated if no serverCert configuration is given in AB_JOLOKIA_OPTS
• AB_JOLOKIA_PASSWORD : Password for authentication. By default authentication is switched off.
• AB_JOLOKIA_ID : Agent ID to use ($HOSTNAME by default, which is the container id)
• AB_JOLOKIA_OPTS : Additional options to be appended to the agent opts. They should be given in the format "key=value,key=value,..."

Some options for integration in various environments:

• AB_JOLOKIA_AUTH_OPENSHIFT : Switch on client authentication for OpenShift TLS communication. The value of this parameter can be a relative distinguished name which must be contained in a presented client certificate. Enabling this parameter will automatically switch Jolokia into https communication mode. The default CA cert is set to /var/run/secrets/kubernetes.io/serviceaccount/ca.crt

⁠jmx_exporter configuration

• AB_JMX_EXPORTER_OPTS : Configuration to use for jmx_exporter (in the format <port>:<path to config>)
• AB_JMX_EXPORTER_PORT : Port to use for the JMX Exporter. Default: 9779
• AB_JMX_EXPORTER_CONFIG : Path to configuration to use for jmx_exporter: Default: /opt/agent-bond/jmx_exporter_config.json

Features:

• Tomcat Version: 6.0.45
• Java Base Image: fabric8/java-centos-openjdk8-jdk:1.5.1
• Port: 8080
• User admin (Password: admin) has been added to access the admin applications /host-manager and /manager)
• Documentation and examples have been removed
• Command: /opt/tomcat/bin/deploy-and-run.sh which links .war files from /maven to /opt/tomcat/webapps and then calls undefined run
• Sets -Djava.security.egd=file:/dev/./urandom for faster startup times (though a bit less secure)

⁠Debugging

You can enable remote debugging by setting JAVA_DEBUG to any value:

• JAVA_DEBUG If set remote debugging will be switched on
• JAVA_DEBUG_PORT Port used for remote debugging. Default: 5005