12.5. Customizing source-to-image images

Procedure

1. Look at the value of the io.openshift.s2i.scripts-url label to determine the location of the scripts inside of the builder image:

   $ podman inspect --format='{{ index .Config.Labels "io.openshift.s2i.scripts-url" }}' wildfly/wildfly-centos7

   Example output

   image:///usr/libexec/s2i

   You inspected the wildfly/wildfly-centos7 builder image and found out that the scripts are in the /usr/libexec/s2i directory.

2. Create a script that includes an invocation of one of the standard scripts wrapped in other commands:

   .s2i/bin/assemble script

   #!/bin/bash
   echo "Before assembling"
   
   /usr/libexec/s2i/assemble
   rc=$?
   
   if [ $rc -eq 0 ]; then
       echo "After successful assembling"
   else
       echo "After failed assembling"
   fi
   
   exit $rc

   This example shows a custom assemble script that prints the message, runs the standard assemble script from the image, and prints another message depending on the exit code of the assemble script.

   重要

   When wrapping the run script, you must use exec for invoking it to ensure signals are handled properly. The use of exec also precludes the ability to run additional commands after invoking the default image run script.

   .s2i/bin/run script

   #!/bin/bash
   echo "Before running application"
   exec /usr/libexec/s2i/run