"javap" use throws error in containers

[1000TurquoisePogs]

Each server startup uses this code to detect if they should do things unique to java 8 vs java 11+ on z/OS:

JAVA_VERSION=$(${JAVA_HOME}/bin/javap -verbose java.lang.String \
    | grep "major version" \
    | cut -d " " -f5)
ADD_OPENS=""
if [ $JAVA_VERSION -ge 61 ]; then
    ADD_OPENS="--add-opens=java.base/java.lang=ALL-UNNAMED
                --add-opens=java.base/java.lang.invoke=ALL-UNNAMED
...
fi

This doesn't work for containers.
Containers print javap not found or similar.
It seems harmless now but to avoid it becoming an issue later I would recommend changing the code slightly:

if [ "${ZWE_RUN_ON_ZOS}" = "true" ]; then
  JAVA_VERSION=$(${JAVA_HOME}/bin/javap -verbose java.lang.String \
      | grep "major version" \
      | cut -d " " -f5)
  ADD_OPENS=""
  if [ $JAVA_VERSION -ge 61 ]; then
      ADD_OPENS="--add-opens=java.base/java.lang=ALL-UNNAMED
                  --add-opens=java.base/java.lang.invoke=ALL-UNNAMED
  ...
  fi
fi

That is, ZWE_RUN_ON_ZOS is a variable that can be used to detect whether to do a z/OS-specific action.

[pablocarle]

Hi @1000TurquoisePogs,
This code is there to support running Zowe v2 with both Java 8 and Java 17 runtimes.
I think in containers we want to keep the possibility of running Zowe v2 with either of these versions.

Maybe the solution is to find an alternative way of determining the Java version that doesn't depend on javap, but I'm assuming it may be because in the containers there's only a JRE and not the JDK binaries?