Correct GDASApp paths (#2435)

The changes in this PR 
- account for changes in GDASApp directory structure
- generalize how the path to the GDASApp python ioda library is
specified

Resolves #2434

jobs/JGDAS_GLOBAL_OCEAN_ANALYSIS_PREP

@@ -34,7 +34,8 @@ RUN=${GDUMP} YMD=${gPDY} HH=${gcyc} generate_com -rx \
 
 # Add UFSDA to PYTHONPATH
 ufsdaPATH="${HOMEgfs}/sorc/gdas.cd/ush/"
-pyiodaPATH="${HOMEgfs}/sorc/gdas.cd/build/lib/python3.7/"
+# shellcheck disable=SC2311
+pyiodaPATH="${HOMEgfs}/sorc/gdas.cd/build/lib/python$(detect_py_ver)/"
 PYTHONPATH="${PYTHONPATH:+${PYTHONPATH}:}${ufsdaPATH}:${pyiodaPATH}"
 export PYTHONPATH
 

jobs/rocoto/prepatmiodaobs.sh

@@ -14,8 +14,9 @@ export jobid="${job}.$$"
 ###############################################################
 # setup python path for workflow and ioda utilities
 wxflowPATH="${HOMEgfs}/ush/python:${HOMEgfs}/ush/python/wxflow/src"
-PYIODALIB="${HOMEgfs}/sorc/gdas.cd/build/lib/python3.7"
-PYTHONPATH="${PYIODALIB}:${wxflowPATH}:${PYTHONPATH}"
+# shellcheck disable=SC2311
+pyiodaPATH="${HOMEgfs}/sorc/gdas.cd/build/lib/python$(detect_py_ver)/"
+PYTHONPATH="${pyiodaPATH}:${wxflowPATH}:${PYTHONPATH}"
 export PYTHONPATH
 
 ###############################################################

jobs/rocoto/prepsnowobs.sh

@@ -14,7 +14,9 @@ export jobid="${job}.$$"
 ###############################################################
 # setup python path for workflow utilities and tasks
 wxflowPATH="${HOMEgfs}/ush/python:${HOMEgfs}/ush/python/wxflow/src"
-gdasappPATH="${HOMEgfs}/sorc/gdas.cd/iodaconv/src:${HOMEgfs}/sorc/gdas.cd/build/lib/python3.7"
+# shellcheck disable=SC2311
+pyiodaPATH="${HOMEgfs}/sorc/gdas.cd/build/lib/python$(detect_py_ver)/"
+gdasappPATH="${HOMEgfs}/sorc/gdas.cd/sorc/iodaconv/src:${pyiodaPATH}"
 PYTHONPATH="${PYTHONPATH:+${PYTHONPATH}:}${wxflowPATH}:${gdasappPATH}"
 export PYTHONPATH
 

ush/preamble.sh

@@ -172,6 +172,22 @@ function generate_com() {
 # shellcheck disable=
 declare -xf generate_com
 
+function detect_py_ver() {
+    # 
+    # Returns the major.minor version of the currently active python executable
+    #
+    regex="[0-9]+\.[0-9]+"
+    # shellcheck disable=SC2312
+    if [[ $(python --version) =~ ${regex} ]]; then
+	    echo "${BASH_REMATCH[0]}"
+    else
+	    echo "FATAL ERROR: Could not detect the python version"
+	    exit 1
+    fi
+}
+# shellcheck disable=
+declare -xf detect_py
+
 # Turn on our settings
 set_strict
 set_trace