Generalise the DS starting script and add it to the itango tools

Femto-DS/Femto-DS.sh

-runThis=$(basename ${0})
-runThis=${runThis//.sh/.py}
-if [ -f ${runThis} ]; then
-    myDir=${PWD}
-else
-    myDir=${PWD}/$(dirname ${0})
-fi
-
-if [ ${#} -eq 1 ]; then
-    instance="${1}"
-else
-    echo "The instance of this device server must be provided!"
-    exit -1
-fi
-containerPath=${myDir//${HOME}\//\/hosthome\/}
-docker exec -it itango python3 ${containerPath}/${runThis} ${instance}

RandomData-DS/RandomData-DS.sh

-runThis=$(basename ${0})
-runThis=${runThis//.sh/.py}
-if [ -f ${runThis} ]; then
-    myDir=${PWD}
-else
-    myDir=${PWD}/$(dirname ${0})
-fi
-
-if [ ${#} -eq 1 ]; then
-    instance="${1}"
-else
-    echo "The instance of this device server must be provided!"
-    exit -1
-fi
-containerPath=${myDir//${HOME}\//\/hosthome\/}
-docker exec -it itango python3 ${containerPath}/${runThis} ${instance}

tools/itango/start-DS.sh

+function help()
+{
+    why="${1}"
+    echo -e "*** Cannot start the Python device server.\n${why}\n\n* The Python file for the device server must be the 1st parameter that is provided.\n* The instance of this device server must be the 2nd parameter that is provided."
+    exit -1
+}
+
+# Check if the mandatory parameters are present:
+# ${1}:  device server's Python file
+# ${2}:  instance of the device server's executable in the configDB
+case ${#} in
+    0)
+        help "The device server's Python file and the instance are missing."
+        ;;
+    1)
+        help "The device server's instance is missing."
+        ;;
+    *)
+        deviceServer="${1}"
+        shift
+        instance="${1}"
+        shift
+        ;;
+esac
+
+# Find the path to the device server's Python file that is
+# relative to the /hosthome directory (in Docker the user's
+# mounted ${HOME}).
+# ATTENTION
+# This is assuming that the device server's Python file exists
+# on the Docker's host in the user's ${HOME} directory.
+runThis=$(basename ${deviceServer})
+runThis=${runThis//.sh/.py}
+if [ -f ${runThis} ]; then
+    myDir=${PWD}
+else
+    myDir=${PWD}/$(dirname ${deviceServer})
+fi
+deviceServerPath=${myDir//${HOME}\//\/hosthome\/}
+
+docker exec -it itango python3 ${deviceServerPath}/${runThis} ${instance} ${@}