Got EVLA CMS restores working via casa_envoy, using casa_restorepipescript.py when it exists

Restores have been manually tested both with a PPR in the arguments (but no piperestorescript in the cal tar) and without one (with a piperestorescript in the cal tar). No other use-cases of casa_envoy have been manually tested.

To test restores with piperestorescript:

1. Copy the following from /lustre/aoc/cluster/pipeline/dsoc-dev/workspaces/skagan_testing/test_data/with_piperestorescript_2 into your own testing directory:
   1. rawdata/
   2. metadata.json
2. Add empty products and working directories
3. Remove rawdata/products
4. Call /lustre/aoc/cluster/pipeline/dsoc-dev/workspaces/skagan_testing/skagan-casa_envoy3 --restore metadata.json

Without piperestorescript (differences bolded):

1. Copy the following from /lustre/aoc/cluster/pipeline/dsoc-dev/workspaces/skagan_testing/test_data/sans_piperestorescript_with_ppr_in_args into your own testing directory:
   1. rawdata/
   2. metadata.json
   3. PPR.xml
2. Add empty products and working directories
3. Remove rawdata/products
4. Call /lustre/aoc/cluster/pipeline/dsoc-dev/workspaces/skagan_testing/skagan-casa_envoy3 --restore metadata.json PPR.xml

apps/cli/executables/pexable/casa_envoy/casa_envoy/configure.py

@@ -36,14 +36,19 @@ class CasaConfigure:
         """
         Set required environment variables
 
+        No need to audit them afterwards for None's since the keys and values in `os.environ` must all be strings.
+        Source: https://docs.python.org/3.10/library/os.html#os.environ
+
         :return:
         """
         os.environ["SCIPIPE_ROOTDIR"] = self.parameters["rootDirectory"]
 
         # If user specified CASA Version, use it.
-        if "casaHome" in self.metadata_content:
-            os.environ["CASA_HOME"] = self.metadata_content.get("casaHome")
-        elif "main" in self.metadata_content and "CASA_HOME" in self.metadata_content["main"]:
+        if self.metadata_content.get("casaHome") is not None:
+            os.environ["CASA_HOME"] = self.metadata_content["casaHome"]
+        elif (
+            self.metadata_content.get("main") is not None and self.metadata_content["main"].get("CASA_HOME") is not None
+        ):
             # Catch case of VLASS nesting
             os.environ["CASA_HOME"] = self.metadata_content["main"]["CASA_HOME"]
         else:
@@ -54,31 +59,10 @@ class CasaConfigure:
                 os.environ["CASA_HOME"] = self.parameters["homeForReprocessing"]
 
         os.environ["LANG"] = "en_US.UTF-8"
-        os.environ["PPR_FILENAME"] = self.parameters["ppr"]
-
-        self.check_processing_env()
-
-    def check_processing_env(self):
-        """
-        Varify processing environment is ready for CASA
-
-        :return:
-        """
-        self.logger.info("Checking processing environment:")
-
-        env_list = ["SCIPIPE_ROOTDIR", "CASA_HOME", "PPR_FILENAME", "LANG"]
-        result_list = []
-
-        for var in env_list:
-            env = os.environ.get(var)
-            result_list.append(env)
-            self.logger.info(f"{var}: {env}")
-
-        if "None" in result_list:
-            self.logger.error("Environment setup Failed!")
-            sys.exit(1)
-        else:
-            self.logger.info("Environment ready for processing")
+        # Restores oftentimes use a piperestorescript instead of a PPR.xml
+        # AuditFiles would catch an erroneously absent PPR
+        if self.parameters.get("ppr") is not None:
+            os.environ["PPR_FILENAME"] = self.parameters["ppr"]
 
 
 class StandardRunner(RunnerABC):