Address feedback from PR

- Instead of having a possibly null string pointer as the argument to
   enable_* and process_event, have wrapper versions that assume a
   default falco ruleset. The default ruleset name is a static member of
   the falco_engine class, and the default ruleset id is created/found
   in the constructor.
 - This makes the whole mechanism simple enough that it doesn't require
   seprarate testing, so remove the capability within falco to read a
   ruleset from the environment and remove automated tests that specify
   a ruleset.
 - Make pattern/tags/ruleset arguments to enable_* functions const.

(I'll squash this down before I commit)

test/falco_test.py

@@ -23,8 +23,6 @@ class FalcoTest(Test):
         self.should_detect = self.params.get('detect', '*', default=False)
         self.trace_file = self.params.get('trace_file', '*')
 
-        self.env = {}
-
         if not os.path.isabs(self.trace_file):
             self.trace_file = os.path.join(self.basedir, self.trace_file)
 
@@ -125,10 +123,6 @@ class FalcoTest(Test):
         if self.run_tags == '':
             self.run_tags=[]
 
-        self.ruleset = self.params.get('ruleset', '*', default='')
-        if self.ruleset != '':
-            self.env["FALCO_RULESET"] = self.ruleset
-
     def check_rules_warnings(self, res):
 
         found_warning = sets.Set()
@@ -250,7 +244,7 @@ class FalcoTest(Test):
         for tag in self.run_tags:
             cmd += ' -t {}'.format(tag)
 
-        self.falco_proc = process.SubProcess(cmd, env=self.env)
+        self.falco_proc = process.SubProcess(cmd)
 
         res = self.falco_proc.run(timeout=180, sig=9)
 

test/falco_tests.yaml.in

@@ -483,75 +483,3 @@ trace_files: !mux
       - open_11: 1
       - open_12: 0
       - open_13: 0
-
-  # Trying one of the combinations with a ruleset specified. Should get same output and no errors.
-  run_tags_c_ruleset:
-    detect: True
-    detect_level: WARNING
-    rules_file:
-      - rules/tagged_rules.yaml
-    trace_file: trace_files/open-multiple-files.scap
-    run_tags: [c]
-    ruleset: my-ruleset
-    detect_counts:
-      - open_1: 0
-      - open_2: 0
-      - open_3: 1
-      - open_4: 0
-      - open_5: 1
-      - open_6: 1
-      - open_7: 1
-      - open_8: 0
-      - open_9: 1
-      - open_10: 1
-      - open_11: 0
-      - open_12: 0
-      - open_13: 0
-
-  # Disabling one rule with a ruleset specified. Should get that one rule missing and no errors.
-  disabled_with_ruleset:
-    detect: True
-    detect_level: WARNING
-    rules_file:
-      - rules/tagged_rules.yaml
-    trace_file: trace_files/open-multiple-files.scap
-    disabled_rules:
-      - "open_4"
-    ruleset: my-ruleset
-    detect_counts:
-      - open_1: 1
-      - open_2: 1
-      - open_3: 1
-      - open_4: 0
-      - open_5: 1
-      - open_6: 1
-      - open_7: 1
-      - open_8: 1
-      - open_9: 1
-      - open_10: 1
-      - open_11: 1
-      - open_12: 1
-      - open_13: 1
-
-  # Enabling all rules with a ruleset specified. Should get all rules matching.
-  default_with_ruleset:
-    detect: True
-    detect_level: WARNING
-    rules_file:
-      - rules/tagged_rules.yaml
-    trace_file: trace_files/open-multiple-files.scap
-    ruleset: my-ruleset
-    detect_counts:
-      - open_1: 1
-      - open_2: 1
-      - open_3: 1
-      - open_4: 1
-      - open_5: 1
-      - open_6: 1
-      - open_7: 1
-      - open_8: 1
-      - open_9: 1
-      - open_10: 1
-      - open_11: 1
-      - open_12: 1
-      - open_13: 1