Analyzedb - add test case for analyze root partition

Added a test for following scenario:
When analyzedb is run without --skip_root_partition flag like below,
it should also analyze the root partitions.

`analyzedb -d <dbname> -s <schema> -a`

The root parition table gets listed only in the report file (and not in
any state files), hence added appropriate routines for checking the root
partition in the report file.
Signed-off-by: NJemish Patel <jpatel@pivotal.io>

gpMgmt/test/behave/mgmt_utils/analyzedb.feature

@@ -1684,6 +1684,16 @@ Feature: Incrementally analyze the database
       And "public.sales_1_prt_2" should appear in the latest state files
       And "public.sales_1_prt_3" should appear in the latest state files
 
+      @analyzedb_core @analyzedb_root_and_partition_tables @refresh_root_stats
+    Scenario: Partition tables, (entries for all parts, no change, some parts, root parts), request root stats
+      Given no state files exist for database "incr_analyze"
+      And the user runs "analyzedb -a -d incr_analyze -t public.sales"
+      When the user runs "analyzedb -a -d incr_analyze -t public.sales"
+      Then analyzedb should print There are no tables or partitions to be analyzed to stdout
+      And "public.sales_1_prt_2" should appear in the latest state files
+      And "public.sales_1_prt_3" should appear in the latest state files
+      And "public.sales" should appear in the latest report file
+
     # request mid-level
      @analyzedb_core @analyzedb_partition_tables
     Scenario: Multi-level partition and request mid-level

gpMgmt/test/behave/mgmt_utils/steps/analyzedb_mgmt_utils.py

+import re
 import os
 import shutil
 from gppylib.db import dbconn
@@ -101,6 +102,13 @@ def impl(context, col_name, qualified_table):
         else:
             assert False, "unexpected column %s of table %s found in state file %s" % (column, qualified_table, os.path.basename(filename))
 
+@given('"{qualified_table}" appears in the latest report file')
+@then('"{qualified_table}" should appear in the latest report file')
+def impl(context, qualified_table):
+    found,filename = table_found_in_report_file(context.dbname, qualified_table)
+    if not found:
+        assert False, "table %s not found in report file %s" % (qualified_table, os.path.basename(filename))
+
 @then('output should contain either "{output1}" or "{output2}"')
 def impl(context, output1, output2):
     pat1 = re.compile(output1)
@@ -155,6 +163,15 @@ def table_found_in_state_file(dbname, qualified_table):
             return False,state_file
     return True,state_file
 
+def table_found_in_report_file(dbname, qualified_table):
+    report_file = get_latest_analyze_report_file(dbname)
+    found = False
+    for line in get_lines_from_file(report_file):
+        if qualified_table == line:
+            return True,report_file
+
+    return False,report_file
+
 def column_found_in_state_file(dbname, qualified_table, col_name_list):
     comma_name = ','.join(qualified_table.split('.'))
     files = get_latest_analyze_state_files(dbname)
@@ -207,6 +224,28 @@ def get_latest_analyze_state_files(dbname):
             ret.append(os.path.join(state_files_dir, f))
     return ret
 
+def get_latest_analyze_report_file(dbname):
+    """
+    return the latest report file (absolute path)
+    """
+    master_data_dir = os.environ.get('MASTER_DATA_DIRECTORY')
+    analyze_dir = os.path.join(master_data_dir, 'db_analyze', dbname)
+    if not os.path.exists(analyze_dir):
+        return []
+
+    folders = sorted(os.listdir(analyze_dir), reverse=True)
+    if len(folders) == 0:
+        return []
+
+    report_file_dir = os.path.join(analyze_dir, folders[0])
+    files = os.listdir(report_file_dir)
+
+    for f in files:
+        if 'report' in f:
+            return os.path.join(report_file_dir, f)
+
+    raise Exception("Missing report file in folder %s" % report_file_dir)
+
 def create_table_with_column_list(conn, storage_type, schemaname, tablename, col_name_list, col_type_list):
     col_name_list = col_name_list.strip().split(',')
     col_type_list = col_type_list.strip().split(',')