[crm] add checking for CRM interval range (sonic-net#2293)

- What I did
Add checking for range for CRM interval

- How I did it
Add attribute click.IntRange(1, 9999) and UT to verify it (according to CRM HLD)

- How to verify it
Run UT
Manual testing: crm config polling interval 100000000 (receive error)

- Previous command output (if the output of a command-line utility has changed)
crm config polling interval 4566466
crm config polling interval --help
Usage: crm config polling interval [OPTIONS] INTERVAL

  CRM polling interval configuration

Options:
  --help  Show this message and exit.

- New command output (if the output of a command-line utility has changed)
crm config polling interval 4566466
Usage: crm config polling interval [OPTIONS] INTERVAL
Try "crm config polling interval --help" for help.

Error: Invalid value for "INTERVAL": 4566466 is not in the valid range of 1 to 9999.

crm config polling interval --help
Usage: crm config polling interval [OPTIONS] INTERVAL

  CRM polling interval configuration in seconds (range: 1-9999)

Options:
  --help  Show this message and exit.

Signed-off-by: Andriy Yurkiv <ayurkiv@nvidia.com>

crm/main.py

@@ -237,9 +237,9 @@ def polling(ctx):
 
 @polling.command()
 @click.pass_context
-@click.argument('interval', type=click.INT)
+@click.argument('interval', type=click.IntRange(1, 9999))
 def interval(ctx, interval):
-    """CRM polling interval configuration"""
+    """CRM polling interval configuration in seconds (range: 1-9999)"""
     ctx.obj["crm"].config('polling_interval', interval)
 
 @config.group()

tests/crm_test.py

@@ -1033,6 +1033,8 @@
 
 """
 
+crm_config_interval_too_big = "Error: Invalid value for \"INTERVAL\": 30000 is not in the valid range of 1 to 9999."
+
 class TestCrm(object):
     @classmethod
     def setup_class(cls):
@@ -1053,6 +1055,18 @@ def test_crm_show_summary(self):
         assert result.exit_code == 0
         assert result.output == crm_new_show_summary
 
+    def test_crm_config_polling_interval(self):
+        runner = CliRunner()
+        db = Db()
+        result = runner.invoke(crm.cli, ['config', 'polling', 'interval', '10'], obj=db)
+        print(sys.stderr, result.output)
+        assert result.exit_code == 0
+        result = runner.invoke(crm.cli, ['config', 'polling', 'interval', '30000'], obj=db)
+        print(sys.stderr, result.output)
+        assert result.exit_code == 2
+        assert crm_config_interval_too_big in result.output
+
+
     def test_crm_show_thresholds_acl_group(self):
         runner = CliRunner()
         db = Db()