[dhcp_server] add show range cli (#17262)

* add show range

* add support for single ip

dockers/docker-dhcp-server/cli-plugin-tests/mock_config_db.json

@@ -1,4 +1,7 @@
 {
+    "FEATURE|dhcp_server": {
+        "state": "enabled"
+    },
     "DHCP_SERVER_IPV4|Vlan100": {
         "gateway": "100.1.1.1",
         "lease_time": "3600",
@@ -15,16 +18,13 @@
         "value": "dummy_value"
     },
     "DHCP_SERVER_IPV4_RANGE|range1": {
-        "ranges": [
+        "range": "100.1.1.3,100.1.1.5"
-            "100.1.1.3",
-            "100.1.1.5"
-        ]
     },
     "DHCP_SERVER_IPV4_RANGE|range2": {
-        "ips": [
+        "range": "100.1.1.9,100.1.1.8"
-            "100.1.1.7",
+    },
-            "100.1.1.8"
+    "DHCP_SERVER_IPV4_RANGE|range3": {
-        ]
+        "range": "100.1.1.10"
     },
     "DHCP_SERVER_IPV4_IP|eth0": {
         "ip": "240.127.1.2"

dockers/docker-dhcp-server/cli-plugin-tests/test_show_dhcp_server.py

@@ -55,3 +55,58 @@ Vlan1001|<Unknown>  10:70:fd:b6:13:02  192.168.0.3  2023-03-01 03:16:21  2023-03
         result = runner.invoke(show_dhcp_server.dhcp_server.commands["ipv4"].commands["lease"], ["Vlan1001"], obj=db)
         assert result.exit_code == 0, "exit code: {}, Exception: {}, Traceback: {}".format(result.exit_code, result.exception, result.exc_info)
         assert result.stdout == expected_stdout
+
+    def test_show_dhcp_server_ipv4_range_without_name(self, mock_db):
+        expected_stdout = """\
+Range    IP Start    IP End      IP Count
+-------  ----------  ----------  ----------------------
+range1   100.1.1.3   100.1.1.5   3
+range2   100.1.1.9   100.1.1.8   range value is illegal
+range3   100.1.1.10  100.1.1.10  1
+"""
+        runner = CliRunner()
+        db = clicommon.Db()
+        db.db = mock_db
+        result = runner.invoke(show_dhcp_server.dhcp_server.commands["ipv4"].commands["range"], [], obj=db)
+        assert result.exit_code == 0, "exit code: {}, Exception: {}, Traceback: {}".format(result.exit_code, result.exception, result.exc_info)
+        assert result.stdout == expected_stdout
+
+    def test_show_dhcp_server_ipv4_range_with_name(self, mock_db):
+        expected_stdout = """\
+Range    IP Start    IP End       IP Count
+-------  ----------  ---------  ----------
+range1   100.1.1.3   100.1.1.5           3
+"""
+        runner = CliRunner()
+        db = clicommon.Db()
+        db.db = mock_db
+        result = runner.invoke(show_dhcp_server.dhcp_server.commands["ipv4"].commands["range"], ["range1"], obj=db)
+        assert result.exit_code == 0, "exit code: {}, Exception: {}, Traceback: {}".format(result.exit_code, result.exception, result.exc_info)
+        assert result.stdout == expected_stdout
+
+    def test_show_dhcp_server_ipv4_range_wrong_data(self, mock_db):
+        expected_stdout = """\
+Range    IP Start    IP End     IP Count
+-------  ----------  ---------  ----------------------
+range2   100.1.1.9   100.1.1.8  range value is illegal
+"""
+        runner = CliRunner()
+        db = clicommon.Db()
+        db.db = mock_db
+        result = runner.invoke(show_dhcp_server.dhcp_server.commands["ipv4"].commands["range"], ["range2"], obj=db)
+        assert result.exit_code == 0, "exit code: {}, Exception: {}, Traceback: {}".format(result.exit_code, result.exception, result.exc_info)
+        assert result.stdout == expected_stdout
+
+    def test_show_dhcp_server_ipv4_range_single_ip(self, mock_db):
+        expected_stdout = """\
+Range    IP Start    IP End        IP Count
+-------  ----------  ----------  ----------
+range3   100.1.1.10  100.1.1.10           1
+"""
+        runner = CliRunner()
+        db = clicommon.Db()
+        db.db = mock_db
+        result = runner.invoke(show_dhcp_server.dhcp_server.commands["ipv4"].commands["range"], ["range3"], obj=db)
+        assert result.exit_code == 0, "exit code: {}, Exception: {}, Traceback: {}".format(result.exit_code, result.exception, result.exc_info)
+        assert result.stdout == expected_stdout
+

dockers/docker-dhcp-server/cli/show/plugins/show_dhcp_server.py

@@ -12,9 +12,13 @@ def ts_to_str(ts):
 
 
 @click.group(cls=clicommon.AliasedGroup)
-def dhcp_server():
+@clicommon.pass_db
+def dhcp_server(db):
     """Show dhcp_server related info"""
-    pass
+    ctx = click.get_current_context()
+    dbconn = db.db
+    if dbconn.get("CONFIG_DB", "FEATURE|dhcp_server", "state") != "enabled":
+        ctx.fail("Feature dhcp_server is not enabled")
 
 
 @dhcp_server.group(cls=clicommon.AliasedGroup)
@@ -42,5 +46,38 @@ def lease(db, dhcp_interface):
     click.echo(tabulate(table, headers=headers))
 
 
+def count_ipv4(start, end):
+    ip1 = int(ipaddress.IPv4Address(start))
+    ip2 = int(ipaddress.IPv4Address(end))
+    return ip2 - ip1 + 1
+
+
+@ipv4.command()
+@click.argument('range_name', required=False)
+@clicommon.pass_db
+def range(db, range_name):
+    if not range_name:
+        range_name = "*"
+    headers = ["Range", "IP Start", "IP End", "IP Count"]
+    table = []
+    dbconn = db.db
+    for key in dbconn.keys("CONFIG_DB", "DHCP_SERVER_IPV4_RANGE|" + range_name):
+        name = key.split("|")[1]
+        entry = dbconn.get_all("CONFIG_DB", key)
+        range_ = entry["range"].split(",")
+        if len(range_) == 1:
+            start, end = range_[0], range_[0]
+        elif len(range_) == 2:
+            start, end = range_
+        else:
+            table.append([name, "", "", "range value is illegal"])
+            continue
+        count = count_ipv4(start, end)
+        if count < 1:
+            count = "range value is illegal"
+        table.append([name, start, end, count])
+    click.echo(tabulate(table, headers=headers))
+
+
 def register(cli):
     cli.add_command(dhcp_server)