Add DHCP discovery for known Elgato devices (#168002)

homeassistant/components/elgato/config_flow.py

@@ -12,6 +12,8 @@ from homeassistant.config_entries import ConfigFlow, ConfigFlowResult
 from homeassistant.const import CONF_HOST, CONF_MAC
 from homeassistant.core import callback
 from homeassistant.helpers.aiohttp_client import async_get_clientsession
+from homeassistant.helpers.device_registry import format_mac
+from homeassistant.helpers.service_info.dhcp import DhcpServiceInfo
 from homeassistant.helpers.service_info.zeroconf import ZeroconfServiceInfo
 
 from .const import DOMAIN
@@ -23,7 +25,6 @@ class ElgatoFlowHandler(ConfigFlow, domain=DOMAIN):
     VERSION = 1
 
     host: str
-    port: int
     serial_number: str
     mac: str | None = None
 
@@ -70,6 +71,32 @@ class ElgatoFlowHandler(ConfigFlow, domain=DOMAIN):
         """Handle a flow initiated by zeroconf."""
         return self._async_create_entry()
 
+    async def async_step_dhcp(
+        self, discovery_info: DhcpServiceInfo
+    ) -> ConfigFlowResult:
+        """Handle DHCP discovery of a known Elgato device.
+
+        Only devices already configured (matched via ``registered_devices``)
+        reach this step. It is used to keep the stored host in sync with the
+        current IP address of the device.
+        """
+        mac = format_mac(discovery_info.macaddress)
+
+        for entry in self._async_current_entries():
+            if (entry_mac := entry.data.get(CONF_MAC)) is None or format_mac(
+                entry_mac
+            ) != mac:
+                continue
+            if entry.data[CONF_HOST] != discovery_info.ip:
+                self.hass.config_entries.async_update_entry(
+                    entry,
+                    data=entry.data | {CONF_HOST: discovery_info.ip},
+                )
+                self.hass.config_entries.async_schedule_reload(entry.entry_id)
+            return self.async_abort(reason="already_configured")
+
+        return self.async_abort(reason="no_devices_found")
+
     @callback
     def _async_show_setup_form(
         self, errors: dict[str, str] | None = None

homeassistant/components/elgato/manifest.json

@@ -3,6 +3,11 @@
   "name": "Elgato Light",
   "codeowners": ["@frenck"],
   "config_flow": true,
+  "dhcp": [
+    {
+      "registered_devices": true
+    }
+  ],
   "documentation": "https://www.home-assistant.io/integrations/elgato",
   "integration_type": "device",
   "iot_class": "local_polling",

homeassistant/components/elgato/quality_scale.yaml

@@ -39,11 +39,7 @@ rules:
   # Gold
   devices: done
   diagnostics: done
-  discovery-update-info:
-    status: todo
-    comment: |
-      The integration doesn't update the device info based on DHCP discovery
-      of known existing devices.
+  discovery-update-info: done
   discovery: done
   docs-data-update: todo
   docs-examples: todo

homeassistant/components/elgato/strings.json

@@ -2,7 +2,8 @@
   "config": {
     "abort": {
       "already_configured": "[%key:common::config_flow::abort::already_configured_device%]",
-      "cannot_connect": "[%key:common::config_flow::error::cannot_connect%]"
+      "cannot_connect": "[%key:common::config_flow::error::cannot_connect%]",
+      "no_devices_found": "[%key:common::config_flow::abort::no_devices_found%]"
     },
     "error": {
       "cannot_connect": "[%key:common::config_flow::error::cannot_connect%]"

homeassistant/generated/dhcp.py

@@ -173,6 +173,10 @@ DHCP: Final[list[dict[str, str | bool]]] = [
         "domain": "dlink",
         "hostname": "dsp-w215",
     },
+    {
+        "domain": "elgato",
+        "registered_devices": True,
+    },
     {
         "domain": "elkm1",
         "registered_devices": True,

tests/components/elgato/test_config_flow.py

@@ -7,10 +7,11 @@ from elgato import ElgatoConnectionError
 import pytest
 
 from homeassistant.components.elgato.const import DOMAIN
-from homeassistant.config_entries import SOURCE_USER, SOURCE_ZEROCONF
+from homeassistant.config_entries import SOURCE_DHCP, SOURCE_USER, SOURCE_ZEROCONF
 from homeassistant.const import CONF_HOST, CONF_MAC, CONF_SOURCE
 from homeassistant.core import HomeAssistant
 from homeassistant.data_entry_flow import FlowResultType
+from homeassistant.helpers.service_info.dhcp import DhcpServiceInfo
 from homeassistant.helpers.service_info.zeroconf import ZeroconfServiceInfo
 
 from tests.common import MockConfigEntry
@@ -254,3 +255,79 @@ async def test_zeroconf_during_onboarding(
     assert len(mock_setup_entry.mock_calls) == 1
     assert len(mock_elgato.info.mock_calls) == 1
     assert len(mock_onboarding.mock_calls) == 1
+
+
+@pytest.mark.usefixtures("mock_elgato")
+async def test_dhcp_discovery_updates_host(
+    hass: HomeAssistant,
+    mock_config_entry: MockConfigEntry,
+) -> None:
+    """Test DHCP discovery of a known device updates its stored host."""
+    mock_config_entry.add_to_hass(hass)
+    await hass.config_entries.async_setup(mock_config_entry.entry_id)
+    await hass.async_block_till_done()
+
+    result = await hass.config_entries.flow.async_init(
+        DOMAIN,
+        context={CONF_SOURCE: SOURCE_DHCP},
+        data=DhcpServiceInfo(
+            hostname="elgato",
+            ip="127.0.0.42",
+            macaddress="aabbccddeeff",
+        ),
+    )
+    await hass.async_block_till_done()
+
+    assert result["type"] is FlowResultType.ABORT
+    assert result["reason"] == "already_configured"
+    assert mock_config_entry.data[CONF_HOST] == "127.0.0.42"
+
+
+@pytest.mark.usefixtures("mock_elgato")
+async def test_dhcp_discovery_same_host(
+    hass: HomeAssistant,
+    mock_config_entry: MockConfigEntry,
+) -> None:
+    """Test DHCP discovery does nothing when the host is already up to date."""
+    mock_config_entry.add_to_hass(hass)
+    await hass.config_entries.async_setup(mock_config_entry.entry_id)
+    await hass.async_block_till_done()
+
+    result = await hass.config_entries.flow.async_init(
+        DOMAIN,
+        context={CONF_SOURCE: SOURCE_DHCP},
+        data=DhcpServiceInfo(
+            hostname="elgato",
+            ip="127.0.0.1",
+            macaddress="aabbccddeeff",
+        ),
+    )
+
+    assert result["type"] is FlowResultType.ABORT
+    assert result["reason"] == "already_configured"
+    assert mock_config_entry.data[CONF_HOST] == "127.0.0.1"
+
+
+@pytest.mark.usefixtures("mock_elgato")
+async def test_dhcp_discovery_no_match(
+    hass: HomeAssistant,
+    mock_config_entry: MockConfigEntry,
+) -> None:
+    """Test DHCP discovery aborts when no matching entry is configured."""
+    mock_config_entry.add_to_hass(hass)
+    await hass.config_entries.async_setup(mock_config_entry.entry_id)
+    await hass.async_block_till_done()
+
+    result = await hass.config_entries.flow.async_init(
+        DOMAIN,
+        context={CONF_SOURCE: SOURCE_DHCP},
+        data=DhcpServiceInfo(
+            hostname="elgato",
+            ip="127.0.0.42",
+            macaddress="001122334455",
+        ),
+    )
+
+    assert result["type"] is FlowResultType.ABORT
+    assert result["reason"] == "no_devices_found"
+    assert mock_config_entry.data[CONF_HOST] == "127.0.0.1"