Home Assistant: auto-detect Supervisor instance and token

util/homeassistant/instance.go

@@ -4,9 +4,43 @@ import (
 	"fmt"
 	"sync"
 
+	"github.com/evcc-io/evcc/plugin/auth"
+	"github.com/evcc-io/evcc/util"
 	"golang.org/x/oauth2"
 )
 
+func init() {
+	auth.Register("homeassistant", NewHomeAssistantFromConfig)
+}
+
+// NewHomeAssistantFromConfig creates a Home Assistant token source from configuration
+func NewHomeAssistantFromConfig(other map[string]any) (oauth2.TokenSource, error) {
+	var cc struct {
+		URI      string
+		Home     string // TODO remove deprecated
+		Insecure bool
+	}
+
+	if err := util.DecodeOther(other, &cc); err != nil {
+		return nil, err
+	}
+
+	uri := cc.URI
+
+	if uri == "" && cc.Home != "" {
+		uri = instanceUriByName(cc.Home)
+		if uri == "" {
+			return nil, fmt.Errorf("unknown instance: %s", cc.Home)
+		}
+	}
+
+	if ts, ok := supervisorTokenSource(uri); ok {
+		return ts, nil
+	}
+
+	return NewOAuth(uri, cc.Insecure)
+}
+
 type proxyInstance struct {
 	mu        sync.Mutex
 	home, uri string
@@ -43,12 +77,15 @@ func (inst *proxyInstance) Token() (*oauth2.Token, error) {
 	defer inst.mu.Unlock()
 
 	if inst.TokenSource == nil {
-		ts, err := NewHomeAssistant(uri, inst.insecure)
-		if err != nil {
-			return nil, err
+		if ts, ok := supervisorTokenSource(uri); ok {
+			inst.TokenSource = ts
+		} else {
+			ts, err := NewOAuth(uri, inst.insecure)
+			if err != nil {
+				return nil, err
+			}
+			inst.TokenSource = ts
 		}
-
-		inst.TokenSource = ts
 	}
 
 	return inst.TokenSource.Token()

util/homeassistant/oauth2.go

@@ -2,7 +2,6 @@ package homeassistant
 
 import (
 	"context"
-	"fmt"
 	"net"
 	"net/http"
 	"net/url"
@@ -17,34 +16,8 @@ import (
 
 // https://developers.home-assistant.io/docs/auth_api
 
-func init() {
-	auth.Register("homeassistant", NewHomeAssistantFromConfig)
-}
-
-func NewHomeAssistantFromConfig(other map[string]any) (oauth2.TokenSource, error) {
-	var cc struct {
-		URI      string
-		Home     string // TODO remove deprecated
-		Insecure bool
-	}
-
-	if err := util.DecodeOther(other, &cc); err != nil {
-		return nil, err
-	}
-
-	uri := cc.URI
-
-	if uri == "" && cc.Home != "" {
-		uri = instanceUriByName(cc.Home)
-		if uri == "" {
-			return nil, fmt.Errorf("unknown instance: %s", cc.Home)
-		}
-	}
-
-	return NewHomeAssistant(uri, cc.Insecure)
-}
-
-func NewHomeAssistant(uri string, insecure bool) (oauth2.TokenSource, error) {
+// NewOAuth creates a Home Assistant OAuth token source
+func NewOAuth(uri string, insecure bool) (oauth2.TokenSource, error) {
 	uri = strings.TrimRight(uri, "/") // normalize
 
 	extUrl := network.Config().ExternalURL()

util/homeassistant/supervisor.go

@@ -0,0 +1,34 @@
+package homeassistant
+
+import (
+	"os"
+	"strings"
+
+	"golang.org/x/oauth2"
+)
+
+const (
+	// SupervisorURI is the Home Assistant Core API endpoint when running as a Home Assistant add-on
+	SupervisorURI = "http://supervisor/core"
+	// SupervisorToken is the environment variable name containing the bearer token
+	SupervisorToken = "SUPERVISOR_TOKEN"
+	// SupervisorInstance is the discovered instance name for the Supervisor integration
+	SupervisorInstance = "HomeAssistant via EVCC App"
+)
+
+func init() {
+	if hasSupervisorToken() {
+		addInstance(SupervisorInstance, SupervisorURI)
+	}
+}
+
+func hasSupervisorToken() bool {
+	return os.Getenv(SupervisorToken) != ""
+}
+
+func supervisorTokenSource(uri string) (oauth2.TokenSource, bool) {
+	if token := os.Getenv(SupervisorToken); token != "" && strings.TrimRight(uri, "/") == SupervisorURI {
+		return oauth2.StaticTokenSource(&oauth2.Token{AccessToken: token}), true
+	}
+	return nil, false
+}

util/homeassistant/supervisor_test.go

@@ -0,0 +1,91 @@
+package homeassistant
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/evcc-io/evcc/util"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestSupervisorToken(t *testing.T) {
+	t.Setenv(SupervisorToken, "test_supervisor_token")
+
+	ts, ok := supervisorTokenSource(SupervisorURI)
+	require.True(t, ok)
+
+	tok, err := ts.Token()
+	require.NoError(t, err)
+	assert.Equal(t, "test_supervisor_token", tok.AccessToken)
+
+	// SupervisorURI variant with trailing slash should still match
+	tsSlash, ok := supervisorTokenSource(SupervisorURI + "/")
+	require.True(t, ok)
+
+	tokSlash, err := tsSlash.Token()
+	require.NoError(t, err)
+	assert.Equal(t, "test_supervisor_token", tokSlash.AccessToken)
+
+	// empty uri does not match supervisor
+	_, ok = supervisorTokenSource("")
+	assert.False(t, ok)
+
+	// other uri does not match supervisor
+	_, ok = supervisorTokenSource("http://homeassistant.local:8123")
+	assert.False(t, ok)
+
+	// from config with SupervisorURI
+	ts3, err := NewHomeAssistantFromConfig(map[string]any{"uri": SupervisorURI})
+	require.NoError(t, err)
+
+	tok3, err := ts3.Token()
+	require.NoError(t, err)
+	assert.Equal(t, "test_supervisor_token", tok3.AccessToken)
+
+	// when SUPERVISOR_TOKEN is unset, NewHomeAssistantFromConfig should fall back to the standard OAuth token source
+	t.Setenv(SupervisorToken, "")
+
+	ts4, err := NewHomeAssistantFromConfig(map[string]any{"uri": SupervisorURI})
+	require.NoError(t, err)
+
+	_, err = ts4.Token()
+	require.Error(t, err)
+	assert.ErrorContains(t, err, "login required")
+
+	// connection requires uri
+	_, err = NewConnection(util.NewLogger("test"), "", "", false)
+	assert.Error(t, err)
+
+	conn, err := NewConnection(util.NewLogger("test"), SupervisorURI, "", false)
+	require.NoError(t, err)
+	assert.Equal(t, SupervisorURI, conn.URI())
+
+	// test authenticated request using connection
+	var authHeader string
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		authHeader = r.Header.Get("Authorization")
+		w.Header().Set("Content-Type", "application/json")
+		w.Write([]byte(`[{"entity_id":"sensor.test","state":"10"}]`))
+	}))
+	defer srv.Close()
+
+	testConn, err := NewConnection(util.NewLogger("test"), srv.URL, "", false)
+	require.NoError(t, err)
+	// override instance token source directly or test via proxyInstance
+	testConn.instance.TokenSource = ts
+
+	states, err := testConn.GetStates()
+	require.NoError(t, err)
+	assert.Len(t, states, 1)
+	assert.Equal(t, "Bearer test_supervisor_token", authHeader)
+}
+
+func TestSupervisorDiscovery(t *testing.T) {
+	t.Setenv(SupervisorToken, "test_supervisor_token")
+
+	addInstance(SupervisorInstance, SupervisorURI)
+	assert.Equal(t, SupervisorURI, instanceUriByName(SupervisorInstance))
+	assert.Equal(t, SupervisorInstance, instanceNameByUri(SupervisorURI))
+}