TUN-9319: Add dynamic loading of features to connections via ConnectionOptionsSnapshot

Make sure to enforce snapshots of features and client information for each connection
so that the feature information can change in the background. This allows for new features
to only be applied to a connection if it completely disconnects and attempts a reconnect.

Updates the feature refresh time to 1 hour from previous cloudflared versions which
refreshed every 6 hours.

Closes TUN-9319

client/config.go

@@ -0,0 +1,74 @@
+package client
+
+import (
+	"fmt"
+	"net"
+
+	"github.com/google/uuid"
+	"github.com/rs/zerolog"
+
+	"github.com/cloudflare/cloudflared/features"
+	"github.com/cloudflare/cloudflared/tunnelrpc/pogs"
+)
+
+// Config captures the local client runtime configuration.
+type Config struct {
+	ConnectorID uuid.UUID
+	Version     string
+	Arch        string
+
+	featureSelector features.FeatureSelector
+}
+
+func NewConfig(version string, arch string, featureSelector features.FeatureSelector) (*Config, error) {
+	connectorID, err := uuid.NewRandom()
+	if err != nil {
+		return nil, fmt.Errorf("unable to generate a connector UUID: %w", err)
+	}
+	return &Config{
+		ConnectorID:     connectorID,
+		Version:         version,
+		Arch:            arch,
+		featureSelector: featureSelector,
+	}, nil
+}
+
+// ConnectionOptionsSnapshot is a snapshot of the current client information used to initialize a connection.
+//
+// The FeatureSnapshot is the features that are available for this connection. At the client level they may
+// change, but they will not change within the scope of this struct.
+type ConnectionOptionsSnapshot struct {
+	client              pogs.ClientInfo
+	originLocalIP       net.IP
+	numPreviousAttempts uint8
+	FeatureSnapshot     features.FeatureSnapshot
+}
+
+func (c *Config) ConnectionOptionsSnapshot(originIP net.IP, previousAttempts uint8) *ConnectionOptionsSnapshot {
+	snapshot := c.featureSelector.Snapshot()
+	return &ConnectionOptionsSnapshot{
+		client: pogs.ClientInfo{
+			ClientID: c.ConnectorID[:],
+			Version:  c.Version,
+			Arch:     c.Arch,
+			Features: snapshot.FeaturesList,
+		},
+		originLocalIP:       originIP,
+		numPreviousAttempts: previousAttempts,
+		FeatureSnapshot:     snapshot,
+	}
+}
+
+func (c ConnectionOptionsSnapshot) ConnectionOptions() *pogs.ConnectionOptions {
+	return &pogs.ConnectionOptions{
+		Client:              c.client,
+		OriginLocalIP:       c.originLocalIP,
+		ReplaceExisting:     false,
+		CompressionQuality:  0,
+		NumPreviousAttempts: c.numPreviousAttempts,
+	}
+}
+
+func (c ConnectionOptionsSnapshot) LogFields(event *zerolog.Event) *zerolog.Event {
+	return event.Strs("features", c.client.Features)
+}

client/config_test.go

@@ -0,0 +1,50 @@
+package client
+
+import (
+	"net"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/cloudflare/cloudflared/features"
+)
+
+func TestGenerateConnectionOptions(t *testing.T) {
+	version := "1234"
+	arch := "linux_amd64"
+	originIP := net.ParseIP("192.168.1.1")
+	var previousAttempts uint8 = 4
+
+	config, err := NewConfig(version, arch, &mockFeatureSelector{})
+	require.NoError(t, err)
+	require.Equal(t, version, config.Version)
+	require.Equal(t, arch, config.Arch)
+
+	// Validate ConnectionOptionsSnapshot fields
+	connOptions := config.ConnectionOptionsSnapshot(originIP, previousAttempts)
+	require.Equal(t, version, connOptions.client.Version)
+	require.Equal(t, arch, connOptions.client.Arch)
+	require.Equal(t, config.ConnectorID[:], connOptions.client.ClientID)
+
+	// Vaidate snapshot feature fields against the connOptions generated
+	snapshot := config.featureSelector.Snapshot()
+	require.Equal(t, features.DatagramV3, snapshot.DatagramVersion)
+	require.Equal(t, features.DatagramV3, connOptions.FeatureSnapshot.DatagramVersion)
+
+	pogsConnOptions := connOptions.ConnectionOptions()
+	require.Equal(t, connOptions.client, pogsConnOptions.Client)
+	require.Equal(t, originIP, pogsConnOptions.OriginLocalIP)
+	require.False(t, pogsConnOptions.ReplaceExisting)
+	require.Equal(t, uint8(0), pogsConnOptions.CompressionQuality)
+	require.Equal(t, previousAttempts, pogsConnOptions.NumPreviousAttempts)
+}
+
+type mockFeatureSelector struct{}
+
+func (m *mockFeatureSelector) Snapshot() features.FeatureSnapshot {
+	return features.FeatureSnapshot{
+		PostQuantum:     features.PostQuantumPrefer,
+		DatagramVersion: features.DatagramV3,
+		FeaturesList:    []string{features.FeaturePostQuantum, features.FeatureDatagramV3_1},
+	}
+}