Spruce up errors a bit

go/daemon/daemon.go

@@ -378,7 +378,7 @@ func (d *Daemon) SetConfig(
 		d,
 		func(ctx context.Context, n joinedNetwork) (struct{}, error) {
 			if n.config != nil {
-				return struct{}{}, ErrUserManagedNetworkConfig
+				return struct{}{}, ErrManagedNetworkConfig
 			}
 
 			// TODO needs to check that public addresses aren't being shared

go/daemon/daemon_test.go

@@ -202,7 +202,7 @@ func TestDaemon_SetConfig(t *testing.T) {
 		assert.NoError(t, err)
 	})
 
-	t.Run("ErrUserManagedNetworkConfig", func(t *testing.T) {
+	t.Run("ErrManagedNetworkConfig", func(t *testing.T) {
 		var (
 			creationParams = bootstrap.NewCreationParams("AAA", "a.com")
 			networkA       = network.NewMockNetwork(t)
@@ -222,6 +222,6 @@ func TestDaemon_SetConfig(t *testing.T) {
 
 		networkConfig.VPN.Tun.Device = "foo"
 		err := h.daemon.SetConfig(h.ctx, networkConfig)
-		assert.ErrorIs(t, err, ErrUserManagedNetworkConfig)
+		assert.ErrorIs(t, err, ErrManagedNetworkConfig)
 	})
 }

go/daemon/errors.go

@@ -10,7 +10,7 @@ const (
 	errCodeAlreadyJoined
 	errCodeNoMatchingNetworks
 	errCodeMultipleMatchingNetworks
-	errCodeUserManagedNetworkConfig
+	errCodeManagedNetworkConfig
 )
 
 var (
@@ -35,10 +35,10 @@ var (
 		"Multiple networks matched the search string",
 	)
 
-	// ErrUserManagedNetworkConfig is returned when attempting to modify a
+	// ErrManagedNetworkConfig is returned when attempting to modify a
 	// network config which is managed by the user.
-	ErrUserManagedNetworkConfig = jsonrpc2.NewError(
+	ErrManagedNetworkConfig = jsonrpc2.NewError(
-		errCodeUserManagedNetworkConfig,
+		errCodeManagedNetworkConfig,
-		"Network configuration is managed by the user",
+		"Network configuration is managed by the daemon.yml",
 	)
 )

go/daemon/jsonrpc2/client_http.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"net/http"
 	"net/url"
@@ -75,7 +76,9 @@ func (c *httpClient) Call(
 	dec := json.NewDecoder(res.Body)
 
 	resID, err := decodeResponse(dec, rcv)
-	if err != nil {
+	if errors.As(err, new(Error)) {
+		return err
+	} else if err != nil {
 		return fmt.Errorf("decoding response: %w", err)
 	} else if resID != id {
 		return fmt.Errorf(

go/daemon/jsonrpc2/client_rw.go

@@ -3,6 +3,7 @@ package jsonrpc2
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 )
@@ -27,7 +28,9 @@ func (c rwClient) Call(
 	}
 
 	resID, err := decodeResponse(c.dec, rcv)
-	if err != nil {
+	if errors.As(err, new(Error)) {
+		return err
+	} else if err != nil {
 		return fmt.Errorf("decoding response: %w", err)
 	} else if resID != id {
 		return fmt.Errorf(

go/daemon/rpc.go

@@ -29,7 +29,7 @@ type RPC interface {
 	GetNetworks(context.Context) ([]bootstrap.CreationParams, error)
 
 	// SetConfig extends the [network.RPC] method of the same name such that
-	// [ErrUserManagedNetworkConfig] is returned if the picked network is
+	// [ErrManagedNetworkConfig] is returned if the picked network is
 	// configured as part of the [daecommon.Config] which the Daemon was
 	// initialized with.
 	//