Add multi-network support to daemon

It's still not possible to pick a network from the command-line, so this
is a bit broken, but the daemon component should handle it correctly at
least.

go/bootstrap/bootstrap.go

@@ -12,6 +12,7 @@ import (
 	"net/netip"
 	"path/filepath"
 	"sort"
+	"strings"
 
 	"dev.mediocregopher.com/mediocre-go-lib.git/mctx"
 )
@@ -52,6 +53,42 @@ func (p CreationParams) Annotate(aa mctx.Annotations) {
 	aa["networkDomain"] = p.Domain
 }
 
+// Matches returns true if the given string matches some aspect of the
+// CreationParams.
+func (p CreationParams) Matches(str string) bool {
+	if strings.HasPrefix(p.ID, str) {
+		return true
+	}
+
+	if strings.EqualFold(p.Name, str) {
+		return true
+	}
+
+	if strings.EqualFold(p.Domain, str) {
+		return true
+	}
+
+	return false
+}
+
+// Conflicts returns true if either CreationParams has some parameter which
+// overlaps with that of the other.
+func (p CreationParams) Conflicts(p2 CreationParams) bool {
+	if p.ID == p2.ID {
+		return true
+	}
+
+	if strings.EqualFold(p.Name, p2.Name) {
+		return true
+	}
+
+	if strings.EqualFold(p.Domain, p2.Domain) {
+		return true
+	}
+
+	return false
+}
+
 // Bootstrap contains all information which is needed by a host daemon to join a
 // network on boot.
 type Bootstrap struct {

go/daemon/config.go

@@ -47,22 +47,15 @@ func pickNetworkConfig(
 ) (
 	daecommon.NetworkConfig, bool,
 ) {
-	if c, ok := daemonConfig.Networks[creationParams.ID]; ok {
+	if len(daemonConfig.Networks) == 1 { // DEPRECATED
+		if c, ok := daemonConfig.Networks[daecommon.DeprecatedNetworkID]; ok {
 			return c, true
 		}
-
-	if c, ok := daemonConfig.Networks[creationParams.Name]; ok {
-		return c, true
 	}
 
-	if c, ok := daemonConfig.Networks[creationParams.Domain]; ok {
+	for searchStr, networkConfig := range daemonConfig.Networks {
-		return c, true
+		if creationParams.Matches(searchStr) {
-	}
+			return networkConfig, true
-
-	{ // DEPRECATED
-		c, ok := daemonConfig.Networks[daecommon.DeprecatedNetworkID]
-		if len(daemonConfig.Networks) == 1 && ok {
-			return c, true
 		}
 	}
 

go/daemon/ctx.go

@@ -0,0 +1,20 @@
+package daemon
+
+import (
+	"context"
+	"isle/daemon/jsonrpc2"
+)
+
+const metaKeyNetworkSearchStr = "daemon.networkSearchStr"
+
+// WithNetwork returns the Context so that, when used against a daemon RPC
+// endpoint, the endpoint knows which network is being targetted for the call.
+// The network can be identified by its ID, name, or domain.
+func WithNetwork(ctx context.Context, searchStr string) context.Context {
+	return jsonrpc2.WithMeta(ctx, metaKeyNetworkSearchStr, searchStr)
+}
+
+func getNetworkSearchStr(ctx context.Context) string {
+	v, _ := jsonrpc2.GetMeta(ctx)[metaKeyNetworkSearchStr].(string)
+	return v
+}

go/daemon/daemon.go

@@ -66,7 +66,7 @@ type Daemon struct {
 	networksRuntimeDir toolkit.Dir
 
 	l        sync.RWMutex
-	network network.Network
+	networks map[string]network.Network
 }
 
 // New initializes and returns a Daemon.
@@ -96,6 +96,7 @@ func New(
 		daemonConfig:  daemonConfig,
 		envBinDirPath: envBinDirPath,
 		opts:          opts,
+		networks:      map[string]network.Network{},
 	}
 
 	{
@@ -113,18 +114,14 @@ func New(
 		}
 	}
 
-	loadableNetworks, err := LoadableNetworks(d.networksStateDir)
+	loadableNetworks, err := loadableNetworks(d.networksStateDir)
 	if err != nil {
 		return nil, fmt.Errorf("listing loadable networks: %w", err)
 	}
 
-	if len(loadableNetworks) > 1 {
+	for _, creationParams := range loadableNetworks {
-		return nil, fmt.Errorf(
+		id := creationParams.ID
-			"more then one loadable Network found: %+v", loadableNetworks,
+		ctx = mctx.WithAnnotator(ctx, creationParams)
-		)
-	} else if len(loadableNetworks) == 1 {
-		id := loadableNetworks[0].ID
-		ctx = mctx.WithAnnotator(ctx, loadableNetworks[0])
 
 		networkStateDir, networkRuntimeDir, err := networkDirs(
 			d.networksStateDir, d.networksRuntimeDir, id, true,
@@ -135,9 +132,9 @@ func New(
 			)
 		}
 
-		networkConfig, _ := pickNetworkConfig(daemonConfig, loadableNetworks[0])
+		networkConfig, _ := pickNetworkConfig(daemonConfig, creationParams)
 
-		d.network, err = network.Load(
+		d.networks[id], err = network.Load(
 			ctx,
 			logger.WithNamespace("network"),
 			id,
@@ -187,7 +184,9 @@ func (d *Daemon) CreateNetwork(
 	d.l.Lock()
 	defer d.l.Unlock()
 
-	if d.network != nil {
+	if joined, err := alreadyJoined(ctx, d.networks, creationParams); err != nil {
+		return fmt.Errorf("checking if already joined to network: %w", err)
+	} else if joined {
 		return ErrAlreadyJoined
 	}
 
@@ -222,7 +221,7 @@ func (d *Daemon) CreateNetwork(
 	}
 
 	d.logger.Info(ctx, "Network created successfully")
-	d.network = n
+	d.networks[creationParams.ID] = n
 	return nil
 }
 
@@ -245,7 +244,9 @@ func (d *Daemon) JoinNetwork(
 	d.l.Lock()
 	defer d.l.Unlock()
 
-	if d.network != nil {
+	if joined, err := alreadyJoined(ctx, d.networks, creationParams); err != nil {
+		return fmt.Errorf("checking if already joined to network: %w", err)
+	} else if joined {
 		return ErrAlreadyJoined
 	}
 
@@ -278,7 +279,7 @@ func (d *Daemon) JoinNetwork(
 	}
 
 	d.logger.Info(ctx, "Network joined successfully")
-	d.network = n
+	d.networks[networkID] = n
 	return nil
 }
 
@@ -292,12 +293,13 @@ func withNetwork[Res any](
 	d.l.RLock()
 	defer d.l.RUnlock()
 
-	if d.network == nil {
+	network, err := pickNetwork(ctx, d.networks, d.networksStateDir)
+	if err != nil {
 		var zero Res
-		return zero, ErrNoNetwork
+		return zero, nil
 	}
 
-	return fn(ctx, d.network)
+	return fn(ctx, network)
 }
 
 // GetHost implements the method for the network.RPC interface.
@@ -417,32 +419,28 @@ func (d *Daemon) Shutdown() error {
 	d.l.Lock()
 	defer d.l.Unlock()
 
-	if d.network != nil {
+	var (
-		return d.network.Shutdown()
+		errCh = make(chan error, len(d.networks))
+		errs  []error
+	)
+
+	for id := range d.networks {
+		var (
+			id = id
+			n  = d.networks[id]
+		)
+
+		go func() {
+			if err := n.Shutdown(); err != nil {
+				errCh <- fmt.Errorf("shutting down network %q: %w", id, err)
 			}
-	return nil
+			errCh <- nil
-
+		}()
-	//var (
+	}
-	//	errCh = make(chan error, len(d.networks))
+
-	//	errs  []error
+	for range cap(errCh) {
-	//)
+		errs = append(errs, <-errCh)
-
+	}
-	//for id := range d.networks {
+
-	//	id := id
+	return errors.Join(errs...)
-	//	n := d.networks[id]
-	//	go func() {
-	//		if err := n.Shutdown(); err != nil {
-	//			errCh <- fmt.Errorf("shutting down network %q: %w", id, err)
-	//		}
-	//		errCh <- nil
-	//	}()
-	//}
-
-	//for range cap(errCh) {
-	//	if err := <-errCh; err != nil {
-	//		errs = append(errs, err)
-	//	}
-	//}
-
-	//return errors.Join(errs...)
 }

go/daemon/errors.go

@@ -8,6 +8,8 @@ import (
 const (
 	errCodeNoNetwork = daecommon.ErrorCodeRangeDaemon + iota
 	errCodeAlreadyJoined
+	errCodeNoMatchingNetworks
+	errCodeMultipleMatchingNetworks
 )
 
 var (
@@ -16,6 +18,19 @@ var (
 	ErrNoNetwork = jsonrpc2.NewError(errCodeNoNetwork, "No network configured")
 
 	// ErrAlreadyJoined is returned when the daemon is instructed to create or
-	// join a new network, but it is already joined to a network.
+	// join a new network, but it is already joined to that network.
 	ErrAlreadyJoined = jsonrpc2.NewError(errCodeAlreadyJoined, "Already joined to a network")
+
+	// ErrNoMatchingNetworks is returned if the search string didn't match any
+	// networks.
+	ErrNoMatchingNetworks = jsonrpc2.NewError(
+		errCodeNoMatchingNetworks, "No networks matched the search string",
+	)
+
+	// ErrMultipleMatchingNetworks is returned if the search string matched
+	// multiple networks.
+	ErrMultipleMatchingNetworks = jsonrpc2.NewError(
+		errCodeMultipleMatchingNetworks,
+		"Multiple networks matched the search string",
+	)
 )

go/daemon/jsonrpc2/client.go

@@ -13,7 +13,11 @@ type Client interface {
 	// receiver pointer, unless it is nil in which case the result will be
 	// discarded.
 	//
+	// If the Context was produced using WithMeta then that metadata will be
+	// carried with the request to the server via the Meta field of the
+	// RequestParams.
+	//
 	// If an error result is returned from the server that will be returned as
 	// an Error struct.
-	Call(ctx context.Context, rcv any, method string, params ...any) error
+	Call(ctx context.Context, rcv any, method string, args ...any) error
 }

go/daemon/jsonrpc2/client_http.go

@@ -49,14 +49,14 @@ func NewUnixHTTPClient(unixSocketPath, reqPath string) Client {
 }
 
 func (c *httpClient) Call(
-	ctx context.Context, rcv any, method string, params ...any,
+	ctx context.Context, rcv any, method string, args ...any,
 ) error {
 	var (
 		body = new(bytes.Buffer)
 		enc  = json.NewEncoder(body)
 	)
 
-	id, err := encodeRequest(enc, method, params)
+	id, err := encodeRequest(ctx, enc, method, args)
 	if err != nil {
 		return fmt.Errorf("encoding request: %w", err)
 	}

go/daemon/jsonrpc2/client_rw.go

@@ -19,9 +19,9 @@ func NewReadWriterClient(rw io.ReadWriter) Client {
 }
 
 func (c rwClient) Call(
-	ctx context.Context, rcv any, method string, params ...any,
+	ctx context.Context, rcv any, method string, args ...any,
 ) error {
-	id, err := encodeRequest(c.enc, method, params)
+	id, err := encodeRequest(ctx, c.enc, method, args)
 	if err != nil {
 		return fmt.Errorf("encoding request: %w", err)
 	}

go/daemon/jsonrpc2/dispatcher.go

@@ -18,19 +18,21 @@ type methodDispatchFunc func(context.Context, Request) (any, error)
 func newMethodDispatchFunc(
 	method reflect.Value,
 ) methodDispatchFunc {
-	paramTs := make([]reflect.Type, method.Type().NumIn()-1)
+	argTs := make([]reflect.Type, method.Type().NumIn()-1)
-	for i := range paramTs {
+	for i := range argTs {
-		paramTs[i] = method.Type().In(i + 1)
+		argTs[i] = method.Type().In(i + 1)
 	}
 
 	return func(ctx context.Context, req Request) (any, error) {
-		callVals := make([]reflect.Value, 0, len(paramTs)+1)
+		ctx = context.WithValue(ctx, ctxKeyMeta(0), req.Params.Meta)
+
+		callVals := make([]reflect.Value, 0, len(argTs)+1)
 		callVals = append(callVals, reflect.ValueOf(ctx))
 
-		for i, paramT := range paramTs {
+		for i, argT := range argTs {
-			paramPtrV := reflect.New(paramT)
+			argPtrV := reflect.New(argT)
 
-			err := json.Unmarshal(req.Params[i], paramPtrV.Interface())
+			err := json.Unmarshal(req.Params.Args[i], argPtrV.Interface())
 			if err != nil {
 				// The JSON has already been validated, so this is not an
 				// errCodeParse situation. We assume it's an invalid param then,
@@ -38,13 +40,13 @@ func newMethodDispatchFunc(
 				// returning an Error of its own.
 				if !errors.As(err, new(Error)) {
 					err = NewInvalidParamsError(
-						"JSON unmarshaling param %d into %T: %v", i, paramT, err,
+						"JSON unmarshaling arg %d into %T: %v", i, argT, err,
 					)
 				}
 				return nil, err
 			}
 
-			callVals = append(callVals, paramPtrV.Elem())
+			callVals = append(callVals, argPtrV.Elem())
 		}
 
 		var (
@@ -82,7 +84,8 @@ type dispatcher struct {
 //	MethodName(context.Context, ...ParamType) (ResponseType, error)
 //	MethodName(context.Context, ...ParamType) error
 //
-// will be available via RPC calls.
+// will be available via RPC calls. Any Meta data in the request can be obtained
+// within the method handler by calling GetMeta on the method's Context.
 func NewDispatchHandler(i any) Handler {
 	v := reflect.ValueOf(i)
 	if v.Kind() != reflect.Pointer {

go/daemon/jsonrpc2/handler.go

@@ -57,15 +57,16 @@ func NewMLogMiddleware(logger *mlog.Logger) Middleware {
 				ctx,
 				"rpcRequestID", req.ID,
 				"rpcRequestMethod", req.Method,
+				"rpcRequestMeta", req.Params.Meta,
 			)
 
 			if logger.MaxLevel() >= mlog.LevelDebug.Int() {
 				ctx := ctx
-				for i := range req.Params {
+				for i := range req.Params.Args {
 					ctx = mctx.Annotate(
 						ctx,
-						fmt.Sprintf("rpcRequestParam%d", i),
+						fmt.Sprintf("rpcRequestArgs%d", i),
-						string(req.Params[i]),
+						string(req.Params.Args[i]),
 					)
 				}
 				logger.Debug(ctx, "Handling RPC request")

go/daemon/jsonrpc2/jsonrpc2.go

@@ -3,6 +3,7 @@
 package jsonrpc2
 
 import (
+	"context"
 	"crypto/rand"
 	"encoding/json"
 	"fmt"
@@ -11,11 +12,19 @@ import (
 
 const version = "2.0"
 
+// RequestParams are the parameters passed in a Request. Meta contains
+// information that is not directly related to what is being requested, while
+// Args are the request's actual arguments.
+type RequestParams struct {
+	Meta map[string]any    `json:"meta,omitempty"`
+	Args []json.RawMessage `json:"args,omitempty"`
+}
+
 // Request encodes an RPC request according to the spec.
 type Request struct {
 	Version string        `json:"jsonrpc"` // must be "2.0"
 	Method  string        `json:"method"`
-	Params  []json.RawMessage `json:"params,omitempty"`
+	Params  RequestParams `json:"params,omitempty"`
 	ID      string        `json:"id"`
 }
 
@@ -37,18 +46,18 @@ func newID() string {
 // encodeRequest writes a request to an io.Writer, returning the ID of the
 // request.
 func encodeRequest(
-	enc *json.Encoder, method string, params []any,
+	ctx context.Context, enc *json.Encoder, method string, args []any,
 ) (
 	string, error,
 ) {
 	var (
-		paramsBs = make([]json.RawMessage, len(params))
+		argsBs = make([]json.RawMessage, len(args))
 		err    error
 	)
-	for i := range params {
+	for i := range args {
-		paramsBs[i], err = json.Marshal(params[i])
+		argsBs[i], err = json.Marshal(args[i])
 		if err != nil {
-			return "", fmt.Errorf("encoding param %d as JSON: %w", i, err)
+			return "", fmt.Errorf("encoding arg %d as JSON: %w", i, err)
 		}
 	}
 
@@ -57,7 +66,10 @@ func encodeRequest(
 		reqEnvelope = Request{
 			Version: version,
 			Method:  method,
-			Params:  paramsBs,
+			Params: RequestParams{
+				Meta: GetMeta(ctx),
+				Args: argsBs,
+			},
 			ID: id,
 		}
 	)

go/daemon/jsonrpc2/jsonrpc2_test.go

@@ -48,6 +48,16 @@ func (i dividerImpl) Noop(ctx context.Context) error {
 	return nil
 }
 
+func (i dividerImpl) Divide2FromMeta(ctx context.Context) (int, error) {
+	var (
+		meta   = GetMeta(ctx)
+		top    = int(meta["top"].(float64))
+		bottom = int(meta["bottom"].(float64))
+	)
+
+	return i.Divide2(ctx, top, bottom)
+}
+
 func (dividerImpl) Hidden(ctx context.Context, p struct{}) (int, error) {
 	return 0, errors.New("Shouldn't be possible to call this!")
 }
@@ -57,6 +67,7 @@ type divider interface {
 	Divide(ctx context.Context, p DivideParams) (int, error)
 	One(ctx context.Context) (int, error)
 	Noop(ctx context.Context) error
+	Divide2FromMeta(ctx context.Context) (int, error)
 }
 
 var testHandler = func() Handler {
@@ -124,6 +135,19 @@ func testClient(t *testing.T, client Client) {
 		}
 	})
 
+	t.Run("success/meta", func(t *testing.T) {
+		ctx = WithMeta(ctx, "top", 6)
+		ctx = WithMeta(ctx, "bottom", 2)
+
+		var res int
+		err := client.Call(ctx, &res, "Divide2FromMeta")
+		if err != nil {
+			t.Fatal(err)
+		} else if res != 3 {
+			t.Fatalf("expected 2, got %d", res)
+		}
+	})
+
 	t.Run("err/application", func(t *testing.T) {
 		err := client.Call(ctx, nil, "Divide", DivideParams{})
 		if !errors.Is(err, ErrDivideByZero) {

go/daemon/jsonrpc2/meta.go

@@ -0,0 +1,30 @@
+package jsonrpc2
+
+import (
+	"context"
+	"maps"
+)
+
+type ctxKeyMeta int
+
+// WithMeta returns a Context where the given key will be set to the given value
+// in the Meta field of all JSONRPC2 requests made using Clients from this
+// package.
+func WithMeta(ctx context.Context, key string, value any) context.Context {
+	m, _ := ctx.Value(ctxKeyMeta(0)).(map[string]any)
+	if m == nil {
+		m = map[string]any{}
+	} else {
+		m = maps.Clone(m)
+	}
+
+	m[key] = value
+	return context.WithValue(ctx, ctxKeyMeta(0), m)
+}
+
+// GetMeta returns all key/values which have been set on the Context using
+// WithMeta. This may return nil if WithMeta was never called.
+func GetMeta(ctx context.Context) map[string]any {
+	m, _ := ctx.Value(ctxKeyMeta(0)).(map[string]any)
+	return m
+}

go/daemon/network.go

@@ -1,6 +1,7 @@
 package daemon
 
 import (
+	"context"
 	"fmt"
 	"isle/bootstrap"
 	"isle/daemon/network"
@@ -41,9 +42,9 @@ func networkDirs(
 	return
 }
 
-// LoadableNetworks returns the CreationParams for each Network which is able to
+// loadableNetworks returns the CreationParams for each Network which is able to
 // be loaded.
-func LoadableNetworks(
+func loadableNetworks(
 	networksStateDir toolkit.Dir,
 ) (
 	[]bootstrap.CreationParams, error,
@@ -71,3 +72,60 @@ func LoadableNetworks(
 
 	return creationParams, nil
 }
+
+func pickNetwork(
+	ctx context.Context,
+	networks map[string]network.Network,
+	networksStateDir toolkit.Dir,
+) (
+	network.Network, error,
+) {
+	if len(networks) == 0 {
+		return nil, ErrNoNetwork
+	}
+
+	creationParams, err := loadableNetworks(networksStateDir)
+	if err != nil {
+		return nil, fmt.Errorf("getting loadable networks: %w", err)
+	}
+
+	var (
+		networkSearchStr   = getNetworkSearchStr(ctx)
+		matchingNetworkIDs = make([]string, 0, len(networks))
+	)
+
+	for _, creationParam := range creationParams {
+		if networkSearchStr == "" || creationParam.Matches(networkSearchStr) {
+			matchingNetworkIDs = append(matchingNetworkIDs, creationParam.ID)
+		}
+	}
+
+	if len(matchingNetworkIDs) == 0 {
+		return nil, ErrNoMatchingNetworks
+	} else if len(matchingNetworkIDs) > 1 {
+		return nil, ErrMultipleMatchingNetworks
+	}
+
+	return networks[matchingNetworkIDs[0]], nil
+}
+
+func alreadyJoined(
+	ctx context.Context,
+	networks map[string]network.Network,
+	creationParams bootstrap.CreationParams,
+) (
+	bool, error,
+) {
+	for networkID, network := range networks {
+		existingCreationParams, err := network.GetNetworkCreationParams(ctx)
+		if err != nil {
+			return false, fmt.Errorf(
+				"getting creation params of network %q: %w", networkID, err,
+			)
+		} else if existingCreationParams.Conflicts(creationParams) {
+			return true, nil
+		}
+	}
+
+	return false, nil
+}

go/daemon/rpc.go

@@ -25,6 +25,13 @@ type RPC interface {
 	// All network.RPC methods are automatically implemented by Daemon using the
 	// currently joined network. If no network is joined then any call to these
 	// methods will return ErrNoNetwork.
+	//
+	// All calls to these methods must be accompanied with a context produced by
+	// WithNetwork, in order to choose the network. These methods may return
+	// these errors, in addition to those documented on the individual methods:
+	//
+	// - ErrNoMatchingNetworks
+	// - ErrMultipleMatchingNetworks
 	network.RPC
 }