afd8a3e9d0
- Add brotli compression (level 5) to long-lived SSE event streams (HandleGameEvents, HandleSnakeEvents) to reduce wire payload - Fix all errcheck violations with nolint annotations for best-effort calls - Fix goimports: separate stdlib, third-party, and local import groups - Fix staticcheck: add package comments, use tagged switch - Zero lint issues remaining
70 lines
1.5 KiB
Go
70 lines
1.5 KiB
Go
// Package nats sets up an embedded NATS server for real-time pub/sub
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// messaging between game clients.
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package nats
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import (
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"context"
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"fmt"
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"log/slog"
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"net"
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"os"
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"strconv"
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"github.com/delaneyj/toolbelt"
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"github.com/delaneyj/toolbelt/embeddednats"
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natsserver "github.com/nats-io/nats-server/v2/server"
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"github.com/nats-io/nats.go"
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)
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func SetupNATS(ctx context.Context) (*nats.Conn, func(), error) {
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natsPort, err := getFreeNatsPort()
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if err != nil {
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return nil, nil, fmt.Errorf("obtaining NATS port: %w", err)
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}
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ns, err := embeddednats.New(ctx, embeddednats.WithNATSServerOptions(&natsserver.Options{
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NoSigs: true,
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Port: natsPort,
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}))
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if err != nil {
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return nil, nil, fmt.Errorf("creating embedded nats server: %w", err)
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}
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ns.WaitForServer()
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slog.Info("NATS started", "port", natsPort)
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nc, err := ns.Client()
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if err != nil {
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return nil, nil, fmt.Errorf("creating nats client: %w", err)
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}
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cleanup := func() {
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nc.Close()
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ns.Close() //nolint:errcheck
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}
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return nc, cleanup, nil
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}
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func getFreeNatsPort() (int, error) {
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if p, ok := os.LookupEnv("NATS_PORT"); ok {
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natsPort, err := strconv.Atoi(p)
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if err != nil {
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return 0, fmt.Errorf("parsing NATS_PORT: %w", err)
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}
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if isPortFree(natsPort) {
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return natsPort, nil
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}
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}
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return toolbelt.FreePort()
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}
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func isPortFree(port int) bool {
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ln, err := net.Listen("tcp", fmt.Sprintf(":%d", port))
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if err != nil {
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return false
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}
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ln.Close() //nolint:errcheck // checking port availability
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return true
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}
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