func()

in internal/gitaly/gitaly.go [78:137]

• 43 lines of code
• 5 McCabe index (conditional complexity)

func (c *Client) newConnection(ctx context.Context, cmd Command) (conn *grpc.ClientConn, err error) {
	defer func() {
		label := "ok"
		if err != nil {
			label = "fail"
		}
		metrics.GitalyConnectionsTotal.WithLabelValues(label).Inc()
	}()

	if cmd.Address == "" {
		return nil, fmt.Errorf("no gitaly_address given")
	}

	serviceName := correlation.ExtractClientNameFromContext(ctx)
	if serviceName == "" {
		serviceName = "gitlab-shell-unknown"

		log.WithContextFields(ctx, log.Fields{"service_name": serviceName}).Warn("No gRPC service name specified, defaulting to gitlab-shell-unknown")
	}

	serviceName = fmt.Sprintf("%s-%s", serviceName, cmd.ServiceName)

	connOpts := gitalyclient.DefaultDialOpts
	connOpts = append(
		connOpts,
		grpc.WithChainStreamInterceptor(
			grpctracing.StreamClientTracingInterceptor(),
			grpc_prometheus.StreamClientInterceptor,
			grpccorrelation.StreamClientCorrelationInterceptor(
				grpccorrelation.WithClientName(serviceName),
			),
		),

		grpc.WithChainUnaryInterceptor(
			grpctracing.UnaryClientTracingInterceptor(),
			grpc_prometheus.UnaryClientInterceptor,
			grpccorrelation.UnaryClientCorrelationInterceptor(
				grpccorrelation.WithClientName(serviceName),
			),
		),

		// In https://gitlab.com/groups/gitlab-org/-/epics/8971, we added DNS discovery support to Praefect. This was
		// done by making two changes:
		// - Configure client-side round-robin load-balancing in client dial options. We added that as a default option
		// inside gitaly client in gitaly client since v15.9.0
		// - Configure DNS resolving. Due to some technical limitations, we don't use gRPC's built-in DNS resolver.
		// Instead, we implement our own DNS resolver. This resolver is exposed via the following configuration.
		// Afterward, workhorse can detect and handle DNS discovery automatically. The user needs to setup and set
		// Gitaly address to something like "dns:gitaly.service.dc1.consul"
		gitalyclient.WithGitalyDNSResolver(gitalyclient.DefaultDNSResolverBuilderConfig()),
	)

	if cmd.Token != "" {
		connOpts = append(connOpts,
			grpc.WithPerRPCCredentials(gitalyauth.RPCCredentialsV2(cmd.Token)),
		)
	}

	return gitalyclient.DialSidechannel(ctx, cmd.Address, c.SidechannelRegistry, connOpts)
}