feat: basic server functionality

cmd/chnsd/main.go

@@ -1,9 +1,76 @@
 // Copyright 2023 Blink Labs, LLC.
-// 
+//
 // Use of this source code is governed by an MIT-style
 // license that can be found in the LICENSE file or at
 // https://opensource.org/licenses/MIT.
 
 package main
 
-func main() {}
+import (
+	"flag"
+	"fmt"
+	"net/http"
+	_ "net/http/pprof"
+	"os"
+
+	"github.com/blinklabs-io/chnsd/internal/config"
+	"github.com/blinklabs-io/chnsd/internal/dns"
+	"github.com/blinklabs-io/chnsd/internal/logging"
+)
+
+var cmdlineFlags struct {
+	configFile string
+}
+
+func main() {
+	flag.StringVar(&cmdlineFlags.configFile, "config", "", "path to config file to load")
+	flag.Parse()
+
+	// Load config
+	cfg, err := config.Load(cmdlineFlags.configFile)
+	if err != nil {
+		fmt.Printf("Failed to load config: %s\n", err)
+		os.Exit(1)
+	}
+
+	// Configure logging
+	logging.Setup()
+	logger := logging.GetLogger()
+	// Sync logger on exit
+	defer func() {
+		if err := logger.Sync(); err != nil {
+			// We don't actually care about the error here, but we have to do something
+			// to appease the linter
+			return
+		}
+	}()
+
+	/*
+		// Test node connection
+		if oConn, err := node.GetConnection(); err != nil {
+			logger.Fatalf("failed to connect to node: %s", err)
+		} else {
+			oConn.Close()
+		}
+	*/
+
+	// Start debug listener
+	if cfg.Debug.ListenPort > 0 {
+		logger.Infof("starting debug listener on %s:%d", cfg.Debug.ListenAddress, cfg.Debug.ListenPort)
+		go func() {
+			err := http.ListenAndServe(fmt.Sprintf("%s:%d", cfg.Debug.ListenAddress, cfg.Debug.ListenPort), nil)
+			if err != nil {
+				logger.Fatalf("failed to start debug listener: %s", err)
+			}
+		}()
+	}
+
+	// Start DNS listener
+	logger.Infof("starting DNS listener on %s:%d", cfg.Dns.ListenAddress, cfg.Dns.ListenPort)
+	if err := dns.Start(); err != nil {
+		logger.Fatalf("failed to start DNS listener: %s", err)
+	}
+
+	// Wait forever
+	select {}
+}

go.mod

@@ -1,3 +1,25 @@
 module github.com/blinklabs-io/chnsd
 
 go 1.19
+
+require (
+	github.com/blinklabs-io/gouroboros v0.47.0
+	github.com/kelseyhightower/envconfig v1.4.0
+	github.com/miekg/dns v1.1.55
+	go.uber.org/zap v1.24.0
+	gopkg.in/yaml.v2 v2.4.0
+)
+
+require (
+	github.com/fxamacker/cbor/v2 v2.4.0 // indirect
+	github.com/jinzhu/copier v0.3.5 // indirect
+	github.com/pkg/errors v0.9.1 // indirect
+	github.com/x448/float16 v0.8.4 // indirect
+	go.uber.org/atomic v1.7.0 // indirect
+	go.uber.org/multierr v1.6.0 // indirect
+	golang.org/x/crypto v0.10.0 // indirect
+	golang.org/x/mod v0.9.0 // indirect
+	golang.org/x/net v0.10.0 // indirect
+	golang.org/x/sys v0.9.0 // indirect
+	golang.org/x/tools v0.7.0 // indirect
+)

go.sum

@@ -0,0 +1,46 @@
+github.com/benbjohnson/clock v1.1.0 h1:Q92kusRqC1XV2MjkWETPvjJVqKetz1OzxZB7mHJLju8=
+github.com/blinklabs-io/gouroboros v0.47.0 h1:N8SoWoT6h6m+w60OU5qNGNyAHj/MxJzSZaw6cnR1Dc8=
+github.com/blinklabs-io/gouroboros v0.47.0/go.mod h1:J3Zf9Fx65LoLldIZB4+dZZpsUsGfwXMQQKQOhNBNlwY=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/fxamacker/cbor/v2 v2.4.0 h1:ri0ArlOR+5XunOP8CRUowT0pSJOwhW098ZCUyskZD88=
+github.com/fxamacker/cbor/v2 v2.4.0/go.mod h1:TA1xS00nchWmaBnEIxPSE5oHLuJBAVvqrtAnWBwBCVo=
+github.com/jinzhu/copier v0.3.5 h1:GlvfUwHk62RokgqVNvYsku0TATCF7bAHVwEXoBh3iJg=
+github.com/jinzhu/copier v0.3.5/go.mod h1:DfbEm0FYsaqBcKcFuvmOZb218JkPGtvSHsKg8S8hyyg=
+github.com/kelseyhightower/envconfig v1.4.0 h1:Im6hONhd3pLkfDFsbRgu68RDNkGF1r3dvMUtDTo2cv8=
+github.com/kelseyhightower/envconfig v1.4.0/go.mod h1:cccZRl6mQpaq41TPp5QxidR+Sa3axMbJDNb//FQX6Gg=
+github.com/miekg/dns v1.1.55 h1:GoQ4hpsj0nFLYe+bWiCToyrBEJXkQfOOIvFGFy0lEgo=
+github.com/miekg/dns v1.1.55/go.mod h1:uInx36IzPl7FYnDcMeVWxj9byh7DutNykX4G9Sj60FY=
+github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
+github.com/stretchr/testify v1.8.0 h1:pSgiaMZlXftHpm5L7V1+rVB+AZJydKsMxsQBIJw4PKk=
+github.com/x448/float16 v0.8.4 h1:qLwI1I70+NjRFUR3zs1JPUCgaCXSh3SW62uAKT1mSBM=
+github.com/x448/float16 v0.8.4/go.mod h1:14CWIYCyZA/cWjXOioeEpHeN/83MdbZDRQHoFcYsOfg=
+go.uber.org/atomic v1.7.0 h1:ADUqmZGgLDDfbSL9ZmPxKTybcoEYHgpYfELNoN+7hsw=
+go.uber.org/atomic v1.7.0/go.mod h1:fEN4uk6kAWBTFdckzkM89CLk9XfWZrxpCo0nPH17wJc=
+go.uber.org/goleak v1.1.11 h1:wy28qYRKZgnJTxGxvye5/wgWr1EKjmUDGYox5mGlRlI=
+go.uber.org/multierr v1.6.0 h1:y6IPFStTAIT5Ytl7/XYmHvzXQ7S3g/IeZW9hyZ5thw4=
+go.uber.org/multierr v1.6.0/go.mod h1:cdWPpRnG4AhwMwsgIHip0KRBQjJy5kYEpYjJxpXp9iU=
+go.uber.org/zap v1.24.0 h1:FiJd5l1UOLj0wCgbSE0rwwXHzEdAZS6hiiSnxJN/D60=
+go.uber.org/zap v1.24.0/go.mod h1:2kMP+WWQ8aoFoedH3T2sq6iJ2yDWpHbP0f6MQbS9Gkg=
+golang.org/x/crypto v0.10.0 h1:LKqV2xt9+kDzSTfOhx4FrkEBcMrAgHSYgzywV9zcGmM=
+golang.org/x/crypto v0.10.0/go.mod h1:o4eNf7Ede1fv+hwOwZsTHl9EsPFO6q6ZvYR8vYfY45I=
+golang.org/x/mod v0.9.0 h1:KENHtAZL2y3NLMYZeHY9DW8HW8V+kQyJsY/V9JlKvCs=
+golang.org/x/mod v0.9.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
+golang.org/x/net v0.10.0 h1:X2//UzNDwYmtCLn7To6G58Wr6f5ahEAQgKNzv9Y951M=
+golang.org/x/net v0.10.0/go.mod h1:0qNGK6F8kojg2nk9dLZ2mShWaEBan6FAoqfSigmmuDg=
+golang.org/x/sync v0.1.0 h1:wsuoTGHzEhffawBOhz5CYhcrV4IdKZbEyZjBMuTp12o=
+golang.org/x/sys v0.9.0 h1:KS/R3tvhPqvJvwcKfnBHJwwthS11LRhmM5D59eEXa0s=
+golang.org/x/sys v0.9.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/tools v0.7.0 h1:W4OVu8VVOaIO0yzWMNdepAulS7YfoS3Zabrm8DOXXU4=
+golang.org/x/tools v0.7.0/go.mod h1:4pg6aUX35JBAogB10C9AtvVL+qowtN4pT3CGSQex14s=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
+gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=

internal/config/config.go

@@ -0,0 +1,105 @@
+package config
+
+import (
+	"fmt"
+	"os"
+
+	ouroboros "github.com/blinklabs-io/gouroboros"
+	"github.com/kelseyhightower/envconfig"
+	"gopkg.in/yaml.v2"
+)
+
+type Config struct {
+	Logging LoggingConfig `yaml:"logging"`
+	Metrics MetricsConfig `yaml:"metrics"`
+	Dns     DnsConfig     `yaml:"dns"`
+	Debug   DebugConfig   `yaml:"debug"`
+	Node    NodeConfig    `yaml:"node"`
+}
+
+type LoggingConfig struct {
+	Healthchecks bool   `yaml:"healthchecks" envconfig:"LOGGING_HEALTHCHECKS"`
+	Level        string `yaml:"level" envconfig:"LOGGING_LEVEL"`
+}
+
+type DnsConfig struct {
+	ListenAddress string `yaml:"address" envconfig:"DNS_LISTEN_ADDRESS"`
+	ListenPort    uint   `yaml:"port" envconfig:"DNS_LISTEN_PORT"`
+}
+
+type DebugConfig struct {
+	ListenAddress string `yaml:"address" envconfig:"DEBUG_ADDRESS"`
+	ListenPort    uint   `yaml:"port" envconfig:"DEBUG_PORT"`
+}
+
+type MetricsConfig struct {
+	ListenAddress string `yaml:"address" envconfig:"METRICS_LISTEN_ADDRESS"`
+	ListenPort    uint   `yaml:"port" envconfig:"METRICS_LISTEN_PORT"`
+}
+
+type NodeConfig struct {
+	Network      string `yaml:"network" envconfig:"CARDANO_NETWORK"`
+	NetworkMagic uint32 `yaml:"networkMagic" envconfig:"CARDANO_NODE_NETWORK_MAGIC"`
+	Address      string `yaml:"address" envconfig:"CARDANO_NODE_SOCKET_TCP_HOST"`
+	Port         uint   `yaml:"port" envconfig:"CARDANO_NODE_SOCKET_TCP_PORT"`
+	SocketPath   string `yaml:"socketPath" envconfig:"CARDANO_NODE_SOCKET_PATH"`
+}
+
+// Singleton config instance with default values
+var globalConfig = &Config{
+	Logging: LoggingConfig{
+		Level:        "info",
+		Healthchecks: false,
+	},
+	Dns: DnsConfig{
+		ListenAddress: "",
+		ListenPort:    8053,
+	},
+	Debug: DebugConfig{
+		ListenAddress: "localhost",
+		ListenPort:    0,
+	},
+	Metrics: MetricsConfig{
+		ListenAddress: "",
+		ListenPort:    8081,
+	},
+	Node: NodeConfig{
+		Network:    "mainnet",
+		SocketPath: "/node-ipc/node.socket",
+	},
+}
+
+func Load(configFile string) (*Config, error) {
+	// Load config file as YAML if provided
+	if configFile != "" {
+		buf, err := os.ReadFile(configFile)
+		if err != nil {
+			return nil, fmt.Errorf("error reading config file: %s", err)
+		}
+		err = yaml.Unmarshal(buf, globalConfig)
+		if err != nil {
+			return nil, fmt.Errorf("error parsing config file: %s", err)
+		}
+	}
+	// Load config values from environment variables
+	// We use "dummy" as the app name here to (mostly) prevent picking up env
+	// vars that we hadn't explicitly specified in annotations above
+	err := envconfig.Process("dummy", globalConfig)
+	if err != nil {
+		return nil, fmt.Errorf("error processing environment: %s", err)
+	}
+	// Populate network magic value from network name
+	if globalConfig.Node.Network != "" {
+		network := ouroboros.NetworkByName(globalConfig.Node.Network)
+		if network == ouroboros.NetworkInvalid {
+			return nil, fmt.Errorf("unknown network: %s", globalConfig.Node.Network)
+		}
+		globalConfig.Node.NetworkMagic = network.NetworkMagic
+	}
+	return globalConfig, nil
+}
+
+// Config returns the global config instance
+func GetConfig() *Config {
+	return globalConfig
+}

internal/dns/dns.go

@@ -0,0 +1,54 @@
+package dns
+
+import (
+	"fmt"
+
+	"github.com/blinklabs-io/chnsd/internal/config"
+	"github.com/blinklabs-io/chnsd/internal/logging"
+
+	"github.com/miekg/dns"
+)
+
+func Start() error {
+	cfg := config.GetConfig()
+	listenAddr := fmt.Sprintf("%s:%d", cfg.Dns.ListenAddress, cfg.Dns.ListenPort)
+	// Setup handler
+	dns.HandleFunc(".", handleTest)
+	// UDP listener
+	serverUdp := &dns.Server{Addr: listenAddr, Net: "udp", TsigSecret: nil, ReusePort: true}
+	go startListener(serverUdp)
+	// TCP listener
+	serverTcp := &dns.Server{Addr: listenAddr, Net: "tcp", TsigSecret: nil, ReusePort: true}
+	go startListener(serverTcp)
+	return nil
+}
+
+func startListener(server *dns.Server) {
+	if err := server.ListenAndServe(); err != nil {
+		logging.GetLogger().Fatalf("failed to start DNS listener: %s", err)
+	}
+}
+
+func handleTest(w dns.ResponseWriter, r *dns.Msg) {
+	logger := logging.GetLogger()
+	m := new(dns.Msg)
+	m.SetReply(r)
+
+	queryStr := fmt.Sprintf(
+		"%s %s",
+		dns.Type(r.Question[0].Qtype).String(),
+		r.Question[0].Name,
+	)
+
+	logger.Infof("request: %s", queryStr)
+
+	t := &dns.TXT{
+		Hdr: dns.RR_Header{Name: "test.zone.", Rrtype: dns.TypeTXT, Class: dns.ClassINET, Ttl: 0},
+		Txt: []string{queryStr},
+	}
+
+	m.Answer = append(m.Answer, t)
+	if err := w.WriteMsg(m); err != nil {
+		logger.Errorf("failed to write response: %s", err)
+	}
+}

internal/logging/logging.go

@@ -0,0 +1,54 @@
+package logging
+
+import (
+	"log"
+	"time"
+
+	"github.com/blinklabs-io/chnsd/internal/config"
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+)
+
+type Logger = zap.SugaredLogger
+
+var globalLogger *Logger
+
+func Setup() {
+	cfg := config.GetConfig()
+	// Build our custom logging config
+	loggerConfig := zap.NewProductionConfig()
+	// Change timestamp key name
+	loggerConfig.EncoderConfig.TimeKey = "timestamp"
+	// Use a human readable time format
+	loggerConfig.EncoderConfig.EncodeTime = zapcore.TimeEncoderOfLayout(time.RFC3339)
+
+	// Set level
+	if cfg.Logging.Level != "" {
+		level, err := zapcore.ParseLevel(cfg.Logging.Level)
+		if err != nil {
+			log.Fatalf("error configuring logger: %s", err)
+		}
+		loggerConfig.Level.SetLevel(level)
+	}
+
+	// Create the logger
+	l, err := loggerConfig.Build()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// Store the "sugared" version of the logger
+	globalLogger = l.Sugar()
+}
+
+func GetLogger() *zap.SugaredLogger {
+	return globalLogger
+}
+
+func GetDesugaredLogger() *zap.Logger {
+	return globalLogger.Desugar()
+}
+
+func GetAccessLogger() *zap.Logger {
+	return globalLogger.Desugar().With(zap.String("type", "access")).WithOptions(zap.WithCaller(false))
+}