Go client for the API, lobbyctl tool

Makefile

@@ -8,6 +8,6 @@ clean:
 .PHONY: build
 build:
 	mkdir -p ./bin
-	export CGO_ENABLED=0
-	go build -o ./bin/lobbyd daemon/*.go
+	export CGO_ENABLED=0 && go build -o ./bin/lobbyd daemon/*.go
+	export CGO_ENABLED=0 && go build -o ./bin/lobbyctl ctl/*.go
 	

client/main.go

@@ -0,0 +1,176 @@
+package client
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/go-resty/resty/v2"
+	"github.com/rosti-cz/server_lobby/server"
+)
+
+// Encapsulation of Lobby's client code
+type LobbyClient struct {
+	Proto string
+	Host  string
+	Port  uint
+	Token string
+}
+
+func (l *LobbyClient) init() {
+	if len(l.Proto) == 0 {
+		l.Host = "http"
+	}
+	if len(l.Host) == 0 {
+		l.Host = "localhost"
+	}
+	if l.Port == 0 {
+		l.Port = 1313
+	}
+}
+
+// calls the backend API with given method, path and request body and returns status code, response body and error if there is any.
+// Method can be GET, POST or DELETE.
+// Path should start with / and it can contain query parameters too.
+func (l *LobbyClient) call(method, path, body string) (uint, string, error) {
+	client := resty.New().R()
+
+	if len(l.Token) != 0 {
+		client = client.SetHeader("Authorization", fmt.Sprintf("Token %s", l.Token))
+	}
+
+	if strings.ToUpper(method) == "GET" {
+		resp, err := client.Get(fmt.Sprintf("%s://%s:%d%s", l.Proto, l.Host, l.Port, path))
+		if err != nil {
+			return 0, "", err
+		}
+		return uint(resp.StatusCode()), string(resp.Body()), nil
+	} else if strings.ToUpper(method) == "POST" {
+		resp, err := client.SetBody(body).Post(fmt.Sprintf("%s://%s:%d%s", l.Proto, l.Host, l.Port, path))
+		if err != nil {
+			return 0, "", err
+		}
+		return uint(resp.StatusCode()), string(resp.Body()), nil
+	} else if strings.ToUpper(method) == "DELETE" {
+		resp, err := client.SetBody(body).Delete(fmt.Sprintf("%s://%s:%d%s", l.Proto, l.Host, l.Port, path))
+		if err != nil {
+			return 0, "", err
+		}
+		return uint(resp.StatusCode()), string(resp.Body()), nil
+	} else {
+		return 0, "", errors.New("unsupported method")
+	}
+
+}
+
+// Returns discovery object of local machine
+func (l *LobbyClient) GetDiscovery() (server.Discovery, error) {
+	l.init()
+
+	var discovery server.Discovery
+
+	path := "/v1/discovery"
+	method := "GET"
+
+	status, body, err := l.call(method, path, "")
+	if err != nil {
+		return discovery, err
+	}
+	if status != 200 {
+		return discovery, fmt.Errorf("non-200 response: %s", body)
+	}
+
+	err = json.Unmarshal([]byte(body), &discovery)
+	if err != nil {
+		return discovery, fmt.Errorf("response parsing error: %v", err)
+	}
+
+	return discovery, nil
+}
+
+// Returns all registered discovery packets
+func (l *LobbyClient) GetDiscoveries() ([]server.Discovery, error) {
+	l.init()
+
+	path := "/v1/discoveries"
+	method := "GET"
+
+	var discoveries []server.Discovery
+
+	status, body, err := l.call(method, path, "")
+	if err != nil {
+		return discoveries, err
+	}
+	if status != 200 {
+		return discoveries, fmt.Errorf("non-200 response: %s", body)
+	}
+
+	err = json.Unmarshal([]byte(body), &discoveries)
+	if err != nil {
+		return discoveries, fmt.Errorf("response parsing error: %v", err)
+	}
+
+	return discoveries, nil
+}
+
+// Find discoveries by their labels
+func (l *LobbyClient) FindByLabels(labels server.Labels) (server.Discoveries, error) {
+	l.init()
+
+	path := fmt.Sprintf("/v1/discoveries?labels=%s", strings.Join(labels.StringSlice(), ","))
+	method := "GET"
+
+	var discoveries server.Discoveries
+
+	status, body, err := l.call(method, path, "")
+	if err != nil {
+		return discoveries, err
+	}
+	if status != 200 {
+		return discoveries, fmt.Errorf("non-200 response: %s", body)
+	}
+
+	err = json.Unmarshal([]byte(body), &discoveries)
+	if err != nil {
+		return discoveries, fmt.Errorf("response parsing error: %v", err)
+	}
+
+	return discoveries, nil
+}
+
+// Adds runtime labels for the local machine
+func (l *LobbyClient) AddLabels(labels server.Labels) error {
+	l.init()
+
+	path := "/v1/labels"
+	method := "POST"
+
+	status, body, err := l.call(method, path, strings.Join(labels.StringSlice(), "\n"))
+	if err != nil {
+		return err
+	}
+	if status != 200 {
+		return fmt.Errorf("non-200 response: %s", body)
+	}
+
+	return nil
+}
+
+// Removes runtime labels of the local machine
+func (l *LobbyClient) DeleteLabels(labels server.Labels) error {
+	l.init()
+
+	path := "/v1/labels"
+	method := "DELETE"
+
+	status, body, err := l.call(method, path, strings.Join(labels.StringSlice(), "\n"))
+	if err != nil {
+		return err
+	}
+	if status != 200 {
+		return fmt.Errorf("non-200 response: %s", body)
+	}
+
+	return nil
+}

ctl/config.go

@@ -0,0 +1,29 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/kelseyhightower/envconfig"
+)
+
+// Config keeps info about configuration of this daemon
+type Config struct {
+	Token string `envconfig:"TOKEN" required:"false"`                    // Authentication token, if empty auth is disabled
+	Proto string `envconfig:"PROTOCOL" required:"false" default:"http"`  // selected http or https protocols, default is http
+	Host  string `envconfig:"HOST" required:"false" default:"127.0.0.1"` // IP address or hostname where lobbyd is listening
+	Port  uint   `envconfig:"PORT" required:"false" default:"1313"`      // Same thing but the port part
+}
+
+// GetConfig return configuration created based on environment variables
+func GetConfig() *Config {
+	var config Config
+
+	err := envconfig.Process("", &config)
+	if err != nil {
+		fmt.Println(err.Error())
+		os.Exit(1)
+	}
+
+	return &config
+}

ctl/format.go

@@ -0,0 +1,43 @@
+package main
+
+import (
+	"fmt"
+	"strconv"
+
+	"github.com/rosti-cz/server_lobby/server"
+)
+
+func printDiscovery(discovery server.Discovery) {
+	fmt.Printf("Hostname:\n  %s\n", discovery.Hostname)
+
+	if len(discovery.Labels) > 0 {
+		fmt.Printf("Labels:\n")
+		for _, label := range discovery.Labels {
+			fmt.Printf("  %s\n", label)
+		}
+	}
+}
+
+func printDiscoveries(discoveries []server.Discovery) {
+	maxHostnameWidth := 0
+	for _, discovery := range discoveries {
+		if len(discovery.Hostname) > maxHostnameWidth {
+			maxHostnameWidth = len(discovery.Hostname)
+		}
+	}
+
+	for _, discovery := range discoveries {
+		if len(discovery.Labels) == 0 {
+			fmt.Println(discovery.Hostname)
+		} else {
+			hostname := fmt.Sprintf("%"+strconv.Itoa(maxHostnameWidth)+"s", discovery.Hostname)
+			fmt.Printf("%s    %s\n", hostname, discovery.Labels[0].String())
+			if len(discovery.Labels) > 1 {
+				for _, label := range discovery.Labels[1:] {
+					fmt.Printf("%"+strconv.Itoa(maxHostnameWidth+4)+"s%s\n", " ", label)
+				}
+			}
+		}
+		fmt.Println()
+	}
+}

ctl/main.go

@@ -0,0 +1,117 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/rosti-cz/server_lobby/client"
+	"github.com/rosti-cz/server_lobby/server"
+)
+
+func Usage() {
+	flag.Usage()
+	fmt.Println("")
+	fmt.Println("Commands:")
+	fmt.Println("  discovery                      returns discovery packet of the server where the client is connected to")
+	fmt.Println("  discoveries                    returns list of all registered discovery packets")
+	fmt.Println("  labels add LABEL [LABEL] ...   adds new runtime labels")
+	fmt.Println("  labels del LABEL [LABEL] ...   deletes runtime labels")
+}
+
+func main() {
+	config := GetConfig()
+
+	// Setup flags
+	proto := flag.String("proto", "", "Select HTTP or HTTPS protocol")
+	host := flag.String("host", "", "Hostname or IP address of lobby daemon")
+	port := flag.Uint("port", 0, "Port of lobby daemon")
+	token := flag.String("token", "", "Token needed to communicate lobby daemon, if empty auth is disabled")
+
+	flag.Parse()
+
+	// Replace empty values from flags by values from environment variables
+	if *proto == "" {
+		proto = &config.Proto
+	}
+	if *host == "" {
+		host = &config.Host
+	}
+	if *port == 0 {
+		port = &config.Port
+	}
+	if *token == "" {
+		token = &config.Token
+	}
+
+	// Validation
+	if *proto != "http" && *proto != "https" {
+		fmt.Println("Protocol can be only http or https")
+	}
+
+	// Setup lobby client library
+	client := client.LobbyClient{
+		Proto: strings.ToLower(*proto),
+		Host:  *host,
+		Port:  *port,
+		Token: *token,
+	}
+
+	// Process rest of the arguments
+	if len(flag.Args()) == 0 {
+		Usage()
+		os.Exit(0)
+	}
+
+	switch flag.Args()[0] {
+	case "discoveries":
+		discoveries, err := client.GetDiscoveries()
+		if err != nil {
+			fmt.Println(err)
+		}
+		printDiscoveries(discoveries)
+	case "discovery":
+		discovery, err := client.GetDiscovery()
+		if err != nil {
+			fmt.Println(err)
+		}
+		printDiscovery(discovery)
+	case "labels":
+		if len(flag.Args()) < 3 {
+			fmt.Println("ERROR: not enough arguments for labels command")
+			fmt.Println("")
+			Usage()
+			os.Exit(0)
+		}
+
+		labels := server.Labels{}
+		labelsString := flag.Args()[2:]
+		for _, labelString := range labelsString {
+			labels = append(labels, server.Label(labelString))
+		}
+
+		if flag.Args()[1] == "add" {
+			err := client.AddLabels(labels)
+			if err != nil {
+				fmt.Printf("ERROR: %v\n", err)
+				os.Exit(2)
+			}
+		} else if flag.Args()[1] == "del" {
+			err := client.DeleteLabels(labels)
+			if err != nil {
+				fmt.Printf("ERROR: %v\n", err)
+				os.Exit(2)
+			}
+		} else {
+			fmt.Printf("ERROR: wrong labels subcommand\n\n")
+			Usage()
+			os.Exit(2)
+		}
+
+	default:
+		Usage()
+		os.Exit(0)
+	}
+
+}

go.mod

@@ -4,6 +4,7 @@ go 1.16
 
 require (
 	github.com/dgrijalva/jwt-go v3.2.0+incompatible // indirect
+	github.com/go-resty/resty/v2 v2.6.0
 	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/kelseyhightower/envconfig v1.4.0
 	github.com/labstack/echo v3.3.10+incompatible
@@ -13,6 +14,5 @@ require (
 	github.com/shirou/gopsutil/v3 v3.21.7
 	github.com/stretchr/testify v1.7.0
 	github.com/valyala/fasttemplate v1.2.1 // indirect
-	golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4 // indirect
 	google.golang.org/protobuf v1.27.1 // indirect
 )

go.sum

@@ -6,6 +6,8 @@ github.com/dgrijalva/jwt-go v3.2.0+incompatible h1:7qlOGliEKZXTDg6OTjfoBKDXWrumC
 github.com/dgrijalva/jwt-go v3.2.0+incompatible/go.mod h1:E3ru+11k8xSBh+hMPgOLZmtrrCbhqsmaPHjLKYnJCaQ=
 github.com/go-ole/go-ole v1.2.5 h1:t4MGB5xEDZvXI+0rMjjsfBsD7yAgp/s9ZDkL1JndXwY=
 github.com/go-ole/go-ole v1.2.5/go.mod h1:pprOEPIfldk/42T2oK7lQ4v4JSDwmV0As9GaiUsvbm0=
+github.com/go-resty/resty/v2 v2.6.0 h1:joIR5PNLM2EFqqESUjCMGXrWmXNHEU9CEiK813oKYS4=
+github.com/go-resty/resty/v2 v2.6.0/go.mod h1:PwvJS6hvaPkjtjNg9ph+VrSD92bi5Zq73w/BIH7cC3Q=
 github.com/golang/protobuf v1.4.0-rc.1/go.mod h1:ceaxUfeHdC40wWswd/P6IGgMaK3YpKi5j83Wpe3EHw8=
 github.com/golang/protobuf v1.4.0-rc.1.0.20200221234624-67d41d38c208/go.mod h1:xKAWHe0F5eneWXFV3EuXVDTCmh+JuBKY0li0aMyXATA=
 github.com/golang/protobuf v1.4.0-rc.2/go.mod h1:LlEzMj4AhA7rCAGe4KMBDvJI+AwstrUpVNzEA03Pprs=

server/types.go

@@ -9,3 +9,14 @@ func (l Label) String() string {
 
 // Labels stores multiple Label records
 type Labels []Label
+
+// StringSlice return slice of Label as strings
+func (l *Labels) StringSlice() []string {
+	labelsString := []string{}
+
+	for _, label := range *l {
+		labelsString = append(labelsString, label.String())
+	}
+
+	return labelsString
+}