started working on the backend

backend/pkg/config/config.go

@@ -0,0 +1,95 @@
+package config
+
+import (
+	"bytes"
+	"fmt"
+	"log"
+	"os"
+	"time"
+
+	"github.com/golang-jwt/jwt/v5"
+	"github.com/johannesbuehl/golunteer/backend/pkg/lib"
+	"github.com/rs/zerolog"
+	"gopkg.in/yaml.v3"
+)
+
+type ReservationConfig struct {
+	Expiration time.Duration
+}
+
+type ConfigStruct struct {
+	ConfigYaml
+	LogLevel      zerolog.Level
+	SessionExpire time.Duration
+}
+
+var Config ConfigStruct
+
+type Payload struct {
+	jwt.RegisteredClaims
+	CustomClaims map[string]any
+}
+
+func (config ConfigStruct) SignJWT(val any) (string, error) {
+	valMap, err := lib.StrucToMap(val)
+
+	if err != nil {
+		return "", err
+	}
+
+	payload := Payload{
+		RegisteredClaims: jwt.RegisteredClaims{
+			ExpiresAt: jwt.NewNumericDate(time.Now().Add(config.SessionExpire)),
+			IssuedAt:  jwt.NewNumericDate(time.Now()),
+		},
+		CustomClaims: valMap,
+	}
+
+	t := jwt.NewWithClaims(jwt.SigningMethodHS256, payload)
+
+	return t.SignedString([]byte(config.ClientSession.JwtSignature))
+}
+
+func loadConfig() ConfigStruct {
+	Config := ConfigYaml{}
+
+	yamlFile, err := os.ReadFile("config.yaml")
+	if err != nil {
+		panic(fmt.Sprintf("Error opening config-file: %q", err))
+	}
+
+	reader := bytes.NewReader(yamlFile)
+
+	dec := yaml.NewDecoder(reader)
+	dec.KnownFields(true)
+	err = dec.Decode(&Config)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error parsing config-file: %v", err)
+		os.Exit(1)
+	}
+
+	if logLevel, err := zerolog.ParseLevel(Config.LogLevel); err != nil {
+		panic(fmt.Errorf("can't parse log-level: %v", err))
+	} else {
+		var configStruct ConfigStruct
+
+		// parse the durations
+		if session_expire, err := time.ParseDuration(Config.ClientSession.Expire); err != nil {
+			log.Fatalf(`Error parsing "client_session.expire": %v`, err)
+
+			// parse the templates
+		} else {
+			configStruct = ConfigStruct{
+				ConfigYaml:    Config,
+				LogLevel:      logLevel,
+				SessionExpire: session_expire,
+			}
+		}
+
+		return configStruct
+	}
+}
+
+func init() {
+	Config = loadConfig()
+}

backend/pkg/config/configYAML.go

@@ -0,0 +1,75 @@
+package config
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"time"
+
+	"gopkg.in/yaml.v3"
+)
+
+var CONFIG_PATH = "config.yaml"
+
+type ConfigYaml struct {
+	LogLevel string `yaml:"log_level"`
+	Database struct {
+		Host     string `yaml:"host"`
+		User     string `yaml:"user"`
+		Password string `yaml:"password"`
+		Database string `yaml:"database"`
+	} `yaml:"database"`
+	Server struct {
+		Port int `yaml:"port"`
+	} `yaml:"server"`
+	ClientSession struct {
+		JwtSignature string `yaml:"jwt_signature"`
+		Expire       string `yaml:"expire"`
+	} `yaml:"client_session"`
+}
+
+type CacheConfig struct {
+	Expiration time.Duration
+	Purge      time.Duration
+}
+
+var YamlConfig ConfigYaml
+
+func _loadConfig() ConfigYaml {
+	config := ConfigYaml{}
+
+	yamlFile, err := os.ReadFile(CONFIG_PATH)
+	if err != nil {
+		panic(fmt.Sprintf("Error opening config-file: %v", err))
+	}
+
+	reader := bytes.NewReader(yamlFile)
+
+	dec := yaml.NewDecoder(reader)
+	dec.KnownFields(true)
+	err = dec.Decode(&config)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error parsing config-file: %v", err)
+		os.Exit(1)
+	}
+
+	return config
+}
+
+func WriteConfig() {
+	buf := bytes.Buffer{}
+	enc := yaml.NewEncoder(&buf)
+	enc.SetIndent(2)
+	// Can set default indent here on the encoder
+	if err := enc.Encode(&YamlConfig); err != nil {
+		panic(err)
+	} else {
+		if err := os.WriteFile(CONFIG_PATH, buf.Bytes(), 0644); err != nil {
+			panic(err)
+		}
+	}
+}
+
+func init() {
+	YamlConfig = _loadConfig()
+}