created setup and backend structure

backend/.devcontainer/devcontainer.json

@@ -0,0 +1,22 @@
+// For format details, see https://aka.ms/devcontainer.json. For config options, see the
+// README at: https://github.com/devcontainers/templates/tree/main/src/go
+{
+	"name": "Go",
+	// Or use a Dockerfile or Docker Compose file. More info: https://containers.dev/guide/dockerfile
+	"image": "mcr.microsoft.com/devcontainers/go:1-1.23-bookworm"
+
+	// Features to add to the dev container. More info: https://containers.dev/features.
+	// "features": {},
+
+	// Use 'forwardPorts' to make a list of ports inside the container available locally.
+	// "forwardPorts": [],
+
+	// Use 'postCreateCommand' to run commands after the container is created.
+	// "postCreateCommand": "go version",
+
+	// Configure tool-specific properties.
+	// "customizations": {},
+
+	// Uncomment to connect as root instead. More info: https://aka.ms/dev-containers-non-root.
+	// "remoteUser": "root"
+}

backend/.gitignore

@@ -0,0 +1 @@
+config.yaml

backend/config.go

@@ -0,0 +1,72 @@
+package main
+
+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"`
+	ClientSession struct {
+		JwtSignature string `yaml:"jwt_signature"`
+		Expire       string `yaml:"expire"`
+	} `yaml:"client_session"`
+}
+
+type CacheConfig struct {
+	Expiration time.Duration
+	Purge      time.Duration
+}
+
+var config 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(&config); err != nil {
+		panic(err)
+	} else {
+		if err := os.WriteFile(CONFIG_PATH, buf.Bytes(), 0644); err != nil {
+			panic(err)
+		}
+	}
+}
+
+func init() {
+	config = loadConfig()
+}

backend/go.mod

@@ -0,0 +1,3 @@
+module github.com/johannesbuehl/golunteer/backend
+
+go 1.23.4

backend/setup.go

@@ -0,0 +1,118 @@
+package main
+
+import (
+	"database/sql"
+	"fmt"
+	"math/rand/v2"
+	"os"
+	"regexp"
+	"strings"
+
+	"github.com/go-sql-driver/mysql"
+	"golang.org/x/crypto/bcrypt"
+)
+
+func createPassword(l int) string {
+	passwordChars := [...]string{`A`, `B`, `C`, `D`, `E`, `F`, `G`, `H`, `I`, `J`, `K`, `L`, `M`, `N`, `O`, `P`, `Q`, `R`, `S`, `T`, `U`, `V`, `W`, `X`, `Y`, `Z`, `Ä`, `Ö`, `Ü`, `a`, `b`, `c`, `d`, `e`, `f`, `g`, `h`, `i`, `j`, `k`, `l`, `m`, `n`, `o`, `p`, `q`, `r`, `s`, `t`, `u`, `v`, `w`, `x`, `y`, `z`, `ä`, `ö`, `ü`, `ß`, `0`, `1`, `2`, `3`, `4`, `5`, `6`, `7`, `8`, `9`, `!`, `"`, `§`, `$`, `%`, `&`, `/`, `(`, `)`, `=`, `?`, `@`, `{`, `}`, `[`, `]`, `#`, `+`, `'`, `*`, `,`, `.`, `-`, `;`, `:`, `_`, `<`, `>`, `|`, `°`}
+	var password string
+
+	for ii := 0; ii < l; ii++ {
+		password += passwordChars[rand.IntN(len(passwordChars))]
+	}
+
+	return password
+}
+
+func exit(e error) {
+	fmt.Printf("%v\n", e)
+	os.Exit(1)
+}
+
+func main() {
+	fmt.Println("connecting to database")
+
+	// connect to the database
+	sqlConfig := mysql.Config{
+		AllowNativePasswords: true,
+		Net:                  "tcp",
+		User:                 config.Database.User,
+		Passwd:               config.Database.Password,
+		Addr:                 config.Database.Host,
+		DBName:               config.Database.Database,
+	}
+
+	db, err := sql.Open("mysql", sqlConfig.FormatDSN())
+	if err != nil {
+		exit(err)
+	}
+
+	// load the sql-script
+	fmt.Println(`reading "setup.sql"`)
+	var sqlScriptCommands []byte
+	if c, err := os.ReadFile("setup.sql"); err != nil {
+		exit(err)
+	} else {
+		sqlScriptCommands = c
+	}
+
+	// read the currently availabe tables
+	fmt.Println("reading available tables in database")
+	if rows, err := db.Query("SHOW TABLES"); err != nil {
+		exit(err)
+	} else {
+		defer rows.Close()
+
+		fmt.Println("checking for already existing tables in database")
+		for rows.Next() {
+			var name string
+
+			if err := rows.Scan(&name); err != nil {
+				exit(err)
+			} else {
+				// check wether for the table there exists a create command
+
+				if match, err := regexp.Match(fmt.Sprintf(`(?i)^create table %s`, name), sqlScriptCommands); err != nil {
+					exit(err)
+				} else {
+					if match {
+						exit(fmt.Errorf("can't setup databases: table %q already exists", name))
+					}
+				}
+			}
+		}
+	}
+
+	// everything is good (so far), create the tables
+	fmt.Println("Creating the individual tables:")
+	for _, cmd := range strings.Split(string(sqlScriptCommands), ";") {
+		db.Exec(cmd)
+	}
+
+	fmt.Println("Creating admin-password:")
+
+	// create an admin-password
+	const passwordLength = 20
+	password := createPassword(passwordLength)
+
+	// hash the admin-password
+	if passwordHash, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost); err != nil {
+		exit(err)
+	} else {
+		fmt.Println("\thashed password")
+
+		// create an admin-user
+		if _, err := db.Exec("INSERT INTO USERS (name, password) VALUES ('admin', ?)", passwordHash); err != nil {
+			exit(err)
+		}
+
+		fmt.Println("\twrote hashed password to database")
+	}
+
+	fmt.Printf("created user \"admin\" with password %s\n", password)
+
+	// create a jwt-signature
+	config.ClientSession.JwtSignature = createPassword(100)
+
+	// write the modified config-file
+	writeConfig()
+}