sermoni

commit 6bee8c9c07faf1f1a60ff4305d60d5e305db4f8c
parent 9af11077e2eb769b4a077f23fd5990f2d40a3b8a
Author: Vetle Haflan <vetle@haflan.dev>
Date:   Fri, 10 Apr 2020 12:41:05 +0200

Start work on database

Diffstat:
A
db.go
 | 
110
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
A
main.go
 | 
20
++++++++++++++++++++

2 files changed, 130 insertions(+), 0 deletions(-)
diff --git a/db.go b/db.go
@@ -0,0 +1,110 @@
+package main
+
+import (
+	"crypto/rand"
+	"crypto/sha256"
+	"errors"
+	"fmt"
+	"time"
+
+	"go.etcd.io/bbolt"
+)
+
+const defaultPageTitle = "sermoni"
+
+// bbolt keys
+var (
+	bucketKeyConfig       = []byte("config")
+	bucketKeyServices     = []byte("services")
+	bucketKeyEvents       = []byte("events")
+	keyPassHash           = []byte("passhash")
+	keyPageTitle          = []byte("pagetitle")
+	keyServiceName        = []byte("name")
+	keyServiceDescription = []byte("description")
+	keyServicePeriod      = []byte("period")
+)
+
+// ErrConfigBucket is returned when bbolt is unable to open the config bucket
+// TODO: I'm not sure if this is the idiomatic way to use errors
+var ErrConfigBucket = errors.New("unable to open config bucket")
+
+// Global bbolt DB struct
+var db *bbolt.DB
+
+// openDB opens the database for the given file name or creates it if it doesn't exist
+func initDB(dbFileName string) error {
+	fmt.Printf("Init db '%v'\n", dbFileName)
+	var err error
+	db, err = bbolt.Open(dbFileName, 0600, &bbolt.Options{Timeout: 1 * time.Second})
+	if err != nil {
+		return err
+	}
+	// Create the necessary bbolt buckets if they don't exist
+	err = db.Update(func(tx *bbolt.Tx) error {
+		if _, err := tx.CreateBucketIfNotExists(bucketKeyConfig); err != nil {
+			return err
+		}
+		if _, err := tx.CreateBucketIfNotExists(bucketKeyServices); err != nil {
+			return err
+		}
+		if _, err := tx.CreateBucketIfNotExists(bucketKeyEvents); err != nil {
+			return err
+		}
+		return nil
+	})
+	if err != nil {
+		return err
+	}
+	// Check if the config is initialized - configure if not
+	var configured bool
+	err = db.View(func(tx *bbolt.Tx) error {
+		b := tx.Bucket(bucketKeyConfig)
+		if b == nil {
+			return ErrConfigBucket
+		}
+		passhash := b.Get(keyPassHash)
+		configured = passhash != nil
+		return nil
+	})
+	if !configured {
+		return reconfigure("", defaultPageTitle)
+	}
+	return nil
+}
+
+// reconfigure takes a passphrase and a page title for the web page
+// and updates the database with this new configuration.
+// If passphrase is the empty string, a random phrase will be generated.
+func reconfigure(passphrase string, pageTitle string) error {
+	var passphraseBytes []byte
+	if passphrase == "" {
+		passphraseBytes = make([]byte, 24)
+		rand.Read(passphraseBytes)
+		passphrase = string(passphraseBytes)
+		fmt.Printf("Generated passphrase: %v\n", passphrase)
+	} else {
+		passphraseBytes = []byte(passphrase)
+	}
+	passhash := sha256.Sum256(passphraseBytes)
+	return db.Update(func(tx *bbolt.Tx) error {
+		b := tx.Bucket(bucketKeyConfig)
+		if b == nil {
+			return ErrConfigBucket
+		}
+		var err error
+		// [:] is needed to get a slice from the [32]byte array
+		if err = b.Put(keyPassHash, passhash[:]); err != nil {
+			return err
+		}
+		if err = b.Put(keyPageTitle, []byte(pageTitle)); err != nil {
+			return err
+		}
+		return nil
+	})
+}
+
+// closeDB is just a wrapper around db.Close() in order to keep all database
+// management in one file
+func closeDB() {
+	db.Close()
+}
diff --git a/main.go b/main.go
@@ -0,0 +1,20 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+)
+
+func main() {
+	// TODO: Use getopt package instead of flags?
+	port := flag.Int("p", 8080, "Port")
+	dbFile := flag.String("d", "sermoni.db", "Database file")
+	//password := flag.String("w", "", "Password for the web interface")
+	flag.Parse()
+	if err := initDB(*dbFile); err != nil {
+		log.Fatal(err)
+	}
+	defer closeDB()
+	fmt.Printf("Server running on port %v", *port)
+}