database: switching from mysql to sqlite

Currently we only need the db to keep track of the files that were
already downloaded, thus we only use one database and only one table.
A complete sql database is a bit too bulky for this purpose.
By using sqlite we can minimize and embed the db.

README.md

@@ -56,21 +56,20 @@ Run `python3 run.py -h` for a help menu and see which ones are important for you
 #### Environment-variables
 
 Set the following variables with the -e tag.
-| Name | Usage | Default |
-| ---- |------ | ------- |
-| `USER` | username on the studip server | `admin` |
-| `PSWD` | password on the studip server | `admin` |
-| `URL` | url of the studip server | `admin` |
-| `HOST` | ip of the mysql instance to connect | `mysql` |
-| `DB_USER` | username of the mysql instance to connect | `root` |
-| `DB_PSWD` | password of the mysql instance to connect | `root` |
-| `INTERVAl` | update interval in seconds | `86400` |
+
+| Name       | Usage                         | Default |
+| ---------- | ----------------------------- | ------- |
+| `USER`     | username on the studip server | `admin` |
+| `PSWD`     | password on the studip server | `admin` |
+| `URL`      | url of the studip server      | `admin` |
+| `INTERVAl` | update interval in seconds    | `86400` |
 
 #### Volumes
 
 Set the following volumes with the -v tag.
-| Volume-Name | Container mount | Description |
-| ----------- | --------------- | ----------------------------------- |
+
+| Volume-Name   | Container mount    | Description                               |
+| ------------- | ------------------ | ----------------------------------------- |
 | `studip_data` | `/studip/src/data` | directory for studip files to be saved to |
 
 #### docker-compose.yml

docker-compose.yml

@@ -8,24 +8,9 @@ services:
             PSWD: 'pswd'
             URL: 'https://url.tld'
             INTERVAL: 86400
-            HOST: 'mysql'
-            DB_USER: root
-            DB_PSWD: 'pswddb'
         volumes:
             - studip:/studip/data
-        depends_on:
-            - mysql
-
-    mysql:
-        image: mysql:5.6
-        restart: unless-stopped
-        environment:
-            MYSQL_ROOT_PASSWORD: 'pswddb'
-        volumes:
-            - mysql:/var/lib/mysql
 
 volumes:
     studip:
         driver: local
-    mysql:
-        driver: local

docker-entry.sh

@@ -1,3 +1,3 @@
-#!/bin/bash
+#!/bin/sh
 
-while true; do python /studip/run.py -o /studip/data -u $USER -p $PSWD -s $URL --db_user $DB_USER --db_passwd $DB_PSWD --host $HOST && sleep $INTERVAL; done
+while true; do python /studip/run.py -o /studip/data -u $USER -p $PSWD -s $URL && sleep $INTERVAL; done

src/mysql.py → src/database.py

@@ -1,41 +1,30 @@
 import time
 import logging as log
+import os
 
-import pymysql
+import pysqlite3
 
 
 class Database:
 
-    def __init__(self, host, port, name, user, passwd, reset_dl):
-        self.HOST = host
-        self.PORT = port
-        self.NAME = name
-        self.USER = user
-        self.PASSWD = passwd
+    def __init__(self, reset_dl):
         self.RESET_DL = reset_dl
         self.TABLE_FILE = 'files'
+        self.DB_DIR = os.path.dirname(os.path.realpath(__file__))
         self.setup_db()
 
     def connect(self):
-        """Connect to an existing database instance based on the object attributes.
+        """Connect to an existing database instance based on the object
+        attributes.
         """
-        return pymysql.connect(
-            host=self.HOST,
-            port=self.PORT,
-            user=self.USER,
-            password=self.PASSWD,
-            charset='utf8mb4',
-            cursorclass=pymysql.cursors.DictCursor
-        )
+        path = os.path.join(self.DB_DIR, "data.db")
+        return pysqlite3.connect(path)
 
     def setup_db(self):
-        """Creates a database with tables.
-        """
+        """Creates a database with tables."""
+        log.info("check database")
         db = self.connect()
         crs = db.cursor()
-        sql_query = "CREATE DATABASE IF NOT EXISTS " + self.NAME
-        crs.execute(sql_query)
-        db.select_db(self.NAME)
         query = "CREATE TABLE IF NOT EXISTS " + self.TABLE_FILE + \
             "(id CHAR(32) NOT NULL," + \
             "ch_date INT(11) NOT NULL," + \
@@ -51,12 +40,11 @@ class Database:
         time(int): time the file was downloaded
         """
         db = self.connect()
-        db.select_db(self.NAME)
         crs = db.cursor()
         log.debug('file: ' + file_id + ' time: ' + time)
         query = "INSERT INTO " + self.TABLE_FILE + "(`id`,`ch_date`)" + \
                 "VALUES ('" + file_id + "','" + time + "')" + \
-                "ON DUPLICATE KEY UPDATE `ch_date` = '" + time + "'"
+                "ON CONFLICT(`id`) DO UPDATE SET `ch_date` = '" + time + "'"
         crs.execute(query)
         db.commit()
 
@@ -72,11 +60,10 @@ class Database:
         if self.RESET_DL:
             return None
         db = self.connect()
-        db.select_db(self.NAME)
         crs = db.cursor()
         query = "SELECT ch_date FROM files WHERE id ='" + file_id + "'"
         crs.execute(query)
         res = crs.fetchone()
         if res != None:
-            return res['ch_date']
+            return res[0]
         return None

src/requirements.txt

@@ -1,3 +1,2 @@
-tqdm==4.46.1
-requests==2.23.0
-PyMySQL==0.9.3
+pysqlite3==0.4.3
+requests==2.24.0

src/run.py

@@ -6,7 +6,7 @@ import logging as log
 
 from studip import Studip
 from crawler import Crawler
-from mysql import Database
+from database import Database
 
 
 parser = argparse.ArgumentParser(description='Download Files from StudIP.')
@@ -21,14 +21,6 @@ parser.add_argument('--chunk', type=int, default=1024 *
                     1024, help='chunksize for downloading data')
 parser.add_argument('-r', '--reset_dl_date', action='store_true',
                     help='downloads everything and ignores last download date')
-parser.add_argument('--host', type=str, default='localhost', help='mysql host')
-parser.add_argument('--port', type=int, default=3306, help='mysql port')
-parser.add_argument('--db_name', type=str, default='studip',
-                    help='mysql database name')
-parser.add_argument('--db_user', type=str, default='root',
-                    help='mysql database user')
-parser.add_argument('--db_passwd', type=str,
-                    default='secret-pw', help='mysql database password')
 parser.add_argument('-d', '--debug_output', action='store_true',
                     help='display debug information about the process')
 parser.add_argument('-q', '--quiet', action='store_true',
@@ -53,8 +45,7 @@ BASE_DIR = os.path.abspath(args.output)
 USERNAME = args.user
 PASSWORD = args.passwd
 
-db = Database(args.host, args.port, args.db_name,
-              args.db_user, args.db_passwd, args.reset_dl_date)
+db = Database(args.reset_dl_date)
 
 studip = Studip(args.chunk, args.url, (USERNAME, PASSWORD), db)
 

src/studip.py

@@ -146,13 +146,10 @@ class Studip:
         last_dl = self.db.get_last_file_dl(doc)
         if last_dl == None or last_dl < doc_chdate:
             rsp2 = self.auth_req('/api.php/file/' + doc + '/download')
-            #total_size = int(rsp2.headers.get('content-length', 0))
             log.info('downloading ' + doc_name)
-            #progbar = tqdm(total=total_size, unit='iB', unit_scale=True)
             try:
                 with open(doc_name, 'wb') as doc_file:
                     for chunk in rsp2.iter_content(self.CHUNK_SIZE):
-                        #progbar.update(len(chunk))
                         doc_file.write(chunk)
                 self.db.set_last_file_dl(str(doc), str(int(time.time())))
             except OSError:
@@ -172,7 +169,7 @@ class Studip:
         try:
             subdirs = rsp.json()['subfolders']
         except ValueError:
-            return res_docs
+            return res_subdirs
         for subdir in subdirs:
             try:
                 sub_id = subdir['id']