概述

flasklet是Flask的封装，它实现了Flask应用程序的模块化开发。有了它，RESTFUL API开发者可以按照固定的开发模式，把相似功能的API封装在一个python package里。比如，我们开发了一个wedb的包，封装了sqlalchemy，并提供RESTFUL API访问路径。要使用flasklet启用该模块，只需要运行如下命令：

 python -m flasklet.flasklet -m '["wedb.restful"]' -c '{"SQLALCHEMY_DATABASE_URI":"mysql+mysqlconnector://52goadmin:************@quanklife.com:3306/52go?charset=utf8","WEDB_ROOT_URL":"/wedb"}'

注意命令选项：
-m选项后面的["wedb.restful"]指定了flasklet要装载的模块列表
-c是应用程序环境配置项，参数的每一项键值对被传入到各个模块中
以上命令告诉flasklet：
-装入wedb.restful模块
-使用mysql+mysqlconnector://52goadmin:************@quanklife.com:3306/52go连接数据库
-/wedb为API的根路径

flasklet源代码

flasklet代码可以用如下命令获取并安装：

git clone ssh://dev@quanklife.com:5010/opt/codes/52go
cd 52go
python setup.py install

flasklet帮助

使用如下命令，可获取帮助：

python -m flasklet.flasklet -h

帮助文本如下：

Usage: flasklet.py [options]

Options:
  -h, --help            show this help message and exit
  -H HOST, --host=HOST  IP address to bind.
  -p PORT, --port=PORT  The listen port.
  -u STATIC_URL_PATH, --static-url-path=STATIC_URL_PATH
                        The static url path
  -f STATIC_FOLDER, --static-folder=STATIC_FOLDER
                        The static folder.
  -t TEMPLATE_FOLDER, --template-folder=TEMPLATE_FOLDER
                        The templates folder.
  --home-page=HOME_PAGE
                        Home page.
  -m MODULE_LIST, --module-list=MODULE_LIST
                        Extended routes.
  -c CONFIG, --config=CONFIG
                        Extended routes.
  -l LOGGING_LEVEL, --logging-level=LOGGING_LEVEL
                        Set logging level.
  -C CONFIG_FILE, --config-file=CONFIG_FILE
                        To specify the config file including all options.
                        To see how to write a config file, please open the
                        flashlet.conf.

-h, --help 获取帮助
-H HOST, --host=HOST 指定绑定的IP地址，缺省为0.0.0.0
-p PORT, --port=PORT 指定http监听的端口
-u STATIC_URL_PATH, --static-url-path=STATIC_URL_PATH 指定静态url路径
-f STATIC_FOLDER, --static-folder=STATIC_FOLDER 指定静态文件夹
-t TEMPLATE_FOLDER, --template-folder=TEMPLATE_FOLDER 指定模板文件夹
--home-page=HOME_PAGE 指定首页
-m MODULE_LIST, --module-list=MODULE_LIST 指定模块列表，格式为'["module1","module2","module3"]'
-c CONFIG, --config=CONFIG 指定Flask运行的环境变量
-l LOGGING_LEVEL, --logging-level=LOGGING_LEVEL 指定日志级别，有DEBUG,INFO,WARNING,CRITICAL
-C CONFIG_FILE, --config-file=CONFIG_FILE 使用配置文件。如果使用配置文件，其他的选项将失效

如下是一个配置文件的例子：

#flasklet.conf
[server]
    host=0.0.0.0
    port=80

[route]
    static_url_path=/static
    static_folder=static
    template_folder=templates
    home_page=index.html

[module]
    wefile=weos.wefile
[app]

[logging]
    level=DEBUG

以上配置文件名为flasklet.conf，flasklet这样运行：

python -m flasklet.flasklet -C flasklet.conf

wefile源代码

以下是wefile.py的源代码。其中，init_flask_app是任何一个为flasklet编写的模块必须提供的函数。init_flask_app函数在flasklet中调用，传入app对象，wefile使用app对象的add_url_rule函数初始化url与函数的路由，这样，就轻松提供一个restful风格的API。

# -*- coding: utf-8 -*-
##
# @file wefile.py
# @brief Implementation of file system for restful call. Http client will call
# list_dir, walk_dir, get_file, put_file, del_file, exists functions with 
# corresponding urls.
# @author Zheng Zuowu/52go
# @version 0.0.2
# @date 2019-12-23

import logging
import os
import json
from flask import request,Response

dir_root = None

##
# @brief To initialize the module for flask app.
#
# @param app The instance of flask.
#
# @return None
def init_flask_app(app):
    rest_root_url = app.config['REST_ROOT_URL']
    logging.debug('rest_root_url=%s'%rest_root_url)
    global dir_root
    dir_root = app.config['DIR_ROOT']
    logging.debug('dir_root=%s'%dir_root)
    app.add_url_rule(rest_root_url+'/list_dir/<path:filepath>', 'list_dir', list_dir)
    app.add_url_rule(rest_root_url+'/list_dir', 'list_dir', list_dir,defaults={'filepath': ''})
    app.add_url_rule(rest_root_url+'/get_file/<path:filepath>', 'get_file', get_file)
    app.add_url_rule(rest_root_url+'/put_file/<path:filepath>', 'put_file', put_file, methods=['POST'])
    app.add_url_rule(rest_root_url+'/del_file/<path:filepath>', 'del_file', del_file)
    app.add_url_rule(rest_root_url+'/exists/<path:filepath>', 'exists', exists)
    
##
# @brief To list dir of the specified path. Http client will get the dir list 
# by passing url 'http[s]://host/weos/list_dir/<path:filepath>'
#
# @return A dict of dir.
def list_dir(filepath):
    path = dir_root + '/' + filepath
    while path.find('//') >=0:
        path = path.replace('//','/')
    
    d_list = os.listdir(path)
    d_dict = {}
    
    for d in d_list:
        if os.path.isdir(path+'/'+d):
            d_dict[d] = {}
        elif os.path.isfile(path+'/'+d):
            d_dict[d] = (path+'/'+d).replace(dir_root, '').replace('//','/')
        
    return json.dumps(d_dict)

##
# @brief For http client to download the specified file with url 'http[s]://host/weos/get_file/<path:filepath>'
#
# @param filepath The relative filepath.
#
# @return The Response object for the file content.
def get_file(filepath):
    path = dir_root +'/'+ filepath
    while path.find('//') >=0:
        path = path.replace('//','/')
    logging.debug('path=%s'%path)
    try:
        fp = open(path, 'rb')
        content = fp.read()
        return Response(content, content_type='application/octet-stream')
    except FileNotFoundError as e:
        logging.critical(e)
        return Response(str(e).replace(dir_root, ''), status=404)
#
# @brief For http client to upload the specified file with url
# 'http[s]://host/weos/put_file/<path:filepath>'
#
# @param filepath The relative filepath.
#
# @return The Response object showing if done or not.

def put_file(filepath):
    path = dir_root +'/'+ filepath
    while path.find('//') >=0:
        path = path.replace('//','/')
    logging.debug('path=%s'%path)
    try:
        if os.path.exists(path):
            return Response('File %s exists'%filepath, status=409)
        
        data = request.get_data()
        fp = open(path, 'wb')
        fp.write(data)
        fp.flush()
        fp.close()
        return Response('File %s uploaded.'%filepath,status=200)
    except Exception as e:
        if os.path.exists(path):
            os.remove(path)
        return Response(str(e).replace(dir_root, ''), status=404)
    
#
# @brief For http client to del the specified file with url
# 'http[s]://host/weos/del_file/<path:filepath>'
#
# @param filepath The relative filepath.
#
# @return The Response object showing if done or not.
def del_file(filepath):
    path = dir_root +'/'+ filepath
    while path.find('//') >=0:
        path = path.replace('//','/')
    logging.debug('path=%s'%path)
    try:
        os.remove(path)
        return Response('File %s deleted.'%filepath,status=200)
    except FileNotFoundError as e:
        return Response(str(e).replace(dir_root, ''), status=404)

#
# @brief For http client to check if the specified file exists with url
# 'http[s]://host/weos/del_file/<path:filepath>'
#
# @param filepath The relative filepath.
#
# @return The Response object showing if it exists or not.
def exists(filepath):
    path = dir_root +'/'+ filepath
    while path.find('//') >=0:
        path = path.replace('//','/')
    logging.debug('path=%s'%path)
    if os.path.exists(path):
        return Response('File %s exists.'%filepath, status=200)
    else:
        return Response('File %s does not exist.'%filepath,status=404)

# EOF