Scrapyd 改进第二步: Web Interface 添加 STOP 和 START 超链接, 一键调用 Scrapyd API

0.提出问题

Scrapyd 提供的开始和结束项目的API如下，参考 Scrapyd 改进第一步: Web Interface 添加 charset=UTF-8, 避免查看 log 出现中文乱码，准备继续在页面上进一步添加 START 和 STOP 超链接。

http://scrapyd.readthedocs.io/en/stable/api.html#schedule-json

Example request:

$ curl http://localhost:6800/schedule.json -d project=myproject -d spider=somespider

Example response:

{"status": "ok", "jobid": "6487ec79947edab326d6db28a2d86511e8247444"}

http://scrapyd.readthedocs.io/en/stable/api.html#cancel-json

Example request:

$ curl http://localhost:6800/cancel.json -d project=myproject -d job=6487ec79947edab326d6db28a2d86511e8247444

Example response:

{"status": "ok", "prevstate": "running"}

1.解决思路

尝试直接通过浏览器地址栏 GET 请求页面 http://localhost:6800/schedule.json?project=myproject&spider=somespider

返回提示需要使用 POST 请求

{"node_name": "pi-desktop", "status": "error", "message": "Expected one of [b'HEAD', b'object', b'POST']"}

那就继续通过 URL 查询对传参，通过 JS 发起 POST 异步请求吧

2.修改 Scrapyd 代码

/site-packages/scrapyd/website.py

改动位置：

(1) table 添加最后两列，分别用于 UTF-8 和 STOP/START 超链接，见红色代码

    def render(self, txrequest):
        cols = 10 ######## 8
        s = "<html><head><meta charset='UTF-8'><title>Scrapyd</title></head>"
        s += "<body>"
        s += "<h1>Jobs</h1>"
        s += "<p><a href='..'>Go back</a></p>"
        s += "<table border='1'>"
        s += "<tr><th>Project</th><th>Spider</th><th>Job</th><th>PID</th><th>Start</th><th>Runtime</th><th>Finish</th><th>Log</th>"
        if self.local_items:
            s += "<th>Items</th>"
            #cols = 9 ########
            cols += 1 ########

(2) 有两处需要添加 UTF-8 超链接，分别对应 Running 和 Finished，见红色代码

前面 Running 部分添加 UTF-8 超链接后继续添加 STOP 超链接，见蓝色代码

            s += "<td><a href='/logs/%s/%s/%s.log'>Log</a></td>" % (p.project, p.spider, p.job)
            s += "<td><a href='/logs/UTF-8.html?project=%s&spider=%s&job=%s' target='_blank'>UTF-8</a></td>" % (p.project, p.spider, p.job) ########
            s += "<td><a href='/logs/scrapyd.html?opt=cancel&project=%s&job_or_spider=%s' target='_blank'>STOP</a></td>" % (p.project, p.job) ########

后面 Finished 部分添加 UTF-8 超链接后继续添加 START 超链接，见蓝色代码

            s += "<td><a href='/logs/%s/%s/%s.log'>Log</a></td>" % (p.project, p.spider, p.job)
            s += "<td><a href='/logs/UTF-8.html?project=%s&spider=%s&job=%s' target='_blank'>UTF-8</a></td>" % (p.project, p.spider, p.job) ########
            s += "<td><a href='/logs/scrapyd.html?opt=schedule&project=%s&job_or_spider=%s' target='_blank'>START</a></td>" % (p.project, p.spider) ########

(3) 完整代码

from datetime import datetime

import socket

from twisted.web import resource, static
from twisted.application.service import IServiceCollection

from scrapy.utils.misc import load_object

from .interfaces import IPoller, IEggStorage, ISpiderScheduler

from six.moves.urllib.parse import urlparse

class Root(resource.Resource):

    def __init__(self, config, app):
        resource.Resource.__init__(self)
        self.debug = config.getboolean('debug', False)
        self.runner = config.get('runner')
        logsdir = config.get('logs_dir')
        itemsdir = config.get('items_dir')
        local_items = itemsdir and (urlparse(itemsdir).scheme.lower() in ['', 'file'])
        self.app = app
        self.nodename = config.get('node_name', socket.gethostname())
        self.putChild(b'', Home(self, local_items))
        if logsdir:
            self.putChild(b'logs', static.File(logsdir.encode('ascii', 'ignore'), 'text/plain'))
        if local_items:
            self.putChild(b'items', static.File(itemsdir, 'text/plain'))
        self.putChild(b'jobs', Jobs(self, local_items))
        services = config.items('services', ())
        for servName, servClsName in services:
          servCls = load_object(servClsName)
          self.putChild(servName.encode('utf-8'), servCls(self))
        self.update_projects()

    def update_projects(self):
        self.poller.update_projects()
        self.scheduler.update_projects()

    @property
    def launcher(self):
        app = IServiceCollection(self.app, self.app)
        return app.getServiceNamed('launcher')

    @property
    def scheduler(self):
        return self.app.getComponent(ISpiderScheduler)

    @property
    def eggstorage(self):
        return self.app.getComponent(IEggStorage)

    @property
    def poller(self):
        return self.app.getComponent(IPoller)


class Home(resource.Resource):

    def __init__(self, root, local_items):
        resource.Resource.__init__(self)
        self.root = root
        self.local_items = local_items

    def render_GET(self, txrequest):
        vars = {
            'projects': ', '.join(self.root.scheduler.list_projects())
        }
        s = """
<html>
<head><meta charset='UTF-8'><title>Scrapyd</title></head>
<body>
<h1>Scrapyd</h1>
<p>Available projects: <b>%(projects)s</b></p>
<ul>
<li><a href="/jobs">Jobs</a></li>
""" % vars
        if self.local_items:
            s += '<li><a href="/items/">Items</a></li>'
        s += """
<li><a href="/logs/">Logs</a></li>
<li><a href="http://scrapyd.readthedocs.org/en/latest/">Documentation</a></li>
</ul>

<h2>How to schedule a spider?</h2>

<p>To schedule a spider you need to use the API (this web UI is only for
monitoring)</p>

<p>Example using <a href="http://curl.haxx.se/">curl</a>:</p>
<p><code>curl http://localhost:6800/schedule.json -d project=default -d spider=somespider</code></p>

<p>For more information about the API, see the <a href="http://scrapyd.readthedocs.org/en/latest/">Scrapyd documentation</a></p>
</body>
</html>
""" % vars
        return s.encode('utf-8')

class Jobs(resource.Resource):

    def __init__(self, root, local_items):
        resource.Resource.__init__(self)
        self.root = root
        self.local_items = local_items

    def render(self, txrequest):
        cols = 10 ######## 8
        s = "<html><head><meta charset='UTF-8'><title>Scrapyd</title></head>"
        s += "<body>"
        s += "<h1>Jobs</h1>"
        s += "<p><a href='..'>Go back</a></p>"
        s += "<table border='1'>"
        s += "<tr><th>Project</th><th>Spider</th><th>Job</th><th>PID</th><th>Start</th><th>Runtime</th><th>Finish</th><th>Log</th>"
        if self.local_items:
            s += "<th>Items</th>"
            #cols = 9 ########
            cols += 1 ########
        s += "</tr>"
        s += "<tr><th colspan='%s' style='background-color: #ddd'>Pending</th></tr>" % cols
        for project, queue in self.root.poller.queues.items():
            for m in queue.list():
                s += "<tr>"
                s += "<td>%s</td>" % project
                s += "<td>%s</td>" % str(m['name'])
                s += "<td>%s</td>" % str(m['_job'])
                s += "</tr>"
        s += "<tr><th colspan='%s' style='background-color: #ddd'>Running</th></tr>" % cols
        for p in self.root.launcher.processes.values():
            s += "<tr>"
            for a in ['project', 'spider', 'job', 'pid']:
                s += "<td>%s</td>" % getattr(p, a)
            s += "<td>%s</td>" % p.start_time.replace(microsecond=0)
            s += "<td>%s</td>" % (datetime.now().replace(microsecond=0) - p.start_time.replace(microsecond=0))
            s += "<td></td>"
            s += "<td><a href='/logs/%s/%s/%s.log'>Log</a></td>" % (p.project, p.spider, p.job)
            s += "<td><a href='/logs/UTF-8.html?project=%s&spider=%s&job=%s' target='_blank'>UTF-8</a></td>" % (p.project, p.spider, p.job) ########
            s += "<td><a href='/logs/scrapyd.html?opt=cancel&project=%s&job_or_spider=%s' target='_blank'>STOP</a></td>" % (p.project, p.job) ########
            if self.local_items:
                s += "<td><a href='/items/%s/%s/%s.jl'>Items</a></td>" % (p.project, p.spider, p.job)
            s += "</tr>"
        s += "<tr><th colspan='%s' style='background-color: #ddd'>Finished</th></tr>" % cols
        for p in self.root.launcher.finished:
            s += "<tr>"
            for a in ['project', 'spider', 'job']:
                s += "<td>%s</td>" % getattr(p, a)
            s += "<td></td>"
            s += "<td>%s</td>" % p.start_time.replace(microsecond=0)
            s += "<td>%s</td>" % (p.end_time.replace(microsecond=0) - p.start_time.replace(microsecond=0))
            s += "<td>%s</td>" % p.end_time.replace(microsecond=0)
            s += "<td><a href='/logs/%s/%s/%s.log'>Log</a></td>" % (p.project, p.spider, p.job)
            s += "<td><a href='/logs/UTF-8.html?project=%s&spider=%s&job=%s' target='_blank'>UTF-8</a></td>" % (p.project, p.spider, p.job) ########
            s += "<td><a href='/logs/scrapyd.html?opt=schedule&project=%s&job_or_spider=%s' target='_blank'>START</a></td>" % (p.project, p.spider) ########
            if self.local_items:
                s += "<td><a href='/items/%s/%s/%s.jl'>Items</a></td>" % (p.project, p.spider, p.job)
            s += "</tr>"
        s += "</table>"
        s += "</body>"
        s += "</html>"

        txrequest.setHeader('Content-Type', 'text/html; charset=utf-8')
        txrequest.setHeader('Content-Length', len(s))

        return s.encode('utf-8')

/site-packages/scrapyd/website.py

3.新建 scrapyd.html

根据 http://scrapyd.readthedocs.io/en/stable/config.html 确定 Scrapyd 所使用的 logs_dir，在该目录下添加如下文件

<html>
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>scrapyd</title>
</head>

<body>
<p>仅用于内网环境下执行 scrapyd API</p>
<div id="result"></div>

<script>
function parseQueryString(url) {
    var urlParams = {};
    url.replace(
        new RegExp("([^?=&]+)(=([^&]*))?", "g"),
        function($0, $1, $2, $3) {
            urlParams[$1] = $3;
        }
    );
    return urlParams;
}

function curl(opt, project, job_or_spider) {
    console.log(opt);
    console.log(project);
    console.log(job_or_spider);    
    var formdata = new FormData();
    formdata.append('project', project);
    if(opt == 'cancel') {
        formdata.append('job', job_or_spider);
    } else {
        formdata.append('spider', job_or_spider);
    }

    var req = new XMLHttpRequest();
    req.onreadystatechange = function() {
        if (this.readyState == 4) {
            if (this.status == 200) {
                document.querySelector('#result').innerHTML = this.responseText;
            } else {
                alert('status code: ' + this.status);
            }
        } else {
            document.querySelector('#result').innerHTML = this.readyState;
        }
    };
    req.open('post', window.location.protocol+'//'+window.location.host+'/'+opt+'.json', Async = true);    req.send(formdata);
}

var kwargs = parseQueryString(location.search);
if (kwargs.opt == 'cancel' || kwargs.opt == 'schedule') {
    curl(kwargs.opt, kwargs.project, kwargs.job_or_spider);          
} 
</script>
</body>
</html>