在Koyeb运行Selenium Chrome时遇SessionNotCreatedException错误求助

我有一个Python爬虫脚本，通过Selenium访问网站抓取数据，对比本地文本文件检测内容变更，有差异时向指定邮箱发送通知。脚本在Macbook Pro M3Pro（Silicon）本地运行正常，最初用Firefox开发，在Koyeb部署失败后换成Chrome，两种浏览器在本地均能正常运行，但在Koyeb上始终无法启动Chrome，报错如下：

Traceback (most recent call last):
  File "/workspace/main.py", line 84, in <module>
    latestNews=getLatestNews()
               ^^^^^^^^^^^^^^^
  File "/workspace/main.py", line 55, in getLatestNews
    driver = webdriver.Chrome(options=chrome_options) 
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/.heroku/python/lib/python3.12/site-packages/selenium/webdriver/chrome/webdriver.py", line 45, in __init__
    super().__init__(
  File "/app/.heroku/python/lib/python3.12/site-packages/selenium/webdriver/chromium/webdriver.py", line 66, in __init__
    super().__init__(command_executor=executor, options=options)
  File "/app/.heroku/python/lib/python3.12/site-packages/selenium/webdriver/remote/webdriver.py", line 212, in __init__
    self.start_session(capabilities)
  File "/app/.heroku/python/lib/python3.12/site-packages/selenium/webdriver/remote/webdriver.py", line 299, in start_session
    response = self.execute(Command.NEW_SESSION, caps)["value"]
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/.heroku/python/lib/python3.12/site-packages/selenium/webdriver/remote/webdriver.py", line 354, in execute
    self.error_handler.check_response(response)
  File "/app/.heroku/python/lib/python3.12/site-packages/selenium/webdriver/remote/errorhandler.py", line 229, in check_response
    raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.SessionNotCreatedException: Message: session not created: Chrome failed to start: exited normally.
  (session not created: DevToolsActivePort file doesn't exist)
  (The process started from chrome location /app/.cache/selenium/chrome/linux64/127.0.6533.119/chrome is no longer running, so ChromeDriver is assuming that Chrome has crashed.)
Stacktrace:
#0 0x562e0a5f96ca <unknown>
#1 0x562e0a2ca600 <unknown>
#2 0x562e0a302485 <unknown>
#3 0x562e0a2fe2f8 <unknown>
#4 0x562e0a348ce8 <unknown>
#5 0x562e0a33c643 <unknown>
#6 0x562e0a30cd31 <unknown>
#7 0x562e0a30d79e <unknown>
#8 0x562e0a5c125b <unknown>
#9 0x562e0a5c51f2 <unknown>
#10 0x562e0a5ae615 <unknown>
#11 0x562e0a5c5d82 <unknown>
#12 0x562e0a59325f <unknown>
#13 0x562e0a5e8e68 <unknown>
#14 0x562e0a5e9040 <unknown>
#15 0x562e0a5f849c <unknown>
#16 0x7fdcb0bd5609 start_thread

我的代码文件 #

main.py

import smtplib
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart
import time
from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.common.action_chains import ActionChains
from selenium.webdriver.support import expected_conditions
from selenium.webdriver.support.wait import WebDriverWait
from selenium.webdriver.common.keys import Keys
from selenium.webdriver.common.desired_capabilities import DesiredCapabilities
from selenium.webdriver.chrome.options import Options
import os
os.environ['MOZ_HEADLESS'] = '1'

def send_email(subject, body, to_email):

    smtp_server = "smtp.zoho.eu"
    smtp_port = 587
    from_email = "<mail>"  
    password = "<password>" 

    # Create the email
    msg = MIMEMultipart()
    msg['From'] = from_email
    msg['To'] = to_email
    msg['Subject'] = subject

    # Attach the email body
    msg.attach(MIMEText(body, 'plain'))

    try:
        # Set up the server
        server = smtplib.SMTP(smtp_server, smtp_port)
        server.starttls()  # Upgrade the connection to a secure encrypted SSL/TLS connection
        server.login(from_email, password)

        # Send the email
        server.sendmail(from_email, to_email, msg.as_string())
        print("Email sent successfully to: "+to_email+" !")

    except Exception as e:
        print(f"Failed to send email: {e}")

    finally:
        server.quit()  # Close the connection to the server

def getLatestNews():
    
    # Start Selenium
    chrome_options = Options()
    chrome_options.add_argument("--headless")
    chrome_options.add_argument("--no-sandbox")
    chrome_options.add_argument("--disable-dev-shm-usage")
    driver = webdriver.Chrome(options=chrome_options) 
    driver.implicitly_wait(6)
    driver.get("<LINK>")
    if((driver.find_element(By.XPATH, "//li[4]/a").text)=="Select Language TR\nTR"):
        driver.find_element(By.XPATH, "//li[4]/a").click()
        driver.find_element(By.XPATH, "//div[2]/div[8]/a").click()
        
    # Get the data from Web 
    latestNews = (driver.find_element(By.XPATH, "//div[3]/div[2]/div/a").text) + " " + (driver.find_element(By.XPATH, "//span[2]").text)+ " " + (driver.find_element(By.XPATH, "//div[2]/div/span").text) + " " + (driver.find_element(By.XPATH, "//div[2]/span").text)
    print(latestNews)
    driver.close()
    return latestNews
    
def is_changed(latestNews):
    f = open("latestNews.txt", "r")
    if(f.read()!=latestNews):
        f = open("latestNews.txt", "w")
        f.write(latestNews)
        f.close()
        return True
    f.close()
    return False
    
def mailDelivery(latestNews):
    mailList= ["mail@gmail.com","example@gmail.com","test@gmail.com","test@gmail.com","othertest@gmail.com"]
    for i in mailList:
        send_email("Topic", "Some text\n\n"+latestNews, i)
    
while(True):
    latestNews=getLatestNews()
    if (is_changed(latestNews)):
        mailDelivery(latestNews)
    else:
        print("No difference")
    time.sleep(3600)

requirements.txt

selenium

Procfile

web: python main.py

补充说明：使用Koyeb免费套餐，仅提供低性能CPU和512MB内存，已查阅大量StackOverflow方案但未解决，也未找到Koyeb上运行Selenium的相关案例。

针对Koyeb的容器环境限制（尤其是内存）和Chrome启动失败的问题，按以下步骤修改：

1. 添加系统依赖文件 #

创建apt.txt文件，安装Chrome运行所需的系统库：

chromium-browser
chromium-chromedriver
libnss3-dev
libgconf-2-4
libxss1
libappindicator1
libasound2
libatk1.0-0
libc6
libcairo2
libcups2
libdbus-1-3
libexpat1
libfontconfig1
libgcc1
libgdk-pixbuf2.0-0
libglib2.0-0
libgtk-3-0
libnspr4
libpango-1.0-0
libpangocairo-1.0-0
libstdc++6
libx11-6
libx11-xcb1
libxcb1
libxcomposite1
libxcursor1
libxdamage1
libxext6
libxfixes3
libxi6
libxrandr2
libxrender1
libxss1
libxtst6
ca-certificates
fonts-liberation
libappindicator3-1
libnss3
lsb-release
xdg-utils

2. 优化Chrome启动参数 #

修改getLatestNews()函数中的Chrome配置，适配低内存环境：

def getLatestNews():
    # Start Selenium
    chrome_options = Options()
    # 新版无头模式，更稳定
    chrome_options.add_argument("--headless=new")
    chrome_options.add_argument("--no-sandbox")
    chrome_options.add_argument("--disable-dev-shm-usage")
    # 内存优化参数
    chrome_options.add_argument("--disable-gpu")
    chrome_options.add_argument("--disable-extensions")
    chrome_options.add_argument("--disable-images")  # 禁用图片节省内存
    chrome_options.add_argument("--blink-settings=imagesEnabled=false")
    chrome_options.add_argument("--window-size=1920,1080")
    chrome_options.add_argument("--single-process")  # 单进程减少内存占用
    chrome_options.add_argument("--disable-application-cache")
    chrome_options.add_argument("--disable-background-networking")
    chrome_options.add_argument("--disable-default-apps")
    chrome_options.add_argument("--disable-translate")
    chrome_options.add_argument("--disable-popup-blocking")
    chrome_options.add_argument("--disable-logging")
    chrome_options.add_argument("--log-level=3")
    chrome_options.add_argument("--silent")
    
    # 指定系统安装的Chromium路径，避免版本兼容问题
    chrome_options.binary_location = "/usr/bin/chromium-browser"
    
    driver = webdriver.Chrome(options=chrome_options) 
    driver.implicitly_wait(3)  # 缩短等待时间
    driver.get("<LINK>")
    # ... 后续代码不变
    
    # 替换driver.close()为driver.quit()，彻底释放资源
    driver.quit()
    return latestNews

3. 修改Procfile为Worker进程 #

Koyeb默认将web进程当作HTTP服务检测端口，脚本是后台任务，无需端口监听，修改Procfile：

worker: python main.py

4. 优化文件读写逻辑 #

修复is_changed()函数的资源泄漏问题，处理文件不存在的情况：

def is_changed(latestNews):
    target_content = latestNews.strip()
    try:
        with open("latestNews.txt", "r") as f:
            current_content = f.read().strip()
    except FileNotFoundError:
        # 文件不存在则创建并写入
        with open("latestNews.txt", "w") as f:
            f.write(target_content)
        return True
    
    if current_content != target_content:
        with open("latestNews.txt", "w") as f:
            f.write(target_content)
        return True
    return False

5. 升级requirements.txt，管理驱动版本 #

添加webdriver-manager自动匹配ChromeDriver版本：

selenium==4.15.0
webdriver-manager==4.0.1

修改driver初始化代码：

from webdriver_manager.chrome import ChromeDriverManager
from selenium.webdriver.chrome.service import Service

# ... 在getLatestNews里
driver = webdriver.Chrome(
    service=Service(ChromeDriverManager().install()),
    options=chrome_options
)

内容的提问来源于stack exchange，提问作者Tiwo