IOError：[Errno 2]使用绝对路径，linux上没有这样的文件或目录

Question

我很难找到解决这个问题的办法。我使用的绝对路径绝对存在于文件系统中。在同一个脚本中使用相同的精确路径时，

if host.file(logPath).exists:
    print("Exists: " + logPath)

我得到了

Exists: /var/opt/jws/jws3.0/v7/testinfra_node1/logs/catalina.out

但在尝试时：

with open(logPath, "rt") as log:

我得到了：

>               with open(logPath, "rt") as log:
E               IOError: [Errno 2] No such file or directory: '/var/opt/jws/jws3.0/v7/testinfra_node1/logs/catalina.out'

下面是整个代码(这是一个用于测试JWT安装的testinfra脚本)：

import pytest
import testinfra
import time
import os

@pytest.mark.parametrize("jws_version", [("3.0")])

def test_server_recycle(host, jws_version):
    instances = host.check_output("cat /var/opt/jws/jws" + jws_version + "/init/init_instances | grep -oP '(\/.*?\/)((?:[^\/]|\\\\/)+?)(?:(?<!\\\\)\s|$)'")
last = ""
for last in iter(instances.splitlines()):
    pass
last = last.strip().encode('ascii','ignore')
print(last)

instanceName = ""
for instanceName in iter(last.split("/")):
    pass
print(instanceName)

binPath = last + "/bin/"
logDir = last + "/logs/"
logPath = os.path.join(logDir, "catalina.out")
print(logPath)

runningAt0 = isInstanceRunning(host, instanceName)
if host.file(logPath).exists:
    print("Exists: " + logPath)

if (runningAt0):
    with host.sudo():
        host.run(os.path.join(binPath, "shutdown.sh"))    
        with open(logPath, "rt") as log:
            result = waitForEntry(log, "INFO  org.apache.catalina.core.StandardService- Stopping service Catalina","ERROR")
        assert not result.eq("ERROR")
        assert not isInstanceRunning(host, instanceName)
        host.run(os.path.join(binPath, "/bin/startup.sh"))
        with open(logPath, "rt") as log:
            result = waitForEntry(log, "INFO  org.apache.catalina.startup.Catalina- Server startup in","ERROR")
        assert not result.eq("ERROR")
        assert isInstanceRunning(host, instanceName)
else:
    with host.sudo():
        host.run(os.path.join(binPath, "startup.sh"))
        with open(logPath, "rt") as log:
            result = waitForEntry(log, "INFO  org.apache.catalina.core.StandardService- Stopping service Catalina","ERROR")
        assert not result.eq("ERROR")
        assert isInstanceRunning(host, instanceName)
        host.run(os.path.join(binPath, "shutdown.sh"))
        with open(logPath, "rt") as log:
            result = waitForEntry(log, "INFO  org.apache.catalina.startup.Catalina- Server startup in","ERROR")
        assert not result.eq("ERROR")
        assert not isInstanceRunning(host, instanceName)

def isInstanceRunning(host, instanceName):
    processes = host.check_output("ps auwwx | grep catalina.startup.Bootstrap")
    if  "-Dtomcat.inst.name=" + instanceName in processes:
        return True
    else:
        return False

def waitForEntry(file, entry1, entry2):
    while 1:
        file.seek(0,2)
        line = file.readline()
        if entry1 in line:
            return entry1
        else:
            if entry2 in line:
                return entry2
            else:
                time.sleep(0.1)

而不是

host.file(logPath).exists

我也一直在努力

print(host.check_output("cat " + logPath))

它很好地打印了文件内容。

对如何处理这件事有什么想法吗？事先非常感谢！

编辑:下面是我执行脚本的方式：

py.test -v -host=user@host tomcat_test_recycle.py --sudo

Answer 1

testinfra包似乎将测试远程服务器的状态集成到pytest中。因此

host.file(logPath).exists

和

host.check_output("cat " + logPath)

正在检查远程服务器上的存在和内容，而

open(logPath, "rb") 

在本地机器上运行。文件不在本地机器上，而是在host上。