connecting to a remote server and downloading and extracting binary tar file using python

Question

I would like to connect to a remote server, download and extract binary tar file into a specific directory on that host. I am using python 2.6.8

1. What would be a simple way to ssh to that server?

2. I see the below errors on my script to download the tar file and extract it

   Traceback (most recent call last): File "./wgetscript.py", line 16, in tar = tarfile.open(file_tmp) File "/usr/lib64/python2.6/tarfile.py", line 1653, in open return func(name, "r", fileobj, **kwargs) File "/usr/lib64/python2.6/tarfile.py", line 1715, in gzopen fileobj = bltn_open(name, mode + "b") TypeError: coercing to Unicode: need string or buffer, tuple found

#!/usr/bin/env python

import os
import tarfile
import urllib

url = 'http://**************/Lintel/Mongodb/mongodb-linux-x86_64-enterprise-suse12-3.2.6.tgz'

fullfilename = os.path.join('/tmp/demo1','file.tgz')
file_tmp = urllib.urlretrieve(url,fullfilename)
print file_tmp
base_name = os.path.basename(url)
print base_name
file_name, file_extension = os.path.splitext(base_name)
print file_name, file_extension
tar = tarfile.open(file_tmp)
nameoffile = os.path.join('/tmp/demo1','file')
tar.extractall(file_name,nameoffile)
tar.close()

Answer 1

There are 2 errors here:

• urllib.urlretrieve (or urllib.requests.urlretrieve in Python 3) returns a tuple: filename, httprequest. You have to unpack the result in 2 values (or in the original fullfilename)
• download is OK but the tarfile module doesn't work the way to think it works: tar.extractall takes 2 arguments: path of the .tar/.tgz file and optional list of members (that you can get with tar.getmembers() in your case). For this example, I propose that we drop that filter and extract all the contents in the temp directory.

Fixed code:

url = 'http://**************/Lintel/Mongodb/mongodb-linux-x86_64-enterprise-suse12-3.2.6.tgz'
temp_dir = '/tmp/demo1'

fullfilename = os.path.join(temp_dir,'file.tgz')
# urllib.request in Python 3
file_tmp,http_message = urllib.urlretrieve(url,fullfilename)
base_name = os.path.basename(url)
file_name, file_extension = os.path.splitext(base_name)
tar = tarfile.open(file_tmp)

#print(tar.getmembers()[0:5])  # would print 5 first members of the archive

tar.extractall(os.path.join(temp_dir,file_name))
tar.close()