Cannot write a script to "svn export" in Python - python

I would like to write a script that will tell another server to SVN export a SVN repository.
This is my python script:
import os
# svn export to crawlers
for s in ['work1.main','work2.main']:
cmd = 'ssh %s "cd /home/zes/ ; svn --force export svn+ssh://174.113.224.177/home/svn/dragon-repos"' % s
print cmd
os.system(cmd)
Very simple. It will ssh into work1.main, then cd to a correct directory. Then call SVN export command.
However, when I run this script...
$ python export_to_crawlers.py
ssh work1.main "cd /home/zes/ ; svn --force export svn+ssh://174.113.224.177/home/svn/dragon-repos"
Permission denied, please try again.
Permission denied, please try again.
Permission denied (publickey,gssapi-with-mic,password).
svn: Connection closed unexpectedly
ssh work2.main "cd /home/zes/ ; svn --force export svn+ssh://174.113.224.177/home/svn/dragon-repos"
Host key verification failed.
svn: Connection closed unexpectedly
Why do I get this error and cannot export the directory? I can manually type the commands in the command line and it will work. Why can't it work in the script?
If I change to this...it will not work. and instead, nothing will happen.
cmd = 'ssh %s "cd /home/zes/ ;"' % s

This is a problem with SSH.
Permission denied, please try again.
This means that ssh can't login. Either your ssh agent doesn't have the correct key loaded, you're running the script as a different user or the environment isn't passed on correctly. Check that the variables SSH_AUTH_SOCK and SSH_AGENT_PID are passed to the subprocess of your python script.
Host key verification failed.
This error means that the remote host isn't known to ssh. This means that the host key is not found in the file $HOME/.ssh/known_hosts. Again, make sure that you're checking the home directory of the effective user of the script.
[EDIT] When you run the script, then python will become the "input" of ssh: ssh is no longer connected to a console and will ask python for the password to login. Since python has no idea what ssh wants, it ignores the request. ssh tries three times and dies.
To solve it, run these commands before you run the Python script:
eval $(ssh-agent)
ssh-add path-to-your-private-key
Replace path-to-your-private-key with the path to your private key (the one which you use to login). ssh-add will ask for your password and the ssh-agent will save it in a secure place. It will also modify your environment. So when SSH runs the next time, it will notice that an ssh agent is running and ask it first. Since the ssh-agent knows the password, ssh will login without bothering Python.
To solve the second issue, run the second ssh command manually once. ssh will then add the second host to its files and won't ask again.
[EDIT2] See this howto for a detailed explanation how to login on a remote server via ssh with your private key.

I guess that it is related to ssh. Are you using a public key to automatically connect. I think that your shell knows this key but it is not the case of python.
I am not sure but it's just an idea. I hope it helps

Check out the pxssh module that is part of the pyexpect project:
https://pexpect.readthedocs.org/en/latest/api/pxssh.html
It simplifies dealing with automating ssh-ing into machines.

Related

Running a python script which uses paramiko to ssh into other server and perform db refresh from jenkins

I have a python script that does some Database operations from an ec2 server by SSHing into another server using paramiko. The script runs fine when I run it directly from the server as ec2-user but when I run the same from Jenkins I get a permission error on /home/ec2-user/.ssh/id_rsa file.
used python3.8 /home/ec2-user/db_refresh.py command to run the script from Jenkins
After some reading and with the help of whomai command, I found that's expected since Jenkins runs the scripts as Jenkins user and no one part from the owner has permissions to read private keys in ~/.ssh/ folder.
I could change the permission so that everyone can read ec2-user's private key but I think that would be a terrible idea(As far as I've read) and I think ssh wouldn't even work if anyone apart from the owner has read permission to that private key(I remember reading it somewhere but not sure)
sshcon = paramiko.SSHClient()
sshcon.connect(MYSQL_HOST, username=SSH_USERNAME, key_filename='/home/ec2-user/.ssh/id_rsa')
That is how SSH into my database server using paramiko.
Can I run my scripts from jenkins as ec2-user or is there some other way that I can overcome this.
In the end, it turned to be quite simple(stupid me)
I just created a key pair for Jenkins user and used it for doing my operations.
One thing to note is since jenkins is service account normal su jenkins won't work. I had to do this sudo su -s /bin/bash jenkins.

Creating a directory from one server to the next

I am using Python to create a directory remotely from one server to the next. My code entails:
executedString = "sudo ssh -i mykey.pem server_ip %s" % (name_of_directory)
os.popen(executedString)
I also tried os.system() but that didn't work. The funny thing is that, when I run this through the terminal it works. However, when I executed it from my Python script, it doesn't.
I ensured that all the files were owned by the same user group and that didn't help.
Please note that I am also running this via CGI which is where code does not get executed even though the rest of the code works otherwise.
Please advise.
I realized it was an authentication key host issue when printed out all the logs of the ssh activity. The solution to this problem was that I copied the ~/.ssh to /root directory.
I can only presume that either the key was not present in root or it was looking for auth key in root since only root can run the group/user owned by www-data.
It appears your executing a shell to a UNIX host via a PIPE. I'm thinking your command line should be the following:
executedString = "sudo ssh -i mykey.pem server_ip **mkdir** %s" % (directory_name)

Remote environment variable from file with Fabric

I am trying to just do a simple echo $MYVAR on a remote server with Fabric.
The environment variable is in my ~/.bashrc file on the remote host.
I have tried:
run("source /home/<myusername>/.bashrc && echo $MYVAR")
This just prints an empty string. Running it when logged in on the remote machine prints "5", the value in the bashrc file. Does anyone know why this would be?
I need the environment variable to be set from a file on the remote host, and not decided by Fabric.
I am running the ssh commands as <myusername>, so the username seems correct. This seems like a duplicate of this question, except that maybe they were running things as the wrong user. I also tried the shell argument to run, with no luck.
I haven't tried the various context manager-ish things, as they just seem to be a shorthand for command1 && command2.
First, as explained in the answer you link to, fabric uses a login shell, not and interactive shell, meaning your ~/.bahsrc is not going to be source'd on the remote. You should export your variable in your ~/.bash_profile or ~/.profile.
Without the relevant content of your remote ~/.bashrc it's impossible to tell why your command fails.

SSH to a server and exit Python script (in the same shell)

I'm running a script that's determining login information for me, and in the end is outputting the login information that I need to use.
I am running the script in a terminal, and now I want it to SSH me with the credentials it has, exit the Python script on my computer and connect my current terminal to the new server.
Say I already have my sshHost, sshUser and sshPass as variables in the script. How do I run an SSH command in the current terminal and connect to that server?
I tried subprocess and spur, however I didn't really manage to get that going.
I would really appreciate your help and thanks in advance.
assuming the python prints the settings to stdout;
#!/bin/sh
export $(credentials.py)
exec ssh hostname

How to run git fetch over ssh in a windows subprocess

I've got some code which needs to grab code from github periodically (on a Windows machine).
When I do pulls manually, I use GitBash, and I've got ssh keys running for the repos I check so everything is fine. However when I try to run the same actions in a python subprocess I don't have the ssh services which GitBash provides and I'm unable to authenticate to the repo.
How should I proceed from here. I can think of a couple of different options:
I could revert to using https:// fetches. This is problematic because the repos I'm fetching use 2-factor authentication and are going to be running unattended. Is there a way to access an https repo that has 2fa from a command line?
I've tried calling sh.exe with arguments that will fire off ssh-agent and then issuing my commands so that everything is running more or less the way it does in gitBash, but that doesn't seem to work:
"C:\Program Files (x86)\Git\bin\sh.exe" -c "C:/Program\ Files\ \(x86\)/Git/bin/ssh-agent.exe; C:/Program\ Files\ \(x86\)/Git/bin/ssh.exe -t git#github.com"
produces
SSH_AUTH_SOCK=/tmp/ssh-SiVYsy3660/agent.3660; export SSH_AUTH_SOCK;
SSH_AGENT_PID=8292; export SSH_AGENT_PID;
echo Agent pid 8292;
Could not create directory '/.ssh'.
The authenticity of host 'github.com (192.30.252.129)' can't be established.
RSA key fingerprint is XXXXXXXXXXX
Are you sure you want to continue connecting (yes/no)? yes
Failed to add the host to the list of known hosts (/.ssh/known_hosts).
Permission denied (publickey).
Could I use an ssh module in python like paramiko to establish a connection? It looks to me like that's only for ssh'ing into a remote terminal. Is there a way to make it provide an ssh connection that git.exe can use?
So, I'd be grateful if anybody has done this before or has a better alternative
The git bash set the HOME environment variable, which allows git to find the ssh keys (in %HOME%/.ssh)
You need to make sure the python process has or define HOME to the same PATH.
As explained in "Python os.environ[“HOME”] works on idle but not in a script", you need to set HOME to %USERPROFILE% (or, in python, to os.path.expanduser("~") ).

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