Using fabric 2.4 and trying to set up ssh keys to remotely connect to various linux servers?
Python is new to me, I've followed example on this site and Read python doc but still unclear to me.
Currently running python on windows and my script is able to connect to remote linux servers because i have connection string defined as follows:
ssh_connect = Connection(host='servername', user='user1', connect_kwargs={'password': 'blahblah'})
I am running python script from my window server and instead of defining the connection string, I would like it to use ssh key. I have the id_rsa.pub file from the linux server. I would like to setup up on my windows box and have the script use that for connections?
You can always just pass a key via Fabric through it's command line arguments. This is definitely kind of a vague question, especially since it's running fabric on Windows, which to my knowledge is not technically supported by them, though it does work.
fab -i /Path/to/key
Source: fab --help and the official documentation here
Related
I have an Ubuntu instance on Google Cloud Platform (GCP). I want to use it as an HTTP server to access files. I simply use this python command, type it in bash:
python3 -m http.server 8000
This will run http.server module as a script, construct a simple HTTP server and listen at port 8000.
Problem is that, since I use GCP instance, I must connect to it remotely (for example I use SSH shell provided by GCP). When I close the SSH shell, the python HTTP server will stop. So what should I do to make sure that the server still runs after I close the shell?
I did searched on Google, and I tried to use
nohup python3 -m http.server 8000 &
This command, I quote, will run the instruction as a background program and persist running after exiting bash. But it seems that this doesn't work for my situation.
Anybody can help?
Try the screen command. I think it's easier to use and also more flexible than nohup as you can also reattach processes after detaching then. See this answer for details.
The http.server module is not meant to be a full-fledged webserver.
You'll want to set up something like Apache instead, see Running a basic Apache web server.
I have a pretty simple task: using ssh, I want to create a tunnel that forwards traffic from my local machine to a specific port on a remote machine. I can do this from the command line:
ssh -N -L 123:127.0.0.1:456 user#remotehost
Then if I run:
telnet localhost 123
it's the equivalent of logging into remotehost and running
telnet 127.0.0.1 456
I've managed to do this with something along the lines of;
subprocess.Popen(['ssh', '-N', '-L', '%i:127.0.0.1:%i' % (new_port, old_port), ssh_user + '#' + ip_addr])
But now I want to move away from that and use only Python - no external processes.
I've tried using fabric.context_managers.remote_tunnel but unless I've misunderstood this is meant for creating a tunnel that starts at a remote location, not from the local machine. That is, it is the equivalent of SSHing into a remote machine and creating an SSH tunnel from there, which is silly for my purpose. I suppose I could set the remote host to actually be the local machine but this seems inefficient and honestly I don't even understand how to do that.
I've also tried forward.py on paramiko and it doesn't work because my private key is encrypted. I'd like to modify the script to handle that, and also just simplify it for my needs, but both the script and the paramiko library are daunting and I don't know how to begin.
Surely there's an easy way to do this? I seem to be so close yet so far.
What do you mean by "pure Python"? Subprocess is bundled with standard python installation.
Subprocess and Fabric are designed for such tasks, why would you want to move away from them?
If you have, minimal tasks to be performed remotely e.g. check memory, hostname, etc. you can go ahead with suprocess. However if you have some big requirements, I would suggest going with fabric.
For your purpose where you have to work on the same machine, why not use subprocess with check_call or Popen. As an alternative, you can change your code altogether so as to be able to get into Unix core to achieve what the Linux commands do.
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("~") ).
I've been using Paramiko today to work with a Python SSH connection, and it is useful.
However one thing I'd really like to be able to do over the SSH is to utilise some Pythonic sugar. As far as I can tell I can only use the inbuilt Paramiko functions, and if I want to anything using Python on the remote side I would need to use a script which I have placed on there, and call it.
Is there a way I can send Python commands over the SSH connection rather than having to make do only with the limitations of the Paramiko SSH connection? Since I am running the SSH connection through Paramiko within a Python script, it would only seem right that I could, but I can't see a way to do so.
RPyC could be what you're looking for. It gives you access to another machine's Python environment directly from the local script.
>>> import rpyc
>>> conn = rpyc.classic.connect("someremotehost.com")
>>> conn.modules.sys.path
['D:\\projects\\rpyc\\servers', 'd:\\projects', .....]
To establish a connection over SSL or SSH, see:
http://rpyc.sourceforge.net/docs/secure-connection.html#ssl
Well, that is what SSH created for - to be a secure shell, and the commands are executed on the remote machine (you can think of it as if you were sitting at a remote computer itself, and that either doesn't mean you can execute Python commands in a shell, though you're physically interact with a machine).
You can't send Python commands simply because Python do not have commands, it executes Python scripts.
So everything you can do is a "thing" that will make next steps:
Wrap a piece of Python code into file.
scp it to the remote machine.
Execute it there.
Remove the script (or cache it for further execution).
Basically shell commands are remote machine's programs themselves, so you can think of those scripts like shell extensions (python programs with command-line parameters, e.g.).
I'm using this tool to set up a ssh server on Windows. I'm trying to open the standard Python shell through a remote ssh connection but I simply can't get it to work. If I type 'python' in my ssh command line nothing happens, it just seems to wait for more input. My server machine however, shows a new python process running after I do this.
Running scripts works fine, though.
Do I need to use another Python shell, some other ssh server, some different configs?
Thanks
My guess is that Python is not recognising the stdin on the SSH shell as a terminal. I don't know why that would be.
However, try running "python -i" to overcome it.
The problem is probably that you're running the Windows Python executable, which expects a Windows console environment to run in, over a channel which doesn't support the features of Windows console. You might find Andy Koppe's conin to be useful.