User-level command shell change for accessing remote machine with paramiko - bash

I use some code connecting with remote machine with use of paramiko library. The connection is established over tunnelling ssh connection bound to one of the localhost ports. The default shell on the remote machine is tcsh, but my code requires it to run bash. I have tested the sshing some simple commands and it works fine.
$ ssh localhost -p 2222 'echo $0'
tcsh
To change the login shell I have added to my .tcshrc file following two lines:
setenv SHELL /bin/bash
exec /bin/bash --login
The following thing works:
$ ssh localhost -p 2222
[user#remote ~]$ echo $0
/bin/bash
But not the following:
$ ssh localhost -p 2222 'echo $0'
which gives no response. The same for the connections with paramiko established by the code I want to use.
At the moment I am limited only to user-level solutions and would rather not play with the paramiko-using-code itself. Is there anything else I could try here?

Related

needrestart behaves differently when run by ansible instead of a manual ssh connection

I am trying to run the needrestart tool by ansible to check for processes with outdated libraries.
When I run needstart with the command or shell modules from ansible it says that I need to restart my ssh daemon. When I run needrestart manually it says that there are no processes with outdated libraries.
When I restart the ssh daemon it does not make a difference. But after rebooting the remote server the ssh daemon is not listed as a service I should restart anymore.
So I really do not understand the difference between the ssh connection from ansible and my manual ssh connection that causes the different behavior of needrestart.
Any help would be appreciated!
Thank you in advance and best regards
Max
My local machine
$ python -V
Python 2.7.13
$ ansible --version
ansible 2.2.0.0
$ cat ansible.cfg
[defaults]
inventory = hosts
ask_vault_pass = True
retry_files_enabled = False
I am using a ssh proxy to connect to the server:
ansible_ssh_common_args='-o ProxyCommand="ssh -W %h:%p -q user#jumphost.example.com"'
The remote server
$ cat /etc/debian_version
8.6
$ python -V
Python 2.7.9
Using ansible
$ ansible example.com -m command -a 'needrestart -b -l -r l'
Vault password:
example.com | SUCCESS | rc=0 >>
NEEDRESTART-VER: 1.2
NEEDRESTART-SVC: ssh.service
$ ansible example.com -m shell -a 'needrestart -b -l -r l'
Vault password:
example.com | SUCCESS | rc=0 >>
NEEDRESTART-VER: 1.2
NEEDRESTART-SVC: ssh.service
Using SSH
$ ssh example.com 'needrestart -b -l -r l'
NEEDRESTART-VER: 1.2
Killed by signal 1.
It looks like you have an active connection with older version of ssh process. When ssh restarts it does not terminate current copies which keeps active connections. If it would do this, than ssh servers sudo service ssh restart would kill active connection and you'll have a broken server.
So, when you do systemctl restart sshd, you restart only ssh-part, which accepts new connection. All existing connections are served by old ssh.
Why do ansible keep ssh old ssh connection between runs? Because of the ControlMaster feature. It keeps active ssh connection between runs to speed up new runs.
What to do? Close active ssh connections on your machine. Try ps aux|grep ssh and you'll see a process which serves as ControlMaster. Kill it, and outdated connection should be closed.

In Linux, How do you automatically run commands with custom parameters you feed it on SSH login?

This question:
https://superuser.com/questions/355029/linux-how-to-automatically-run-commands-on-ssh-login#355030
Only tells me how to run static commands. What it does not tell me is how I can feed it parameters. So say for example, I would like something like this to happen:
$ ssh boat#programming.com -p 2222 --parameter1 "boat programming"
Last login: Sat Dec 10 03:59:37 2016 from some place
boat programming
# .bashrc executes something like this:
echo $parameter1
If I have to use a language like expect, fine, but ideally I would like to keep this straightforward and simple.
Save this short script (on your remote system) with name run in a directory which is part of your $PATH variable (on your remote system) and make it executable.
#!/bin/bash
echo "$2"
Use it this way:
ssh boat#programming.com -p 2222 run --parameter1 "'boat programming'"
Output:
boat programming
The way, in theory, to do this is to put parameter1 in your environment, and let the remote process inherit it from ssh.
$ parameter1="boat programming" ssh boat#programming.com -p 2222
In practice, this probably will not work, because it requires the remote sshd agent to be running with the PermitUserEnvironment option enable, which is not true by default.
The only way to force this would be to run bash explicitly on the remote host with the appropriate environment.
$ ssh boat#programming.com -p 2222 'parameter1="boat programming" bash -i'
Here is my working solution:
0) If you want to automate password entry (Completely optional):
sudo apt install sshpass
1) SSH into your server, and create a file called run
#!/bin/bash
echo $parameter1
2) Make it executable
chmod +x run
3) Handle the parameters like this (Concatenate these lines.):
Avoid manual input of the password. (Be Careful!)
sshpass -p "$YOURPASSWORD"
Standard SSH login
ssh -o StrictHostKeyChecking=no boat#programming.com -p 2222
Parameters must go first. Use single quotes within double quotes otherwise day will be returned as an unknown command error:
parameter1="'happy day'"
Give an absolute path to the program you wrote.
/path/to/run
Alltogether:
sshpass -p "$YOURPASSWORD" ssh -o StrictHostKeyChecking=no boat#programming.com -p 2222 parameter1="'happy day'" /path/to/run

Transfer a file to remote machine(ubuntu) while running bash remotely

I have written a bash script which I should run on the remote server(ubuntu) with GUI(zenity) interface and I will issue below command on the local machine.
sshpass -p $PASS ssh root#$SERVER 'bash' < /tmp/dep.sh | tee >(zenity --progress --title "Tomcat Deployer" --text "Connecting to Tomcat Server..." --width=400 --height=150) >>/tmp/temp.log;
I want to transfer a file from my local machine to server and I want to achieve this placing an enter in bash file(/tmp/dep.sh) in the above command itself without opening a new session on server.
I prefer below command to transfer the file to server and I should place this in the bash script(/tmp/dep.sh) and it should run on server to copy the file from my local machine. I don't want to specify my local ip as a variable and use as source in the blow command as the script is used on other machines too and thus ip changes. And I should not transfer the file from my local to server writing a separate rsync & ssh creating one more ssh session.
rsync --rsh="sshpass -p '$PASS' ssh" '$local:$APPATH/$app.war' /tmp
Anybody can do any magic to transfer the file from local to server with the above connected ssh session with the help of above rsync or by other means and without opening new separate connection?
Thank you!
Edit 1:
Could this be achieved with single ssh session(single command)?:
rsync --rsh="sshpass -p serverpass ssh -o StrictHostKeyChecking=no" /home/user1/Desktop/app.war root#192.168.1.5:/tmp;
sshpass -p serverpass ssh -o StrictHostKeyChecking=no root#192.168.1.5 '/etc/init.d/tomcat start'
You'll want to use SSH multiplexing. This is done using the ControlMaster and ControlPath options. Here's an article on it.

bash script to ssh into a box and get me to a python shell

I want to write a script that will get me straight to a python shell on another box so that i don't have to first run ssh and second run python.
When I do "ssh hostname python" it just hangs - it's something to do with the fact that python is interactive. "ssh hostname cat x" works fine.
Is there some ssh option that will make this work?
ssh -t user#host python
The -t flag forces ssh to allocate a pseudo-terminal to the connection. Normally it won't do this if a command is given on the ssh command line, which results in python running in a non-interactive mode.
actually figured it out, i needed to do ssh -t hostname python
You need the -t option to force the allocation of a pseudo-tty
ssh -t host python

How to use SSH to run a local shell script on a remote machine?

I have to run a local shell script (windows/Linux) on a remote machine.
I have SSH configured on both machine A and B. My script is on machine A which will run some of my code on a remote machine, machine B.
The local and remote computers can be either Windows or Unix based system.
Is there a way to run do this using plink/ssh?
If Machine A is a Windows box, you can use Plink (part of PuTTY) with the -m parameter, and it will execute the local script on the remote server.
plink root#MachineB -m local_script.sh
If Machine A is a Unix-based system, you can use:
ssh root#MachineB 'bash -s' < local_script.sh
You shouldn't have to copy the script to the remote server to run it.
This is an old question, and Jason's answer works fine, but I would like to add this:
ssh user#host <<'ENDSSH'
#commands to run on remote host
ENDSSH
This can also be used with su and commands which require user input. (note the ' escaped heredoc)
Since this answer keeps getting bits of traffic, I would add even more info to this wonderful use of heredoc:
You can nest commands with this syntax, and that's the only way nesting seems to work (in a sane way)
ssh user#host <<'ENDSSH'
#commands to run on remote host
ssh user#host2 <<'END2'
# Another bunch of commands on another host
wall <<'ENDWALL'
Error: Out of cheese
ENDWALL
ftp ftp.example.com <<'ENDFTP'
test
test
ls
ENDFTP
END2
ENDSSH
You can actually have a conversation with some services like telnet, ftp, etc. But remember that heredoc just sends the stdin as text, it doesn't wait for response between lines
I just found out that you can indent the insides with tabs if you use <<-END!
ssh user#host <<-'ENDSSH'
#commands to run on remote host
ssh user#host2 <<-'END2'
# Another bunch of commands on another host
wall <<-'ENDWALL'
Error: Out of cheese
ENDWALL
ftp ftp.example.com <<-'ENDFTP'
test
test
ls
ENDFTP
END2
ENDSSH
(I think this should work)
Also see
http://tldp.org/LDP/abs/html/here-docs.html
Also, don't forget to escape variables if you want to pick them up from the destination host.
This has caught me out in the past.
For example:
user#host> ssh user2#host2 "echo \$HOME"
prints out /home/user2
while
user#host> ssh user2#host2 "echo $HOME"
prints out /home/user
Another example:
user#host> ssh user2#host2 "echo hello world | awk '{print \$1}'"
prints out "hello" correctly.
This is an extension to YarekT's answer to combine inline remote commands with passing ENV variables from the local machine to the remote host so you can parameterize your scripts on the remote side:
ssh user#host ARG1=$ARG1 ARG2=$ARG2 'bash -s' <<'ENDSSH'
# commands to run on remote host
echo $ARG1 $ARG2
ENDSSH
I found this exceptionally helpful by keeping it all in one script so it's very readable and maintainable.
Why this works. ssh supports the following syntax:
ssh user#host remote_command
In bash we can specify environment variables to define prior to running a command on a single line like so:
ENV_VAR_1='value1' ENV_VAR_2='value2' bash -c 'echo $ENV_VAR_1 $ENV_VAR_2'
That makes it easy to define variables prior to running a command. In this case echo is our command we're running. Everything before echo defines environment variables.
So we combine those two features and YarekT's answer to get:
ssh user#host ARG1=$ARG1 ARG2=$ARG2 'bash -s' <<'ENDSSH'...
In this case we are setting ARG1 and ARG2 to local values. Sending everything after user#host as the remote_command. When the remote machine executes the command ARG1 and ARG2 are set the local values, thanks to local command line evaluation, which defines environment variables on the remote server, then executes the bash -s command using those variables. Voila.
<hostA_shell_prompt>$ ssh user#hostB "ls -la"
That will prompt you for password, unless you have copied your hostA user's public key to the authorized_keys file on the home of user .ssh's directory. That will allow for passwordless authentication (if accepted as an auth method on the ssh server's configuration)
I've started using Fabric for more sophisticated operations. Fabric requires Python and a couple of other dependencies, but only on the client machine. The server need only be a ssh server. I find this tool to be much more powerful than shell scripts handed off to SSH, and well worth the trouble of getting set up (particularly if you enjoy programming in Python). Fabric handles running scripts on multiple hosts (or hosts of certain roles), helps facilitate idempotent operations (such as adding a line to a config script, but not if it's already there), and allows construction of more complex logic (such as the Python language can provide).
cat ./script.sh | ssh <user>#<host>
chmod +x script.sh
ssh -i key-file root#111.222.3.444 < ./script.sh
Try running ssh user#remote sh ./script.unx.
Assuming you mean you want to do this automatically from a "local" machine, without manually logging into the "remote" machine, you should look into a TCL extension known as Expect, it is designed precisely for this sort of situation. I've also provided a link to a script for logging-in/interacting via SSH.
https://www.nist.gov/services-resources/software/expect
http://bash.cyberciti.biz/security/expect-ssh-login-script/
ssh user#hostname ". ~/.bashrc;/cd path-to-file/;. filename.sh"
highly recommended to source the environment file(.bashrc/.bashprofile/.profile). before running something in remote host because target and source hosts environment variables may be deffer.
I use this one to run a shell script on a remote machine (tested on /bin/bash):
ssh deploy#host . /home/deploy/path/to/script.sh
if you wanna execute command like this
temp=`ls -a`
echo $temp
command in `` will cause errors.
below command will solve this problem
ssh user#host '''
temp=`ls -a`
echo $temp
'''
If the script is short and is meant to be embedded inside your script and you are running under bash shell and also bash shell is available on the remote side, you may use declare to transfer local context to remote. Define variables and functions containing the state that will be transferred to the remote. Define a function that will be executed on the remote side. Then inside a here document read by bash -s you can use declare -p to transfer the variable values and use declare -f to transfer function definitions to the remote.
Because declare takes care of the quoting and will be parsed by the remote bash, the variables are properly quoted and functions are properly transferred. You may just write the script locally, usually I do one long function with the work I need to do on the remote side. The context has to be hand-picked, but the following method is "good enough" for any short scripts and is safe - should properly handle all corner cases.
somevar="spaces or other special characters"
somevar2="!##$%^"
another_func() {
mkdir -p "$1"
}
work() {
another_func "$somevar"
touch "$somevar"/"$somevar2"
}
ssh user#server 'bash -s' <<EOT
$(declare -p somevar somevar2) # transfer variables values
$(declare -f work another_func) # transfer function definitions
work # call the function
EOT
The answer here (https://stackoverflow.com/a/2732991/4752883) works great if
you're trying to run a script on a remote linux machine using plink or ssh.
It will work if the script has multiple lines on linux.
**However, if you are trying to run a batch script located on a local
linux/windows machine and your remote machine is Windows, and it consists
of multiple lines using **
plink root#MachineB -m local_script.bat
wont work.
Only the first line of the script will be executed. This is probably a
limitation of plink.
Solution 1:
To run a multiline batch script (especially if it's relatively simple,
consisting of a few lines):
If your original batch script is as follows
cd C:\Users\ipython_user\Desktop
python filename.py
you can combine the lines together using the "&&" separator as follows in your
local_script.bat file:
https://stackoverflow.com/a/8055390/4752883:
cd C:\Users\ipython_user\Desktop && python filename.py
After this change, you can then run the script as pointed out here by
#JasonR.Coombs: https://stackoverflow.com/a/2732991/4752883 with:
`plink root#MachineB -m local_script.bat`
Solution 2:
If your batch script is relatively complicated, it may be better to use a batch
script which encapsulates the plink command as well as follows as pointed out
here by #Martin https://stackoverflow.com/a/32196999/4752883:
rem Open tunnel in the background
start plink.exe -ssh [username]#[hostname] -L 3307:127.0.0.1:3306 -i "[SSH
key]" -N
rem Wait a second to let Plink establish the tunnel
timeout /t 1
rem Run the task using the tunnel
"C:\Program Files\R\R-3.2.1\bin\x64\R.exe" CMD BATCH qidash.R
rem Kill the tunnel
taskkill /im plink.exe
This bash script does ssh into a target remote machine, and run some command in the remote machine, do not forget to install expect before running it (on mac brew install expect )
#!/usr/bin/expect
set username "enterusenamehere"
set password "enterpasswordhere"
set hosts "enteripaddressofhosthere"
spawn ssh $username#$hosts
expect "$username#$hosts's password:"
send -- "$password\n"
expect "$"
send -- "somecommand on target remote machine here\n"
sleep 5
expect "$"
send -- "exit\n"
You can use runoverssh:
sudo apt install runoverssh
runoverssh -s localscript.sh user host1 host2 host3...
-s runs a local script remotely
Useful flags:
-g use a global password for all hosts (single password prompt)
-n use SSH instead of sshpass, useful for public-key authentication
If it's one script it's fine with the above solution.
I would set up Ansible to do the Job. It works in the same way (Ansible uses ssh to execute the scripts on the remote machine for both Unix or Windows).
It will be more structured and maintainable.
It is unclear if the local script uses locally set variables, functions, or aliases.
If it does this should work:
myscript.sh:
#!/bin/bash
myalias $myvar
myfunction $myvar
It uses $myvar, myfunction, and myalias. Let us assume they is set locally and not on the remote machine.
Make a bash function that contains the script:
eval "myfun() { `cat myscript.sh`; }"
Set variable, function, and alias:
myvar=works
alias myalias='echo This alias'
myfunction() { echo This function "$#"; }
And "export" myfun, myfunction, myvar, and myalias to server using env_parallel from GNU Parallel:
env_parallel -S server -N0 --nonall myfun ::: dummy
Extending answer from #cglotr. In order to write inline command use printf, it useful for simple command and it support multiline using char escaping '\n'
example :
printf "cd /to/path/your/remote/machine/log \n tail -n 100 Server.log" | ssh <user>#<host> 'bash -s'
See don't forget to add bash -s
I created a solution that works better for me by combining the use of a heredoc from Yarek T's answer with the piped cat method from cglotr's answer along with some other tricks for non-interactive login (using sshpass), using variables from the local and remote host in the script, and enabling sudo commands. The code is longer just because it includes some additional tricks that are likely desired, but the original questioner didn't ask for them.
The problem I have with Yarek's answer is that all the warnings and commands in the heredoc print to the screen. The problem I have with cglotr's answer is that is requires a script file and a complex command with additional interaction to execute the script. With my solution, I write a script that does everything by simply calling the script with the remote host IP address as the first argument like this:
./MYSCRIPT REMOTE_IP_ADDRESS
The script to be run on the remote host is saved to a variable within the script on the local host using a heredoc so that you don't need to do any quote escaping. Then, the variable containing the script is echo piped to sshpass. Be sure to indent the commands with tabs and not spaces (you'll get spaces instead of tabs when you copy the code). Here is an example of the remote script within the local script.
!/bin/bash
# Input argument 1 should be the target host IP address (required)
RX_IP="/(\b25[0-5]|\b2[0-4][0-9]|\b[01]?[0-9][0-9]?)(\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}/"
IS_IP=$(echo $1 | sed -nr "${RX_IP}p" | wc -l)
if (( $IS_IP )); then
USERNAME=remoteuser
HOSTNAME=$1
# Export the SSH password to environment variable for sshpass and sudo.
# The space before the command prevents saving the command to history.
export SSHPASS=mypassword;
while read -r -d '' SCRIPT <<-EOS
# Enable sudo commands with the following command.
# The space before echo prevents saving the command to history.
echo $SSHPASS | sudo -Sv
# Do stuff here. Escape variables to be be accessed on the remote host.
# For example, escape print variable in an awk command:
# This command lists all USB block device partitions.
ls -l /dev /dev/mapper | awk '/^b/ && /sd[a-z][1-9]/ {print \$10}'
exit
EOS
echo "$SCRIPT" | sshpass -e ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null ${USERNAME}#${HOSTNAME} &>/dev/null
echo 'DONE'
else
echo "Missing IP address of target host."
echo "Usage: ./SCRIPT_NAME IP_ADDRESS
fi
You need to install sshpass on the local host like this (for Debian based distros).
sudo apt install sshpass
There is another approach ,you can copy your script in your host with scp command then execute it easily .
First, copy the script over to Machine B using scp
[user#machineA]$ scp /path/to/script user#machineB:/home/user/path
Then, just run the script
[user#machineA]$ ssh user#machineB "/home/user/path/script"
This will work if you have given executable permission to the script.

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