Why pypsh instead of dsh?

Because managing group files with dsh is tedious. Pypsh requires no configuration, it just works.

Similar to dsh, pypsh can be used to execute a command on multiple hosts in parallel. In addition it is also possible to copy a file to multiple hosts at once. See below for further usage instructions.

The command or file copy operation will be executed on any host that is in the known_hosts file and matches the given regular expression.

This means in order for pypsh to know about a host it is necessary to connect to it at least once with plain ssh.

Command Execution

To execute a command on a group of hosts matching a given regular expression:

pypsh <hostregex> <cmd-to-execute>

E.g.:

pypsh "role\d+\.customer\.your\.domain" "uptime"

Instead of executing the commands in parallel it is also possible to execute the commands one after another. To do so use:

pypsh "role\d+\.customer\.your\.domain" --interval 0.1 cmd "uptime"

Or to wait between the commands (which might be useful when restarting services like elasticsearch that are part of a cluster):

pypsh "role\d+\.customer\.your\.domain" -i 60 cmd "uptime"

pypsh can also read from stdin. So it is possible to pipe command into it:

echo "uptime" | pypsh "myhosts[0-9]"

Copy file to multiple hosts

To copy a given file to a group of hosts:

pypsh "my\.domains\d+\.com" copy /tmp/here/myfile.txt /tmp/remote/file.txt

Installation

pypsh can be installed using pip:

pip install pypsh

Development

To work on pypsh checkout the git repository, create a virtual environment and install the dependencies:

git clone https://github.com/mfussenegger/pypsh.git
cd pypsh
mkvirtualenv pypsh
pip install -r requirements.txt

Sometimes it is useful to point the pypsh command to the local development branch:

pip install --upgrade --force-reinstall --editable .

But usually it is sufficient to invoke it like this:

python pypsh/main.py ...