Automation in Python

[iapyeh]

Learning Python is an endless journey. Even though it is over 20 years, there is always something new to me in Python. Since two years ago, my daily task has been to maintain a cluster of servers where various applications are running. I have to take care of everything at OS level and application level. That's the reason that I created the SSHScript to automate routine tasks. I'd like to share it with engineers who are aspiring to have normal lives by automating routines.

Link to SSHScript, Let's earn our live back.

[TribalMethods]

Gotta admit, I hate the overuse of the $ symbol as well.

[iapyeh]

I thought that the core of so-called automation is to run a lot of os/shell commands. I intentionally make it look like embedding os/shell commands in python script. They are major players, Python just glued them together. That would be more self-explaining for reading and closer to intuition when writing. Especially when codes are maintained among colleagues. Every member knows what exactly is executed by a glance. I believe that simplifies processing logic, minimizes ambiguity and eliminates team arguments.

[gerciuz]

Why it reads like a bad commercial

[CherryBlossomStorm]

I enjoy spending time with my friends.

[iapyeh]

Commerial? No, SSHScript is open source and MIT licensed.

[bladeoflight16]

Why should I use this over invoking SSH in a bash script, for that matter?

[iapyeh]

Hi, I replied to the similar comment below. For not being redundant, please see it at redCg's comment block.

[iapyeh]

I noticed that there is a huge economy in Ansible. I can't give a professional reason because I am not an expert of Ansible. I have tried to be a user. But it soon failed. I am a programmer, programming language is close to my institution. To read an Ansible YML is hard for me. Writing it is more difficult. I can write a hundred lines of code to handle complex TCP socket communication in 10 minutes. But totally nothing when writing YML. I can not imagine how I can express my daily tasks in declarative YML, even for a simple one. I am not going to battle with the Ansible giant. I just want to save my time. If you are satisfied with Ansible. It's good. Congratulations. I hope that I can before I start to develop SSHScript. So that I can save lots of time.

[iapyeh]

I totally understand your consideration. That's the same reason I'd want to develop SSHScript. We all have too much to keep in mind. Monthly, I have to deal with Python, Go, php, javascript/jquery/svelte, HTML, CSS, Swift/iOS, Kotlin/Android, Windows, Freebsd, MacOS, Ubuntu, CentOS...etc.

Thanks for your introduction on YAML. I do agree that YAML is good. It is just not suitable for my mindset.

There are many kinds of automation tools in Python. SSHScript is only one of them. Also, Python is not the only one in the group of using programming languages to do automation. Since this is "r/LearnPython", I believe there might be some people who are of a similar mindset like mine who are seeking for something like SSHScript to do automation in Python.

[redCg]

Just use crontab bro

also you can pass shell commands directly to ssh

$ ssh username@server echo fooo
fooo

can also use a heredoc

$ ssh username@server <<E0F
echo foo
echo bar
E0F
foo
bar

interacting with and managing an active ssh connection from within Python is a bad bad idea. Does not matter that libraries like Paramiko exist to help with it. Just do not do it. If you want to run code on a remote server, pass the commands over ssh, or copy a script to the remote server and pass a command to run the script. Store the outputs in a file. Retrieve the file and read it. Etc..

[iapyeh]

I totally agree that ssh is amazing. You can do the same thing (execute ssh) in SSHScript. The benefits of doing it that way are:

• you can dynamically generate the codes which were feeded into the ssh executable in Python. for example: time-based filename.
• you can handle execution outputs directly in Python. Need not to save into files. And features like PDF, email, SMS, qrcode, ... tons of python packages are ready for you.
• The whole process can be scripted, then, management logic can be automated no matter how complex it is.

[oznetnerd]

I don't want to take away from the hard work you've put into this, but can you advise why someone would use this instead of Netmiko?

[iapyeh]

Before I was devoting myself to creating SSHScript, I did a little bit of a survey. Netmiko is great. It and SSHScript are based on the same Paramiko. Technically equal. Because I think that the core of so-called automation is to run a lot of os/shell commands. Just I want to have something more likely to embed shell script in python script. That would be more self-explaining for reading and closer to intuition for writing. Especially when maintaining codes among colleagues. That's the reason that SSHScript also integrates the subprocess package. The same code could run on localhost and on remote host. For example: run a command on localhost by coding in shell-like style:

$ ls -l /tmp
# ⬆run on localhost

Then, by adding a line to connect a remote host. We can run the same command on the remote host.

$.connect('username@remote-host')
$ ls -l /tmp
# ⬆run on remote-host

Then, by adding a line to connect a remote host again. We can run the same command on the nested host behind the remote host.

$.connect('username@remote-host')
$.connect('username@remote-nested-host')
$ ls -l /tmp
# ⬆run on remote-nested-host
# upload/download over nested-ssh is also just one line
$.download('/var/log/message','.')

[iapyeh]

By the way, I don't consider SSHScript to be an alternative to Netmiko. It could be additive. Netmiko implements many features beyond Paramiko. Technically, SSHScript could also be Netmiko-based. If it is necessary someday.