Your 1st Python Hive Bot Deployment

Context

<p dir="auto">This is for beginners.<br /> For when your first Python bot or script for Hive goes to production.<br /> I am not the right guy to post about clean code, but I've learned a few things.<br /> I've made some mistakes and will make more, but maybe I can help you avoid some. <p dir="auto"><img src="https://images.hive.blog/768x0/https://files.peakd.com/file/peakd-hive/felixxx/EorySYrJyMpYZG2zMY4pf5feMJJZ7noKRs8LMyL9LMQ2Fpt4CnuDsvEfMpYoJVSdgHm.png" alt="tipps.png" srcset="https://images.hive.blog/768x0/https://files.peakd.com/file/peakd-hive/felixxx/EorySYrJyMpYZG2zMY4pf5feMJJZ7noKRs8LMyL9LMQ2Fpt4CnuDsvEfMpYoJVSdgHm.png 1x, https://images.hive.blog/1536x0/https://files.peakd.com/file/peakd-hive/felixxx/EorySYrJyMpYZG2zMY4pf5feMJJZ7noKRs8LMyL9LMQ2Fpt4CnuDsvEfMpYoJVSdgHm.png 2x" /> <h2>server ban <p dir="auto">When querying from a public Hive node, that means using https.<br /> The nodes are behind firewalls and other protection.<br /> If you spam queries, you can get banned by these systems.<br /> That's not cool for you and also it's friendlier to just avoid that altogether. <h2>loop <p dir="auto">To infinitely loop a reoccuring job, like a daily compilation of votes or something, <a href="https://en.wikipedia.org/wiki/Cron" target="_blank" rel="noreferrer noopener" title="This link will take you away from hive.blog" class="external_link">cron can be good. Or <a href="https://schedule.readthedocs.io/en/stable/index.html" target="_blank" rel="noreferrer noopener" title="This link will take you away from hive.blog" class="external_link">schedule. But even then: If you have to make a lot of calls at once, maybe better include time.sleep(2). At least don't blindly iterate over pages of results. <h2>3 second loop <p dir="auto">I'll be writing a lot more about calling for a new block every 3 seconds (block stream).<br /> For now: it's pointless to do the query more than once every 3 seconds.<br /> The main loop should idle for the rest of the time. (time.sleep(3 - (time.time() - start_time))) <h2>async vs. threads <p dir="auto">While true: At the end it's just an infinite loop anyways, but <a href="https://docs.python.org/3/library/asyncio-eventloop.html#asyncio.loop.run_forever" target="_blank" rel="noreferrer noopener" title="This link will take you away from hive.blog" class="external_link">asyncio.loop.run_forever looks nicer.<br /> If it's the first time you see co-routines: Don't worry.<br /> Forget about <a href="https://stackoverflow.com/questions/27435284/multiprocessing-vs-multithreading-vs-asyncio" target="_blank" rel="noreferrer noopener" title="This link will take you away from hive.blog" class="external_link">multiprocessing, btw. <h2>signal interrupt <p dir="auto">Using <a href="https://stackoverflow.com/questions/1112343/how-do-i-capture-sigint-in-python" target="_blank" rel="noreferrer noopener" title="This link will take you away from hive.blog" class="external_link">an example, I came up with this: <pre><code>import signal, time user_interrupt = False def interrupt_signal_handler(sig, frame): global user_interrupt user_interrupt = True signal.signal(signal.SIGINT, interrupt_signal_handler) def thing(): print("CTRL + C can't...") time.sleep(1) print("...interrupt me") while user_interrupt == False: thing() <p dir="auto">At least you can break out of the loop somehow cleaner.<br /> <strong>Edit: <blockquote> <p dir="auto">It's more important, when working with threads, and then you should combine it with threading.Events, like in <a href="https://www.youtube.com/watch?v=A97QLHAqNuw" target="_blank" rel="noreferrer noopener" title="This link will take you away from hive.blog" class="external_link">this video <p dir="auto">You can also use signal for <a href="https://runebook.dev/en/articles/python/library/signal/signal.signal" target="_blank" rel="noreferrer noopener" title="This link will take you away from hive.blog" class="external_link">networking and interprocess communication. Powerful. <h2>Linux <p dir="auto">At the end, you'll most likely want to install it all on a server and that's when you'll find that Linux is best for that. At which point you might as well use Linux layer itself to handle task queues and processes, like I already mentioned, when I wrote about cron. And the link, one paragraph above, even demonstrates network sockets. <p dir="auto">That's taking it a bit far though; Most bots can probably live in a single main loop, but keep scalability in mind at least. <p dir="auto">Still ontopic: <a href="https://stackoverflow.com/questions/17544307/how-do-i-run-python-script-using-arguments-in-windows-command-line" target="_blank" rel="noreferrer noopener" title="This link will take you away from hive.blog" class="external_link">terminal arguments could be useful. <h2>Server Security <p dir="auto">Talking about remote servers and their security is not something I should be giving advice about.<br /> Still better than nothing: <strong>login via <a href="https://ubuntu.com/server/docs/openssh-server" target="_blank" rel="noreferrer noopener" title="This link will take you away from hive.blog" class="external_link">ssh, use <a href="https://en.wikipedia.org/wiki/Fail2ban" target="_blank" rel="noreferrer noopener" title="This link will take you away from hive.blog" class="external_link">Fail2Ban and <a href="https://ubuntu.com/server/docs/firewalls" target="_blank" rel="noreferrer noopener" title="This link will take you away from hive.blog" class="external_link">ufw. <h2>Errors <p dir="auto">Here's a good <a href="https://www.youtube.com/watch?v=8kTlzR4HhWo" target="_blank" rel="noreferrer noopener" title="This link will take you away from hive.blog" class="external_link">video on error handling in Python.<br /> In short: don't make errors.<br /> Whether in development or production: if it's a critical error, it should probably crash and you need to fix it. If the error isn't critical, and you can't avoid it, catch and and make it a warning. <h2>Storage <p dir="auto">When your bot crashes, Hive probably keeps running.<br /> When restarting, it can be important to know where it stopped.<br /> Those problems can only be solved by storage and <strong>forget writing your own storage system with file writing and other such experiments.<br /> <a href="https://www.sqlalchemy.org/" target="_blank" rel="noreferrer noopener" title="This link will take you away from hive.blog" class="external_link">SQLAlchemy (especially sessions) can make stuff robust and scalable. And once you understand it, you already have a strong foundation to learn <a href="https://flask.palletsprojects.com/en/3.0.x/" target="_blank" rel="noreferrer noopener" title="This link will take you away from hive.blog" class="external_link">flask next... <h2>Service <p dir="auto">It can be fun in the beginning, but servicing bots and managing servers and whatever 24/7 can be a nightmare. So before you commit, think about long term, too.<br /> It can eat up hours and breaks at the worst moments and causes stress.<br /> If it turns into a job, it better be worth it. <h2>Conclusion <p dir="auto">Don't be <strong>that guy.<br /> Shit bots can cause trouble, so please be considerate.<br /> Expecially when broadcasting: Once something was sent, it's out in the world (of blocks) forever. <p dir="auto">That's all I could think of right now. I commented some place else that infinite loops are cringe, so I wanted to share some alternatives and considerations. In the links you should find helpful concepts to get you started on the right foot at least. <p dir="auto"><strong>Please comment, if you want to add something or ask or whatever.