Puppet works okayish but when you have a large fleet of what are basically IoT devices, you start getting an unpleasant failure rate. Push one bad network config and you've 'bricked' thousands of machines.
I am being a bit vague intentionally, hope you can understand. But to help imagine, the scale of our problem is pretty big, you've probably even had some interaction with one of our machines.
For a household-name IoT device, we did about 10000+ hours worth of testing on an array of devices for every update candidate. Think a walk-in closet chock full of devices covering every surface. This included thousands of hours of pure power-interruption scenarios, all automated.
We had a "alpha" and "beta" branch for internal users for ~a month before updates hit customers. If we bricked a device we could replace it.
For all update channels, we set a percentage of devices to deterministically receive updates. We start with 1% (probably 0.0001% now...) and double the rollout every day or so if things look good.
We had the ability to "roll back" to the last good firmware, which is stored on a partition on the device. This is almost never used.
Devices update in the background, unobtrusively. Once the update is complete, the device waits for a quiet window in which to reboot and try out the new firmware. Boot-time tests and a custom watchdog monitor the device to make sure everything works, including networking, filesystem, all services start up normally. If there is an anomaly, the device reboots back to the previous firmware, and this is reported home.
After some period of stability (minutes to hours usually) the device marks the update as good and will keep using it. If the device crash loops three times in a row within some window, it reverts to the previous version.
Yes, losing power sucks, and yes devices will get bricked and the filesystem will be corrupt, but you can do lots to ensure this is minimized. Like redundant partitions, leaving ample room in flash storage for bad blocks to prolong the device life, tuning log storage to avoid wasting write cycles and losing data on power loss, lots and lots of metrics and lots and lots and lots of automated integration tests.
If you're really struggling, I can help. Lots of fun problem solving in this space.
That's actually 90% of the solution these days: Use Mender. It wasn't around when I did this, but we likely would've used it, as we built essentially the same thing.
The other 90% is quality control. Distros can't really solve that for you.
> To be fair, to qualify as a solved problem in the industry one would expect either a standard, possibly community-supported, software implementation of the important parts, or at least documentation such that others could read up, learn about your wins, and apply them consistently to their projects, or both.
These are solved problems. Mender exists and documents almost everything I mentioned. Google has published incredibly thorough technical documents describing how Chromecasts and Chromebooks update, and at least the latter solution is Open Source.
If you look, you'd see these problems are not novel, which is why I declared it "not a hard problem space." The prior art is tremendous.
10, 15 years ago? Not so much.
I got _super_ lucky at the startup where I was responsible for OS/updates/security for our IoT devices. Between the design stage and the production run, the price of 4GB SD cards dropped below the price of the 2GB cards on our BOM, so I had an entire spare partition to play with where I could keep a "spare" copy of the entire device image. And we had a "watchdog" microprocessor that could switch the main processor's boot config if it failed to boot. (We were basically running a RaspberryPi and an Arduino connected together. The prototype were exactly that, the final hardware was an iMX233 and an Atmel328 on our own custom board.)
We used Arch Linux with our own pacman repo, so the devices all pulled their own updates automatically. (Also it was super low risk, these were xmas tree lights, so our problem was "we don't want to ruin anyone's xmas!" instead of "If we fuck this up people might go broke and/or die...")
Hopefully it makes some sense!
With regards to bricking thousands of machines, with great power comes great responsibility. Is there no way to test the config before mass deployment? In batches or a canary deployment?
There is no really great deployment story. In the very best case, you have to connect a keyboard, a PxE LAN cable, change some things in the bios, and select the OS you want to clone. But creating the image in the first place takes the better part of a day. Another option is to maybe clone the SSD beforehand. It gets more complicated if you have to flash a certain bios, change settings, and so on. Ideally, we'd just want to connect one cable bundle and "pressure tank" the new system with OS and configuration in a couple of minutes.
This is for the PCs that we sell, the story for the office laptops we use is even worse. There are good tools in the Windows world for deployment, but they all seem geared for installations of 1000s of computers. What if the office you manage (on the side of your normal work) just has 20? There is little point setting up SCCM, WSUS, or newer stuff like Autopilot (which seems pretty cool, but I couldn't figure out how to install MS office with the user's license, or how to install an ERP from Microsoft themselves... that should be 1-click or 1 line of code if you offer such a solution).
What I'd really like is a mixture of Ansible or Puppet with a stupid simple monitoring GUI. Then I'd be able to say
choco install firefox,7zip,vlc
install office,erp
join-domain mycorp,$credentials
For what it's worth, I've had some success with Powershell for package management and domain management, and tools like Clonezilla / Norton Ghost for managing images on small to medium sized fleets of machines (again, both desktop and server). There are also a plethora tools that can interrogate what machines are on a given network, the software installed and their patch levels -- but most of them are not going to be free. However there definitely are alternative options to SCCM and WSUS if they're too "enterprisey" for your needs (I've used a few different ones but I'm afraid I can't recall the names of the more effective solutions in terms of ease of us and features vs license fee).
I hear this a lot, but do they really? As best I can tell they require writing everything from scratch. I went down this path just an exercise to see what end-users were having to deal with. Everything in ansible appears to be re-inventing the wheel.
Sure it's powerful, and it provides a robust framework to do everything, but out of the box it does NOTHING on its own. Want to update ilo(m)? Someone probably has a playbook somewhere you can build on, but you have to go find the playbook, and modify it to meet your needs. Same with updating an OS, or software package or X.
There's no "point at this server, scan the server, figure out the hardware model, os, application packages, and build a default list of things you might want to manage".
Cisco UCS handles a chunk of this for the physical hardware, but it has plenty of issues itself. Same with HPe and Synergy, and Dell/EMC with Openmanage (this may have been replaced, I honestly haven't had to deal with Dell recently).
Honestly it gets a bit frustrating when the response is always "there's this tool that can do it if you just spend 6 months customizing it to your environment!". I think what OP is asking for is some intelligence to automatically discover.
If Ansible can do that, I'm all ears, but I haven't figured out how.
If you want something that just works automatically and is free, well, I don't think you will find. Learning Ansible (or another configuration management tool) well will pay dividends through a lot of your career tho.
Other people's Ansible playbooks are often nice, because people mostly only publish things that stick to "best practice". I'll often use these if the exist and seem well thought out (and can do what I need done).
For things that there isn't an obvious "good choice of existing playbook", I'll sometimes write a "proper" one (we've got a quite good one here that got used a lot when we were deploying a lot of fundamentalist similar Grails/Tomcat/Apache apps with a bunch of common dependancies), or I'll just resort to using Ansible to run remote commands over ssh. If I know how to do it on the server from the command line, it's trivial to do exactly the same thing using Ansible from my laptop (or our bastion or config host). The trick here is making sure you don't write Ansible/ssh that screws up if you run it twice - which mostly isn't too hard to avoid so long as you remember to do so.
> I think what OP is asking for is some intelligence to automatically discover. > If Ansible can do that, I'm all ears, but I haven't figured out how.
I suspect this is a difference in approaches. It's easier in the cloud/vm world, bit I still treat bare metal servers more like cattle than pets. If I get a problem like "OS that doesn't get corrupted from unexpected poweroffs or permanently cut itself off from the network because of a bad config." I just get the box reimaged to a known state, then run the Ansible "update and deploy/configure from scratch" on it.
I don't think trying to build something to "intellegently auto discover" and repair a corrupted OS from hard powerdowns or a totally botched configuration change is a good use of my time... I'll just stand up another server from scratch using tried/tested automation.
Ansible is not even an option for IoT because it doesn't scale well and requires a stable connection. Puppet's agent model works better for large fleets especially if you're crossing multiple gateways.
So if I've got 40 different models of servers, with 10 different models of switches, 8 different operating systems, you're telling me right now there's a playbook for every possible hardware configuration I could have that will update all of that to the latest firmware without significant work on my part? Where is this magical repo?
You will also be able to share as much of the deployment as you want/can between the different models/OSes. Templating configuration variables based on their characteristics.
What you're asking to is akin to "Why cannot I download an app that does what $PRODUCT does but for my business for free? Why do I need to write my own software?"
Having to hire someone to customize ansible is the exact opposite of what op asked for and just reaffirms my point: ansible does nothing without significant customization.
Yes. Ansible is a framework with plugins. Just like Django or Ruby on Rails.
So again: Ansible is not an answer for someone looking for a ready-made solution to managing bare metal, which was my entire premise. Telling people to just use Ansible or Puppet when they're asking for a solution to the problem is just barely more helpful then telling them you can do it with a bash script and SSH for a consulting fee. It's pedantic and misses the point entirely.
I'm not as big of a fan of Puppet but actually puppet also works great for on-prem systems given that's what it was originally designed for. If anything, Puppet makes less sense in the cloud than it does on bare metal.
I'm not disputing you have a complex problem but that just means you need to spend a little more time tuning your solution (not less time like you seem to assume).
And if you want my advice about how to approach a daunting build: break your problem down. First start with delivering easy systems which will have the least impact if it goes wrong. This is to get your confidence up in working with the tool. Then start picking the harder targets that will give you the most reward, so even if your project ends up unfinished you've still fixed the biggest problems in your org. Then work your way backwards until everything is fixed. After a while, some of the easier deliveries will become background jobs you can fit in between support queries or half day sprint tickets (depending on whether you Kanban or Sprint). Before you know it, you'll have everything automated and realise it was far less painful than it appeared before you'd started the project.
Disclaimer: I'm DevOps Manager who has transitioned several orgs to through this process :)
You can use Ansible to manage bare metal - I've done it at two different companies.
Trust me, it works great.
When you decide that your cattle is going to be pets and pets get individual care and feeding, you have to hire a lot of people to do the individual care and feeding.
I've done done management of ~2k Linux systems across 17 generations with Ansible. It is not a big deal. You enforce conventions so you no longer have 2k different servers but rather a feet of Betsys, a fleet of Franks, a dozen of Marshas and a couple of Jacks. And you do not touch the boot configuration because even in 2020 you do not need to touch the boot/network configuration.
Somebody please correct me if this thing exists and is available, I'd love to be wrong!
I'm guessing there's more to this story than you've summarised because those points are pretty easily solved with:
- UPS (if the power outs are that much of a problem then you might need to invest in a generator as well).
- iLo / IPMI (remote management). Though even just running a serial cable out the back of the server is good enough for a remote console in the event of a network failure.
As for managing the config of them, the usual tools like Ansible and Puppet work just as well (in some cases actually better since they were initially designed for on-prem hardware). Likewise for Docker. So don't think you can't run those tools on bare metal Linux. But if you don't want the containerisation-like aspects of Docker but still wanted the deployment tools then you can go a long way with git and shell scripts.
While DevOps really came into popularity with cloud hosting, there's nothing fundamentally new about a lot of the tooling that wasn't possible in the old days of bare metal UNIX and Linux. Us older sysadmins were still doing a lot of the same stuff back then too, we just didn't given it trendy names back then.
10+ years ago I was installing Linux remotely on bare metal hardware via a console server. Then once I had one machine installed I'd take one HDD out of the mirrored RAID array and plug it in the 2nd server so the RAID controller would clone. I could repeat the disk swapping as many times as I wanted as long as I remembered to change the IPs (again, via remote serial console). And this was the lazy way of deploying a fleet of servers quickly. More professional places would push the install onto the server via netboot cloning solutions.