Managed Kubernetes cluster such as GKE for each environment, setup in cloud provider UI since this is not done often. If you automate it with terraform chances are next time you run it, the cloud provider has subtly changed some options and your automation is out-of-date.
Cluster services repository with Helm charts for ingress controller, centralized logging and monitoring, etc. Use a values-${env}.yaml for environment differences. Deploy with CI service such as Jenkins.
Configuration repository for each application with Helm Chart. If it's an app with one service or all services in a single repo this can go in the same repo. If it's an app with services across multiple repos, create a new repo. Use a values-${env}.yaml for environment differences. Deploy with CI service such as Jenkins.
Store secrets in cloud secrets manager and interpolate to Kubernetes secrets at deploy time.
Cloud provider keeps the cluster and VMs up-to-date, CI pipelines do the builds and deployments. No terraform/ansible/other required. Again, this only works for "cloud native" models.
Applications have a unique source repo. Each rep has a build dir. Build dir contains a sundir for docker build, terraform configs (if needed) for dependent infrastructure and a helm chart for deploy.
I have a few things that don't fit the microservice pattern. They are terraform first (root of repo is TF code) and they have a build dir to define the next steps (mostly packer).
As I'm writing this, I think I need to change that and make the top level a README.md file and use the build dir pattern to be consistent.
The goal is to make servers disposable, able to be destroyed and created at will, so configuration management becomes kind of a legacy technology at that point.
Dev/QA/Similar: Either containerize and back to persistent volume, or use a managed DB service such as RDS or Cloud SQL and create a schema per environment. Include a deployment pipeline argument to reset to known state. CI pipeline can be tuned to handling dynamic environments in either case.
Stage/Prod: Use managed DB service such as RDS or Cloud SQL.
The time and cost to automate a DB upgrade with every edge case considered is huge. Rarely makes sense for small/medium business.
The reasons I've seen for doing so are usually penny-wise, pound-foolish. Penny-wise in saving a few dollars (conceptually) on a spreadsheet for per-env/per-cycle, while neglecting the long-tail consequence of your labor factor just growing, potentially forever, without regard for total cost of ownership.
Sorry didn't mean to rant. Hope this helps.
https://www.ansible.com/ is surely a good solution for Bootstraping Linux cloud machines and can be quite flexible. I personally feel like its usage of YAML manifests instead of a domain-specific language can make complex playbooks harder to read and to maintain.
If all you do is to deploy containers on a managed Kubernetes or a similar platform, you might get away with some solution to YAML templating (jsonnet et al) and some shell glue.
I am keeping an eye on https://github.com/purpleidea/mgmt which is a newer contender which many interesting features but lacks more complex examples.
Others like saltstack and chef still see some usage as far as I know, but I've got no personal experience with them.
As you mention, puppet has a steep learning curve, whereas Ansible has a very shallow one. It’s easy to get running in a few minutes!
We use both Puppet and Ansible at work, and its constant complaints and delays with Puppet whereas Ansible is little complaints and no delays.
That's probably because you are not running masterless, which means your puppet master is a bottle neck.
I would argue that masterless puppet is a superior pattern for both scaling creating a hierarchical structures.
It's still good in Enterprise land where taking the time to work out the declarative style and dependency chains is worth it (and you have the people to put on it and the CAB process to review infrastructure changes). For a small to mid sized company I find it gets in the way of iterating fast. I spent waaaay too much time there either fighting the tooling or having to work out dependency chains. Redhat and I-think-AWS-but-I-might-be-thinking-of-Chef also have tooling in this space.
I'll take Chef or Ansible's imperative approach in the environments I work in any day (Mostly ansible playbooks for baking hosts only, I've never been entirely comfortable with having one Ansible Tower/Chef Server/Puppetmaster/etc be authoritative over everything, too large a failure pattern if security controls fail). But again, I'm working in many younger small environments and not large mature ones.
Most of this is also irrelevant for us as we're all in on Docker/ECS for anything new. Config management plays a limited role there over having your tasks/services checked into the individual repos.
- If you have SSH access, you can use it. No matter what environment or company you work for, there’s no agent to install and no need to get approval to use the tool. It’s easy to build up a reproducible library of your shell habits that works locally or remotely, where each step can avoid being repeated in case there’s a need to rerun things.
- If you get into an environment where performance across many machines is more important you can switch to pull based execution. Because of that, I see very little advantage to any of the other tools that outweighs the advantages of Ansible.
I don't get why is this always brought up as a major advantage when discussing CM. Ansible actually installs its Python runtime to target systems. Once I had a server that had full disk root and Ansible failed to work because there was no space left to copy tons of its Python code.
No configuration system is likely to work with a full root partition, though.
I've had this idea for a config management system that compiles all provisioning code to posit shell. One of those years I'll finish it... :-)
I recently learned that ansible supports binary modules, in addition to the OOtB support for modules written in any already-configured scripting language (including shell): https://docs.ansible.com/ansible/2.9/dev_guide/developing_pr...
However, while I know you meant "all the provided modules," it seems they are headed toward a less "batteries included" style and more (pypi|maven|npm|rubygems) style of "the community will sort it out" mechanism of distribution: https://docs.ansible.com/ansible/2.9/user_guide/collections_...
Which I welcome wholeheartedly because landing even the simplest fixes to ansible modules is currently a very laborious and time intensive operation
Example : https://yourlabs.io/oss/bigsudo/blob/master/bigsudo/bootstra...
Bigsudo ansible wrapper always plays that no matter what and as a result ansible never fails because of missing python.
So yeah, it does copy its "runtime". It cannot work purely by running commands over SSH. It needs to copy "its agent" to target, and worse, it does this every time you run it.
What can anything do without any space left?
What I prefer to do is use Terraform to create immutable infrastructure from code. CoreOS and most Linux variants can be configured at boot time (cloud-config, Ignition, etc) to start and run a certain workload. Ideally, all of your workloads would be containerised, so there's no need for configuration drift, or for any management software to be running on the box. If you need to update something, create the next version of your immutable machine and replace the existing ones.
(Context: my team manages dozens of clusters, each with a score of services across thousands of physical hosts. Every minute of every day, multiple things are being scaled up or down, tuned, rearranged to deal with hardware faults or upgrades, new features rolled out, etc. Far from being immutable, this infrastructure is remarkably fluid because that's the only way to run things at such scale.)
Beware of Chesterton's Fence. Just because you haven't learned the reasons for something doesn't mean it's wrong, and the new shiny often re-introduces problems that were already solved (along with some of its own) because of that attitude.
My understanding of immutable infrastructure is the same as immutable data structures: once you create something, you don't mess with it. If you need a different something, you create a new one and destroy the old one.
That doesn't mean that the whole picture isn't changing all the time. Indeed, I think immutability makes systems overall more fluid, because it's easier to reason about changes. Mutability adds a lot of complexity, and when mutable things interact, the number of corner cases grows very quickly. In those circumstances, people can easily learn to fear change, which drastically reduces fluidity.
It seemed like a fine idea to me. The best way to be sure that everything can be rebuilt is to regularly rebuild everything. It also solves some security problems, simplifies maintenance, and allows people to be braver around updates.
And just to be clear, I'm very willing to believe that your particular legacy setup isn't a good match for cattle-not-pets practices. But I think that's different than saying it's impossible for anybody to bring an immutable approach to things like storage.
To give a really silly example, adding a node to a cluster is a configuration change. It wouldn't make sense to destroy the cluster and recreate it to add a new node. There are lots of examples like this where if you took the idea of immutable infrastructure to the extreme it would result in really large wastes of effort.
On the other hand, while my suggestion of doing it to add a node sounds ridiculous I'm sure there are circumstances in which it's not only understandable but necessary, due to some aspect of the system.
If your biggest objection to an idea is that you can make up a silly thing that sounds like it might be related, I'm not understanding why we need to have this discussion. I'd like to focus on real issues, thanks.
I also think it's a cool idea to destroy the entire cluster just to add a node, and it sounds ridiculous but also like there's some circumstances where it makes perfect sense.
If your systems are immutable they can run read-only. In the in nineties Tripwire, the integrity checker, popularized it. You could run it off cdrom. Today immutable infrastructure is VMs/containers that can be ran off a SAN or a pass through file system that is readonly. It means snapshots are completely and immediately replicatable. When you need to deploy, you take a base image/container, install a code onto it, run tests to ensure that it is not broken and replicate it as many times as you need, in a read-only state. This approach also has an interesting property where because system is readonly ( as in exported to the instance read-only/mounted by the instance readonly ) it is extremely difficult to do nasty things to it after a break in - if it is difficult to create files, it is difficult to stage exploits.
That's the only kind of infrastructure where configuration management on the instances themselves is not needed
As for the conflicts, I have to say I loathe the way the more dynamic part of configuration works. It might be the most ill conceived and poorly implemented system I've seen in 30+ years of working in the industry. Granted, it does basically work, but at the cost of wasting thousands of engineers' time every day. The conflicts occur because (a) it abuses source control as its underlying mechanism and (b) it generates the actual configs (what gets shipped to the affected machines) from the user-provided versions in a non-deterministic way which causes spurious differences. All of its goals - auditability, validation, canaries, caching, etc. - could be achieved without such aggravation if the initial design hadn't been so mind-bogglingly stupid.
But I digress. Sorry not sorry. ;) To answer your question, my personal solution is to take advantage of the fact that I'm on the US east coast and commit most of my changes before everybody else gets active.
State is always the enemy in technology.
I can't even imagine managing hundreds of servers whose state is unpredictable at any moment and they can't be terminated and replaced with a fresh instance for fear of losing something.
I work in data storage. Am I the enemy, then? ;)
> can't even imagine managing hundreds of servers whose state is unpredictable at any moment
Be careful not to conflate immutability with predictability. The state of these servers is predictable. All of the information necessary to reconstruct them is on a single continuous timeline in source control. But that doesn't mean they're immutable because the head of that timeline is moving very rapidly.
> can't be terminated and replaced with a fresh instance for fear of losing something.
No, there's (almost) no danger of losing any data because everything's erasure-coded at a level of redundancy that most people find surprising until they learn the reasons (e.g. large-scale electrical outages). But there's definitely a danger of losing availability. You can't just cold-restart a whole service that's running on thousands of hosts and being used continuously by even more thousands without a lot of screaming. Rolling changes are an absolute requirement. Some take minutes. Some take hours. Some take days. Many of these services have run continuously for years, barely resembling the code or config they had when they first started, and their users wouldn't have it any other way. It might be hard to imagine, but it's an every-day reality for my team.
You’re the prison guard.
I don't trust predictability. Drift is always a nightmare. Nothing is ever as predictable as you would like it to be.
>You can't just cold-restart a whole service that's running on thousands of hosts and being used continuously by even more thousands without a lot of screaming.
If it's architected well you can :)
Except that state and its manipulation is usually the primary value in technology.
> I can't even imagine managing hundreds of servers whose state is unpredictable at any moment and they can't be terminated and replaced with a fresh instance for fear of losing something.
Yes, that sounds awful. That's why we have backups and, if necessary, redundancy and high availability.
Exactly and thats why you put state in data stores and keep your servers immutable.
Are Ansible/Puppet/Chef any good for managing the hardware you mentioned?
Ansible is used in networking, which many vendors having official modules:
* https://github.com/PaloAltoNetworks/ansible-pan
* https://github.com/aristanetworks/ansible-cvp
* https://www.juniper.net/documentation/en_US/junos-ansible/in...
* https://github.com/F5Networks/f5-ansible
There are even frameworks if you want to write things in 'raw' Python as well.
Yes. Well, OK, maybe not good but better than ad hoc.
Avoid managing the underlying os as much as possible. Use vanilla or prebuilt images to deploy these containers on, coreos, Amazon's new bottle rocket (maybe). Or use a service like fargate when possible. All configuration should be declarative to avoid errors.
If you need to build images tools like packer are great. AWS has a recommended "golden Ami pipeline" pattern and a new image builder service if you can't use community images.
I'm speaking imperatively but read these as my own directives. I work for a company that consults and actively helps fortune 500's migrate to the cloud. So some of what I'm saying is not possible or harder on prem and I recognize that.
If I had to, I still like Chef, puppet second favorite mostly because of familiarity. Ansiblee can be used with either of these. And tools like serverspec to validate your images. I don't really use any of this anymore though.
You always have a configuration management system.
Terraform has some limitations. For example, one deployment cannot deploy hosts and their containers [1]. And there is no usable support for rolling deployments [2, 3]. So I've ended up with a 4-stage deployment: host-set1, containers on host-set1, host-set2, containers on host-set2.
I also use Terraform to deploy the servers to my laptop during development. Docker for Mac works well.
Someday, Kubernetes will get some usable documentation on how to do normal things [4]. Then I will use it for deploying containers, load balancers, and persistent volumes. For now, it's too big of a complexity jump over plain Docker.
[1] https://github.com/hashicorp/terraform/issues/2430
[2] https://github.com/hashicorp/terraform/issues/23735#issuecom...
[3] https://github.com/hashicorp/terraform/issues?q=is%3Aissue+%...
"Amazon/Google/Azure takes care of that" is not the answer, unless your comment is predicated on a world where compute can only be rented from big corps... and their methods of managing underlying infrastructure are sacred secrets for which we are to unworthy to comprehend.
For example, I deployed an app backend to DigitalOcean with a load balancer, 2x replicated API server, 2x replicated worker process, managed database, file storage, and static website. Terraform is tracking 114 resources for each deployment.
It seems that automatic removal is poorly supported by Ansible, Chef, Puppet, Salt, etc. One can explicitly add items to a "to_remove" list, but this is error-prone.
Terraform has many limitations and problems, but I have found no better tool.
(although that's of course not strictly "old stuff")
Rather than doing that I take a light touch approach with ansible that will suffice until we can dockerize (which would require the same work, but then it’s a dev project vs now when it’s just a devops thing)
Can you mount all your volumes read-only and run all of your stack? If you cannot, then you do not have immutable infrastructure. You simply happen to agree that no one write anything useful, which with time will absolutely fail because someone, somewhere is going to start storing state on a stateless system giving you "a cow #378 called 'Betsy'"
1. You deploy a completely fresh instance/container, instead of in-place updates 2. You don't actively push changes on a running instance/container
Of course you might have stuff written to disk, such as logs, temp files, etc. But it should be non-essential data, and potentially pushed to a central place in near real-time.
There's no point in trying to manage a database or similar resources this way.
When working solo I use Guix, both Guix and Nix are _seriously_ amazing.
feedback welcome!
Salt (also known as SaltStack) was right.
> Salt is a new approach to infrastructure management built on a dynamic communication bus. Salt can be used for data-driven orchestration, remote execution for any infrastructure, configuration management for any app stack, and much more.
I'm ultra confused about their marketing btw. Their website doesn't even say it's open source. You have to sign up to "try it now". It's like they don't want customers? Or are people who want to understand what they're buying not the target market, somehow?
For reference, this appears to be the Salt primer: https://docs.saltstack.com/en/getstarted/system/index.html
How do I get from this:
> Drive IT security into the 21st century. Amplify the impact of your entire SecOps team with global orchestration and automation that remediates security issues in minutes, not weeks.
to "it's a provisioning tool for servers, like ansible but faster"?
So it's a very good tool to gradually get a legacy system under configuration management and thus source control.
I also use (In order of frequency): Terraform, Invoke (Sometimes there is no substitute for a full programming language like python), Saltstack (1000's of machines in a heterogenous environment)
If I were going to deploy a new app on k8s today, I would probably use something like https://github.com/fluxcd/flux.
I haven't really had a pleasant time with the tooling around serverless ecosystem yet once you get beyond hello worlds and canned code examples.
Why? I would have seen that as Ansible's strong point.
Re: mitogen: Thanks! I saw that once, a long time ago, but couldn't find it again. I'll have to try it; vanilla ansible is fine for me so far, but I'm hardly going to ignore a speed boost that looks basically free to implement.
I really don't see why so many weird, unreadable languages like jsonnet or CUE were created, if there is already a type safe, script-like (Go compiles in miliseconds and there is even go run command), with full pledged IDE autocompletion support, abstractions and templating capabilities, mature dependency management and many many more.. Please tell me why we are inventing thousands weird things if we have ready tools that helps with configuration as well! (:
They are also not doing code reviews to enforce security policies.
If you have DevOps guys who are also software developers, more power to you, but if I approach my DevOps team with:
Hey just code your scripts in this turing-complete languages, they will ask me "what's your username again?" BOFH-style ;)
I totally see this being difficult. To enforce DevOps/Ops to actually do code reviews, and versioned, type-safe configuration, but once you accomplish it - the profits are really worth it!
A full programming language is the natural choice for people who are full programmers. But for people who aren't, they're intimidating and add a lot of complexity. Templating systems are much more approachable for people who have a lot of experience configuring things via big blobs of text.
As a programmer, I would personally rather express everything in a programming language, so I get your perspective here. But it isn't an accident that there are so many ops-focused systems that are different takes on just automating the things people were previously doing manually.
> Templating systems are much more approachable for people who have a lot of experience configuring things via big blobs of text.
I have mixed feelings about this statement. How reading or using jsonnet is easier? I am a principal engineer and I am struggling to work with this, how less expierience people can deal with that efficiently? (:
Gabriel talks about this under the label "worse is better". [1] I agree your preferred approach is better in the long term and at scale. But that only matters in the long term, and only if scale is eventually achieved. Tool adoption is generally a series of short-term decisions, and most projects start small.
I agree mentoring people is great, but neither you nor I have time to mentor all the people just configuring things into becoming good programmers.
Let's create a CONFIGURATOR language (and secretly hide Go underneath)!
That's why IMO we should separate those. (:
If you’re a K8s dev, they recently announced the ability to output Helm3 files rather than deploy directly.
Alternatively, if you have the option of choosing the whole stack, Nix/NixOS and their deployment tools.
I would recommend staying away from large systems like k8s.
0. Self-hosted Gitlab and Gitlab CI.
1. Chef. I'd hardly mention it because it's use is so minimal but we have it setup for our base images for the nitpicky stuff like connecting to LDAP/AD.
2. Terraform for setting up base resources (network, storage, allocating infrastructure VMs for Grafana).
3. Kubernetes. We use a bare minimum of manually maintained configuration files; basically only for the long-lived services hosted in cluster plus the resources they need (ie: databases + persistent volumes), ACL configuration.
4. Spinnaker for managing deployments into Kubernetes. It really simplifies a lot of the day-to-day headaches; we have it poll our Gitlab container repository and deploy automatically when new containers are available. Works tremendously well and is super responsive.
Or Dockerfile/compose for container images.
Cloud resources are managed by Terraform/Terragrunt.
My experience trying to manage longer lived systems like robot computers over time with Ansible has been that it quickly becomes a nightmare as your playbook grows cruft to try to account for the various states the target may be coming from.
Even in the run-once case, though, I think there's a benefit to Ansible's role-based approach to modularization. And again for the dev scenario, it's much easier to run only portions of a playbook than it is to run portions of a shell script.
And finally, the diagnostics and overall failure story are obviously way better for Ansible, too.
Now, all this said, I do still go back and forth. For example, literally right now in another window I'm working a small wrapper that prepares clean environments to build patched Ubuntu kernels in— and it's all just debootstrap, systemd-nspawn, and a bunch of shell script glue.
I still use it as it allows more portability across OS releases and families (as in easier migration), but it also increases the complexity when creating a new task/role/playbook.
In that sense, Dockerfiles with shell-based RUN commands are much easier to manage.
Another advantage of config management over shell might be a better integration with the underlying cloud provider. For instance Ansible supports AWS SSM parameter store, which allows me to use dynamic definitions of some configuration data (RDS database endpoints, for instance) or secrets (no need for Ansible vault)
(To me things like puppet or ansible seem like thin layers over shell and ssh, whereas both Dhall and Cue seem to innovate in ways that are more, uh, je ne sais quoi ;-) YMMV)
No orchestration as well FWIW, we usually have ansible configuring Docker to run and pulling the images...
As for the future I have been meaning to explore Terraform and some Orchestration platforms (Nomad).
config-package-dev is a tool for building site-specific Debian packages that override the config files in other Debian packages. It's useful when you have machines that are easy to reimage / you have some image-based infrastructure, but you do want to do local development too, since it integrates with the dpkg database properly and prevents upgraded distro packages from clobbering your config.
My current team uses it - and started using it before I joined the company (I didn't know we were using it when I joined, and they didn't know I was applying, I discovered this after starting on another team and eventually moved to this team). I take that as a sign that it's objectively useful and I'm not biased :) We also use some amount of CFEngine, and we're generally shifting towards config-package-dev for sitewide configuration / things that apply to a group of machines (e.g. "all developer VMs") and CFEngine or Ansible for machine-specific configuration. Our infrastructure is large but not quite FAANG-scale, and includes a mix of bare metal, private cloud and self-run Kubernetes, and public cloud.
I've previously used it for
- configuring Kerberos, AFS, email, LDAP, etc. for a university, both for university-run computer labs where we owned the machines and could reimage them easily and for personal machines that we didn't want to sysadmin and only wanted to install some defaults
- building an Ubuntu-based appliance where we shipped all updates to customers as image-based updates (a la CrOS or Bottlerocket) but we'd tinker with in-place changes and upgrades on our test machines to keep the edit/deploy/test cycle fast
All of cofiguration management tools( ansible, puppet, chef, salt etc ..) are bloated.
We already have FINE SHELL. Why do we need crappy ugly DSL or weird yaml ??
These days, Newbies write ansible playbooks without even basic unix shell & commands knowledge. What the hell?
I like ssh + pure posix shell approach like
Show HN: Posixcube, a shell script automation framework alternative to Ansible https://news.ycombinator.com/item?id=13378852
http://madhadron.com/posts/choosing_your_base_stack.html
Don't be distracted by FAANG scale. It's not relevant to most software and is usually dictated by what they started using and then deployed lots of engineering time to make work.
My suggestion is to figure out how you will manage your database server and monitoring for it. If you can do that, almost everything else can fall into line as needed.
DigitalOcean might be fine. So is Arch Linux. But if someone just wants to get on with what they're interested in with a minimum of fuss over time, it wouldn't be the right recommendation.
I still think there's too much setup to get started - but am somewhat convinced ansible does a better job than a bunch of bespoke shell would (partly because ansible comes with some "primitives"/concepts such as "make sure this version of this file is in this location on that server - which is quick to get wrong across heterogeneous distributions).
We're moving towards managed kubernetes (for applications currently largely deployed with Docker and docker-compose on individual vms).
I do think the "make an appliance;run an appliance;replace the appliance" life cycle makes a lot of sense - I'm not sure if k8s does yet.
I think we could be quite happy on a docker swarm style setup - but apparently everything but k8s is being killed or at least left for dead by various upstream.
And k8s might be expensive to run in the cloud (a vm pr pod?) - but it comes with abstractions we (everyone) needs.
Trying to offload to SaaS that which makes sense as SaaS - primarily managed db (we're trying out elephant sql) - and some file storage (100s of MB large Pdf files).
For bespoke servers we lean a bit on etckeeper in order to at least keep track of changes. If we were to invest in something beyond k8s (it's such a big hammer, that one become a bit reluctant to put it down once picked up..) I'd probably look at gnu guix.
... and peer pressure (which is probably not a good reason)
It's like terraform, except you can't review things for mistakes until it's already in the process of nuking something. Which is terrible when you're inheriting an environment.
I find Jenkins X really interesting for my applications. It seems to solve a lot of issues related to CI/CD and automation in Kubernetes. however, still lacks multi-cluster support.
I'd love to talk to you about it in more detail and get you involved in the experiments around it - feel free to email me at ejones@cloudbees.com if you'd like to be involved or chat more about it.
I very much dislike ansible's YAML-based language and would hate to use it for configuration management beyond tiny systems, but it's pretty decent as a replacement for clusterssh and custom scripts.
Puppet maintains the base image with the core system.
Special systems are recreated by applying system specific classes to a base image.
Application software is installed via packages with git commit-ids being versions.
Nothing is upgraded, rather a new instances are rolled out and the old instances are destroyed.
This also ensures that we always know that we can recreate our entire infrastructure because we do that for rapidly changing systems several times a day and for all systems at least monthly.
This makes our operational workflow match the disaster recovery, which is god sent.
I’ve tried Puppet and SaltStack, and I constantly find they are harder and more complex than Ansible. I can get something going in Ansible in short order.
Ansible really is my hammer.
What I like about SOPs is that we still leverage AWS keystore to store our master key, but we store encrypted secrets in git. This is helpful as we have a history of rotations (great for rollbacks, audits, etc). Additionally, SOPs doesn’t encrypt yaml keys, so one can tell what a secret is but not its values.
A small startup shouldn't use any configuration management (assuming configuration management means software like Puppet, Chef, Salt, and Ansible). That is because small startups shouldn't be running anything on VMs (or bare metal). There are so many fully managed solutions out there. There is no reason to be running on VM, SSHing to servers, etc. App Engine, Heroku, GKE, Cloud Run, whatever.
Once you get to the point where you need to run VMs (or bare metal), there are many options. A lot of systems are going to a more image + container based solution. Think something like Container-Optimized OS[1] or Bottlerocket[2], where most of the file system is read-only, it is updated by swapping images (no package updates), and everything runs in containers.
If you are actually interested in config management, I'll give my opinions, and a bit of history. I've used all four of the current major config management systems (Puppet, Chef, Salt, and Ansible).
Puppet was the first of the bunch, it had its issues, but it was better than previous config managements systems. Twitter was one of the first big tech companies to use Puppet, and AFAIK they still do.
Chef was next, it was created by people to did Puppet consulting for a living. It follows a very similar model to Puppet, and solves most of the problems with Puppet, while introducing some problems of its own (mainly complexity in getting started). In my opinion Chef is a clear win over Puppet, and I don't think there is a good reason to pick Puppet anymore. One of the biggest advantages is that the config language is an actual programming language (Ruby). All the other systems started with language that was missing things like loops, and they have slowly grafted on programming language features. It is so much nicer to use an actual programming language. Facebook is a huge Chef user.
Salt was next. It was created by someone who wanted to run commands on a bunch of servers. It grew into a configuration management system. The underlying architecture of Salt is very nice, it is basically a bunch of nodes communicating over a message bus. Salt has different "renderers"[3], which are the language you write the config in, including ones that use a real programming language (Python). I'll back to Salt in a minute.
Ansible... it is very popular. This is going to sound harsh, but I'm just going to say it. I think is it popular with people who don't know how to use configuration management systems. You know how the Flask framework started as an April Fool's joke[4], where the author created something with what he thought were obviously bad ideas, but people liked some of them. Ansible is so obviously bad, at its core, that I actually went and read the first dozen Git commits to see if there were any signs that is was an April Fool's joke.
There was a time a few years ago when Ansible's website said things like "agentless", "masterless", "fast", "secure", "just YAML". They are all a joke.
Ansible isn't agentless. It has a network agent that you have to install and configure (SSH). Yes, to do it correctly you have to actually configure SSH, a user, keys, etc. It also has a runtime agent that you have to install (Python). You have to install Python, and all the Python dependencies your Ansible code needs. Then it has the actual code of the agent, which it copies to the machine each time it runs, which is stupidly inefficient. It is actually easier to install and configure the agents of all the other config management systems than it is to properly install, configure, and secure Ansible's agent(s).
Masterless isn't a good thing, and a proper Ansible setup wouldn't be masterless. The way Ansible is designed is that developers run the Ansible code from their laptops. That means anyone making code changes needs to be able to be able to SSH to every single server in production, with root permissions. And it also risks them running code that hasn't been committed to Git or approved. Any reasonable Ansible setup will have a server from which it runs, Tower, a CI system, etc.
Fast. Ha! I benchmarked it against Salt, wrote the same code in both, that managed the exact some things. Using local execution so Ansible wouldn't have an SSH disadvantage. Ansible was 9 times slower for a run with no changes (which is important because 99.9% of runs have no or few changes). It is even slower in real life. Why is it so slow? Well, SSH is part of it. SSH is wonderful, but it isn't a high performance RPC system. But an even bigger part of the slowness is the insane code execution. You'd think that when you use the `package` or `apt` modules to ensure a package is installed, that it would internally call some `package.installed` function/method. And that the arguments you pass are passed to the function. That is what all the other configuration management systems do. But not Ansible. No, it execs a script, passing the arguments as args to the script. That means every time you want to ensure a package is still installed (it is, you just want to make sure it is), Ansible execs a whole new Python VM to run the "function". It is incredibly inefficient.
Secure. Having a network that allows anyone to SSH to any machine in production and get root isn't the first step I'd take in making servers secure.
It isn't just YAML. It is a programming language that happens to sort of look like YAML. It has its own loop and variable syntax, in YAML. Then it has Jinja templating on top of that. "Just YAML" isn't a feature. To do config management correctly you need actual programming language features, so use an actual programming language.
If I had to pick one again, I'd pick Salt. Specifically I'd use Salt with PyObjects[5] and PillarStack[6].
But I'll reiterate, you shouldn't start with a config management system. Start with something fully managed. Once you need a config management system, take the time to do it correctly. Like it should be a six week project, not a thing you do in an hour. Chef and Salt will take more time to get started, but if setup correctly they will be much better than any Ansible setup. If you don't have the time or knowledge to do Chef or Salt correctly, then you don't have the time or knowledge to manage VMs correctly, so don't.
[1] https://cloud.google.com/container-optimized-os
[2] https://aws.amazon.com/bottlerocket/
[3] https://docs.saltstack.com/en/latest/ref/renderers/
[4] https://en.wikipedia.org/wiki/Flask_(web_framework)#History
[5] https://docs.saltstack.com/en/latest/ref/renderers/all/salt....
[6] https://docs.saltstack.com/en/master/ref/pillar/all/salt.pil...
This is the most important thing I've learned from using all of the mentioned options, as well as older options like cfengine. Please make it easy to work in an actual programming language instead of an unholy mix of yaml and jinja! I think Ruby excels for this, as well as Clojure or a Scheme, because it's so easy to write "internal" DSLs.
It is silly to ask "what should be used at FAANG scale", because either you are working at a FAANG and you are using what they use, or you are very unlikely to ever be at that scale -- and somewhere along the journey to getting there, you will either find or write the system that you need.
Also, odd and a little creepy that you're stalking my comments but I hope you enjoyed my brain droppings. ;)
For teams that have a large IaaS footprint: Chef (agent-less actually adds complexity in this environment.)
Puppet for a polished production. Puppet has robust and stable ecosystems and infrastructure. It is a client-server model from the beginning. It is easier to create and put in the production library of all your puppet modules. It has hiera for central config values and secrets management. At the same time, I hate the Puppet's resource relations. Puppet's architecture feels like something developed in 1991, an ugly monster monolith and extremely heavy.
Terraform. For actual low-level infrastructure management. And I don't like to put whole high-level host configuration into IaaC! IaaC has minimal host configuration capabilities. Set hostname, set IP, register with Puppet or call ansible - only a few lines in user-data or bash-script on boot, which then calls actual configuration management!
Gitlab-CI - switched from Jenkins. Concourse-ci looks extremely interesting! Also reviewing some GitOps frameworks. Kubernetes - bare-metal runs self-made puppet-based pure k8s. Also, kops and EKS for AWS. Applications in k8s are managed via Helm.
Compared to Puppet Ansible is less enterprissy, it is more like a hipster tool. I would like to replace the Puppet with Ansible. But maybe I need the help from all of YOU who have voted for Ansible. How do you achieve Puppet's level of management with Ansible? How do you achieve client-server setup with ansbile - somehow I do not see lot's of people using ansible-pull? (Without using Tower!) You create cronjob with ansible-pull on a node boot? :D Or whole your ansible usage is limited to running ansible-playbook from your console manually? Ok maybe you sometimes put it in the last action of your CI/CD pipeline ;) Nodes classification and review? Central config values management for everything?
I use hashi Vault and lots of other things too. Some questions are rhetoric. I've just expressed my mistrust in ansible which doesn't feel complete. :(
How to do you manage a fleet of 1000, 500 or even 200 hosts with ansible? When after provisioning you need to review your fleet, count groups, list groups, check states. Ah, you want to suggest Consul for that role? :)
Kubernetes for the win. It will replace config management diversity. It gives you node discovery, state review, and much much much more.
[1] https://www.chef.io/customers/facebook/
[2] https://engineering.fb.com/core-data/facebook-configuration-...
[0] https://www.chef.io/customers/facebook/ [1] https://engineering.fb.com/data-center-engineering/tupperwar...
Question though: how do you manage the possible rebooting-containers-loop after a host reboot? I had to throw in more memory to prevent this but it feels like a (expensive|unnecessary) workaround. Anyone figured out how to let multiple containers start after each other (while not in 1 docker-compose.yaml)?