Immutable Infrastructure is the future

http://michaeldehaan.net/post/118717252307/immutable-infrastructure-is-the-future

by geerlingguy • 11 years ago

125 51 11 years ago

geerlingguy2• 11 years ago

A couple relevant snippets:

  Caveat - I think images must come from a build system.
  Using anybody’s canned images as a baseline is reckless.

  Config tools still have a place - in building the automated
  systems that allow folks to focus on business logic, but I
  think there are going to move down-stack to doing things
  like automating OpenStack.  The longer term future is about
  cloud/virt systems like this provisioning themselves, but
  they are still yet a bit too complicated in the way they are
  going about it, but I feel it’s coming.

(The post's author, Michael DeHaan, wrote Ansible in 2012, but left the project earlier this year to pursue other interests.)

My thoughts on the subject are much the same—but I think it'll take a few years for the tooling to reach the level of polish we currently have with best-of-breed CM and general provisioning tools. It's not as easy to go from 0-to-infrastructure with a Docker-based workflow (especially if you have your own registry, etc.) as opposed to a VM-plus-CM-based workflow.

mpdehaan26• 11 years ago

author here.

"but left the project earlier this year to pursue other interests" - Hi Jeff! I haven't really shared reasons for leaving the company to date and can't go into that.

I also don't think it will take years and think immutable is there today.

I think we're there today with a bit of skill and minor bit of work on top, but a little bit of work from cloud/virt solutions will push us over the hump - to be able to codify the upgrade-flip idiomatically within cloud/virt systems, so you don't need something else to do it for you. I do look forward to that being surfaced.

Things like Amazon's ECS in particular strike me as particularly interesting.

geerlingguy2• 11 years ago

I think we're there today with a bit of skill and minor bit of work on top, but a little bit of work from cloud/virt solutions will push us over the hump.

I think that's true, but my timeline is based on how long I see it taking 'mainstream' enterprise companies to adopt immutable infra—for many of the orgs I've worked with, they've only recently completed a sea change from dedicated servers to virtualized 'cloud' deployments.

So it really depends on who you're working with; many businesses are making the move today, but cautiously. Once the early adopters complete rolling things out to production and working out the kinks, we'll finally get to the late majority/stability, and I won't have to commiserate with the thousands of sysadmins stuck with dozens, hundreds, or thousands of VMs :)

runlevel1• 11 years ago

I'd like to see a polished common configuration API.

Currently, we have Chef, Puppet, Ansible, and Salt (amongst others) all working to create a sane common abstraction on top of a rainbow of configuration files and command-line arguments.

Each of them have their strengths, and frankly they're all impressive in their own right. But there's only so much you can do to reign in the chaos of the bazaar.

The Docker workflow certainly has its merits. It's great for narrowing dev-prod parity and repeatability. I've embraced it, but I'm a bit anxious that we, as a community, might end up creating bigger black boxes -- Dockerfiles upon Dockerfiles.

zdw• 11 years ago

I'd like to see a polished common configuration API.

https://xkcd.com/927/

atsaloli• 11 years ago

What effort is this? URL please?

mpdehaan26• 11 years ago

Hmm, I think your boxes can be still pretty transparent in that case - if anything more so, as you've got single-bash files versus perhaps directories and directories of content?

In most organizations, all those Dockerfiles should be yours, and in source control.

Relying on the blobs from others shouldn't be neccessary for most applications. Yes - in large organizations, a management problem probably does arise, but I think if you find copy/paste rising up you have to push that down into the base image, basically?

I don't think a configuration API helps to be honest - what you would do is turn them all into a "greatest common divisor" type scenario, where as they feel different because they were trying to be different.

I think you're best solved by organizationally mandating one of them within your company, as painful as that may be.

kolev• 11 years ago

Wrong! It's the present!

akurilin• 11 years ago

Very interested in this subject. Is there a comprehensive guide on how I can pull this off TODAY with e.g. AWS?

eropple2• 11 years ago

It's only one piece of the puzzle, but at my last company I wrote deploy_thing[1] for exactly this. An immutable config bundle and an immutable artifact tag combine to create a deploy that can be launched and put into production with an AWS auto-scaling group. Need to change a configuration, you burn down the auto-scaling group. This was a transitional step for us before moving to Mesos, but it's a good example, I think, of how to approach the problem from a minimum-viable level.

(I'm currently playing with moving it to OpenStack.)

[1] https://github.com/eropple/deploy_thing

bender80• 11 years ago

The URL is throwing 404, probably due to it being private.

Would love to see it. I am working on something similar.

yo-code-sucks• 11 years ago

Make a dockerfile, make sure it works and you understand it. Then go into Elastic Beanstalk and click new application and there is an option for loading a dockerfile, boom. For you this may work, for me it's more complex.

parasubvert3• 11 years ago

With containers, there's http://lattice.cf , which deploys Docker containers in this style with routing and load balancing; it's a simplified version of Cloud Foundry.

With VMs, there's http://bosh.io which has a bit of a learning curve but is ground up designed to be about designing & deploying immutable software releases

axelfontaine• 11 years ago

If you are on the JVM, our service does exactly this today: https://boxfuse.com

No base images, minimal immutable images generated on the fly with only what your application needs, directly deployable on VirtualBox and AWS, with zero downtime updates using ELBs or Elastic IPs.

olalonde• 11 years ago

Deis is relatively simple to install and get started with (http://deis.io). They have a CloudFormation config to deploy on AWS.

Darragh_Hayes• 11 years ago

At nearForm we're also very interested in this, which is why we've been working on nscale - our own deployment solution. v0.16 was released yesterday featuring autoscaling support.

"nscale is an open toolkit supporting configuration, build and deployment of connected container sets. nscale is ideally used to support the development and operation of microservice based systems." https://github.com/nearform/nscale

Here's an interesting blog post written about the deployment immutable systems. http://www.nearform.com/nodecrunch/deployment-how-to-do-it-f...

andrewchambers2• 11 years ago

Stateless servers with kubernetes seem like a great thing to do this sort of thing with.

nickbauman5• 11 years ago

Why go that low, though? Why not go with Managed VMs first?

andrewchambers2• 11 years ago

Kubernetes gives you freedom about where to run your stuff since it works on multiple providers and your own hardware. Once you learn how to set it up, it isn't too bad.

Google managed kubernetes cluster gives you the best of both worlds anyway.

falcolas3• 11 years ago

Ultimately in the end it means more time for everyone to focus on business logic versus thinking about deployments, so I’m a fan of that.

I find this amusing: our company is migrating to Docker right now, and over in operations I'm spending more and more time thinking about deployments than I've had to since I started doing operations work.

I have to think about "what major functionality has changed in Docker in the last three months, and how does that impact any/all of our images?"

I have to think about creating frequently updated base images, and how to deploy these updated base images across our regions.

I have to think about making the image layers as small as possible, to limit the bandwidth impact of updating images.

I have to think about making as few image layers as possible to avoid DevMapper IO overhead.

I have to think about externally mapped volumes to keep necessary IO as fast as possible.

I have to think about asymmetric TCP, docker vs host network interfaces, natting, and service discovery.

I have to think about private registries, token based authentication systems, and redundancy.

My developers have been able to focus on business logic since they hired an ops team. Will the amount of thinking go down over time? Some of it: the bits which can be automated fade to the back (at least until the core Docker functionality changes yet again), but there are bits and pieces will necessarily change with every deploy.

parasubvert3• 11 years ago

Or you could adopt a platform that has made a lot of those opinionated decisions in a pre-integrated config.

There's a chance it might not be a fit but then it's a matter of whether it's easier to start somewhere and tweak it vs. starting ground up.

dasil0033• 11 years ago

The difference is the pain you are experiencing with Docker is potentially transient, whereas the problems with configuration management on the wild internet are intractable, and even unquantifiable. With Docker the scope of changes you have to deal with is at least knowable.

I say "potentially" because I think the jury is still out whether Docker can live up to its promise. Clearly it has a real purpose and value add above traditional configuration management, but the churn is an indication of how hard a problem it is. Plus, even in an ideal case, you still have to deal with security updates and other inevitable version updates and things that invalidate your current images.

KaiserPro5• 11 years ago

The big problem is that docker/container image creation is now buried deep inside an app's build system. This means that your build system is now a critical part of your infrastructure.

marcosdumay• 11 years ago

What do I gain compared to creating a puppet deployment setup, and set my machines from there?

I see no benefit from Docker (but that's why I don't know it well). Any code that does not come directly from the source control is risky, and docker incentives the worst possible building workflow, that is the developer builds everything on his machine, and pass the binaries along for deployment. That's as bad as developing on production.

Rapzid• 11 years ago

Curious this isn't it? It seems that to most application developers docker is merely a faster, different vagrant.. That they have to run in a virtualbox vm because they are on OSX.. The best PaaS experience is pushing code that the PaaS provider then checks out to construct the docker container for you :|

This isn't to say there are not benefits and as a "DevOps Engineer", yay fun stuff people need me to work on!(in addition to security, performance, automation, etc), but hmmm.. There are wins in some areas and added complexity too. Plenty of work to go around.

mpdehaan26• 11 years ago

I don't see this. I think application developers are largely still running out of source control, whether that be in VirtualBox or Fusion or whatever... and Docker files are possibly replacing package build steps.

Maybe it's the case though.

I still think most of the press that Vagrant gets is really "yay, cheap virtualization" attributed to Virtual Box, rather than the workflow - but maybe some people's development environments really are that hard to set up. I like VMware Fusion a bit more.

Still, when a dev env is hard to setup, I like to see automation to do this that doesn't presume I'm running it in a virtualized container. So this could be the same script that a Docker file calls to deploy in production -- whether that's bash, some config tool, etc -- but at least then you are not assuming someone chooses to adopt Vagrant, or is running virtualized, in all cases.

My point in not adopting Vagrant is decidedly minor - I like VMWare Fusion, and I didn't really want to pay for the Vagrant plugin, because my developer machines don't need to be purged that often, and developer-env setup is pretty much running a script, and often the application just runs out of source control. So there's not a lot of dev-env machine rebuild churn.

mpdehaan26• 11 years ago

Yeah, storage seems somewhat rough in particular.

This wasn't meant to be a Docker post. AWS or any cloud that allows messing with load balancers gets you pretty much there too.

However, I like that it provides a localized image builder a lot, and I like docker files themselves a lot, and the idea that it's cross-cloud. I think the other edges can get smoothed out.

nickbauman5• 11 years ago

While PaaS has not become a reality for everyone...

A telling aside. Much of what he wants already exists in Google App Engine (and probably in Elastic Beanstalk, too, but I haven't tried it) — sans the need to manage the underlying OS.

Interesting Google is going the other way with Managed VMs running on top of Kubernetes. Perhaps they will meet in the middle somewhere?

w4tson• 11 years ago

I thought Google was running containers in kubernetes? AFAIK you can install Kubs on VMs

nickbauman5• 11 years ago

We're both correct.

kevinschumacher• 11 years ago

"Managed VMs" is a service offering within Google App Engine that lets you use any runtime (e.g., Python, Node.js, Go, C) but get the benefits of the GAE PaaS auto-scaling, versioning, etc.

It actually works by shipping a docker container to the Google Container Registry (privately scoped to your project), spinning up a "VM" that shows up in your Compute Engine instances list that you can then SSH into if you want (this is why you're both right; they call it Managed VMs, it shows up in your GCE instance list, but they literally are, I think, running your docker container, probably with Kubernetes under the hood).

dorfsmay2• 11 years ago

Yes, I agree, but the issue is still how do you build that infrastructure (be it an AMI, a docker image etc..)?

Docker file sare simplistic, so you end up using the same tools that were available before (ansible, salt, bash etc...).

What we're doing right now is move what we used to do at "configuration time" to "build time".

mpdehaan26• 11 years ago

My point was you don't need to use the tools you use today, except to do the version flip (and probably to deploy the subtrate - unless you are doing a cloud-image solution and not trying to do something on-premise). And this will get better when cloud providers embrace higher level cluster operations more natively.

And build time is the way to go for everything you can push down into build time. There still may be some need for service-discovery type applications.

dorfsmay2• 11 years ago

Agreed, moving more and more stuff to the build, lighting up an image should be nearly instant, so we can do auto-scala etc... so no more "pip install -r" when bringing up an image, that's now part of the build.

But the landscape for tools to build that image, be it a docker image or an AMI, right now, is the same. I find myself "going back" to ansible but now using it to build images rather than change online VMs (could be any tool, I know ansible and it suits my way of thinking).

tomc1985• 11 years ago

So by immutable he means... systems you don't patch? That's it?

KaiserPro5• 11 years ago

I quite like immutable infrastructure. It means you have a rollout/roll back with a flip of a dns/connection.

However I see a lot of things about docker and think two things:

1) most people really wany a mainframe 2) shared filesystems really are brlilliant.

Let me unpack that:

a mainframe provides a massive amount of hardware, a hypervisor and scheduler. This means that you can control a bunch of isolated processes through one one system easily. Something that you can't really do in docker yet (fleet/kubernetes arn't there yet. in a mainframe you can use a single script to control an entire system)

Quite a lot of web config management is about shipping packages to different machines. Almost all of this config, and therefore complication can be removed by using a shared filesystem.

For example we have many version of java. For some reason they are in seperate repos. This means that if you want to change version (openJDK to oracle etc) you have to change config. With a shared file system, in the $PATH, you'd just say oracalejava-1.8 $programme or java-1.7 $programme

If you make your deploys to a similar shared filesystem, then to change config is basically a case of ssh machine, kill old process, launche new process. Job done.

This makes each machine a dumb execution system, minimal state is contained in each node.

With NFS coming to AWS, that'll be the model for my new infrastructure. the reason why? because it works. In HPC thats how we've been managing high scale workloads for years.

ABS• 11 years ago

For those looking into this topic only now we interviewed 6 people who have been doing this for some time, collected their answers and published them + did a hangout with them here: https://highops.com/insights/immutable-infrastructure-6-ques... (pure content, no sales pitch anywhere)

Immutable Infrastructure is the future

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