Well the post kinda answers that already:
>All this with only a bit of C code, as part of the systemd suite. No new dependencies. No Go, no Python, no other runtime.
I can't really say that I know much about Docker but I have gotten the impression that it's an enourmous and monolithic project hence CoreOS went to create their own container runtime called Rocket
>Unfortunately, a simple re-usable component is not how things are playing out. Docker now is building tools for launching cloud servers, systems for clustering, and a wide range of functions: building images, running images, uploading, downloading, and eventually even overlay networking, all compiled into one monolithic binary running primarily as root on your server. The standard container manifesto was removed. We should stop talking about Docker containers, and start talking about the Docker Platform. It is not becoming the simple composable building block we had envisioned.
The systemd stack is composed of small components like systemd-nspawn, systemd-machined and systemd-import that are all written in C with very few dependencies so it remains small.
Btrfs for my / for more than one year now. I use btrfs for longer, but data corruption totally crashed my last install and I could not recover ... I mainly use the snapshot feature for testing on containers. I keep an up-to-date "base" archlinux subvolume and snapshot it for running my tests, and then delete the snapshot. Both operations are instants. Docker is also using it as its filesystem backend.
One problem I sometime run into is that when I run out of free space my system slows down and sometimes freezes completely. Also, df -h
will not show the true remaining free space and you will have to use btrfs filesystem show
for that. The CoreOS documentation has a page for btrfs troubleshooting with some info regarding this particularity.
Note that After= does not imply that the predecessor service is running, just the order in which they are started. If the first service is a prerequisite to the second starting in a healthy state, use both After= and Requires=.
E.g. most LAMP stack applications like WordPress require MySQL to be started before PHP can serve requests. In this case, modify apache/httpd.service to contain the following: [Unit] Requires=mysql.service After=mysql.service
If you are modifying vendor-supplied service files, your changes may be lost when the service is updated. Consider using systemd drop-in files to override the vendor file rather than editing it directly- your changes will not be affected by updates.
Yeah, but wading through the fanboy fluff- is it established that with default settings
Because reading the original COreOS advisory that RH typo copied I am seeing
> RunC allowed additional container processes via runc exec to be ptraced by the pid 1 of the container. This allows the main processes of the container, if running as root, to gain access to file-descriptors of these new processes during the initialization and can lead to container escapes or modification of runC state before the process is fully placed inside the container.
Fundamentally, you are misunderstanding what docker is.
It is not a virtual machine of any sort. It is a framework for process isolation. You need the base OS because every docker image uses the host's kernel. It is just isolated away from all other software and libraries on the system via namespace and cgroups. (for linux anyway, I have no idea how it works on windows)
You could use something like CoreOS, which is a stripped down linux meant for container hosting only.
Looking into it briefly, it appears you can mount your NFS shares to a given host then mount them through to your containers as volumes.
If you want a good understanding of custom resources and operators in go, I highly recommend the operator-sdk tutorial. If you want some heavier reading on the topic, the original article that introduced the idea is a good source too.
You don't want to be off writing a controller for everything, but it would definitely help give you a better understanding of how they work (and how simple they are to write). Then realize that everything in Kubernetes works that way and you'll begin to develop a lower-level understanding of the APIs.
But it was just no a DB designed for that. It was DB designed to store configs for your clusters and have few primitives (events, leases etc.) to help manage it. It was not designed as general purpose DB in the first place
rhel atomic and coreos are sharing lots of solutions I would say that they share some of the solutions with each other.
https://coreos.com/os/docs/latest/install-debugging-tools.html
https://www.google.com/amp/developers.redhat.com/blog/2015/04/21/introducing-the-atomic-command/amp/
Using Docker, as a reference:
Docker images are intended to be a precompiled set of configuration steps, ready to be deployed into an OS of your choice (much like other kinds of images). Typically you see change control on docker images performed in GitHub. Alternatively, you could store a built docker image in an artifact repository, such as Jfrog, Artifactory, ECR, etc. To create these images you need to build from a dockerfile. The dockerfile, as seen from the link, is very similar to a config script, with the intent that the final step run is the return condition for docker. That is, if whatever is run in that step (usually it's a service of some kind) fails or ends, the container will stop.
Deploying docker containers requires you to have the docker service running on a BaseOS of some kind. Ideally the BaseOS is particularly thin (VMW created PhotonOS for this, but CoreOS is a popular alternative) since all of the libraries and third party components should be in / acquired in the docker image. To perform the deployment you want some config management in place; ansible, systemd, whatever. Context with coreos and systemd.
Why you, /u/derpjutsu, specifically need to use containers is something you'll need to figure out. Usually the benefit of containers come from their small footprint, strict control (from a security perspective), easy accessibility in a microservice architecture, and natural fit into an "infrastructure-as-code" environment.
I wrote a blog, for just this reason: https://coreos.com/blog/what-is-kubernetes.html
There's an attached whitepaper that goes into a bit more detail on the "Why" of containers and Kubernetes. But, be forewarned that it'll ask ya for an email address
If you're looking to learn step by step, these 2 guides take the cake.
Kelsey Hightowers guide is my kubernetes bible:
https://github.com/kelseyhightower/kubernetes-the-hard-way
CoreOS guide is also damn awesome:
https://coreos.com/kubernetes/docs/latest/getting-started.html
They are. The addition of a Red Hat employee (among others) as a maintainer to the appc spec is what triggered most of the articles that have come out on the topic this week:
Unless there is some specific need for Ubuntu, you should move to a container-specific distro like CoreOS's Container Linux, which is self-updating using A/B partitions for fall-back. Container-specific distros are much lighter weight, and don't have package managers meaning you never have to worry about keeping any packages up to date on the nodes.
Also, as the updates happen automatically, there is no delay between a release being published and the upgrades being deployed to your fleet. There is no manual intervention or operator overhead required, often allowing CVE's to be mitigated before your operations team is even aware of them.
You can use the Container Linux Update Operator to control the rollout of updates, ensuring minimal impact on your cluster workloads while updates are being deployed.
> Couple it with cloud-init and it's mighty powerful
Ignition is the new hotness.
>It should also be noted, Red Hat recently purchased CoreOS, which is specifically designed to do Docker workloads like you're describing. Since it's now part of the Fedora Project, it might be worth looking into.
https://coreos.com/blog/fedora-coreos-red-hat-coreos-and-future-container-linux
Learning Linux and learning to work with Linux servers in the cloud with containerized applications are mutually exclusive objectives.
That being said, any aspiring Linux user interested in cloud publishing will want to quaint themselves with CoreOS
Because systemd-networkd's authors think that, and I suspect they know what they're doing. It's mainly intended for static environments.
Connman and network-manager are targeted at mobile devices.
CoreOS shouldn't run in the containers. The way we did it was to have one VM running CoreOS and then the containers running in that VM. We used https://coreos.com/docs/running-coreos/platforms/vagrant/ and ran a single node cluster for the development environment. If you are talking about a production environment then CoreOS would be the host OS and the containers running on it.
For us each docker image was based on the appropriate base image for the process that was running.
ExecStartPre
commands runs in the same environment as the service. They are launched by systemd.
systemd lets you specify the environment variables. Read https://coreos.com/os/docs/latest/using-environment-variables-in-systemd-units.html
If the service already has an ExecStartPre
line and you want to override this you can do ExecStartPre=
(empty command) to reset the list. Then you can add as many lines of ExecStartPre
as you want to run commands before the service starts.
This is really good to quickly start a testing environment, or even deploy onto a small infrastructure. My team was able to immediately start testing and experimenting with kubeadm, even locally with virtualbox vms. Kubeadm, however, does not support HA installations (redundant api servers, etc).
Anyone looking for a larger, more robust deployment, should definitely look into Kubespray. We've redeployed kubernetes a couple of times in a lab environment using it, and it seems to work really well, especially for barebone installations with Ubuntu VMs on top.
Aside from that, honourable mentions go to CoreOS and Kubernetes The Hard Way installation guides. KTHW provides direct help deploying to GCE and AWS, while CoreOS's is aimed towards their proprietary enterprise solution. Both of them have a lot of details that can be valuable to others.
> ... why there needs to be an article about this at all ...
Here's why: https://medium.com/aws-activate-startup-blog/coreos-and-startup-infrastructure-that-scales-ae279f6ea2ba
Their customers are waking up to the significantly decreasing business value from paying for RHEL and JBossAS licenses in a reality where hardware certifications are moot because of virtualization, cloud, and now containers, and on the application server side, thick JEE with EJB/CDI/JSF has been all but buried in a shallow grave, and de-facto standard systems created by people who actually use them in everyday work having taken their place.
Openshift is Kubernetes under the covers. As a result, it isn't particularly opinionated on how you go about deploying your applications. You can use any of the methods you've listed out there - they'll all work (although with Helm there are some security considerations around Tiller you may need to care about depending on the version of Helm you use).
The other option to consider is packaging your application as an Operator. This is probably something to consider when you're more comfortable with things like Ansible or Helm, but it is becoming more commonplace and will be the primary method for vendors or ISVs to deliver applications onto OpenShift when 4.x is released later this year.
PXE boot CoreOS, Matchbox, Ignition, Bootkube -> self hosted cluster with hyperkube. Easy as pie 😁
Hope RedHat doesn't fuck up CoreOS
https://coreos.com/matchbox/docs/latest/matchbox.html https://coreos.com/ignition/docs/latest/ https://github.com/kubernetes-incubator/bootkube
But, OP is asking about setting up K8 on a single laptop. And from the rest of it I took it to assume they aren't interested right now in the actual setting up of K8, just using it.
What does Kubespray actually do? I've been meaning to convert my R320s to a Container Linux cluster which seems like what this is sort of targeting. I want to do it "clean" and not have special additions that something like minikube has. It is really more like a script and the end result is a kubernetes cluster or is it a kubespray cluster?
As reference I was going to follow this.
If it helps, Matchbox is an example of booting CoreOS on PXE. https://coreos.com/matchbox/docs/latest/matchbox.html
I work at CoreOS, but I'm not sure about your particular error. I can recommend cross-posting this to https://github.com/coreos/bugs/issues/new
Devs read issues, and are the folks best equipped to help you troubleshoot. Be sure to include relevant debugging info! <3
I am not familiar with Hetzner's specifics but we do a lot of work to make the bare metal install on CoreOS Tectonic as simple as possible. Here is an overview video and the install instructions.
I've also been using the Prometheus operator in my local dev kubernetes cluster recently: https://github.com/coreos/prometheus-operator
General info on kubernetes operators: https://coreos.com/blog/introducing-operators.html
I love how operators capture and automate admin tasks in software and make deploying/managing complicated applications a lot easier. Are there other interesting kubernetes operators out there you all have been using?
I highly recommend CoreOS or a CentOS 7 based Project Atomic. CoreOS is more mature than Atomic but both have more recent version's of Docker. CoreOS stable branch should be modern enough & stable. Add the fact that the OS has no package management and very little userland tools you shouldn't have any stability issues. I wouldn't recommend running alpha but you can get away with Development for obvious use cases and Stable for UAT/Prod
I advise against Amazon linux because it lacks SystemD and they sort of want to lock you into their ecosystem, though useful and helpful. I prefer to stick with SystemD and use my own key/value store with some scheduling like Fleet, Kubernetes or Mesos.
I've been running a 5 node CoreOS cluster for a lot of my home stuff, Unifi controller, Plex media server, other various use cases. Have had zero issues with availability and down time. ConfD really helps keep my servies running when updates get pushed automagically.
Just my .02
References: https://coreos.com/releases/ http://www.projectatomic.io/download/
static analysis a complex topic. there are CS majors writing theses in it regularly and producing new tools/techniques.
besides, how many things in computing have "security" built in at all? I think it's a small miracle that people are investigating it this early into the product life cycle!
that said, I do think Rocket looks more appealing to me. they focused on security and specifications as first-class design goals.
Not a ton.
CoreOS is a super stripped down OS that is basically only meant to run docker containers. It has facilities for running SystemV things, docker, and that's almost it. Basically, if everything you're deploying lives in a containers, it's a great fit. https://coreos.com/
NixOS is a "functional" OS that has a package manager that does immutable deploys. http://nixos.org/
IMO CoreOS seems more mature at this point. However, that's definitely open to debate.
My first thought was to build something on top of systemd to manage systemd across many machines. Then I remembered Fleet which is a technology that a few distros have picked up.
You could use docker on coreos https://coreos.com/using-coreos/docker/ and etcd instead of consul as Registrator works with both. If etcd can write an nginx config and reload nginx when a query changed then that could replace consul template. I think then the two systems would be basically the same.
systemd-networkd has been around since 210 and we are at 215 now. Why is it needed and why did RedHat hire the Arch developer who started it? Because CoreOS.
https://coreos.com/blog/intro-to-systemd-networkd/
Also who doesn't want to be able to accurire a DHCP lease in 750µs compared to the regular 500ms?
It's funny how people like to overreact to systemd. We had the same thing years ago in the Arch Linux community when the switch to systemd was made. People acted like the Apocalypse was upon use and in a year nobody would be using Arch anymore..Weeeelll that didn't happen. Arch is more popular than ever. Now Debian and Ubuntu peeps are acting like they're stepping on uncharted untested territory, lol.
Containers on their own replace some of the need for VMs, but far from all of them. At some point, those containers still need to run in a machine, and the benefits of VMs over bare metal still apply to those machines.
If anything is going to replace many VM stacks, it's something like CoreOS (which does use Docker), but the benefits of that only apply to massive scale operations. Someone hosting a few Rails apps isn't going to have the kind of hardware or needs to really benefit from that.
There's etcd, though I'm not quite sure where it fits (or could fit) into the picture yet:
https://coreos.com/using-coreos/etcd/
It, along with the rest of CoreOS, seems like a very different way of doing things. I'm not sure how things will play out, but it's still something I'll keep an eye on nonetheless.
> If you have Linux and systemd (as well as all the necessary libraries) it should provide you with everything you need to bring up the system
You're describing CoreOS. https://coreos.com/
I found matchbox helps a lot https://coreos.com/matchbox/docs/latest/matchbox.html
It does PXE booting and provisioning "cloud-config style" of your machines and k8s (but anything else too) cluster.
We're using Container Linux with kops to build/update multitenant k8s clusters in AWS from GitLab CI. Red Hat just bought CoreOS and announced they are retiring both RHEL Atomic and Container Linux in a few years and coming out with a new OS (RHEL CoreOS) that they expect folks to move to in the next year or so.
I briefly looked at the GitLab integrated Kubernetes capabilities but for building out the initial multitenant clusters, we wanted an infrastructure-as-code approach which led us towards running kops via GitLab CI to build the clusters. We may still end up using the GitLab integrated monitoring for our app teams to monitor the apps they push up to the clusters.
Anyways, as far as updates, with Container Linux, the OS updates automatically and by default reboots automatically after the update is applied. You would turn off the auto-reboot and use the Container Linux Update Operator to coordinate reboots to not impact availability.
It's literally in the patch notes, dude. No need to read any irc, mailing list, slacks etc. Just the notes. No need to be 100% on top of all the changes, only when you want to apply a change.
If you want to upgrade or install a new version, read the notes of all the versions in between if you're skipping a few. It took 2 minutes to find these.
I wanted to let you know that the docs you referenced (https://coreos.com/kubernetes/docs/latest/kubernetes-on-generic-platforms.html) are being sunsetted and the Tectonic installer from CoreOS are the most tested path forward. Gets you can enterprise-grade Kubernetes set up with bare metal/PXE, very similar to what you were doing, but the CoreOS team has done the hard work and testing for you. Free for up to 10 nodes and uses Terraform for repeatability.
Should get you up and running quickly if you're interested:
https://coreos.com/tectonic/docs/latest/install/bare-metal/metal-terraform.html
If you aren't familiar with the CoreOS Tectonic Installer it is an OSS project that enables Kubernetes with or without the Tectonic components to be installed on various platforms. You can learn more at https://github.com/coreos/tectonic-installer
Yes the CoreOS guide based on etcdctl
is what you want. Related, I wrote a tool called burry that can back up and restore etcd2 clusters (w/ SSL/TLS disabled).
Running a ramdisk.
So, basically it PXE boots a CoreOS image and then just runs in RAM, never touching disk.
It does support it. https://coreos.com/os/docs/latest/booting-with-pxe.html
I see Rancher has an option for HA. Have you messed with that at all?
CloudConfig is a file format used by CoreOS. Nothing is stored in the cloud, the cloud-config is just a file that is provided to the operating system on boot.
It depends on how long-lived your services are, I suppose. From my understanding of the description, it appears as though you would like to spawn a short-lived container to do some work, and once the work has completed, the container exits. I think you are on the right track with the messaging queue, but I would prefer to have the processing backend be a cluster of longer-lived containers, meaning they do not die after processing one unit of work. Instead, they are a stateless cluster of containers, each subscribing to the same queue. If you are looking for a way to join the Flask app, the messaging service, and processing services together from a networking perspective, I would recommend a service discovery tool (like consul or etcd). This helps your applications/containers know about one another without having to statically define where each of the services are. You can simply query the service discovery service to get the IP and port of each container/application. There are also tools like registrator which can automatically register/deregister your container to the service discovery endpoint when a lifecycle event occurs.
That's a good start.
What can you say about https://coreos.com/legal/managed-linux? (Section 5 "Ownership Rights" seems completely inappropriate boilerplate legal wording. And Section 7 "Non-disclosure Terms" is as bad or worse than RHEL terminating rights if you distribute binaries -- this terminates rights for disclosing pretty much anything!).
Sure. CoreOS is implementing trusted computing: https://coreos.com/blog/coreos-trusted-computing/. This gives users deploying software onto their own hardware a way to sign software so that only it will run on that hardware. Conversely, you could sign software such that only this hardware will run this software.
Key management today is a bit of a challenge for the user to wield, but it's shortly going to get a LOT worse to manage because SaaS companies are being asked left and right to deploy their stacks "on premise". This MSaaS stuff (managed SaaS) means, basically, clouds of clouds become the target deployment, as opposed to a single cloud infrastructure as the target deployment (like DO or AWS). Coupled with the challenge of getting services (think SOA services) talking to each other and worse, services from multiple vendors talking to each other, you end up with what might appear to be an infrastructure configuration nightmare.
The solution to all of this is simple: put configuration data, including stuff that describes operational intent, and images for running things, into a data structure that allows decentralized trust to be established between the various services and systems running software.
It's called Wisdom. I'm working on a small PoC for a large company right now for it. I should have something out mid-year for everyone to kick the tires on.
BTW, I'm not the only one working on this: https://guardtime.com/solutions/cloud
Disclaimer: I work for CoreOS
If you're interested in using CoreOS for deployment, or want to avoid using Docker to run Kubernetes, CoreOS natively supports basically everything required to run Kubernetes, and we've written quite a few guides on getting started with Kubernetes.
We have many guides, but our simplest is the single node Kubernetes cluster.
This includes all the fun stuff like setting up TLS even, which means you've got an authenticated Kubernetes API running in just one command.
If that went well, we also have multi-node vagrant instructions, and instructions to get Kubernetes deployed on AWS.
Let me know if you have any questions, you can PM me here, on the coreos-community slack, the kubernetes-users slack (chancez on both) or even the #coreos IRC channel (also chancez).
Can you give examples of specifically what documentation you're having difficulties with?
In your title you seem to be referring to the public discovery service. There's guides on how to use an existing etcd cluster for discovery here: https://coreos.com/etcd/docs/latest/clustering.html#etcd-discovery
Bare metal docs are fairly brief, it's mostly on using coreos-install
onto a disk or using PXE, but that's because those are really the only options. What else would you like to see? Anything in particular?
Hear, hear...lets hear it for CoreOS. Honestly I am quite impressed with CoreOS and how simple it is for administration. I have only had 1 or 2 issues with one of my nodes not upgrading to a newer release when it should have...I just unlocked the locksmithctl or something like that and viola, it updated on it's own.
I was actually glad to hear that the newer releases of CoreOS were NOT using btrfs. I know it was giving them problems, so they went away from it. However, I still have some nodes that I built late last year that ARE still using btrfs and they have given me no issues. It seems that currently half my cluster is using btrfs and half isn't.
I have a guy I work with that I can't get to use CoreOS...he is serving up containers via Docker and Kubernetes in his Ubuntu VM's managed by SaltStack. He either doesn't have time or doesn't see the value in using CoreOS and I believe his containers are over-sized.
On the other hand my buddy works with production CoreOS/Kubernetes/Fleet/Docker (and also assisted me in building my cluster) and he builds lots of containers. Smaller and more streamlined containers are the way to go. His company uses Alpine Linux as the base for a lot of their containers.
An example of container comparison...My buddy and I built a Tmate container to run on my cluster. We based it off of this Tmate slave which is about 500MB and we built this tmate slave which is about 18MB. Both do the same thing, but the one we built will take a lot less resources; less resources used = more containers/node.
The CoreOS fleet model has impressed upon me quite a bit. I use docker containers to isolate daemon related processes and Systemd to orchestrate processes in the context of a system as a whole. If there is no run time dependencies I will forego docker.
I even use Systemd in the user context too!
1: Theoretically no, practically yes ;)
Almost all OSes could be used for a similar technique as linux containers. Technically it isn't as much of a problem as long as the kernel provides features to isolate processes. The problem is providing containers. To provide a container you need access to almost the whole chain of dependencies upwards from the kernel to the program you run. So in practice this is only feasible with Open Source software. You are just not allowed to redistribute Microsofts ISS along with your web application in a container. So windows and MacOS platforms are pretty much out of question for this. Other OS platforms are a different matter. Afraid I am not really up-to-date there but I don't really see any reason why any of the *BSDs shouldn't have something like this as well. But right now it's predominant only on linux platforms.
2: Snappy Ubuntu Core tries to establish itself as container platform OS for servers. it has some interesting features that could serve this purpose pretty well like their transactional patching...meaning they try to make sure that a patch either gets applied completely to a package or not at all. Overall it looks like a system that only works with containers for everything. Also the OS itself is very stripped down with only the absolute necessary. All the "real" functionality is provided through container applications. In the end it is a server distro for the specific purpose of running containers with soe interesting tools to manage containers. It's in "competition" with CoreOS most likely.
> I completely understand wanting to strip systemd from single-purpose VM server OSs. Systemd has no place in a lightweight system like that. [...]
Isn't this exactly what CoreOS was designed for? CoreOS uses systemd last I checked.
I feel like a lot of people think that systemd is bloated, but similar to the Linux kernel, it can be configured to omit various components at build time, and you can also prevent stuff from loading at runtime too and use your own components (like choosing a different syslogger).
Furthermore, I think if you measured memory use and efficiency for all of the functionality that systemd replaces, even in single-purpose VM OSes, you might find that the systemd functionality uses less total memory all in all.
I'm not saying systemd absolutely fits this role, rather, I'm saying I wouldn't rule it out just yet.
> [...] The fact that Linux shares code across a multitude of different devices has been a huge boon in unexpected ways. [...]
Yeah, the best example I can think of is multithreading. Linux's multithreading was originally for server use cases, but suddenly desktops and even phones have multiple cores.
I thought based on this https://coreos.com/validate/
> On May 26, 2020, CoreOS Container Linux reached its end of life. CoreOS Container Linux is no longer maintained or updated, and all users should migrate to another operating system.
That the only option to find docs is on Red Hat pages.
But after your comment, started to look around and found this one https://coreos.github.io/ignition/
Lack of demand and limited resources to bring integration with those distros to the quality that enterprises require. You're welcome to try OKD on them and tell us what you think though !
The great thing about Linux is that you can really fine tune the distro to your use-case and I find that CoreOS sufficiently meets that criteria for OpenShift. Immutability + operator model really simplifies management of the OS layer and those other distros might devolve from this to some extent.
Was going to also recommend Container Linux(formerly CoreOS) and PXE to build a ramdisk then plan on using something like Ceph mounted as RBD for anything persistent "locally" as well as to expose persistent volumes for containers running off the host.
You are right, there's no formal definition - however, here's the project that coined the term:
https://coreos.com/blog/introducing-the-etcd-operator.html
> Today, CoreOS introduced a new class of software in the Kubernetes community called an Operator. An Operator builds upon the basic Kubernetes resource and controller concepts but includes application domain knowledge to take care of common tasks.
> The etcd Operator simulates human operator behaviors in three steps: Observe, Analyze, and Act.
And it then goes on to describe the runbook procedures for cluster recovery and upgrade.
This is runbook automation. What most "operators" do is little more than while true; do kubectl apply -f ...; done
- these operators have no reason to exist and are I believe the real cause behind the OPs frustrations.
Maybe it was this release? Not sure which channel you are using: https://coreos.com/releases/#2512.1.0
From the changelog: Fetch container images in docker format rather than ACI by default in etcd-member.service, flanneld.service, and kubelet-wrapper
You could run backups as a systemd service + timer, see https://coreos.com/os/docs/latest/scheduling-tasks-with-systemd-timers.html for more info.
If restic fails, it will show up as a failed service and you can pick that up easily through your monitoring tools.
systemd's unit ordering mechanism could make sure that for these units, docker and networking should be already running: https://coreos.com/os/docs/latest/getting-started-with-systemd.html (while CoreOS' Container Linux is slowly going away, the documentation can still be useful).
On the retirement notice page for CoreOS there's a link to the firm that will keep CoreOS going, albeit in a different name. On my phone and can't remember what it is, but it's easy to find.
Does anyone know if this Fedora CoreOS is the fabled "stream" Fedora rolling distribution that was extensively written about then disappeared?
Update: https://coreos.com/os/eol/ about half way down; flatcar.
It's sad that the Fedora Atomic project failed so they bought the competition and killed it, in a Microsoft like way. But as they say "no-one ever got fired for buying IBM".
You may want to use the terrafotm-ct-provider. You need to install it manually.
Also, coreOS container Linux reached end of life: https://coreos.com/os/eol/
You may want to try the alternative there or Flatcar Linux: https://www.flatcar-linux.org/
But don't go with coreOS container Linux :)
Firewall rules are defined by Kubernetes as a Network Policy.
OS updates are ideally done on an image basis and shipped as part of your Kubernetes distribution. Ideally, you don't think about updates. You define a maintenance window, the node moves its workloads to another node, and it restarts to the new OS image.
https://coreos.com/why/#updates
Any software installed on the host and not deployed by k8s as a container is an antipattern.
I would add that the benefit of having multiple containers inside of a pod for Kubernetes allows for these containers to share a network namespace (as well as other namespaces such as volumes and secrets). This allows you to have a service connected to your application for logging or monitoring within the namespace for that application adding an additional separation for security. This page from CoreOS seems to provide some helpful information: https://coreos.com/kubernetes/docs/latest/pods.html
Found this little gem thanks to the support team, https://coreos.com/validate/
We have standard support and it took a couple of weeks to get this caught. Not blaming support but perhaps this should be right up there with the ignition config section in the docs.
One way is to use systemd unit files to manage the lifecycle of a container: https://coreos.com/os/docs/latest/getting-started-with-systemd.html#unit-file
This might help.
​
https://coreos.com/etcd/docs/latest/v2/docker_guide.html
​
Not seeing that -peer-addr in the configuration flags.
Have your rule trigger systemd to start a unit for you. You have way more control over the environment your unit runs in that way.
Here is some documentation: https://coreos.com/os/docs/latest/using-systemd-and-udev-rules.html
I like option three. I always refer back to https://coreos.com/os/docs/latest/generate-self-signed-certificates.html
Make a CA, and then a cert. Add the CA to your trusted root. Install the cert on the server.
No futzing around with any nginx or apache noise. Just gimme my ssl certs.
Oosh, BTRFS has been the plague of many a woe in the past, and there's a pretty major gap for RAID5/6. Docker <em>used</em> to use it for their container linux, but moved away. My general preference is for XFS, though at the sub petabyte scale, there's no compelling reason not to use good ol' ext4. And sure, if you go the JBOD route, you could leverage a software raid solution, which is much more flexible in terms of utilizing disks of disparate size. I mention this, because at $110/pop, you're looking at $2600 for new disks. Not the most economical solution, IMO.
CoreOS Container Linux is being integrated into Red Hat OpenShift. It may not have much of an independent future. See: https://coreos.com/blog/fedora-coreos-red-hat-coreos-and-future-container-linux for details.
For anyone coming to read this, turns out etcd already has essentially this exact functionality in its v3 API. The lease API: https://coreos.com/etcd/docs/latest/learning/api.html#lease-api
All the best.
Well, the message "This product is being integrated with Red Hat products. To learn more, read the blog post." on pages like https://coreos.com/tectonic/ makes more than one person a bit uncertain of how wise it is to stay on what used to be CoreOS tech. Will there even be a Tectonic in the future, or will one have to migrate over to OpenShift?
The blog post they refer to states:
> In the meantime, current Tectonic customers will continue to receive support and updates for the platform. They can also have confidence that they will be able to transition to Red Hat OpenShift Container Platform in the future with little to no disruption, as almost all Tectonic features will be retained in Red Hat OpenShift Container Platform.
...and that is not the same as "you can keep using Tectonic, no worries".
Have you considered Container Linux?
I suppose you could do the same with any linux distribution (have a parallel installation and apply updates in a chroot) but that would probably take quite a bit of work.
Sorry, we spent the first couple of pages trying to explain how etcd is a consensus database based upon the Raft algorithm, and how it's the key thing that Kubernetes is built on top of. CoreOS's description may be better? https://coreos.com/etcd/docs/latest/getting-started-with-etcd.html
The problem is to get the ignition file into the booted coreos instance.
The documentation states:
"
There is no straightforward way to provide an Ignition config.
" (source: https://coreos.com/os/docs/latest/booting-with-iso.html)
I already created an ignition file with my public key and a user with a password hash. But I cannot manage to
get this ignition.json into the install script...
Ok so here's how I did it:
First, bang your head against the wall as you need to dull your senses.
Setup an ignition.json file with your publiic key in it:
https://coreos.com/os/docs/latest/installing-to-disk.html#container-linux-configs
Then run:
sudo coreos-install –d /dev/xvda –o xen –C stable -i ignition.json
And login with your private key and passphrase
Sorry if this sounds a bit snarky, but I'd start with one of the docker vagrants and steal configuration from there to get k8s working.
This one works as advertised:
I don't have much Kubernetes experience, however, if you want to double down on Kubernetes (and thus docker), I'd recommend considering specialized OS for containers. I was playing with Rancher OS for a bit, really enjoy the ability to switch docker versions with a simple command. I've also heard great things about Core OS which is specialized for Docker and Kubernetes. If you don't want to leave too far from VMWare, there's also VMWare Photon to play with.
Networking wise and other tooling I don't have recommendation though, sorry.
Red Hat bought CoreOS and “With the acquisition, Container Linux will be reborn as Red Hat CoreOS, a new entry into the Red Hat ecosystem. Red Hat CoreOS will be based on Fedora and Red Hat Enterprise Linux sources”. Therefore classic Container Linux is unmaintained.
EDIT: Forgot to add the source of the quote: https://coreos.com/blog/coreos-tech-to-combine-with-red-hat-openshift
This week I did some cluster re-installs on container linux, first with containerd + kube-proxy + canal, then with rkt + kube-router
Managed to get ignition (version 0.8.0) YAML configs that would completely install Kubernetes in a single-node-master setup on a container linux box.
Maybe you have seen the announcement about the Operator Framework already. You will find a small section about open-sourcing the Metering (aka CoreOS Chargeback) project. That will run on any Kubernetes environment w/o any Tectonic requirements. We are about to finalize the last bits and pieces to make it available for everyone.
I understand your use case, but what's the concrete problem you are trying to solve metering by service/namespace?
(Disclaimer: I am part of the product management team working on this project.)
"etcd v2 will no longer be shipped with Container Linux after June 2018. For information on working with previous versions, please see the etcd 2.3.7 Documentation."
https://coreos.com/etcd/docs/latest/
I am glad to see that it has been removed in April ...
You're largely looking at x86_64. If you're more risk tolerant, there are also a few options for building to other targets https://coreos.com/os/docs/latest/sdk-modifying-coreos.html
If it's a few thousand devices, I suggest posting on the user forums, and a dev can get a bit more technical with ya on the pros/cons of diff options. For instance, it's probably going to make your team feel more at ease to learn more about how Container Linux is tested every release.
This box does hold an embarassing amount of not yet backed-up state -- Nothing mission critical, but there are databases for projects that I don't have backed up anywhere except on the local disk, and to torch the box I'd need to snapshot the FS at the very least (I'm running ceph, so theoretically I could add another node, rebalance, then torch the one node).
I do use ansible, so I definitely understand the savings though (and I'm not sure if I noted it in the article, but I was actually playing with Kubernetes before the incident, another big piece of the servers-as-cattle puzzle) -- I'm just not sure it would have changed much if I had run the update (and fubar'd the boot) from an ansible script or myself. Ansible would have helped on the rebuild though, but technically if I had set up the box with ansible, and this problem happened, it'd happen over and over again until I decided NOT to do the update (then I'd be back to figuring it out and trying to debug it, maybe on a spare machine).
"torching a box and rebuilding" is definitely the goal though (rephrased, treating my servers as cattle and not pets), but I'm not quite there yet -- in particular the backup issue is my biggest worry. I think the system I've used that's gotten me the closest to this was CoreOS's Ignition. CoreOS had multiple partitions for upgrades, and would rollback automatically IIRC if an upgrade failed, and encouraged you to provision systems using Ignition and completely map out your system in YAML basically -- brilliiant as far as I'm concerned.
At the end of the day it seems like it's almost impossible for someone to truly run a group of servers as cattle and torch at will -- surely the DB/data cold-storage servers you'll have to be more careful with? How are people handling this?
I've heard good things about tectonic: https://coreos.com/tectonic/ They definitely simplify a lot of the work that would have to be done to deploy kubernetes on aws.
Not sure where they're at now that they got bought by RedHat
For context to what Crotherz is referring to. CoreOS announced well over a year ago that Fleet would be deprecated in Early (Feb) 2018.
Here is the blog post from Feb 2017: https://coreos.com/blog/migrating-from-fleet-to-kubernetes.html
Its really important to read announcements and release notes for the software you use! If you're running CoreOS, you need to have an idea of the roadmap and to plan accordingly. You can't just take some component for granted. Same with Docker (I'm looking at you --link or Registry v1) or any other software you use. You can't plead ignorance when it breaks, they usually give lots of notice and time to plan accordingly.
Brandon responded to a similar complaint on Twitter. https://twitter.com/BrandonPhilips/status/981939337725075457
> I am sorry for the trouble. This was an effort to remove deprecated software from early on in etcd's history. You can read more from the deprecation post in January 2017: https://coreos.com/blog/toward-etcd-v3-in-container-linux.html How could we have given you a better notification?
I work at CoreOS. If you have a suggestion for a better way to notify you, I'll make sure he sees it.
Our pricing on CoreOS Tectonic is per virtual node/year and is very competitive to other infrastructure offerings; particularly when you account for the features and integration of updates, identity, monitoring, and everything else.
I can reassure you that at no environment size and in no environment (cloud or on-prem) is our pricing close to the level you have there. If you would like a quote please reach out via or https://coreos.com/contact/
We count vnodes as 2 cores which is pretty standard in the industry and we find many organizations are used to buying this way. Although, we are beginning to see interest in finer-grained metered pricing as organizations get more used to cloud offerings.
Brandon Philips, CoreOS
Operators sounded so cool to me when they were first introduced that I'm actually puzzled why there aren't more of them. I sure would have had great use for RethinkDB, PostgreSQL, Redis operators at Transloadit :)
They sound rational. I think you can still use the beanstalk Docker AMI even if you don't use it with beanstalk. You can also use the CoreOS Container Linux AMI it has docker built in already. If you still want to install and manage it yourself start with packer or even just a simple user-data script. Cattle vs Pets. Avoid live updates as much as you can.
Checkout CoreOS Tectonic and the Tectonic Installer. This can install on baremetal and there is active development to suppport VMware if that is what you mean by "vms".
You're not the only one. There are efforts to factor out pieces. The cloud providers are in the process of being moved out, for example.
The new 1.7 API aggregation means that together with custom resource definitions (formerly third-party resources), you can add functionality to Kubernetes that looks like it's completely built-in, even though it's not. Once this stuff settles, I'd expect more of the core functionality to be pulled out.
This guide makes an interesting choice with regards to etcd security, which I'm not sure I'd go with.
etcd stores a load of sensitive cluster information, so unauthorised access to it is a bad thing.
There's an assumption in the guide that you have a "secure network" and therefore don't have to worry about etcd authentication/encryption. The thing is if you have a compromised container (say) and that container, which has an in-cluster IP address can see your etcd server, then it can easily dump the etcd database and get access to the information held in it...
Personally I'd recommend setting up a small CA for etcd and using it's authentication features, there's a good guide to this on the CoreOS site https://coreos.com/etcd/docs/latest/op-guide/security.html
Good Q! This doc on mounting storage might answer part of your question.
As for whether your particular hardware is supported, best way to find out is to just test it.
I have experience with Kubernetes. Its biggest benefits would be that it's self-healing, well-tested, and easy to scale. Look into rolling updates, and how k8s monitors desired state.
The big negatives are that "right way" to do stateful apps (like DBs) is still being figured out (stateful sets).
If you're looking for an easy way to trial k8s, Tectonic makes it dead simple to install. Caveat: I'm biased; I work for CoreOS.
There may be some Java variables in your environment that are not in the service's environment. Here is how to put environmental variables in unit files.
No idea what impact order might have. I'd follow this CoreOS setting up k8s guide and see if it has what you're looking for.
You do not have to use IPNS, you can just keep track of the current top level hash inside your application.
Problem comes then you need to scale it out horizontally over multiple machines, in reality you need a very fast distributed key-value store, something like Etcd3 used by Kubernetes/CoreOS to scale out to 2000 individual servers.
Try this https://coreos.com/kubernetes/docs/latest/kubernetes-on-aws.html
The guide doesn't go through all the options, but once you have initialized the cluster template take a look at the cluster.yaml
file, which lists other config options as comments.
I found that to be a good starting point, but eventually did away with these tools and built out my own CloudFormation scripts with pre-built AMIs that make it easier to bring up a new cluster within existing infrastructure.
For anyone who wants the nosebleed latest and greatest, as well as the CoreOS doc that's referred to: