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Thanks for the writing up, really nice series so far! I would like to know what are the competitors of Kubernetes to run docker in production and if you think K

by aprdm 11y ago

Thanks for the writing up, really nice series so far! I would like to know what are the competitors of Kubernetes to run docker in production and if you think Kubernetes is suitable for small / single man projects? Or what would you advice instead? Cheers

argc 11y ago
I use kubernetes in production at work for a large website and at home for very small projects. It is awesome for both.
krenoten 11y ago
Kubernetes is very much still under development. Most of the work up to 1.0 has gone into refinement of the API, rather than stability. For instance, HA is only now being seriously worked on - and if your API server goes down and you need to start it on another host, if you don't have an external reconvergence mechanism you have to restart every kubelet so they can point to the new one. Mesos is much more mature, but is more low-level, and schedulers like Aurora or Marathon do not give you the same service abstraction, but they have many features not currently present in Kubernetes. But, in return for being more low-level, you can run things that are simply impossible in a declarative system like Kubernetes. Personally I see Kubernetes-on-Mesos as being a really bright future choice, but like pretty much anything other than Marathon/Aurora on Mesos, it's pretty nascent.
- kalmar 11y ago
  > But, in return for being more low-level, you can run things that are simply impossible in a declarative system like Kubernetes. Can you give an example? I know next to nothing about Mesos, Aurora, or Marathon.
  - krenoten 11y ago
    It's like many things that are declarative - you can only do what has been explicitly enabled in the declaration handling logic. This is good and bad. It's good because it restricts what is possible (protecting you slightly more from bad users) and can make learning and using the system easier. But you can't go beyond this. With a non-declarative scheduler you can implement far more interesting (for better or worse) management systems. One area where we've been seeing some interesting work happening is in stateful services running on top of schedulers. With something like postgres, there is interesting logic that must happen for responsible management beyond just throwing up 3 of them. You need to manage replication carefully. When a node goes down somewhere, you need to react somewhere else in a controlled way. With Mesos, you can write a scheduler that encodes your runbook. With kubernetes, you need a lot more out-of-band stuff.
    - TheIronYuppie 11y ago
      Disclaimer: I work at Google on Kubernetes. You're correct that the scheduler in the box is declarative. However, it is easy (well, as easy as writing a framework) to swap out a scheduler that might be a better fit for what you're looking for. See this stackoverflow answer by one of the core Kubernetes team for more info: http://stackoverflow.com/questions/28857993/how-does-kubernetes-scheduler-work http://stackoverflow.com/questions/28857993/how-does-kuberne...
- mkulke 11y ago
  Yeah, the HA information was buried/non-existent in the docs until recently, I guess. We also ran into issues when replacing the master, b/c the kubelets where fixed to an ip and the nodes' configuration was basically immutable (provisioned by cloud-config). What worked for us: Accessing the the master by DNS and putting etcd on a persistent volume. This way we're able to replace the master within a DNS records ttl. As the api server is not a hard requirement for the workload, this is HA enough for us.
kalmar 11y ago
I don't really know what the alternatives are. I'm hoping by the end of this series to convince at least myself that it's reasonably to run for personal projects.
parasubvert 11y ago
There is Lattice, http://lattice.cf http://lattice.cf which is single-tenant Cloud Foundry. You can get it up via Vagrant or Terraform. The underlying scheduler, Diego, has some interesting constructs, like supporting Windows, Docker, and buildpack-built containers (aka. droplets).
- ersoft 11y ago
  I had tried lattice but I don't think it is ready for production usage. When I reported a few security issues on their issue tracker, I've been told that lattice is just a stripped down version of Cloud Foundry designed for development usage. I think it's obvious that k8s is designed for staging/production usage and I can't see where lattice fits there. Also, lattice is not running docker containers, but garden containers. There are a lot of issues on their issue tracker about people not being able to run images from docker registry.
  - parasubvert 11y ago
    Hi, fair points, I would agree Lattice out of the box is not quite ready for production usage, mainly because it has stripped out a lot of the security/multi-tenant features from Cloud Foundry to simplify the experience. That said I would say it is just a matter of time (this Fall) however. I mentioned it because it is a way to wrap one's head around Cloud Foundry ; really the production alternative to K8S is Cloud Foundry today, depending on your goal. (If you must have rootfs control and Docker, then no. If you want to stage/run your app in a scalable, reliable container scheduler with a set rootfs then yes.) As for Garden containers, yes, the main issue has been security -related gaps between Docker images and the Garden runtime, as Garden locks things down differently. Most (not all) of these have been fixed in recent builds, as the push for Diego GA in Cloud Foundry gets close over the next few weeks.
CMCDragonkai 11y ago
Check out http://datacenteroperatingsystem.io/ http://datacenteroperatingsystem.io/
TheIronYuppie 11y ago
Disclaimer: I work at Google on Kubernetes. We would (biasedly) say that Kubernetes is ready for production today, and have lots of public folks (Samsung, eBay, Porch, and thousands more) who are doing so. If you're in any way concerned about the management, feel free to get a trial on GKE (the hosted version of Kubernetes) on the Google Cloud ($300 trial free). We have a 99.5% SLA on it, so it's backed by Google engineers.

by aprdm 11y ago

argc 11y ago

I use kubernetes in production at work for a large website and at home for very small projects. It is awesome for both.

krenoten 11y ago

Kubernetes is very much still under development. Most of the work up to 1.0 has gone into refinement of the API, rather than stability. For instance, HA is only now being seriously worked on - and if your API server goes down and you need to start it on another host, if you don't have an external reconvergence mechanism you have to restart every kubelet so they can point to the new one. Mesos is much more mature, but is more low-level, and schedulers like Aurora or Marathon do not give you the same service abstraction, but they have many features not currently present in Kubernetes. But, in return for being more low-level, you can run things that are simply impossible in a declarative system like Kubernetes. Personally I see Kubernetes-on-Mesos as being a really bright future choice, but like pretty much anything other than Marathon/Aurora on Mesos, it's pretty nascent.

kalmar 11y ago
> But, in return for being more low-level, you can run things that are simply impossible in a declarative system like Kubernetes. Can you give an example? I know next to nothing about Mesos, Aurora, or Marathon.
- krenoten 11y ago
  It's like many things that are declarative - you can only do what has been explicitly enabled in the declaration handling logic. This is good and bad. It's good because it restricts what is possible (protecting you slightly more from bad users) and can make learning and using the system easier. But you can't go beyond this. With a non-declarative scheduler you can implement far more interesting (for better or worse) management systems. One area where we've been seeing some interesting work happening is in stateful services running on top of schedulers. With something like postgres, there is interesting logic that must happen for responsible management beyond just throwing up 3 of them. You need to manage replication carefully. When a node goes down somewhere, you need to react somewhere else in a controlled way. With Mesos, you can write a scheduler that encodes your runbook. With kubernetes, you need a lot more out-of-band stuff.
  - TheIronYuppie 11y ago
    Disclaimer: I work at Google on Kubernetes. You're correct that the scheduler in the box is declarative. However, it is easy (well, as easy as writing a framework) to swap out a scheduler that might be a better fit for what you're looking for. See this stackoverflow answer by one of the core Kubernetes team for more info: http://stackoverflow.com/questions/28857993/how-does-kubernetes-scheduler-work http://stackoverflow.com/questions/28857993/how-does-kuberne...
mkulke 11y ago
Yeah, the HA information was buried/non-existent in the docs until recently, I guess. We also ran into issues when replacing the master, b/c the kubelets where fixed to an ip and the nodes' configuration was basically immutable (provisioned by cloud-config). What worked for us: Accessing the the master by DNS and putting etcd on a persistent volume. This way we're able to replace the master within a DNS records ttl. As the api server is not a hard requirement for the workload, this is HA enough for us.

kalmar 11y ago

I don't really know what the alternatives are. I'm hoping by the end of this series to convince at least myself that it's reasonably to run for personal projects.

parasubvert 11y ago

There is Lattice, http://lattice.cf http://lattice.cf which is single-tenant Cloud Foundry. You can get it up via Vagrant or Terraform. The underlying scheduler, Diego, has some interesting constructs, like supporting Windows, Docker, and buildpack-built containers (aka. droplets).

ersoft 11y ago
I had tried lattice but I don't think it is ready for production usage. When I reported a few security issues on their issue tracker, I've been told that lattice is just a stripped down version of Cloud Foundry designed for development usage. I think it's obvious that k8s is designed for staging/production usage and I can't see where lattice fits there. Also, lattice is not running docker containers, but garden containers. There are a lot of issues on their issue tracker about people not being able to run images from docker registry.
- parasubvert 11y ago
  Hi, fair points, I would agree Lattice out of the box is not quite ready for production usage, mainly because it has stripped out a lot of the security/multi-tenant features from Cloud Foundry to simplify the experience. That said I would say it is just a matter of time (this Fall) however. I mentioned it because it is a way to wrap one's head around Cloud Foundry ; really the production alternative to K8S is Cloud Foundry today, depending on your goal. (If you must have rootfs control and Docker, then no. If you want to stage/run your app in a scalable, reliable container scheduler with a set rootfs then yes.) As for Garden containers, yes, the main issue has been security -related gaps between Docker images and the Garden runtime, as Garden locks things down differently. Most (not all) of these have been fixed in recent builds, as the push for Diego GA in Cloud Foundry gets close over the next few weeks.

CMCDragonkai 11y ago

Check out http://datacenteroperatingsystem.io/ http://datacenteroperatingsystem.io/

TheIronYuppie 11y ago

Disclaimer: I work at Google on Kubernetes. We would (biasedly) say that Kubernetes is ready for production today, and have lots of public folks (Samsung, eBay, Porch, and thousands more) who are doing so. If you're in any way concerned about the management, feel free to get a trial on GKE (the hosted version of Kubernetes) on the Google Cloud ($300 trial free). We have a 99.5% SLA on it, so it's backed by Google engineers.