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The same experiences we switched to using rkt, supervised by upstart (and now systemd). We have an "application" state template in our salt config and every do

by mtanski 10y ago

The same experiences we switched to using rkt, supervised by upstart (and now systemd). We have an "application" state template in our salt config and every docker update something would cause all of them to fail. Thankful the "application" state template abstracted running container enough were we switched from docker -> rkt under the covers without anybody noticing, except now we no longer fearing of container software updates.

pescerosso 10y ago
Hi mtanski, How did you replace docker with rkt? Do you have an howto that you can share?
- flexd 10y ago
  I haven't replaced Docker with rkt on a big scale (or ran Docker on a big scale), but I recently changed over some Docker containers to rkt. First off, this and the rest of the rkt docs is a good starting point https://coreos.com/rkt/docs/latest/rkt-vs-other-projects.html https://coreos.com/rkt/docs/latest/rkt-vs-other-projects.htm... Second, rkt runs Docker images without modifications, so you can swap over really easily https://coreos.com/rkt/docs/latest/running-docker-images.html https://coreos.com/rkt/docs/latest/running-docker-images.htm... rkt uses acbuild (which is part of the application container specification, see https://github.com/appc/spec https://github.com/appc/spec) to build images, and I had a very tiny Docker image just running a single Go process. I just created a shell script that ran the required acbuild commands to get as similar image. A good place to get started is the getting started guide https://coreos.com/rkt/docs/latest/getting-started-guide.html https://coreos.com/rkt/docs/latest/getting-started-guide.htm... Docker runs as a daemon, and rkt doesn't (which is one of the benefits). I just start my rkt container using systemd, so I have a systemd file with 'ExecStart=/usr/bin/rkt run myimage:1.23.4', but you can start the containers with whatever you want. It's also possible to use rkt with Kubernetes, but I have not tried that yet. http://kubernetes.io/docs/getting-started-guides/rkt/ http://kubernetes.io/docs/getting-started-guides/rkt/
mtanski 10y ago
An example of changing behavior that broke us not to long ago: https://github.com/docker/distribution/issues/1662 https://github.com/docker/distribution/issues/1662 . By the time this happened we were already working on the transition, just more motivation.

by mtanski 10y ago

pescerosso 10y ago

Hi mtanski, How did you replace docker with rkt? Do you have an howto that you can share?

flexd 10y ago
I haven't replaced Docker with rkt on a big scale (or ran Docker on a big scale), but I recently changed over some Docker containers to rkt. First off, this and the rest of the rkt docs is a good starting point https://coreos.com/rkt/docs/latest/rkt-vs-other-projects.html https://coreos.com/rkt/docs/latest/rkt-vs-other-projects.htm... Second, rkt runs Docker images without modifications, so you can swap over really easily https://coreos.com/rkt/docs/latest/running-docker-images.html https://coreos.com/rkt/docs/latest/running-docker-images.htm... rkt uses acbuild (which is part of the application container specification, see https://github.com/appc/spec https://github.com/appc/spec) to build images, and I had a very tiny Docker image just running a single Go process. I just created a shell script that ran the required acbuild commands to get as similar image. A good place to get started is the getting started guide https://coreos.com/rkt/docs/latest/getting-started-guide.html https://coreos.com/rkt/docs/latest/getting-started-guide.htm... Docker runs as a daemon, and rkt doesn't (which is one of the benefits). I just start my rkt container using systemd, so I have a systemd file with 'ExecStart=/usr/bin/rkt run myimage:1.23.4', but you can start the containers with whatever you want. It's also possible to use rkt with Kubernetes, but I have not tried that yet. http://kubernetes.io/docs/getting-started-guides/rkt/ http://kubernetes.io/docs/getting-started-guides/rkt/

mtanski 10y ago

An example of changing behavior that broke us not to long ago: https://github.com/docker/distribution/issues/1662 https://github.com/docker/distribution/issues/1662 . By the time this happened we were already working on the transition, just more motivation.