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| title | date | slug | url |
|---|---|---|---|
| Weekly Kubernetes Community Hangout Notes - July 17 2015 | 2015-07-23 | weekly-kubernetes-community-hangout_23 | /blog/2015/07/Weekly-Kubernetes-Community-Hangout_23 |
Every week the Kubernetes contributing community meet virtually over Google Hangouts. We want anyone who's interested to know what's discussed in this forum.
Here are the notes from today's meeting:
Eric Paris: replacing salt with ansible (if we want)
In contrib, there is a provisioning tool written in ansible
The goal in the rewrite was to eliminate as much of the cloud provider stuff as possible
The salt setup does a bunch of setup in scripts and then the environment is setup with salt
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This means that things like generating certs is done differently on GCE/AWS/Vagrant
For ansible, everything must be done within ansible
Background on ansible
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| Does not have clients |
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| Provisioner ssh into the machine and runs scripts on the machine |
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| You define what you want your cluster to look like, run the script, and it sets up everything at once |
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| If you make one change in a config file, ansible re-runs everything (which isn’t always desirable) |
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| Uses a jinja2 template |
Create machines with minimal software, then use ansible to get that machine into a runnable state
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Sets up all of the add-ons
Eliminates the provisioner shell scripts
Full cluster setup currently takes about 6 minutes
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| CentOS with some packages |
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| Redeploy to the cluster takes 25 seconds |
Questions for Eric
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Where does the provider-specific configuration go?
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The only network setup that the ansible config does is flannel; you can turn it off - What about init vs. systemd?
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Should be able to support in the code w/o any trouble (not yet implemented)
Discussion
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Why not push the setup work into containers or kubernetes config?
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To bootstrap a cluster drop a kubelet and a manifest - Running a kubelet and configuring the network should be the only things required. We can cut a machine image that is preconfigured minus the data package (certs, etc)
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The ansible scripts install kubelet & docker if they aren’t already installed - Each OS (RedHat, Debian, Ubuntu) could have a different image. We could view this as part of the build process instead of the install process. - There needs to be solution for bare metal as well. - In favor of the overall goal -- reducing the special configuration in the salt configuration - Everything except the kubelet should run inside a container (eventually the kubelet should as well)
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Running in a container doesn’t cut down on the complexity that we currently have - But it does more clearly define the interface about what the code expects - These tools (Chef, Puppet, Ansible) conflate binary distribution with configuration
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Containers more clearly separate these problems - The mesos deployment is not completely automated yet, but the mesos deployment is completely different: kubelets get put on top on an existing mesos cluster
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The bash scripts allow the mesos devs to see what each cloud provider is doing and re-use the relevant bits - There was a large reverse engineering curve, but the bash is at least readable as opposed to the salt - Openstack uses a different deployment as well - We need a well documented list of steps (e.g. create certs) that are necessary to stand up a cluster
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| This would allow us to compare across cloud providers |
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| We should reduce the number of steps as much as possible |
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| Ansible has 241 steps to launch a cluster |
1.0 Code freeze
How are we getting out of code freeze?
This is a topic for next week, but the preview is that we will move slowly rather than totally opening the firehose
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| We want to clear the backlog as fast as possible while maintaining stability both on HEAD and on the 1.0 branch |
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| The backlog of almost 300 PRs but there are also various parallel feature branches that have been developed during the freeze |
Cutting a cherry pick release today (1.0.1) that fixes a few issues
- Next week we will discuss the cadence for patch releases