Add ability to start multiple containers

[valyala]

The issue

Currently konlet doesn't allow launching multiple containers. It returns the following error when gce-container-declaration mentions more than one container:

Error: Container declaration should include exactly 1 container, 2 found

The solution

It would be great if konlet could launch and manage multiple containers to be on par with real pods from Kubernetes.

[nataliasakowska]

Hi,

thanks a lot for your feedback. Yes, unfortunately currently it is impossible to start a VM with multiple containers but we're evaluating this feature request and your comment is a +1 vote to make this happen.

Thanks, Natalia

[pataquets]

Yes, please! @nataliasakowska, any news on this? Is there any place where we can give & get feedback and vote it? Thanks.

[nataliasakowska]

Hello,

unfortunately I do not have any news but if you want to give feedback and vote for features, https://googlecloudplatform.uservoice.com/forums/302595-compute-engine/filters/top is the best place to do so.

Thanks, Natalia

[fcrespel]

Hi, I'm also very much interested in this feature: it would basically bring the concept of sidecars to VMs, which is a very valid pattern when you need to run Prometheus exporters or Cloud SQL Proxy alongside your application. Right now we need custom startup scripts or cloud-init config to achieve this, which makes things unnecessarily complicated.

Since the underlying YAML format used by Konlet is copied from K8S and supports a list of containers, the current limitation to only start one container just seems arbitrary. @nataliasakowska do you think the product team would be open to changing this, or even accepting pull requests for it? I don't know Go yet but I might be interested in learning it just for this :-)

[nataliasakowska]

Hi,

sorry for late response! Thank you for reaching out. Support for multiple containers is being considered but is not yet planned. Unfortunately we do not currently accept pull requests for this product.

Thanks, Natalia

[eriksw]

@nataliasakowska That UserVoice is no longer available. What's the appropriate venue to escalate interest in this being implemented?

[twistedpair]

+1 here, I was running in limitations here when trying to run a DooD/DinD sidecar in GCE as well.

[lazcamus]

FWIW, you can sidestep this konlet limitation by configuring runcmd in cloud-init:

#cloud-config
runcmd:
  - |
    docker run -d busybox /bin/sleep 1000
    docker run -d busybox /bin/sleep 2000