5 ms·

For Go you can use FROM scratch and save a couple more megabytes.

by U1F984 4y ago

lrvick 4y ago
This works on any language. I only use scratch in prod. Even for nodejs or python... compile a static interpreter binary and truck on. Dev tools like bash, ls, grep, etc, have no place in production and only increase attack surface.
- 8n4vidtmkvmk 4y ago
  once in awhile i use 'kubectl exec ' to run some commands against my running prod containers to debug something or extract an environment variable. can i still do that without a shell or anything?
  - cmckn 4y ago
    You can’t, no. One approach is a “debug sidecar” container in the Pod that has your desired tools. Linkerd, for example, will add such a container if an annotation is present on the Pod: https://linkerd.io/2.11/tasks/using-the-debug-container/ https://linkerd.io/2.11/tasks/using-the-debug-container/ I usually just include a shell, but to each their own.
  - dmart 4y ago
    k8s has first-class support for ephemeral debug containers that share process namespaces for this purpose. Pretty cool feature imo. https://kubernetes.io/docs/tasks/debug/debug-application/debug-running-pod/#ephemeral-container https://kubernetes.io/docs/tasks/debug/debug-application/deb...
    - hdjrudni 4y ago
      That sounds sweet! But I guess DigitalOcean doesn't support it? I'm getting "error: ephemeral containers are disabled for this cluster (error from server: "the server could not find the requested resource")."
- nijave 4y ago
  How do non running utilities increase attack surface? If you're able to execute inside the container couldn't you just write whatever utilities you want in?
  - CameronNemo 4y ago
    Most container workloads I have use a read only root fs.
  - lrvick 4y ago
    There are many exploits that may give one the ability to execute shell commands. If there is no shell or commands to even write a file in the first place, mobility becomes limited.
iruoy 4y ago
You'll need to make sure that the binary is statically linked though.

For Go you can use FROM scratch and save a couple more megabytes.

by U1F984 4y ago

For Go you can use FROM scratch and save a couple more megabytes.

This works on any language. I only use scratch in prod. Even for nodejs or python... compile a static interpreter binary and truck on. Dev tools like bash, ls, grep, etc, have no place in production and only increase attack surface.

8n4vidtmkvmk 4y ago
once in awhile i use 'kubectl exec ' to run some commands against my running prod containers to debug something or extract an environment variable. can i still do that without a shell or anything?
- cmckn 4y ago
  You can’t, no. One approach is a “debug sidecar” container in the Pod that has your desired tools. Linkerd, for example, will add such a container if an annotation is present on the Pod: https://linkerd.io/2.11/tasks/using-the-debug-container/ https://linkerd.io/2.11/tasks/using-the-debug-container/ I usually just include a shell, but to each their own.
- dmart 4y ago
  k8s has first-class support for ephemeral debug containers that share process namespaces for this purpose. Pretty cool feature imo. https://kubernetes.io/docs/tasks/debug/debug-application/debug-running-pod/#ephemeral-container https://kubernetes.io/docs/tasks/debug/debug-application/deb...
  - hdjrudni 4y ago
    That sounds sweet! But I guess DigitalOcean doesn't support it? I'm getting "error: ephemeral containers are disabled for this cluster (error from server: "the server could not find the requested resource")."
nijave 4y ago
How do non running utilities increase attack surface? If you're able to execute inside the container couldn't you just write whatever utilities you want in?
- CameronNemo 4y ago
  Most container workloads I have use a read only root fs.
- lrvick 4y ago
  There are many exploits that may give one the ability to execute shell commands. If there is no shell or commands to even write a file in the first place, mobility becomes limited.

iruoy 4y ago

You'll need to make sure that the binary is statically linked though.