"bash: sysctl: command not found" in debian:stretch-slim

Question

when I pull the debian:stretch-slim from hub.docker.com, and then run a container(root), I find that bash: sysctl: command not found.

How can I use sysctl in debian:stretch-slim?

and many images are builded from debian:stretch-slim, so when I want to use sysctl in some other containers like that:

docker run --rm -it redis:latest --sysctl net.core.somaxconn=2048 redis-server

It will throw ERROR message.

It can be tested like:

docker pull debian:stretch-slim
docker run --rm -it debian:stretch-slim bash
root@7b923f27f7ee:/# sysctl
bash: sysctl: command not found

`root@da79336f6845:/# apt-cache search sysctl`> `root@da79336f6845:/# sysctl`> `bash: sysctl: command not found` — Wei, Feb 20 '19 at 08:42
`root@a5c114840c07:/# /sbin/sysctl -a`> `bash: /sbin/sysctl: No such file or directory` — Wei, Feb 20 '19 at 08:54
I have checked, the `sysctl` does not exist in these path `/sbin/`,`/usr/sbin/`, and the `$PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin` — Wei, Feb 20 '19 at 09:01
If you really need `sysctl` utility in the container - `apt-get update && apt-get install procps`. — Danila Kiver, Feb 20 '19 at 09:33
For others via google, don't forget it needs to be run as root, so `sudo sysctl net.core.somaxconn=2048` on bare metal. — Mint, May 20 '20 at 23:50

score 3 · Accepted Answer · answered Feb 20 '19 at 09:32

3

Start your container with this command:

docker run --rm -it --sysctl net.core.somaxconn=2048 redis:latest redis-server

--sysctl should be docker run's argument and it should not be a command to your redis image

answered Feb 20 '19 at 09:32

Thilak

I am having this error in gitlab-ci runner when trying to use `expo` cli. Where should I add this command? at the docker gitlab ci runner level ? – Dimitri Kopriwa Dec 29 '19 at 21:17
@DimitriKopriwa Can you create a new thread with some detailed information (command used, error details, etc..)? So that it will help us analyze the issue. – Thilak Jan 02 '20 at 05:40
Docker does not support setting all sysctl values. See this link: https://docs.docker.com/engine/reference/commandline/run/#configure-namespaced-kernel-parameters-sysctls-at-runtime. Certain kernel parameters cannot be set within Docker containers. They need to be set on the host computer – Nadir Latif Oct 21 '20 at 11:32

1 Answers1