错误的 docker 图片在 Github Actions

Question

I'm building CI/CD on Github Actions, and I want to use a specific docker image.

I used this yaml file:

jobs:
  build:
    name: Test Image
    runs-on: ubuntu-latest
    container:
      image: lambci/lambda:build-nodejs12.x
    steps:
      - name: What OS is running
        run: uname -a

But I'm getting the wrong image:

Linux b25c9fe8c287 5.4.0-1031-azure #32~18.04.1-Ubuntu SMP Tue Oct 6 10:03:22 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

instead of

Linux 758d8f59b7b6 5.4.39-linuxkit #1 SMP Fri May 8 23:03:06 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux).

What am I doing wrong?

Answer 1

The output of uname -a shows you what kernel is running. There are no kernels shipped with docker images, instead you get the Linux kernel of the host. Docker is a method to run isolated processes, not a virtual machine environment, and therefore you should expect the output of uname -a to vary depending on where you run the image.