🐛 Incorrect merging of cloud-config files with same stages

[venkatnsrinivasan]

Kairos version:

NAME="Ubuntu"
VERSION="20.04.6 LTS (Focal Fossa)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 20.04.6 LTS"
VERSION_ID="20.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=focal
UBUNTU_CODENAME=focal
KAIROS_NAME="kairos-core-ubuntu-20-lts"
KAIROS_VERSION="v2.0.2"
KAIROS_ID="kairos"
KAIROS_ID_LIKE="kairos-core-ubuntu-20-lts"
KAIROS_VERSION_ID="v2.0.2"
KAIROS_PRETTY_NAME="kairos-core-ubuntu-20-lts v2.0.2"
KAIROS_BUG_REPORT_URL="https://github.com/kairos-io/kairos/issues"
KAIROS_HOME_URL="https://github.com/kairos-io/kairos"
KAIROS_IMAGE_REPO="quay.io/kairos/core-ubuntu-20-lts"
KAIROS_IMAGE_LABEL="latest"
KAIROS_GITHUB_REPO="kairos-io/kairos"
KAIROS_VARIANT="core"
KAIROS_FLAVOR="ubuntu-20-lts"

CPU architecture, OS, and Version:
Linux localhost 5.15.0-69-generic #76~20.04.1-Ubuntu SMP Mon Mar 20 15:54:19 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux
Describe the bug
Two config files with same stages dont get merged correctly.

To Reproduce
1 . Boot the kairos-ubuntu-20-lts-v2.0.2.iso in manual mode
2. Create two files under /oem with the following entries
10_config.yaml

#node-config
install:
  auto: true
  reboot: false
  poweroff: false
  grub_options:
     extra_cmdline: "console=tty0"
options:
  device: /dev/sda
stages:
  initramfs:
    - users:
        kairos:
          groups:
            - sudo
          passwd: kairos

20_config.yaml

#node-config
stages:
  initramfs:
    - users:
        foo:
          groups:
            - sudo
          passwd: bar

3. Run kairos-agent install
   Expected behavior
   Both the user entries should be present in the target . Instead the merged config file looks like this
   cat /tmp/xxxx2698469135

#cloud-config

install:
    auto: true
    grub_options:
        extra_cmdline: console=tty0
    poweroff: false
    reboot: false
options:
    device: /dev/sda
stages:
    initramfs:
        - users:
            foo:
                groups:
                    - sudo
                passwd: bar

It does not matter if the stages contain the same steps. e.g. one file can contain initramfs->commands and other contains initramfs->users and only one is present in the result. if we change one of the files to "initramfs.after" it merges correctly

#cloud-config

install:
    auto: true
    grub_options:
        extra_cmdline: console=tty0
    poweroff: false
    reboot: false
options:
    device: /dev/sda
stages:
    initramfs:
        - users:
            kairos:
                groups:
                    - sudo
                passwd: kairos
    initramfs.after:
        - users:
            foo:
                groups:
                    - sudo
                passwd: bar

[mudler]

this looks bad, however merging was introduced recently - but I guess this is problematic as you didn't had merges before, and now we have unpredictable results.

Is this blocking you ? I've just pushed it to the next release, but if this is impacting you a lot we will need to catch a patch release

[mauromorales]

I can confirm that I can reproduce.

The issue comes from the mergo merge here

kairos/pkg/config/collector/collector.go

Line 68 in 3980bf1

return mergo.Merge(c, newConfig, func(c *mergo.Config) { c.Overwrite = true })

Which seems to be known issue :/ darccio/mergo#204

[mauromorales]

The issue is in since we introduced mergo, so could be around 1.6.1 if I'm not mistaken, or otherwise just the v2 releases. The fix has been merged, and 2.0.3 should be out soon.

@venkatnsrinivasan thanks for bringing this to our attention