Autoinstall local repository

I have my own ISO based on Ubuntu 22.04 that I generated myself. Here is my Autoinstall -

#cloud-config
autoinstall:
  version: 1
  identity:
    hostname: foo-ubuntu
    password: "ToReplace"
    username: abcabc
  source:
    id: ubuntu-server-minimal
  early-commands:
  - cat /cdrom/casper/install-sources.yaml | awk 'NR>1 && /^-/{exit};1' > /run/my-sources.yaml
  - mount -o ro,bind /run/my-sources.yaml /cdrom/casper/install-sources.yaml
  late-commands:
    - cp -r /cdrom/copy_to_iso/ /target/opt/
  user-data:
    runcmd:
      - |
        mkdir -vp /opt/INIT/
        mv -v /opt/copy_to_iso/upgrade_or_install_packages/ /opt/
        mv -v /opt/copy_to_iso/foo_installation/* /opt/INIT/ 
        mv -v /opt/copy_to_iso/abc_scripts /opt/abc_scripts
        rm -rvf /opt/copy_to_iso
        bash -x /opt/abc_scripts/copy_system_files.sh
        bash -x /opt/abc_scripts/setup_system_config.sh install_mode

During early-commands and late-commands, I have a local repository with all the needed packages under /cdrom/copy_to_iso/packages. During the user-data section, the location is /opt/packages.

When I install the ISO on a server without an internet connection, the installation ends perfectly well, and all the necessary packages are installed. On the other hand, when I install the ISO on a server with internet connection, I see in the logs that it found a more up-to-date package externally in the internet, and it makes the section of installing the packages from /opt/packages fail.

I saw some related questions on the internet, but I wish to make all the sections in autoinstall work only with my local repository. Here is something that I tried -

how to disable unattended-upgrades during autoinstall (user-data, cloud-config)

Please look on "alternate option to use your local mirror". My problem is that I don't work with http in my local repository, but with "file".

I tried -

#cloud-config
autoinstall:
  apt:
  disable_components: [restricted,multiverse]
  disable_suites: [backports,security]
    primary:
    - arches:
      - default
      uri: file:///cdrom/copy_to_iso/packages/

and also file:/cdrom/copy_to_iso/packages/ - nothing works, and it still installs packages from external repositories.

How should I write it in my case?

This autoinstall configuration might work for you

#cloud-config
autoinstall:
  apt:
    disable_components: [restricted,multiverse]
    disable_suites: [backports,security]
    primary:
    - arches:
      - amd64
      - i386
      uri: http://archive.ubuntu.com/ubuntu
    - arches:
      - default
      uri: http://ports.ubuntu.com/ubuntu-ports
    preferences:
      - package: "*"
        pin: "release a=jammy-updates"
        pin-priority: 200
  late-commands:
    - |
      rm /target/etc/apt/preferences.d/90curtin.pref
      true

This will configure apt using a standard mirror without the given components and suites.

The preferences configuration will disable any updates. More technically, packages from the jammy repository will be preferred over the packages from the jammy-updates repository. This might prevent the problem of finding a more up-to-date package on the Internet. The late-commands will delete this preference configuration so that it will only affect the installation.

It is hard to say how to use your custom repository without knowing more about it. The uri looks reasonable, but even if it does work during installation the installed system will have a broken apt configuration because /cdrom/copy_to_iso/packages will not exist. This could potentially be fixed with more late-commands.