azure-cli: silent no-op on unknown Ubuntu codenames (e.g. resolute / 26.04)

[kleinc80]

Summary

The azure-cli feature silently does nothing — no error, claims Done! — when run on an Ubuntu release whose codename isn't in the feature's hardcoded allowlist. On Ubuntu 26.04 LTS (codename resolute, the current mcr.microsoft.com/devcontainers/base:ubuntu tag as of May 2026), this means containers come up apparently fine but without the Azure CLI installed.

Reproduce

{
  "image": "mcr.microsoft.com/devcontainers/base:ubuntu",
  "features": {
    "ghcr.io/devcontainers/features/azure-cli:1": {}
  }
}

Build output for the feature step:

(*) Installing Azure CLI...
Installing Azure CLI extensions:
Done!
DONE 0.4s

After build:

$ which az; find / -name 'az' -type f 2>/dev/null
$

No binary present anywhere.

Root cause

In src/azure-cli/install.sh (current main):

# line 22
AZCLI_ARCHIVE_VERSION_CODENAMES="stretch bookworm buster bullseye bionic focal jammy noble trixie"

# lines 200–206
if [ "${INSTALL_USING_PYTHON}" != "true" ]; then
    if [[ "${AZCLI_ARCHIVE_ARCHITECTURES}" = *"${architecture}"* ]] \
    && [[ "${AZCLI_ARCHIVE_VERSION_CODENAMES}" = *"${VERSION_CODENAME}"* ]]; then
        install_using_apt || use_pip="true"
    fi
    # ← no `else`: when the codename check fails, nothing runs and use_pip stays unset
fi

if [ "${use_pip}" = "true" ]; then
    install_using_pip_strategy
fi

When VERSION_CODENAME=resolute (or any codename not in the allowlist), neither branch installs anything and the script falls through to the extensions loop and prints Done!. No error, exit 0.

Suggested fixes (any one would address it)

• Add resolute (and future codenames) to AZCLI_ARCHIVE_VERSION_CODENAMES.
• Make a codename-allowlist miss a visible error (echo "Unsupported codename: ${VERSION_CODENAME}" + exit 1).
• Fall back to the pip strategy when the apt path is unavailable, by setting use_pip="true" in an else branch of the inner if.

Related

• PowerShell and possibly other features broken on ubuntu 26.04 base image #1665 — separate but related issue on Ubuntu 26.04 (PowerShell feature, missing gpgv). Different mechanism, same underlying gap in Ubuntu 26.04 support across features.

Workaround

Install Azure CLI in postCreateCommand via pipx install azure-cli instead of using this feature.