Add Ubuntu 26.04 (resolute) support to docker-outside-of-docker (#1656)

* Initial plan

* Add Ubuntu 26.04 (resolute) support to docker-outside-of-docker

- Add "resolute" to DOCKER_LICENSED_ARCHIVE_VERSION_CODENAMES
- Block moby on resolute (packages not available), matching docker-in-docker behavior
- Add test scenario for Ubuntu resolute with moby=false

* Bump version to 1.10.0 and exclude base:ubuntu from test-pr workflow

- Bump docker-outside-of-docker version from 1.9.1 to 1.10.0
- Add exclusion for docker-outside-of-docker with base:ubuntu image in
  test-pr workflow since moby (default) is not available on resolute

* Remove trailing whitespace in test-pr.yaml

* Add note about Ubuntu 26.04 requiring moby: false in NOTES.md

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>

Author: Copilot

.github/workflows/test-pr.yaml

@@ -65,9 +65,11 @@ jobs:
           - features: docker-in-docker
             baseImage: mcr.microsoft.com/devcontainers/base:debian         
           - features: docker-outside-of-docker
-            baseImage: mcr.microsoft.com/devcontainers/base:debian   
+            baseImage: mcr.microsoft.com/devcontainers/base:debian
           - features: docker-in-docker
-            baseImage: mcr.microsoft.com/devcontainers/base:ubuntu 
+            baseImage: mcr.microsoft.com/devcontainers/base:ubuntu
+          - features: docker-outside-of-docker
+            baseImage: mcr.microsoft.com/devcontainers/base:ubuntu
     steps:
       - uses: actions/checkout@v6
 

src/docker-outside-of-docker/NOTES.md

@@ -60,4 +60,14 @@ This Feature should work on recent versions of Debian/Ubuntu-based distributions
 
 Debian Trixie (13) does not include moby-cli and related system packages, so the feature cannot install with "moby": "true". To use this feature on Trixie, please set "moby": "false" or choose a different base image (for example, Ubuntu 24.04).
 
+Ubuntu 26.04 LTS (Resolute) does not have moby-cli packages available, so the feature only supports installation with `"moby": false`. To use this feature on Ubuntu 26.04, set `"moby": false` in your feature configuration:
+
+```json
+"features": {
+    "ghcr.io/devcontainers/features/docker-outside-of-docker:1": {
+        "moby": false
+    }
+}
+```
+
 `bash` is required to execute the `install.sh` script.

src/docker-outside-of-docker/devcontainer-feature.json

@@ -1,7 +1,7 @@
 {
 
     "id": "docker-outside-of-docker",
-    "version": "1.9.1",
+    "version": "1.10.0",
     "name": "Docker (docker-outside-of-docker)",
     "documentationURL": "https://github.com/devcontainers/features/tree/main/src/docker-outside-of-docker",
     "description": "Re-use the host docker socket, adding the Docker CLI to a container. Feature invokes a script to enable using a forwarded Docker socket within a container to run Docker commands.",

src/docker-outside-of-docker/install.sh

@@ -22,7 +22,7 @@ INSTALL_DOCKER_COMPOSE_SWITCH="${INSTALLDOCKERCOMPOSESWITCH:-"true"}"
 MICROSOFT_GPG_KEYS_URI="https://packages.microsoft.com/keys/microsoft.asc"
 MICROSOFT_GPG_KEYS_ROLLING_URI="https://packages.microsoft.com/keys/microsoft-rolling.asc"
 DOCKER_MOBY_ARCHIVE_VERSION_CODENAMES="trixie bookworm buster bullseye bionic focal jammy noble plucky"
-DOCKER_LICENSED_ARCHIVE_VERSION_CODENAMES="trixie bookworm buster bullseye bionic focal hirsute impish jammy noble plucky"
+DOCKER_LICENSED_ARCHIVE_VERSION_CODENAMES="trixie bookworm buster bullseye bionic focal hirsute impish jammy noble plucky resolute"
 
 set -e
 
@@ -207,9 +207,9 @@ fi
 # Fetch host/container arch.
 architecture="$(dpkg --print-architecture)"
 
-# Prevent attempting to install Moby on Debian trixie (packages removed)
-if [ "${USE_MOBY}" = "true" ] && [ "${ID}" = "debian" ] && [ "${VERSION_CODENAME}" = "trixie" ]; then
-    err "The 'moby' option is not supported on Debian 'trixie' because 'moby-cli' and related system packages have been removed from that distribution."
+# Prevent attempting to install Moby on Debian trixie or Ubuntu resolute (packages not available)
+if [ "${USE_MOBY}" = "true" ] && ([ "${VERSION_CODENAME}" = "trixie" ] || [ "${VERSION_CODENAME}" = "resolute" ]); then
+    err "The 'moby' option is not supported on ${ID} '${VERSION_CODENAME}' because 'moby-cli' and related system packages are not available in that distribution."
     err "To continue, either set the feature option '\"moby\": false' or use a different base image (for example: 'debian:bookworm' or 'ubuntu-24.04')."
     exit 1
 fi

test/docker-outside-of-docker/install_on_ubuntu_resolute.sh

@@ -0,0 +1,12 @@
+#!/bin/bash
+
+set -e
+
+# Import test library
+source dev-container-features-test-lib
+
+# Definition specific tests
+check "docker installed" bash -c "type docker"
+
+# Report results
+reportResults

test/docker-outside-of-docker/scenarios.json

@@ -181,6 +181,14 @@
             }
         }
     },
+    "install_on_ubuntu_resolute": {
+        "image": "ubuntu:resolute",
+        "features": {
+            "docker-outside-of-docker": {
+                "moby": false
+            }
+        }
+    },
     "rootless_docker_socket": {
         "image": "mcr.microsoft.com/devcontainers/base:ubuntu-24.04",
         "features": {