Allow installing yarn via corepack on Debian-based systems, too

src/node/devcontainer-feature.json

@@ -1,6 +1,6 @@
 {
     "id": "node",
-    "version": "1.4.1",
+    "version": "1.5.0",
     "name": "Node.js (via nvm), yarn and pnpm",
     "documentationURL": "https://github.com/devcontainers/features/tree/main/src/node",
     "description": "Installs Node.js, nvm, yarn, pnpm, and needed dependencies.",
@@ -36,6 +36,11 @@
             ],
             "default": "latest",
             "description": "Version of NVM to install."
+        },
+        "installYarnUsingApt": {
+            "type": "boolean",
+            "default": true,
+            "description": "On Debian & Ubuntu systems, you can choose whether to install Yarn globally via APT. If this option is set to false, Yarn will be set up via Corepack instead. This setting does not apply to other Linux distributions, where Yarn is always installed using Corepack (with a fallback to installation via NPM in case of an error)."
         }
     },
     "customizations": {

src/node/install.sh

@@ -11,6 +11,7 @@ export NODE_VERSION="${VERSION:-"lts"}"
 export NVM_VERSION="${NVMVERSION:-"latest"}"
 export NVM_DIR="${NVMINSTALLPATH:-"/usr/local/share/nvm"}"
 INSTALL_TOOLS_FOR_NODE_GYP="${NODEGYPDEPENDENCIES:-true}"
+export INSTALL_YARN_USING_APT="${INSTALLYARNUSINGAPT:-true}"  # only concerns Debian-based systems
 
 # Comma-separated list of node versions to be installed (with nvm)
 # alongside NODE_VERSION, but not set as default.
@@ -188,7 +189,7 @@ find_version_from_git_tags() {
 }
 
 install_yarn() {
-    if [ "${ADJUSTED_ID}" = "debian" ]; then
+    if [ "${ADJUSTED_ID}" = "debian" ] && [ "${INSTALL_YARN_USING_APT}" = "true" ]; then
         # for backward compatiblity with existing devcontainer features, install yarn
         # via apt-get on Debian systems
         if ! type yarn >/dev/null 2>&1; then
@@ -202,8 +203,9 @@ install_yarn() {
         fi
     else
         local _ver=${1:-node}
-        # on non-debian systems, prefer corepack, fallback to npm based installation of yarn...
-        # Try to leverage corepack if possible
+        # on non-debian systems or if user opted not to use APT, prefer corepack
+        # Fallback to npm based installation of yarn.
+        # But try to leverage corepack if possible
         # From https://yarnpkg.com:
         # The preferred way to manage Yarn is by-project and through Corepack, a tool
         # shipped by default with Node.js. Modern releases of Yarn aren't meant to be

test/node/debian_yarn_from_corepack.sh

@@ -0,0 +1,20 @@
+#!/bin/bash
+
+set -e
+
+# Optional: Import test library
+source dev-container-features-test-lib
+
+# Definition specific tests
+YARN_VERSION="4.3.0"
+
+# Corepack provides shims for package managers like yarn. When yarn is invoked by the "yarn"
+# command, corepack will interactively request permission to download the yarn binary. To
+# avoid this interactive mode and download the binary automatically, we call "corepack use yarn"
+# instead. Once that command completes, "yarn" can be used normally and in a non-interactive mode.
+check "yarn shim location" bash -c ". /usr/local/share/nvm/nvm.sh && type yarn &> /dev/null"
+check "download yarn" bash -c ". /usr/local/share/nvm/nvm.sh && corepack use yarn@${YARN_VERSION}"
+check "yarn version" bash -c ". /usr/local/share/nvm/nvm.sh && yarn --version | grep ${YARN_VERSION}"
+
+# Report result
+reportResults

test/node/scenarios.json

@@ -185,5 +185,13 @@
                 "version": "lts"
             }
         }
+    },
+    "debian_yarn_from_corepack": {
+        "image": "debian:11",
+        "features": {
+            "node": {
+                "installYarnUsingApt": false
+            }
+        }
     }
 }