fix: install extensions under remote user not root user

Author: DanielleMaywood

src/code-server/install.sh

@@ -9,12 +9,17 @@ fi
 
 curl -fsSL https://code-server.dev/install.sh | sh -s -- $CODE_SERVER_INSTALL_ARGS
 
-IFS=',' read -ra extensions <<<"$EXTENSIONS"
+if [[ -n "$EXTENSIONS" ]]; then
+    IFS=',' read -ra extensions <<<"$EXTENSIONS"
 
-for extension in "${extensions[@]}"
-do
-    code-server --install-extension "$extension"
-done
+    for extension in "${extensions[@]}"
+    do
+        if ! su "$_REMOTE_USER" -c "code-server --install-extension '$extension'"; then
+            echo "ERROR: Failed to install extension '$extension' as user '$_REMOTE_USER'" >&2
+            exit 1
+        fi
+    done
+fi
 
 CODE_SERVER_WORKSPACE="$_REMOTE_USER_HOME"
 

test/code-server/code-server-extensions-remote-user.sh

@@ -0,0 +1,21 @@
+#!/bin/bash
+set -e
+
+# Optional: Import test library bundled with the devcontainer CLI
+source dev-container-features-test-lib
+
+# Feature-specific tests
+check "code-server version" code-server --version
+check "code-server running" pgrep -f 'code-server/lib/node.*/code-server'
+check "code-server listening" lsof -i "@0.0.0.0:8080"
+
+# Verify extensions are installed under the remoteUser's home, not root's.
+# See: https://github.com/coder/devcontainer-features/issues/18
+extensions_dir=/home/vscode/.local/share/code-server/extensions
+
+check "rust-analyzer installed under remoteUser" ls "$extensions_dir"/rust-lang.rust-analyzer-*
+check "python installed under remoteUser"        ls "$extensions_dir"/ms-python.python-*
+check "extensions not installed under root"      test ! -d /root/.local/share/code-server/extensions
+
+# Report results
+reportResults

test/code-server/scenarios.json

@@ -265,5 +265,14 @@
                 "absProxyBasePath": "/user/123/workspace"
             }
         }
+    },
+    "code-server-extensions-remote-user": {
+        "image": "mcr.microsoft.com/devcontainers/base:ubuntu",
+        "remoteUser": "vscode",
+        "features": {
+            "code-server": {
+                "extensions": ["rust-lang.rust-analyzer", "ms-python.python"]
+            }
+        }
     }
 }