Change default shell if installing ZSH (#325)

* Added new option to configure zsh as default shell
Added test scenario
Bumped feature version

* Update test/common-utils/scenarios.json
Co-authored-by: Samruddhi Khandale <skhandale@microsoft.com>

* Update src/common-utils/devcontainer-feature.json
Co-authored-by: Samruddhi Khandale <skhandale@microsoft.com>

* Update test/common-utils/configure_zsh_as_default_shell.sh
Co-authored-by: Samruddhi Khandale <skhandale@microsoft.com>
Co-authored-by: Samruddhi Khandale <skhandale@microsoft.com>

src/common-utils/devcontainer-feature.json

 {
     "id": "common-utils",
-    "version": "1.1.6",
+    "version": "1.2.0",
     "name": "Common Debian Utilities",
     "documentationURL": "https://github.com/devcontainers/features/tree/main/src/common-utils",
     "description": "Installs a set of common command line utilities, Oh My Zsh!, and sets up a non-root user.",
@@ -10,6 +10,11 @@
             "default": true,
             "description": "Install ZSH?"
         },
+        "configureZshAsDefaultShell": {
+            "type": "boolean",
+            "default": false,
+            "description": "Change default shell to ZSH?"
+        },
         "installOhMyZsh": {
             "type": "boolean",
             "default": true,

src/common-utils/install.sh

@@ -13,6 +13,7 @@ set -e
 rm -rf /var/lib/apt/lists/*
 
 INSTALL_ZSH="${INSTALLZSH:-"true"}"
+CONFIGURE_ZSH_AS_DEFAULT_SHELL="${CONFIGUREZSHASDEFAULTSHELL:-"false"}"
 INSTALL_OH_MY_ZSH="${INSTALLOHMYZSH:-"true"}"
 UPGRADE_PACKAGES="${UPGRADEPACKAGES:-"true"}"
 USERNAME="${USERNAME:-"${_REMOTE_USER:-"automatic"}"}"
@@ -378,6 +379,12 @@ if [ "${INSTALL_ZSH}" = "true" ]; then
         ZSH_ALREADY_INSTALLED="true"
     fi
 
+    # Change shell of determined user
+    if [[ "${CONFIGURE_ZSH_AS_DEFAULT_SHELL}" == "true" ]]; then
+      chsh --shell /bin/zsh ${USERNAME}
+    fi
+
+
     # Adapted, simplified inline Oh My Zsh! install steps that adds, defaults to a codespaces theme.
     # See https://github.com/ohmyzsh/ohmyzsh/blob/master/tools/install.sh for official script.
     oh_my_install_dir="${user_rc_path}/.oh-my-zsh"

test/common-utils/configure_zsh_as_default_shell.sh

+#!/bin/bash
+
+set -e
+
+# Optional: Import test library
+source dev-container-features-test-lib
+
+# Definition specific tests
+check "default-shell-is-zsh" bash -c "getent passwd $(whoami) | awk -F: '{ print $7 }' | grep '/bin/zsh'"
+
+# Report result
+reportResults

test/common-utils/scenarios.json

+{
+  "configure_zsh_as_default_shell": {
+    "image": "mcr.microsoft.com/devcontainers/base:ubuntu",
+    "features": {
+      "common-utils": {
+        "configureZshAsDefaultShell": true
+      }
+    }
+  }
+}