Add alpine setup functions and sharable script

script/include/alpine_setup_functions.inc.sh

@@ -0,0 +1,32 @@
+#!/bin/sh
+
+# alpine_setup_functions: Functions used by the run_alpine_setup script
+
+update_system_packages() {
+  apk update
+  apk upgrade
+}
+
+install_package() {
+  local package_name=${1}
+
+  apk add ${1}
+  return $?
+}
+
+add_group() {
+  local group_name="${1}"
+  local gid="${2}"
+
+  addgroup -g "${gid}" -S "${group_name}"
+  return $?
+}
+
+add_user() {
+  local username="${1}"
+  local primary_group="${2}"
+  local uid="${3}"
+
+  adduser -u "${3}" -D -S -G "${primary_group}" "${username}"
+  return $?
+}

script/include/run_alpine_setup

@@ -0,0 +1,25 @@
+# run_alpine_setup: Install basic system requirements for an app to run
+
+# Load alpine setup functions
+source ./script/include/alpine_setup_functions.inc.sh
+
+## Set option defaults
+# If GROUP information is incomplete, use the default one
+if [ -z "${APP_GROUP+is_set}" ] || \
+   [ -z "${APP_GID+is_set}" ]; then
+  APP_GROUP="atat"
+  APP_GROUP_ID="8000"
+fi
+
+# If USER information is incomplete, error out
+if [ -z "${APP_USER+is_set}" ] || \
+   [ -z "${APP_UID+is_set}" ]; then
+  exit 1
+fi
+
+## Main
+update_system_packages
+install_package "bash"
+install_package "dumb-init"
+add_group "${APP_GROUP}" "${APP_GID}"
+add_user "${APP_USER}" "${APP_GROUP}" "${APP_UID}"