Add --download-dir option.

While building an AMI on top of a hardened OS that prevented any files
from being executed from /tmp, I hit an error where the Gruntwork
installer only downloads to /tmp with no other options. This changes
that.

.gitignore

@@ -1 +1,2 @@
+.idea
 *.iml

gruntwork-install

@@ -11,7 +11,7 @@ set -e
 readonly MODULES_DIR="modules"
 readonly MODULE_INSTALL_FILE_NAME="install.sh"
 
-readonly MODULES_DOWNLOAD_DIR="/tmp/gruntwork-script-modules"
+readonly DEFAULT_MODULES_DOWNLOAD_DIR="/tmp/gruntwork-script-modules"
 readonly BIN_DIR="/usr/local/bin"
 
 function print_usage {
@@ -20,15 +20,23 @@ function print_usage {
   echo
   echo "Download a Gruntwork Script Module and install it."
   echo
-  echo "Options:"
+  echo "Required Arguments:"
   echo
-  echo -e "  --repo\t\Required. The repo to install from."
-  echo -e "  --tag\t\t\tRequired. The version of --repo to install. Follows the syntax described at https://github.com/gruntwork-io/fetch#tag-constraint-expressions."
-  echo -e "  --module-name\t\tOptional. The name of a module to install. Can be any folder within the $MODULES_DIR directory of --repo. You must specify exactly one of --module-name or --binary-name."
-  echo -e "  --binary-name\t\tOptional. The name of a binary to install. Can be any file uploaded as a release asset in --repo.  You must specify exactly one of --module-name or --binary-name."
-  echo -e "  --branch\t\tOptional. Download the latest commit from this branch in --repo. This is an alternative to --tag, used only for testing."
-  echo -e "  --module-param\tOptional. A key-value pair of the format key=value you wish to pass to the module as a parameter. May be used multiple times."
-  echo -e "  --help\t\Show this help text and exit."
+  echo -e "  --repo\t\tThe repo to install from."
+  echo -e "  --tag\t\t\tThe version of --repo to install. Follows the syntax described at https://github.com/gruntwork-io/fetch#tag-constraint-expressions."
+  echo
+  echo "Specify exactly one of:"
+  echo
+  echo -e "  --module-name\t\The name of a module to install. Can be any folder within the $MODULES_DIR directory of --repo."
+  echo -e "  --binary-name\t\tThe name of a binary to install. Can be any file uploaded as a release asset in --repo."
+  echo
+  echo "Optional Arguments:"
+  echo
+  echo -e "  --download-dir\t\The directory where the module will be downloaded to and from which it will be installed. Default: $DEFAULT_MODULES_DOWNLOAD_DIR"
+  echo -e "  --module-param\tA key-value pair of the format key=value you wish to pass to the module as a parameter. May be used multiple times."
+  echo -e "  --branch\t\tDownload the latest commit from this branch in --repo. This is an alternative to --tag, used only for testing."
+  echo -e "  --help\t\tShow this help text and exit."
+
   echo
   echo "Example:"
   echo
@@ -72,37 +80,37 @@ function fetch_script_module {
   local readonly module_name="$1"
   local readonly tag="$2"
   local readonly branch="$3"
-  local readonly download_path="$4"
+  local readonly download_dir="$4"
   local readonly repo="$5"
 
   # We want to make sure that all folders down to $download_path/$module_name exists, but that $download_path/$module_name itself is empty.
-  mkdir -p "$download_path/$module_name/"
-  rm -Rf "$download_path/$module_name/"
+  mkdir -p "$download_dir/$module_name/"
+  rm -Rf "$download_dir/$module_name/"
 
   # Note that fetch can safely handle blank arguments for --tag or --branch
   # If both --tag and --branch are specified, --branch will be used
   echo "Downloading module $module_name from $repo"
-  fetch --repo="$repo" --tag="$tag" --branch="$branch" --source-path="/modules/$module_name" "$download_path/$module_name"
+  fetch --repo="$repo" --tag="$tag" --branch="$branch" --source-path="/modules/$module_name" "$download_dir/$module_name"
 }
 
 # Download a binary asset from a GitHub release using fetch (https://github.com/gruntwork-io/fetch)
 function fetch_binary {
   local readonly binary_name="$1"
   local readonly tag="$2"
-  local readonly download_path="$3"
+  local readonly download_dir="$3"
   local readonly repo="$4"
 
   local binary_name_full=""
   binary_name_full=$(determine_binary_name "$binary_name")
 
-  local readonly full_download_path="$download_path/$binary_name_full"
+  local readonly full_download_path="$download_dir/$binary_name_full"
   local readonly full_dest_path="$BIN_DIR/$binary_name"
 
   # We want to make sure that all folders down to $download_path exist, but that $download_path/$binary_name_full does not
-  mkdir -p "$download_path"
-  rm -f "$download_path/$binary_name_full"
+  mkdir -p "$download_dir"
+  rm -f "$download_dir/$binary_name_full"
 
-  fetch --repo="$repo" --tag="$tag" --release-asset="$binary_name_full" "$download_path"
+  fetch --repo="$repo" --tag="$tag" --release-asset="$binary_name_full" "$download_dir"
 
   echo "Moving $full_download_path to $full_dest_path and setting execute permissions"
   sudo mv "$full_download_path" "$full_dest_path"
@@ -112,12 +120,12 @@ function fetch_binary {
 # Validate that at least one file was downloaded from the module; otherwise throw an error.
 function validate_module {
   local readonly module_name="$1"
-  local readonly download_path="$2"
+  local readonly download_dir="$2"
   local readonly tag="$3"
   local readonly branch="$4"
   local reaodnly repo="$5"
 
-  if [[ ! -e "$download_path/$module_name" ]]; then
+  if [[ ! -e "$download_dir/$module_name" ]]; then
     echo "ERROR: No files were downloaded. Are you sure \"$module_name\" is a valid Script Module in $repo (tag = $tag, branch = $branch)?"
     exit 1
   fi
@@ -175,11 +183,12 @@ function convert_module_params_format {
 
 function run_module {
   local readonly module_name="$1"
-  shift
+  local readonly download_dir="$2"
+  shift 2
   local readonly module_params="$@"
 
-  chmod -R u+x "${MODULES_DOWNLOAD_DIR}/${module_name}"
-  ${MODULES_DOWNLOAD_DIR}/${module_name}/${MODULE_INSTALL_FILE_NAME} $module_params
+  chmod -R u+x "${download_dir}/${module_name}"
+  ${download_dir}/${module_name}/${MODULE_INSTALL_FILE_NAME} $module_params
 }
 
 function install_script_module {
@@ -188,6 +197,7 @@ function install_script_module {
   local module_name=""
   local binary_name=""
   local repo=""
+  local download_dir="$DEFAULT_MODULES_DOWNLOAD_DIR"
   local module_params=()
 
   while [[ $# > 0 ]]; do
@@ -219,6 +229,10 @@ function install_script_module {
         module_params+=("$param")
         shift
         ;;
+      --download-dir)
+        download_dir="$2"
+        shift
+        ;;
       --help)
         print_usage
         exit
@@ -249,12 +263,12 @@ function install_script_module {
 
   if [[ ! -z "$module_name" ]]; then
     echo "Installing from $module_name..."
-    fetch_script_module "$module_name" "$tag" "$branch" "$MODULES_DOWNLOAD_DIR" "$repo"
-    validate_module "$module_name" "$MODULES_DOWNLOAD_DIR" "$tag" "$branch" "$repo"
-    run_module "$module_name" "${module_params[@]}"
+    fetch_script_module "$module_name" "$tag" "$branch" "$download_dir" "$repo"
+    validate_module "$module_name" "$download_dir" "$tag" "$branch" "$repo"
+    run_module "$module_name" "$download_dir" "${module_params[@]}"
   else
     echo "Installing $binary_name..."
-    fetch_binary "$binary_name" "$tag" "$MODULES_DOWNLOAD_DIR" "$repo"
+    fetch_binary "$binary_name" "$tag" "$download_dir" "$repo"
   fi
 
   echo "Success!"

test/integration-test.sh

@@ -18,6 +18,9 @@ echo "Checking that the vault-ssh-helper installed correctly"
 echo "Using gruntwork-install to install a module from the module-ecs repo"
 gruntwork-install --module-name "ecs-scripts" --repo "https://github.com/gruntwork-io/module-ecs" --branch "v0.0.1"
 
+echo "Using gruntwork-install to install a module from the module-ecs repo with --download-dir option"
+gruntwork-install --module-name "ecs-scripts" --repo "https://github.com/gruntwork-io/module-ecs" --branch "v0.0.1" --download-dir "~/tmp"
+
 echo "Checking that the ecs-scripts installed correctly"
 configure-ecs-instance --help