Use a mktemp random directory for installation (repeated PR) (#301)

* Use a mktemp random directory for installation

Do not hardcode a static directory for temporary files, as it
might cause problems when running in a multi-user system
(ie: orphan files owned by other users).

Use mktemp -d instead.

Fixes #241

* Rename fail_trap > exit_trap

Co-authored-by: Yusuke Kuoka <[email protected]>

Author: keymon

install-binary.sh

@@ -89,10 +89,20 @@ getDownloadURL() {
   fi
 }
 
+# Temporary dir
+mkTempDir() {
+  HELM_TMP="$(mktemp -d -t "${PROJECT_NAME}-XXXX")"
+}
+rmTempDir() {
+  if [ -d "${HELM_TMP:-/tmp/helm-diff-tmp}" ]; then
+    rm -rf "${HELM_TMP:-/tmp/helm-diff-tmp}"
+  fi
+}
+
 # downloadFile downloads the latest binary package and also the checksum
 # for that binary.
 downloadFile() {
-  PLUGIN_TMP_FILE="/tmp/${PROJECT_NAME}.tgz"
+  PLUGIN_TMP_FILE="${HELM_TMP}/${PROJECT_NAME}.tgz"
   echo "Downloading $DOWNLOAD_URL"
   if type "curl" >/dev/null; then
     curl -L "$DOWNLOAD_URL" -o "$PLUGIN_TMP_FILE"
@@ -104,18 +114,17 @@ downloadFile() {
 # installFile verifies the SHA256 for the file, then unpacks and
 # installs it.
 installFile() {
-  HELM_TMP="/tmp/$PROJECT_NAME"
-  mkdir -p "$HELM_TMP"
   tar xvzf "$PLUGIN_TMP_FILE" -C "$HELM_TMP"
   HELM_TMP_BIN="$HELM_TMP/diff/bin/diff"
   echo "Preparing to install into ${HELM_PLUGIN_DIR}"
   mkdir -p "$HELM_PLUGIN_DIR/bin"
   cp "$HELM_TMP_BIN" "$HELM_PLUGIN_DIR/bin"
 }
 
-# fail_trap is executed if an error occurs.
-fail_trap() {
+# exit_trap is executed if on exit (error or not).
+exit_trap() {
   result=$?
+  rmTempDir
   if [ "$result" != "0" ]; then
     echo "Failed to install $PROJECT_NAME"
     printf '\tFor support, go to https://github.com/databus23/helm-diff.\n'
@@ -134,12 +143,13 @@ testVersion() {
 # Execution
 
 #Stop execution on any error
-trap "fail_trap" EXIT
+trap "exit_trap" EXIT
 set -e
 initArch
 initOS
 verifySupported
 getDownloadURL
+mkTempDir
 downloadFile
 installFile
 testVersion