Check for pipe write permission on start/attach

A common pitfall when starting up Erlang nodes is to
start them as root and then fail silently when switching
to another user, improve this by providing a helpful error
message when this happens.

1 files changed, 11 insertions, 0 deletions

diff --git a/priv/templates/extended_bin b/priv/templates/extended_bin
index 11a0abc..78f25e0 100755
--- a/priv/templates/extended_bin
+++ b/priv/templates/extended_bin
@@ -492,6 +492,11 @@ case "$1" in
 
         test -z "$PIPE_BASE_DIR" || mkdir -m 1777 -p "$PIPE_BASE_DIR"
         mkdir -p "$PIPE_DIR"
+        if [ ! -w "$PIPE_DIR" ]
+        then
+            echo "failed to start, user '$USER' does not have write privileges on '$PIPE_DIR', either delete it or run node as a different user"
+            exit 1
+        fi
 
         relx_run_hooks "$PRE_START_HOOKS"
         "$BINDIR/run_erl" -daemon "$PIPE_DIR" "$RUNNER_LOG_DIR" \
@@ -555,6 +560,12 @@ case "$1" in
             exit 1
         fi
 
+        if [ ! -w "$PIPE_DIR" ]
+        then
+            echo "failed to attach, user '$USER' does not have sufficient privileges on '$PIPE_DIR', please run node as a different user"
+            exit 1
+        fi
+
         shift
         exec "$BINDIR/to_erl" "$PIPE_DIR"
         ;;