From 148d58c3519aca4723edd6eb59fc7150b92e74d7 Mon Sep 17 00:00:00 2001
From: Sean Dague <sean@dague.net>
Date: Thu, 4 May 2017 13:08:25 -0400
Subject: [PATCH] Make devstack fail early for common systemd pitfalls

There are a couple of issues that have ended up being hit by devstack
plugin authors which we can detect and error in a much nicer way
instead of them having a cryptic systemd failure.

Change-Id: I45e4ac363aeefb4503015f9e1b57c58f79b58f40
---
 functions-common | 33 ++++++++++++++++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/functions-common b/functions-common
index 90f540017c..fe608b4a48 100644
--- a/functions-common
+++ b/functions-common
@@ -1480,10 +1480,41 @@ function write_uwsgi_user_unit_file {
     $SYSTEMCTL daemon-reload
 }
 
+function _common_systemd_pitfalls {
+    local cmd=$1
+    # do some sanity checks on $cmd to see things we don't expect to work
+
+    if [[ "$cmd" =~ "sudo" ]]; then
+        local msg=<<EOF
+You are trying to use run_process with sudo, this is not going to work under systemd.
+
+If you need to run a service as a user other than $STACK_USER call it with:
+
+   run_process \$name \$cmd \$group \$user
+EOF
+        die $LINENO $msg
+    fi
+
+    if [[ ! "$cmd" =~ ^/ ]]; then
+        local msg=<<EOF
+The cmd="$cmd" does not start with an absolute path. It will fail to
+start under systemd.
+
+Please update your run_process stanza to have an absolute path.
+EOF
+        die $LINENO $msg
+    fi
+
+}
+
+# Helper function to build a basic unit file and run it under systemd.
 function _run_under_systemd {
     local service=$1
     local command="$2"
     local cmd=$command
+    # sanity check the command
+    _common_systemd_pitfalls "$cmd"
+
     local systemd_service="devstack@$service.service"
     local group=$3
     local user=${4:-$STACK_USER}
@@ -1527,7 +1558,7 @@ function is_running {
 # If an optional group is provided sg will be used to run the
 # command as that group.
 # Uses globals ``USE_SCREEN``
-# run_process service "command-line" [group]
+# run_process service "command-line" [group] [user]
 function run_process {
     local service=$1
     local command="$2"