Use cat instead of read<file
When reading a file, it is expected that
the read process will exit 1 as this is
expected whenever the input reaches an EOF.
Because it is not clear if the 'exit 1' is
from a successful read or a more serious error,
and as this edge-case of 'read' is not well-known,
we instead change this code to read the file using
'cat'.
The new code is moved into a function, is_docker_running.
Furthermore, we now quote the variables and check
for the existance of the pid file for better and safer
error handling.
Change-Id: Idb56b87349a5a84d5d255715cfb7191341363118
Closes-Bug: 1286441
diff --git a/lib/nova_plugins/hypervisor-docker b/lib/nova_plugins/hypervisor-docker
index f8dc6af..1715fd0 100644
--- a/lib/nova_plugins/hypervisor-docker
+++ b/lib/nova_plugins/hypervisor-docker
@@ -57,6 +57,18 @@
iniset $GLANCE_API_CONF DEFAULT container_formats ami,ari,aki,bare,ovf,docker
}
+# is_docker_running - Return 0 (true) if Docker is running, otherwise 1
+function is_docker_running {
+ local docker_pid
+ if [ -f "$DOCKER_PID_FILE" ]; then
+ docker_pid=$(cat "$DOCKER_PID_FILE")
+ fi
+ if [[ -z "$docker_pid" ]] || ! ps -p "$docker_pid" | grep [d]ocker; then
+ return 1
+ fi
+ return 0
+}
+
# install_nova_hypervisor() - Install external components
function install_nova_hypervisor {
# So far this is Ubuntu only
@@ -69,19 +81,15 @@
die $LINENO "Docker is not installed. Please run tools/docker/install_docker.sh"
fi
- local docker_pid
- read docker_pid <$DOCKER_PID_FILE
- if [[ -z $docker_pid ]] || ! ps -p $docker_pid | grep [d]ocker; then
+ if ! (is_docker_running); then
die $LINENO "Docker not running"
fi
}
# start_nova_hypervisor - Start any required external services
function start_nova_hypervisor {
- local docker_pid
- read docker_pid <$DOCKER_PID_FILE
- if [[ -z $docker_pid ]] || ! ps -p $docker_pid | grep [d]ocker; then
- die $LINENO "Docker not running, start the daemon"
+ if ! (is_docker_running); then
+ die $LINENO "Docker not running"
fi
# Start the Docker registry container