Fix opensearch-env always sources the environment from hardcoded file (…

…#875)

distribution/bin/opensearch-env always sources the environment from the default environment file /etc/default/opensearch. This is an issue if we want to run multiple instances of OpenSearch on the same host. This change lets users override the default behavior by not sourcing the default environment file in case OPENSEARCH_PATH_CONF  is set.

Signed-off-by: xuezhou25 <85715413+xuezhou25@users.noreply.github.com>
Signed-off-by: Peter Zhu <zhujiaxi@amazon.com>

distribution/src/bin/opensearch-env

@@ -81,7 +81,9 @@ fi
 
 export HOSTNAME=$HOSTNAME
 
-${source.path.env}
+if [ -z "$OPENSEARCH_PATH_CONF" ]; then
+  ${source.path.env}
+fi
 
 if [ -z "$OPENSEARCH_PATH_CONF" ]; then
   echo "OPENSEARCH_PATH_CONF must be set to the configuration path"