Add devstack steps.

Change-Id: I8006158fd257f220b0fe6ca3cbb7fad30d23ed3b

devstack/README.md

@@ -0,0 +1,39 @@
+# Enabling Venus in DevStack
+
+To enable Venus in DevStack, perform the following steps:
+
+## 1. Enabling Venus in local.conf
+Enable the plugin by adding the following section to `local.conf`
+```
+    [[local|localrc]]
+    enable_plugin venus https://review.opendev.org/openstack/venus
+    enable_plugin venus-dashboard https://review.opendev.org/openstack/venus-dashboard
+```
+## 2. Modify service log format
+After `stack.sh` process finished, replace the lines begin with `logging_default_format_string =` and `logging_context_format_string =` with
+```
+logging_default_format_string = %(asctime)s.%(msecs)03d %(process)d %(levelname)s %(name)s [- req-None - - - - -] %(instance)s%(message)s
+logging_context_format_string = %(asctime)s.%(msecs)03d %(process)d %(levelname)s %(name)s [%(global_request_id)s %(request_id)s 
+```
+
+in files
+- /etc/nova/nova.conf
+- /etc/cinder/cinder.conf
+- /etc/neutron/neutron.conf
+
+Restart nova, cinder and neutron service:
+
+```
+systemctl restart devstack@n-api.service
+systemctl restart devstack@c-api.service
+systemctl restart devstack@q-svc.service
+```
+
+## 3. [Optional] Manually download td-agent and es
+If you want to download td-agent and es yourself when the official download link is not available,
+you cloud get them via the following links:
+
+- https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-5.6.16.deb
+- http://packages.treasuredata.com.s3.amazonaws.com/4/ubuntu/bionic/pool/contrib/t/td-agent/td-agent_4.1.0-1_amd64.deb
+
+And save the files to `/opt/stack/venus/devstack/files`