changing null defaults to empty strings to deal with ansible bug

playbooks/edx-east/edx_continuous_integration.yml

@@ -29,7 +29,8 @@
     - elasticsearch
     - forum
     - { role: "xqueue", update_users: True }
-    - xserver
+    - role: xserver
+      when: XSERVER_GIT_IDENTITY|length > 0
     - certs
     - edx_ansible
     - analytics-api

playbooks/roles/xserver/defaults/main.yml

@@ -9,11 +9,11 @@ XSERVER_RUN_URL: ''
 XSERVER_LOGGING_ENV: 'sandbox'
 XSERVER_SYSLOG_SERVER: ''
 # For 6.00x use "{{ xserver_data_dir }}/data/content-mit-600x~2012_Fall"
-XSERVER_GRADER_DIR: !!null
+XSERVER_GRADER_DIR: ""
 # For 6.00x use "git@github.com:/MITx/6.00x.git"
-XSERVER_GRADER_SOURCE: !!null
+XSERVER_GRADER_SOURCE: ""
 # This must be set to run this role
-XSERVER_GIT_IDENTITY: !!null
+XSERVER_GIT_IDENTITY: ""
 
 XSERVER_LANG: "en_US.UTF-8"
 

playbooks/roles/xserver/tasks/main.yml

@@ -4,12 +4,15 @@
 ---
 
 - name: checking for grader info
-  fail: msg="You must define XSERVER_GRADER_DIR and XSERVER_GRADER_SOURCE to use this role!"
-  when: not XSERVER_GRADER_DIR or not XSERVER_GRADER_SOURCE
+  fail: msg="You must define XSERVER_GRADER_DIR"
+  when: XSERVER_GRADER_DIR|length == 0
+
+- fail: msg="You must define XSERVER_GRADER_SOURCE"
+  when: XSERVER_GRADER_SOURCE|length == 0
 
 - name: checking for git identity
   fail: msg="You must define XSERVER_GIT_IDENTITY to use this role"
-  when: not XSERVER_GIT_IDENTITY
+  when: XSERVER_GIT_IDENTITY|length == 0
 
 - name: create application user
   user: >