Add progress indicators when spawning

- Uses JupyterHub 0.9 feature, no effect for <0.9.
- Closes: #81

.travis.yml

@@ -30,6 +30,7 @@ install:
     - pip install attrs>17.4.0
     - pip install --pre -r jupyterhub/dev-requirements.txt
     - pip install --pre -e jupyterhub
+    - pip install --pre -f travis-wheels/wheelhouse -r requirements.txt
 
 script:
     - travis_retry py.test --lf --cov batchspawner batchspawner/tests -v

batchspawner/batchspawner.py

@@ -15,9 +15,12 @@
   * remote execution via submission of templated scripts
   * job names instead of PIDs
 """
+import asyncio
+from async_generator import async_generator, yield_, yield_from_
 import pwd
 import os
 import re
+import sys
 
 import xml.etree.ElementTree as ET
 
@@ -411,6 +414,23 @@ def stop(self, now=False):
                              self.job_id, self.current_ip, self.port)
                 )
 
+    @async_generator
+    async def progress(self):
+        while True:
+            if self.state_ispending():
+                await yield_({
+                    "message": "Pending in queue...",
+                })
+            elif self.state_isrunning():
+                await yield_({
+                    "message": "Cluster job running... waiting to connect",
+                })
+                return
+            else:
+                await yield_({
+                    "message": "Unknown status...",
+                })
+            await gen.sleep(.1)
 
 class BatchSpawnerRegexStates(BatchSpawnerBase):
     """Subclass of BatchSpawnerBase that uses config-supplied regular expressions

requirements.txt

@@ -1,2 +1,3 @@
+async_generator>=1.8
 jinja2
 jupyterhub>=0.5