jupyterhub: allow config override via env.local

This is basically the same as `ENABLE_JUPYTERHUB_MULTI_NOTEBOOKS` but at
the bottom of the file so it can override everything.
`ENABLE_JUPYTERHUB_MULTI_NOTEBOOKS` is kept for backward-compat.

First useful application is to enable server culling for auto shutdown
of idle kernels and jupyter single server (fixes #67).

birdhouse/config/jupyterhub/jupyterhub_config.py.template

@@ -135,3 +135,5 @@ c.Authenticator.refresh_pre_spawn = True
 blocked_users = {'authtest', '${CATALOG_USERNAME}', 'anonymous'}
 c.Authenticator.blacklist = blocked_users  # v0.9+
 c.Authenticator.blocked_users = blocked_users  # v1.2+
+
+${JUPYTERHUB_CONFIG_OVERRIDE}    # noqa

birdhouse/default.env

@@ -48,6 +48,10 @@ export JUPYTER_LOGIN_BANNER_BOTTOM_SECTION=""
 # server for the change to take effect.
 export JUPYTERHUB_README="$JUPYTERHUB_USER_DATA_DIR/README.ipynb"
 
+# Allow for adding new config or override existing config in
+# config/jupyterhub/jupyterhub_config.py.template.
+export JUPYTERHUB_CONFIG_OVERRIDE=""
+
 # Folder inside "proxy" container to drop extra monitoring config
 export CANARIE_MONITORING_EXTRA_CONF_DIR="/conf.d"
 

birdhouse/env.local.example

@@ -294,6 +294,23 @@ export POSTGRES_MAGPIE_PASSWORD=postgres-qwerty
 # server for the change to take effect.
 #export JUPYTERHUB_README="/path/to/README.ipynb"
 
+# Allow for adding new config or override existing config in
+# config/jupyterhub/jupyterhub_config.py.template.
+#
+# Sample below will shutdown idle server after 3 days and idle kernel after 8 hours.
+#
+#export JUPYTERHUB_CONFIG_OVERRIDE="
+#c.Spawner.args.extend([
+## Shut down the server after N seconds with no kernels or terminals running and no activity.
+#'--NotebookApp.shutdown_no_activity_timeout=259200',  # 3d * 24h/d * 60m/h * 60s/m
+## Timeout (in seconds) after which a kernel is considered idle and ready to be culled.
+#'--MappingKernelManager.cull_idle_timeout=28800',  # 8h * 60m/h * 60s/m
+## Culling kernels which have one or more connections for idle but open notebooks.
+## Otherwise, browser have to be closed for culling to work.
+#'--MappingKernelManager.cull_connected=True',
+#])
+#"
+
 # Extra PyWPS config for **all** WPS services (currently only Flyingpigeon, Finch and Raven supported).
 # export EXTRA_PYWPS_CONFIG="
 # [logging]
@@ -354,4 +371,4 @@ export POSTGRES_MAGPIE_PASSWORD=postgres-qwerty
 # To enable emu: add './optional-components/emu' to EXTRA_CONF_DIRS above.
 
 # Emu WPS service image if that testing component is enabled
-#export EMU_IMAGE="tlvu/emu:watchdog"
+#export EMU_IMAGE="tlvu/emu:watchdog"

birdhouse/pavics-compose.sh

@@ -48,6 +48,7 @@ OPTIONAL_VARS='
   $JUPYTER_LOGIN_BANNER_TOP_SECTION
   $JUPYTER_LOGIN_BANNER_BOTTOM_SECTION
   $JUPYTER_LOGIN_TERMS_URL
+  $JUPYTERHUB_CONFIG_OVERRIDE
   $AUTODEPLOY_EXTRA_REPOS_AS_DOCKER_VOLUMES
   $AUTODEPLOY_PLATFORM_FREQUENCY
   $AUTODEPLOY_NOTEBOOK_FREQUENCY