hub image: omit py-spy from slim image

images/hub/Dockerfile

@@ -20,7 +20,11 @@ RUN --mount=type=cache,target=${PIP_CACHE_DIR} \
     pip install build \
  && pip wheel \
         --wheel-dir=/tmp/wheels \
-        -r requirements.txt
+        -r requirements.txt \
+        # Additional wheels for default-stage. Updates below should be repeated
+        # in default-stage.
+        #
+        py-spy
 
 
 # The final stage - slim version
@@ -72,12 +76,23 @@ CMD ["jupyterhub", "--config", "/usr/local/etc/jupyterhub/jupyterhub_config.py"]
 
 # The final stage - default version
 # ---------------------------------
-# We add a few non-critical apt packages on top of the slim version to provide
-# some debugging utility for k8s admins.
+# We add a few non-critical packages on top of the slim version to provide some
+# additional utility.
 #
-FROM slim-stage
+FROM slim-stage as default-stage
 
 USER root
+
+ARG PIP_CACHE_DIR=/tmp/pip-cache
+RUN --mount=type=cache,target=${PIP_CACHE_DIR} \
+    --mount=type=cache,from=build-stage,source=/build-stage,target=/tmp/wheels \
+    pip install \
+        --find-links=/tmp/wheels/ \
+        # Updates below should be repeated in build-stage.
+        #
+        # py-spy is useful for profiling performance of running hubs
+        py-spy
+
 RUN apt-get update \
  && apt-get install -y --no-install-recommends \
         # misc network utilities
@@ -88,4 +103,5 @@ RUN apt-get update \
         less \
         vim \
  && rm -rf /var/lib/apt/lists/*
+
 USER ${NB_USER}

images/hub/requirements.in

@@ -35,8 +35,3 @@ statsd  # statsd metrics collection (TODO: remove soon, since folks use promethe
 
 # The idle culler service
 jupyterhub-idle-culler
-
-## Useful tools
-
-# py-spy is useful for profiling running hubs
-py-spy

images/hub/requirements.txt

@@ -124,8 +124,6 @@ prometheus-client==0.15.0
     # via jupyterhub
 psycopg2-binary==2.9.4
     # via -r requirements.in
-py-spy==0.3.14
-    # via -r requirements.in
 pyasn1==0.4.8
     # via ldap3
 pycparser==2.21