[MRG] CI reworked and bugs affecting tests fixed

.flake8

@@ -0,0 +1,5 @@
+[flake8]
+select = F
+ignore = E,W,C,F401,F841
+exclude = __init__.py
+

.gitignore

@@ -1,3 +1,12 @@
+# Artifacts from running kubespawner tests with minikube
+bin/
+lib64
+minikube-linux-amd64
+node_modules/
+package-lock.json
+pyvenv.cfg
+share/
+
 # JupyterHub running from kubespawner folder for development purposes
 jupyterhub-proxy.pid
 jupyterhub.sqlite

.travis.yml

@@ -1,22 +1,20 @@
 language: python
 sudo: required
-dist: xenial
+dist: bionic
 
 # install dependencies
 install:
   - pip install --upgrade setuptools pip
-  - |
-    if [[ ! -z "$KUBE_PY" ]]; then
-      # install pinned kubernetes
-      pip install -e ".[test]" "kubernetes==$KUBE_PY.*"
-    else
-      # add --pre so that we test with prereleases of dependencies
-      # to catch compatibility issues before they enter final releases
-      pip install --upgrade --pre -e ".[test]"
-    fi
+  # Only add the --pre flag if $PRE_RELEASES is specified to test pre-releases
+  # of dependencies, and only pin kubernetes if $KUBE_PY is specified.
+  - pip install -e ".[test]" ${PRE_RELEASES:+--pre} ${KUBE_PY:+kubernetes==${KUBE_PY}}
+  - pip freeze
+  # flake8 runs a very quick code analysis
+  # without running any of the code it analyses
+  - flake8 kubespawner
+  # install kubectl, minikube and start minikube
   - source ci/minikube.env
   - ./ci/install-kube.sh
-  - pip freeze
 
 # command to run tests
 script:
@@ -26,14 +24,48 @@ after_success:
   - codecov
 
 matrix:
-  fast_finish: true
-  allow_failures:
-    - python: nightly
+  # NOTE: We may end up updating these set versions with time, when doing that,
+  # these links are relevant.
+  #
+  # ref: KUBE_VERSION's valid values
+  #      https://github.com/kubernetes/kubernetes/tags
+  # ref: KUBE_PY's valid values
+  #      https://github.com/kubernetes-client/python#compatibility
   include:
-    - python: nightly
-    - python: 3.5
-      env: KUBE_PY=7
-    - python: 3.6
-      env: KUBE_PY=7
+    # Test the oldest supported python on
+    # the latest supported kubernetes-client,
+    # and use the latest supported kubernetes
+    # version along for the kubernetes-client.
+    - python: 3.8
+      env: KUBE_PY=8 KUBE_VERSION=1.12.10
     - python: 3.7
-      env: KUBE_PY=8
+      env: KUBE_PY=9 KUBE_VERSION=1.13.12
+    - python: 3.6
+      env: &latest_supported KUBE_PY=10 KUBE_VERSION=1.14.9
+
+    # Allowed failure tests:
+    # ----------------------
+
+    # 1. Test with pre-releases of kubernetes-client/python and other
+    #    python dependencies
+    - &allowed_failure_1
+      python: 3.8
+      env: PRE_RELEASES=TRUE KUBE_VERSION=1.15.3
+
+    # 2. Test with latest stable kubernetes client along with the latest
+    #    kubernetes cluster version
+    - &allowed_failure_2
+      python: 3.8
+      env: KUBE_PY=10 KUBE_VERSION=1.16.3
+
+    # 3. Test with a nightly python build using latest known
+    #    supported configuration.
+    - &allowed_failure_3
+      python: nightly
+      env: *latest_supported
+
+  allow_failures:
+    - *allowed_failure_1
+    - *allowed_failure_2
+    - *allowed_failure_3
+  fast_finish: true

ci/install-kube.sh

@@ -3,10 +3,11 @@
 # this sets up minikube with vm-driver=none, so should not be used anywhere but CI
 set -eux
 
-mkdir -p bin
+mkdir -p bin $HOME/.kube $HOME/.minikube
+touch $KUBECONFIG
 
 # install kubectl, minikube
-# based on https://blog.travis-ci.com/2017-10-26-running-kubernetes-on-travis-ci-with-minikube
+# based on https://github.com/LiliC/travis-minikube
 echo "installing kubectl"
 curl -Lo kubectl https://storage.googleapis.com/kubernetes-release/release/v${KUBE_VERSION}/bin/linux/amd64/kubectl
 chmod +x kubectl
@@ -17,13 +18,24 @@ curl -Lo minikube https://storage.googleapis.com/minikube/releases/v${MINIKUBE_V
 chmod +x minikube
 mv minikube bin/
 
-echo "starting minikube with RBAC"
-sudo CHANGE_MINIKUBE_NONE_USER=true $PWD/bin/minikube start --vm-driver=none --kubernetes-version=v${KUBE_VERSION} --extra-config=apiserver.Authorization.Mode=RBAC --bootstrapper=localkube
+echo "starting minikube"
+sudo $PWD/bin/minikube start --vm-driver=none --kubernetes-version=v${KUBE_VERSION}
+sudo chown -R travis: /home/travis/.minikube/
 minikube update-context
 
-echo "waiting for kubernetes"
+
+# can be used to check a condition of nodes and pods
 JSONPATH='{range .items[*]}{@.metadata.name}:{range @.status.conditions[*]}{@.type}={@.status};{end}{end}'
-until kubectl get nodes -o jsonpath="$JSONPATH" 2>&1 | grep -q "Ready=True"; do
+
+echo "waiting for kube-addon-manager"
+until kubectl -n kube-system get pods -l component=kube-addon-manager -o jsonpath="$JSONPATH" 2>&1 | grep -q "Ready=True"; do
+  sleep 1
+done
+
+echo "waiting for kube-dns"
+until kubectl -n kube-system get pods -l k8s-app=kube-dns -o jsonpath="$JSONPATH" 2>&1 | grep -q "Ready=True"; do
   sleep 1
 done
+
 kubectl get nodes
+kubectl get pods --all-namespaces

ci/minikube.env

@@ -1,5 +1,19 @@
-# environment variables for installing kubernetes on CI
-export MINIKUBE_VERSION=0.28.0
-export HELM_VERSION=2.9.1
-export KUBE_VERSION=1.10.0
+# default values for relevant environment variables
+
+# ref: https://github.com/kubernetes/minikube/releases
+export KUBE_VERSION=${KUBE_VERSION:-1.16.3}
+
+# ref: https://github.com/kubernetes/minikube/releases
+export MINIKUBE_VERSION=${MINIKUBE_VERSION:-1.5.2}
+
+# ref: https://github.com/helm/helm/releases
+export HELM_VERSION=${HELM_VERSION:-2.16.1}
+
+# ref: https://github.com/LiliC/travis-minikube/blob/master/.travis.yml
+export CHANGE_MINIKUBE_NONE_USER=true
+export MINIKUBE_WANTUPDATENOTIFICATION=false
+export MINIKUBE_WANTREPORTERRORPROMPT=false
+export MINIKUBE_HOME=$HOME
+export KUBECONFIG=$HOME/.kube/config
+
 export PATH="$PWD/bin:$PATH"

jupyterhub_config.py

@@ -24,7 +24,7 @@
 host_ip = s.getsockname()[0]
 s.close()
 
-c.KubeSpawner.hub_connect_ip = host_ip
+c.JupyterHub.hub_connect_ip = host_ip
 c.JupyterHub.hub_connect_ip = c.KubeSpawner.hub_connect_ip
 
 c.KubeSpawner.service_account = 'default'

kubespawner/reflector.py

@@ -221,13 +221,20 @@ def _watch_and_update(self):
                     watch_args['timeout_seconds'] = self.timeout_seconds
                 # in case of timeout_seconds, the w.stream just exits (no exception thrown)
                 # -> we stop the watcher and start a new one
-                for ev in w.stream(
-                        getattr(self.api, self.list_method_name),
-                        **watch_args
+                for watch_event in w.stream(
+                    getattr(self.api, self.list_method_name),
+                    **watch_args
                 ):
+                    # Remember that these events are k8s api related WatchEvents
+                    # objects, not k8s Event or Pod representations, they will
+                    # reside in the WatchEvent's object field depending on what
+                    # kind of resource is watched.
+                    #
+                    # ref: https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.16/#watchevent-v1-meta
+                    # ref: https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.16/#event-v1-core
                     cur_delay = 0.1
-                    resource = ev['object']
-                    if ev['type'] == 'DELETED':
+                    resource = watch_event['object']
+                    if watch_event['type'] == 'DELETED':
                         # This is an atomic delete operation on the dictionary!
                         self.resources.pop(resource.metadata.name, None)
                     else: