Merge pull request #915 from mengqiy/addmissingnote

📖 add a note for bootstrapping webhooks for pods

Author: k8s-ci-robot

docs/book/install-and-build.sh

@@ -44,7 +44,7 @@ chmod +x /tmp/mdbook
 echo "grabbing the latest released controller-gen"
 # TODO(directxman12): remove the @v0.2.0-beta.4 once get v0.2.0 released,
 # so that we actually get the latest version
-go get sigs.k8s.io/controller-tools/cmd/controller-gen@v0.2.0-beta.4
+go get sigs.k8s.io/controller-tools/cmd/controller-gen@v0.2.0-beta.5
 
 # make sure we add the go bin directory to our path
 gobin=$(go env GOBIN)

docs/book/src/cronjob-tutorial/running-webhook.md

@@ -57,5 +57,19 @@ kubectl create -f config/samples/batch_v1_cronjob.yaml
 You can also try to create an invalid CronJob (e.g. use an ill-formatted
 schedule field). You should see a creation failure with a validation error.
 
-**Note**: If you are
+<aside class="note warning">
 
+<h1>The Bootstrapping Problem</h1>
+
+If you are deploying a webhook for pods in the same cluster, be
+careful about the bootstrapping problem, since the creation request of the
+webhook pod would be sent to the webhook pod itself, which hasn't come up yet.
+
+To make it work, you can either use [namespaceSelector] if your kubernetes
+version is 1.9+ or use [objectSelector] if your kubernetes version is 1.15+ to
+skip itself.
+
+</aside>
+
+[namespaceSelector]: https://github.com/kubernetes/api/blob/kubernetes-1.14.5/admissionregistration/v1beta1/types.go#L189-L233
+[objectSelector]: https://github.com/kubernetes/api/blob/kubernetes-1.15.2/admissionregistration/v1beta1/types.go#L262-L274

docs/book/theme/css/general.css

@@ -397,3 +397,43 @@ main > details.collapse-code > summary::after {
     fill: black;
     stroke: none;
 }
+
+/* notes */
+aside.note {
+    border: 1px solid var(--searchbar-border-color);
+    border-radius: 3px;
+}
+
+aside.note > * {
+    margin-left: 1em;
+    margin-right: 1em;
+}
+
+/* note title */
+aside.note > h1 {
+    border-bottom: 1px solid var(--searchbar-border-color);
+    margin: 0;
+    padding: 0.5em 1em;
+    font-size: 100%;
+    font-weight: normal;
+}
+
+/* warning notes */
+aside.note.warning > h1 {
+    background: var(--warning-note-background-color, #fcf8f2);
+}
+aside.note.warning > h1::before {
+    /* TODO(directxman12): fill in these colors in theme.
+     * If you're good with colors, feel free to play around with this
+     * in dark mode. */
+    content: "!";
+    color: var(--warning-note-color, #f0ad4e);
+    margin-right: 1em;
+    font-size: 100%;
+    vertical-align: middle;
+    font-weight: bold;
+    padding-left: 0.6em;
+    padding-right: 0.6em;
+    border-radius: 50%;
+    border: 2px solid var(--warning-note-color, #f0ad4e);
+}