Merge pull request #49808 from dims/fix-dynamic-admission-control-in-local-cluster

Automatic merge from submit-queue (batch tested with PRs 48365, 49902, 49808, 48722, 47045)

Add admission controller API to runtime config and externalize ADMISSION_CONTROL

**What this PR does / why we need it**:

Enable the dynamic admission controller registration API by
adding "admissionregistration.k8s.io/v1alpha1" to --runtime-config
to fix problems when starting up local-up-cluster. Also make sure
ADMISSION_CONTROL can be specified externally.

**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #

Fixes #47385

**Special notes for your reviewer**:

**Release note**:

```release-note
NONE
```

hack/local-up-cluster.sh

@@ -91,6 +91,7 @@ export KUBE_CACHE_MUTATION_DETECTOR
 KUBE_PANIC_WATCH_DECODE_ERROR="${KUBE_PANIC_WATCH_DECODE_ERROR:-true}"
 export KUBE_PANIC_WATCH_DECODE_ERROR
 
+ADMISSION_CONTROL=${ADMISSION_CONTROL:-""}
 ADMISSION_CONTROL_CONFIG_FILE=${ADMISSION_CONTROL_CONFIG_FILE:-""}
 
 # START_MODE can be 'all', 'kubeletonly', or 'nokubelet'
@@ -441,6 +442,14 @@ function start_apiserver {
     if [[ -n "${ALLOW_PRIVILEGED}" ]]; then
       priv_arg="--allow-privileged "
     fi
+
+    if [[ ${ADMISSION_CONTROL} == *"Initializers"* ]]; then
+        if [[ -n "${RUNTIME_CONFIG}" ]]; then
+          RUNTIME_CONFIG+=","
+        fi
+        RUNTIME_CONFIG+="admissionregistration.k8s.io/v1alpha1"
+    fi
+
     runtime_config=""
     if [[ -n "${RUNTIME_CONFIG}" ]]; then
       runtime_config="--runtime-config=${RUNTIME_CONFIG}"