Merge pull request #55813 from ihmccreery/prom-to-sd-resource-limits

Automatic merge from submit-queue (batch tested with PRs 56650, 55813, 56911, 56921, 56871). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Reintroduce memory limits removed in #55715

**What this PR does / why we need it**: Reintroduce memory limits removed in #55715, in order to make metadata-proxy QoS be guaranteed.  Xref #55695.

**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes #55797

**Special notes for your reviewer**:

**Release note**:

```release-note
NONE
```

cluster/addons/metadata-proxy/gce/metadata-proxy.yaml

@@ -38,19 +38,28 @@ spec:
       dnsPolicy: Default
       containers:
       - name: metadata-proxy
-        image: gcr.io/google_containers/metadata-proxy:v0.1.5
+        image: gcr.io/google_containers/metadata-proxy:v0.1.6
         securityContext:
           privileged: true
+        # Request and limit resources to get guaranteed QoS.
         resources:
           requests:
-            memory: "32Mi"
+            memory: "25Mi"
             cpu: "30m"
           limits:
-            memory: "32Mi"
+            memory: "25Mi"
             cpu: "30m"
       # BEGIN_PROMETHEUS_TO_SD
       - name: prometheus-to-sd-exporter
         image: gcr.io/google_containers/prometheus-to-sd:v0.2.2
+        # Request and limit resources to get guaranteed QoS.
+        resources:
+          requests:
+            memory: "20Mi"
+            cpu: "2m"
+          limits:
+            memory: "20Mi"
+            cpu: "2m"
         command:
           - /monitor
           - --stackdriver-prefix={{ prometheus_to_sd_prefix }}/addons