HPA example. Upgrade helm-application dependency

Makefile

@@ -8,11 +8,13 @@ examples-clean:
 	rm -f examples/gwcStatefulSet/charts/*.tgz
 	rm -f examples/jdbc/charts/*.tgz
 	rm -f examples/pgconfig-acl/charts/*.tgz
+	rm -f examples/pgconfig-wms-hpa/charts/*.tgz
 	${HELM} uninstall gs-cloud-common || /bin/true
 	${HELM} uninstall gs-cloud-datadir || /bin/true
 	${HELM} uninstall gs-cloud-statefulset || /bin/true
 	${HELM} uninstall gs-cloud-jdbc || /bin/true
 	${HELM} uninstall gs-cloud-pgconfig-acl || /bin/true
+	${HELM} uninstall gs-cloud-pgconfig-wms-hpa || /bin/true
 
 
 .PHONY: dependencies
@@ -26,11 +28,13 @@ gen-expected: dependencies
 	${HELM} dependency update examples/jdbc
 	${HELM} dependency update examples/pgconfig-acl
 	${HELM} dependency update examples/gwcStatefulSet
+	${HELM} dependency update examples/pgconfig-wms-hpa
 	${HELM} template --namespace=default gs-cloud-common examples/common > tests/expected-common.yaml
 	${HELM} template --namespace=default gs-cloud-datadir examples/datadir > tests/expected-datadir.yaml
 	${HELM} template --namespace=default gs-cloud-jdbc examples/jdbc > tests/expected-jdbc.yaml
 	${HELM} template --namespace=default gs-cloud-pgconfig-acl examples/pgconfig-acl > tests/expected-pgconfig-acl.yaml
 	${HELM} template --namespace=default gs-cloud-statefulset examples/gwcStatefulSet > tests/expected-statefulset.yaml
+	${HELM} template --namespace=default gs-cloud-pgconfig-wms-hpa examples/pgconfig-wms-hpa > tests/expected-pgconfig-wms-hpa.yaml
 	sed -i 's/[[:blank:]]\+$$//g'  tests/expected*.yaml
 
 .PHONY: example-common
@@ -62,3 +66,8 @@ example-common-no-nfs: dependencies
 example-pgconfig-acl: example-common-no-nfs
 	${HELM} dependency update examples/pgconfig-acl
 	${HELM} upgrade --install gs-cloud-pgconfig-acl examples/pgconfig-acl
+
+.PHONY: example-pgconfig-wms-hpa
+example-pgconfig-wms-hpa: example-common-no-nfs
+	${HELM} dependency update examples/pgconfig-wms-hpa
+	${HELM} upgrade --install gs-cloud-pgconfig-wms-hpa examples/pgconfig-wms-hpa

examples/pgconfig-wms-hpa/Chart.yaml

@@ -0,0 +1,15 @@
+apiVersion: v2
+appVersion: '1.0'
+description: Basic example with Horizontal Pod Autoscaling applied to WMS instances in geoserver-cloud using pgconfig as catalog persistence component
+name: gs-cloud-hpa
+version: 0.1.0
+dependencies:
+  - name: geoservercloud
+    repository: file://../../
+    version: 0.1.0
+  # Postgres dependency used for pgconfig database
+  # Note: bitnami postgres chart is updated at initialization to add Postgis extension
+  - name: 'postgresql'
+    version: 14.0.0
+    repository: 'https://charts.bitnami.com/bitnami'
+    condition: postgresql.enabled

examples/pgconfig-wms-hpa/README.md

@@ -0,0 +1,204 @@
+# HPA Example
+
+This example demonstrates how to deploy a simple **GeoserverCloud** setup in your local cluster, allowing you to evaluate and understand the behavior of **Horizontal Pod Autoscaling (HPA)**.
+
+## Setup Overview
+
+The deployment includes the following components:
+
+- **WebUI instance**: Provides access to the catalog configuration.
+- **Gateway**: Serves as the entry point to the GeoserverCloud solution.
+- **Two WMS instances**: These initial instances serve the WMS OGC protocol.
+- **REST API instance**: Utilized by a script to create a minimal catalog for testing.
+- **Local PostgreSQL**: Used with the PgConfig profile to minimize startup time by focusing on efficient catalog reads.
+- **RabbitMQ**: Manages event communication across instances.
+
+By following the steps in the next section, you will observe how HPA automatically scales the deployment (up to 100 containers!) in response to stress generated by the provided script.
+
+## Considerations
+
+- Make sure to review the documentation in the `../README.md` file. A local Kubernetes cluster and `kubectl` are required to run this demo.
+- Be aware that running these tests may overload or freeze your machine if your hardware or configuration is inadequate.
+- If needed, adjust the **maxReplicas** value in the `values.yaml` file under the HPA section. The default value is set to 100.
+
+## Steps to Run the Example
+
+At the root level of the repository, follow these steps:
+
+### 1. Execute the example command:
+
+```shell
+make example-pgconfig-wms-hpa
+```
+
+### 2. Verify that all pods are running:
+
+```shell
+kubectl get pods
+```
+
+Ensure all pods have the status `STATUS = Running` and `READY = 1/1`. Example output:
+
+```shell
+NAME                                                     READY   STATUS    RESTARTS   AGE
+gs-cloud-pgconfig-wms-hpa-gsc-gateway-76b46b9c7f-gs976   1/1     Running   0          12m
+gs-cloud-pgconfig-wms-hpa-postgresql-0                   1/1     Running   0          12m
+gs-cloud-pgconfig-wms-hpa-gsc-rest-7fdbcf799f-qshn5      1/1     Running   0          12m
+gs-cloud-pgconfig-wms-hpa-gsc-webui-6cf8f88695-646xt     1/1     Running   0          12m
+gs-cloud-common-rabbitmq-0                               1/1     Running   0          12m
+gs-cloud-pgconfig-wms-hpa-gsc-wms-758dfd8765-qs946       1/1     Running   0          11m
+gs-cloud-pgconfig-wms-hpa-gsc-wms-758dfd8765-pth59       1/1     Running   0          10m
+```
+
+### 3. Define a DNS alias:
+
+This step prevents the use of local references in the scripts creating an entry like the following in `/etc/hosts`
+
+```shell
+192.168.208.2	gscloud.local
+```
+
+You can modify the scripts if needed.
+
+```shell
+kubectl get ingress --no-headers gs-cloud-pgconfig-wm-geoserver-host1 | \
+awk '{printf("%s\t%s\n", $4, $3)}' | sudo tee -a /etc/hosts
+```
+
+### 4. Initialize the catalog:
+
+Run the following command to create a test layer:
+
+```shell
+./examples/pgconfig-wms-hpa/init-catalog.sh
+```
+
+Should output:
+
+```shell
+------------------------------------
+Preparing initialization process ...
+------------------------------------
+Creating workspace 'hpa-test'...
+hpa-test
+------------------------------------
+Creating WMS datastore 'swisstopo_wms'...
+swisstopo_wms
+------------------------------------
+Publishing layer 'ch.bafu.grundwasserkoerper' from datastore 'swisstopo_wms'...
+ch.bafu.grundwasserkoerper
+------------------------------------
+Catalog initialized successfully.
+```
+
+### 5. Monitor the pods:
+
+Use the following command to continuously monitor the pod status (refreshes every second).
+This will let you see the number of `wms` pods increase during stress testing, and decrease back to one pod after a while.
+
+```shell
+watch -n 1 kubectl top pod -l app.kubernetes.io/component=wms --sort-by cpu
+```
+
+Initially it will output something like this, with the only wms pod running by default:
+
+```shell
+Every 1.0s: kubectl top pod -l app.kubernetes.io/component=wms --sort-by cpu
+
+NAME                                                 CPU(cores)   MEMORY(bytes)
+gs-cloud-pgconfig-wms-hpa-gsc-wms-758dfd8765-2frh9   3m           533Mi
+```
+
+The `kubectl get hpa` command is also useful to monitor
+
+```shell
+watch -n 1 kubectl get hpa gs-cloud-pgconfig-wms-hpa-gsc-wms
+
+Every 1.0s: kubectl get hpa gs-cloud-pgconfig-wms-hpa-gsc-wms
+NAME                                REFERENCE                                      TARGETS    MINPODS   MAXPODS   REPLICAS   AGE
+gs-cloud-pgconfig-wms-hpa-gsc-wms   Deployment/gs-cloud-pgconfig-wms-hpa-gsc-wms   3%/70%    1         16        16         23m
+```
+
+### 6. Stress test the server:
+
+> [!NOTE]
+> The `stress-server.sh` script uses Apache Benchmark (`ab` command). If you don't have it, install it with
+>
+> ```shell
+> sudo apt-get install apache2-utils
+> ```
+>
+> or with your Operating System's package manager.
+
+In a new terminal window, run the stress test script. It'll run for 60 seconds making 100 concurrent WMS requests to the cluster:
+
+```shell
+./examples/pgconfig-wms-hpa/stress-server.sh
+```
+
+You will observe in the first terminal how the number of pods scales up and down dynamically during the stress test.
+
+For example, at some point the number of `wms` pods scaled to 4 here as the CPU utilization increased:
+
+```shell
+Every 1.0s: kubectl top pod -l app.kubernetes.io/component=wms --sort-by cpu
+
+NAME                                                 CPU(cores)   MEMORY(bytes)
+gs-cloud-pgconfig-wms-hpa-gsc-wms-758dfd8765-h8nmg   1888m        818Mi
+gs-cloud-pgconfig-wms-hpa-gsc-wms-758dfd8765-xvr2r   1532m        867Mi
+gs-cloud-pgconfig-wms-hpa-gsc-wms-758dfd8765-9kp2g   1318m        845Mi
+gs-cloud-pgconfig-wms-hpa-gsc-wms-758dfd8765-nb2cc   1305m        891Mi
+gs-cloud-pgconfig-wms-hpa-gsc-wms-758dfd8765-9hhlb   1285m        882Mi
+gs-cloud-pgconfig-wms-hpa-gsc-wms-758dfd8765-zpk4d   1267m        860Mi
+gs-cloud-pgconfig-wms-hpa-gsc-wms-758dfd8765-wmdxw   1102m        1398Mi
+gs-cloud-pgconfig-wms-hpa-gsc-wms-758dfd8765-lrlv8   1027m        834Mi
+gs-cloud-pgconfig-wms-hpa-gsc-wms-758dfd8765-6nv2j   968m         826Mi
+gs-cloud-pgconfig-wms-hpa-gsc-wms-758dfd8765-wmvjh   901m         821Mi
+gs-cloud-pgconfig-wms-hpa-gsc-wms-758dfd8765-dtx4k   865m         1301Mi
+gs-cloud-pgconfig-wms-hpa-gsc-wms-758dfd8765-9s4fk   584m         1447Mi
+gs-cloud-pgconfig-wms-hpa-gsc-wms-758dfd8765-gxbj4   460m         985Mi
+gs-cloud-pgconfig-wms-hpa-gsc-wms-758dfd8765-2frh9   367m         953Mi
+```
+
+And with `kubectl get hpa` will observe the status of the **HorizontalPodAutoscaler**, similar to:
+
+```shell
+watch -n 1 kubectl get hpa gs-cloud-pgconfig-wms-hpa-gsc-wms
+
+Every 1.0s: kubectl get hpa gs-cloud-pgconfig-wms-hpa-gsc-wms
+
+NAME                                REFERENCE                                      TARGETS    MINPODS   MAXPODS   REPLICAS   AGE
+gs-cloud-pgconfig-wms-hpa-gsc-wms   Deployment/gs-cloud-pgconfig-wms-hpa-gsc-wms   941%/70%   1         16        14         4m28s
+```
+
+Here, CPU consumption has increased to 941% out of the 70% average utilization configured. As a result, the Deployment was resized to 14 replicas:
+
+```shell
+kubectl get deployment gs-cloud-pgconfig-wms-hpa-gsc-wms
+NAME                                READY   UP-TO-DATE   AVAILABLE   AGE
+gs-cloud-pgconfig-wms-hpa-gsc-wms   14/14   14           14          9m23s
+```
+
+And after a couple minutes the replicas start to ramp down until reaching one:
+
+```shell
+kubectl get deployment gs-cloud-pgconfig-wms-hpa-gsc-wms
+NAME                                READY   UP-TO-DATE   AVAILABLE   AGE
+gs-cloud-pgconfig-wms-hpa-gsc-wms   1/1     1            1           9m25s
+
+kubectl top pod -l app.kubernetes.io/component=wms --sort-by cpu
+NAME                                                 CPU(cores)   MEMORY(bytes)
+gs-cloud-pgconfig-wms-hpa-gsc-wms-758dfd8765-2frh9   4m           971Mi
+
+kubectl get hpa gs-cloud-pgconfig-wms-hpa-gsc-wms
+NAME                                REFERENCE                                      TARGETS   MINPODS   MAXPODS   REPLICAS   AGE
+gs-cloud-pgconfig-wms-hpa-gsc-wms   Deployment/gs-cloud-pgconfig-wms-hpa-gsc-wms   3%/70%    1         16        1          15m
+```
+
+### 7. Clean up the environment:
+
+To remove the deployment and restore your environment, run:
+
+```shell
+make examples-clean
+```

examples/pgconfig-wms-hpa/init-catalog.sh

@@ -0,0 +1,38 @@
+#!/bin/bash
+
+GEOSERVER_URL="http://gscloud.local/geoserver-cloud"
+USER="admin"
+PASSWORD="geoserver"
+
+WORKSPACE="hpa-test"
+DATASTORE="swisstopo_wms"
+WMS_URL="https://wms.geo.admin.ch/?SERVICE=WMS&VERSION=1.3.0&REQUEST=GetCapabilities"
+LAYER_NAME="ch.bafu.grundwasserkoerper"
+
+echo -e "\n------------------------------------"
+echo -e "Preparing initialization process ..."
+curl -u $USER:$PASSWORD -X DELETE "$GEOSERVER_URL/rest/workspaces/$WORKSPACE?recurse=true"
+
+echo -e "------------------------------------"
+echo -e "Creating workspace '$WORKSPACE'..."
+if ! curl -u $USER:$PASSWORD -X POST -H "Content-Type: text/xml" -d "<workspace><name>$WORKSPACE</name></workspace>" $GEOSERVER_URL/rest/workspaces --fail; then
+  echo -e "Error creating workspace\n"
+  exit 1
+fi
+
+echo -e "\n------------------------------------"
+echo -e "Creating WMS datastore '$DATASTORE'..."
+if ! curl -u $USER:$PASSWORD -X POST -H "Content-Type: text/xml" -d "<wmsStore><type>WMS</type><name>$DATASTORE</name><workspace>$WORKSPACE</workspace><capabilitiesURL>$WMS_URL</capabilitiesURL><enabled>true</enabled></wmsStore>" $GEOSERVER_URL/rest/workspaces/$WORKSPACE/wmsstores --fail; then
+  echo -e "\nError creating datastore"
+  exit 1
+fi
+
+echo -e "\n------------------------------------"
+echo -e "Publishing layer '$LAYER_NAME' from datastore '$DATASTORE'..."
+if ! curl -u $USER:$PASSWORD -X POST -H "Content-Type: text/xml" -d "<wmsLayer><name>$LAYER_NAME</name><defaultStyle><name>raster</name></defaultStyle></wmsLayer>" $GEOSERVER_URL/rest/workspaces/$WORKSPACE/wmsstores/$DATASTORE/wmslayers --fail; then
+  echo -e "Error publishing layer\n"
+  exit 1
+fi
+
+echo -e "\n------------------------------------"
+echo -e "Catalog initialized successfully.\n"

examples/pgconfig-wms-hpa/stress-server.sh

@@ -0,0 +1,5 @@
+#!/bin/bash
+
+WMS_URL="http://gscloud.local/geoserver-cloud/wms?SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&FORMAT=image%2Fpng&TRANSPARENT=true&STYLES&LAYERS=hpa-test%3Ach.bafu.grundwasserkoerper&exceptions=application%2Fvnd.ogc.se_inimage&SRS=EPSG%3A2056&WIDTH=769&HEIGHT=359&BBOX=2628297.2396917907%2C1161127.5666655225%2C2745623.985655881%2C1215846.1146757442"
+
+ab -Sdl -t 120 -c 64 "$WMS_URL"