Add antctl check installation to conduct connectivity checks (#6133)

We introduce a new antctl subcommand (antctl check) which can be used to
run sanity checks on a K8s cluster / Antrea deployment.
At the moment, we have "antctl check installation", which can be used to
validate an Antrea installation, by running some connectivity checks. We
only have a limited number of tests for now (inter-Node & intra-Node Pod
connectivity, Pod connectivity to the Internet), but the frameowk should
make it straightforward to add additional tests in the future.
We validate the antctl command in CI using a Github workflow.

For #6061

Signed-off-by: Kanha gupta <kanhag4163@gmail.com>

.github/workflows/kind.yml

@@ -741,6 +741,48 @@ jobs:
           path: log.tar.gz
           retention-days: 30
 
+  run-post-installation-checks:
+    name: Test connectivity using 'antctl check' command
+    needs: [ build-antrea-coverage-image ]
+    runs-on: [ ubuntu-latest ]
+    steps:
+      - name: Free disk space
+        run: |
+          sudo apt-get clean
+          df -h
+      - uses: actions/checkout@v4
+        with:
+          show-progress: false
+      - uses: actions/setup-go@v5
+        with:
+          go-version-file: 'go.mod'
+      - name: Download Antrea image from previous job
+        uses: actions/download-artifact@v4
+        with:
+          name: antrea-ubuntu-cov
+      - name: Load Antrea image
+        run: |
+          docker load -i antrea-ubuntu.tar
+      - name: Install Kind
+        run: |
+          KIND_VERSION=$(head -n1 ./ci/kind/version)
+          curl -Lo ./kind https://github.com/kubernetes-sigs/kind/releases/download/${KIND_VERSION}/kind-$(uname)-amd64
+          chmod +x ./kind
+          sudo mv kind /usr/local/bin
+      - name: Create Kind Cluster
+        run: |
+          kind create cluster --config ci/kind/config-3nodes.yml
+      - name: Load Docker images and deploy Antrea
+        run: |
+          kind load docker-image antrea/antrea-controller-ubuntu-coverage:latest antrea/antrea-agent-ubuntu-coverage:latest
+          kubectl apply -f build/yamls/antrea.yml
+      - name: Build antctl binary
+        run: |
+          make antctl-linux
+      - name: Run antctl command
+        run: |
+          ./bin/antctl-linux check installation
+
   validate-prometheus-metrics-doc:
     name: Validate metrics in Prometheus document match running deployment's
     needs: build-antrea-coverage-image

pkg/antctl/antctl.go

@@ -19,6 +19,7 @@ import (
 
 	agentapis "antrea.io/antrea/pkg/agent/apis"
 	fallbackversion "antrea.io/antrea/pkg/antctl/fallback/version"
+	checkinstallation "antrea.io/antrea/pkg/antctl/raw/check/installation"
 	"antrea.io/antrea/pkg/antctl/raw/featuregates"
 	"antrea.io/antrea/pkg/antctl/raw/multicluster"
 	"antrea.io/antrea/pkg/antctl/raw/proxy"
@@ -633,6 +634,12 @@ $ antctl get podmulticaststats pod -n namespace`,
 		},
 	},
 	rawCommands: []rawCommand{
+		{
+			cobraCommand:      checkinstallation.Command(),
+			supportAgent:      false,
+			supportController: false,
+			commandGroup:      check,
+		},
 		{
 			cobraCommand:      supportbundle.Command,
 			supportAgent:      true,

pkg/antctl/command_definition.go

@@ -70,6 +70,7 @@ const (
 	query
 	mc
 	upgrade
+	check
 )
 
 var groupCommands = map[commandGroup]*cobra.Command{
@@ -93,6 +94,10 @@ var groupCommands = map[commandGroup]*cobra.Command{
 		Short: "Sub-commands for upgrade operations",
 		Long:  "Sub-commands for upgrade operations",
 	},
+	check: {
+		Use:   "check",
+		Short: "Performs pre and post installation checks",
+	},
 }
 
 type endpointResponder interface {

pkg/antctl/command_list.go

@@ -64,7 +64,8 @@ func (cl *commandList) applyToRootCommand(root *cobra.Command, client AntctlClie
 			(runtime.Mode == runtime.ModeController && cmd.supportController) ||
 			(runtime.Mode == runtime.ModeFlowAggregator && cmd.supportFlowAggregator) ||
 			(!runtime.InPod && cmd.commandGroup == mc) ||
-			(!runtime.InPod && cmd.commandGroup == upgrade) {
+			(!runtime.InPod && cmd.commandGroup == upgrade) ||
+			(!runtime.InPod && cmd.commandGroup == check) {
 			if groupCommand, ok := groupCommands[cmd.commandGroup]; ok {
 				groupCommand.AddCommand(cmd.cobraCommand)
 			} else {