feat: add chaos-network workload

cmd/virtwork/main_test.go

@@ -628,7 +628,7 @@ var _ = Describe("CLI end-to-end scenarios", func() {
 
 	Context("when running with default arguments", func() {
 		It("should create VMs for all workloads", func() {
-			// Default run creates 9 VMs: chaos-process=1 + cpu=1 + memory=1 + disk=1 + database=1 + network=2 + tps=2
+			// Default run creates 10 VMs: chaos-process=1 + chaos-network=1 + cpu=1 + memory=1 + disk=1 + database=1 + network=2 + tps=2
 			registry := workloads.DefaultRegistry()
 			totalVMs := 0
 			for _, name := range workloads.AllWorkloadNames() {
@@ -646,8 +646,8 @@ var _ = Describe("CLI end-to-end scenarios", func() {
 				Expect(err).NotTo(HaveOccurred())
 				totalVMs += w.VMCount()
 			}
-			// cpu=1 + database=1 + disk=1 + memory=1 + network=2 + tps=2 = 8
-			Expect(totalVMs).To(Equal(9))
+			// chaos-process=1 + chaos-network=1 + cpu=1 + database=1 + disk=1 + memory=1 + network=2 + tps=2 = 10
+			Expect(totalVMs).To(Equal(10))
 		})
 	})
 

internal/workloads/chaos-network.go

@@ -0,0 +1,118 @@
+// Copyright 2026 Red Hat
+// SPDX-License-Identifier: Apache-2.0
+
+package workloads
+
+import (
+	"fmt"
+
+	"github.com/opdev/virtwork/internal/config"
+)
+
+const chaosNetworkStartScript = `#!/bin/bash
+set -euo pipefail
+
+DEV=$(ip route show default | awk '{print $5; exit}')
+if [ -z "$DEV" ]; then
+  echo "no default route interface found" >&2
+  exit 1
+fi
+
+modprobe sch_netem 2>/dev/null || true
+
+exec /usr/sbin/tc qdisc add dev "$DEV" root netem delay %sms loss %s%% limit 1000
+`
+
+const chaosNetworkStopScript = `#!/bin/bash
+DEV=$(ip route show default | awk '{print $5; exit}')
+[ -n "$DEV" ] && /usr/sbin/tc qdisc del dev "$DEV" root 2>/dev/null
+exit 0
+`
+
+const chaosNetworkSystemdUnit = `[Unit]
+Description=Virtwork network chaos workload (tc/netem)
+After=network-online.target
+Wants=network-online.target
+
+[Service]
+Type=simple
+ExecStart=/usr/local/bin/virtwork-chaos-network-start.sh
+ExecStop=/usr/local/bin/virtwork-chaos-network-stop.sh
+Restart=always
+RestartSec=10
+
+[Install]
+WantedBy=multi-user.target
+`
+
+// ChaosNetworkWorkload generates cloud-init userdata for network chaos injection
+// using tc (traffic control) and netem (network emulation).
+type ChaosNetworkWorkload struct {
+	BaseWorkload
+	Latency    int     // Latency in milliseconds (default: 100)
+	PacketLoss float64 // Packet loss percentage (default: 5.0)
+}
+
+// NewChaosNetworkWorkload creates a ChaosNetworkWorkload with the given configuration
+// and SSH credentials.
+func NewChaosNetworkWorkload(
+	cfg config.WorkloadConfig,
+	sshUser, sshPassword string,
+	sshKeys []string,
+) *ChaosNetworkWorkload {
+	latency := 100
+	packetLoss := 5.0
+
+	// Allow configuration via WorkloadConfig if needed in future
+	// For now, use sensible defaults as specified in the issue
+
+	return &ChaosNetworkWorkload{
+		BaseWorkload: BaseWorkload{
+			Config:            cfg,
+			SSHUser:           sshUser,
+			SSHPassword:       sshPassword,
+			SSHAuthorizedKeys: sshKeys,
+		},
+		Latency:    latency,
+		PacketLoss: packetLoss,
+	}
+}
+
+// Name returns "chaos-network".
+func (w *ChaosNetworkWorkload) Name() string {
+	return "chaos-network"
+}
+
+// CloudInitUserdata returns cloud-init YAML that configures tc/netem for network chaos
+// injection via systemd. Assumes iproute-tc is pre-installed (golden image dependency).
+func (w *ChaosNetworkWorkload) CloudInitUserdata() (string, error) {
+	startScript := fmt.Sprintf(chaosNetworkStartScript,
+		fmt.Sprintf("%d", w.Latency),
+		fmt.Sprintf("%.1f", w.PacketLoss))
+
+	return w.BuildCloudConfig(CloudConfigOpts{
+		Packages: []string{"iproute-tc"},
+		WriteFiles: []WriteFile{
+			{
+				Path:        "/usr/local/bin/virtwork-chaos-network-start.sh",
+				Content:     startScript,
+				Permissions: "0755",
+			},
+			{
+				Path:        "/usr/local/bin/virtwork-chaos-network-stop.sh",
+				Content:     chaosNetworkStopScript,
+				Permissions: "0755",
+			},
+			{
+				Path:        "/etc/systemd/system/virtwork-chaos-network.service",
+				Content:     chaosNetworkSystemdUnit,
+				Permissions: "0644",
+			},
+		},
+		RunCmd: [][]string{
+			{"bash", "-c", "dnf install -y kernel-modules-extra-$(uname -r)"},
+			{"systemctl", "daemon-reload"},
+			{"systemctl", "enable", "--now", "virtwork-chaos-network.service"},
+		},
+	})
+}

internal/workloads/chaos-network_test.go

@@ -0,0 +1,134 @@
+// Copyright 2026 Red Hat
+// SPDX-License-Identifier: Apache-2.0
+
+package workloads_test
+
+import (
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+
+	"github.com/opdev/virtwork/internal/config"
+	"github.com/opdev/virtwork/internal/workloads"
+)
+
+var _ = Describe("ChaosNetworkWorkload", func() {
+	var w *workloads.ChaosNetworkWorkload
+
+	BeforeEach(func() {
+		w = workloads.NewChaosNetworkWorkload(config.WorkloadConfig{
+			Enabled:  true,
+			VMCount:  1,
+			CPUCores: 1,
+			Memory:   "1Gi",
+		}, "virtwork", "", nil)
+	})
+
+	It("should return 'chaos-network' for Name", func() {
+		Expect(w.Name()).To(Equal("chaos-network"))
+	})
+
+	It("should include iproute-tc package", func() {
+		result, err := w.CloudInitUserdata()
+		Expect(err).NotTo(HaveOccurred())
+
+		parsed := parseYAML(result)
+		Expect(parsed).To(HaveKey("packages"))
+		packages := parsed["packages"].([]interface{})
+		Expect(packages).To(ContainElement("iproute-tc"))
+	})
+
+	It("should include start script, stop script, and systemd service in cloud-init", func() {
+		result, err := w.CloudInitUserdata()
+		Expect(err).NotTo(HaveOccurred())
+
+		parsed := parseYAML(result)
+		Expect(parsed).To(HaveKey("write_files"))
+		files := parsed["write_files"].([]interface{})
+		Expect(files).To(HaveLen(3))
+
+		filesByPath := map[string]string{}
+		for _, f := range files {
+			fm := f.(map[string]interface{})
+			filesByPath[fm["path"].(string)] = fm["content"].(string)
+		}
+
+		startScript := filesByPath["/usr/local/bin/virtwork-chaos-network-start.sh"]
+		Expect(startScript).To(ContainSubstring("tc qdisc"))
+		Expect(startScript).To(ContainSubstring("netem"))
+		Expect(startScript).To(ContainSubstring("delay 100ms"), "should include default 100ms latency")
+		Expect(startScript).To(ContainSubstring("loss 5.0%"), "should include default 5% packet loss")
+		Expect(startScript).To(ContainSubstring("ip route show default"), "should auto-detect interface")
+		Expect(startScript).To(ContainSubstring("modprobe sch_netem"), "should load netem kernel module")
+
+		Expect(filesByPath).To(HaveKey("/usr/local/bin/virtwork-chaos-network-stop.sh"))
+		Expect(filesByPath).To(HaveKey("/etc/systemd/system/virtwork-chaos-network.service"))
+	})
+
+	It("should install kernel-modules-extra for running kernel before enabling service", func() {
+		result, err := w.CloudInitUserdata()
+		Expect(err).NotTo(HaveOccurred())
+
+		parsed := parseYAML(result)
+		Expect(parsed).To(HaveKey("runcmd"))
+		runcmds := parsed["runcmd"].([]interface{})
+
+		foundKernelModules := false
+		foundEnable := false
+		kernelModulesIdx := -1
+		enableIdx := -1
+		for i, cmd := range runcmds {
+			cmdSlice := cmd.([]interface{})
+			if len(cmdSlice) >= 3 {
+				if cmdSlice[0] == "bash" && cmdSlice[1] == "-c" {
+					cmdStr := cmdSlice[2].(string)
+					if cmdStr == "dnf install -y kernel-modules-extra-$(uname -r)" {
+						foundKernelModules = true
+						kernelModulesIdx = i
+					}
+				}
+				if cmdSlice[0] == "systemctl" && cmdSlice[1] == "enable" {
+					foundEnable = true
+					enableIdx = i
+					Expect(cmdSlice[2]).To(Equal("--now"))
+				}
+			}
+		}
+		Expect(foundKernelModules).To(BeTrue(), "should install kernel-modules-extra for running kernel")
+		Expect(foundEnable).To(BeTrue(), "should have systemctl enable command")
+		Expect(kernelModulesIdx).To(
+			BeNumerically("<", enableIdx),
+			"kernel modules install should come before service enable")
+	})
+
+	It("should produce valid YAML", func() {
+		result, err := w.CloudInitUserdata()
+		Expect(err).NotTo(HaveOccurred())
+		Expect(result).To(HavePrefix("#cloud-config\n"))
+
+		parsed := parseYAML(result)
+		Expect(parsed).NotTo(BeNil())
+	})
+
+	It("should have no extra disks", func() {
+		Expect(w.ExtraDisks()).To(BeNil())
+	})
+
+	It("should have no data volumes", func() {
+		Expect(w.DataVolumeTemplates()).To(BeNil())
+	})
+
+	It("should have no service", func() {
+		Expect(w.RequiresService()).To(BeFalse())
+		Expect(w.ServiceSpec()).To(BeNil())
+	})
+
+	It("should reflect config in VMResources", func() {
+		res := w.VMResources()
+		Expect(res.CPUCores).To(Equal(1))
+		Expect(res.Memory).To(Equal("1Gi"))
+	})
+
+	It("should have VMCount of 1", func() {
+		Expect(w.VMCount()).To(Equal(1))
+	})
+})

internal/workloads/registry.go

@@ -65,6 +65,9 @@ func DefaultRegistry() Registry {
 		"chaos-process": func(cfg config.WorkloadConfig, opts *RegistryOpts) Workload {
 			return NewChaosProcessWorkload(cfg, opts.SSHUser, opts.SSHPassword, opts.SSHAuthorizedKeys)
 		},
+		"chaos-network": func(cfg config.WorkloadConfig, opts *RegistryOpts) Workload {
+			return NewChaosNetworkWorkload(cfg, opts.SSHUser, opts.SSHPassword, opts.SSHAuthorizedKeys)
+		},
 		"cpu": func(cfg config.WorkloadConfig, opts *RegistryOpts) Workload {
 			return NewCPUWorkload(cfg, opts.SSHUser, opts.SSHPassword, opts.SSHAuthorizedKeys)
 		},

internal/workloads/registry_test.go

@@ -18,8 +18,8 @@ var _ = Describe("Registry", func() {
 		reg = workloads.DefaultRegistry()
 	})
 
-	It("should have 7 entries registered", func() {
-		Expect(reg.List()).To(HaveLen(7))
+	It("should have 8 entries registered", func() {
+		Expect(reg.List()).To(HaveLen(8))
 	})
 
 	It("should return CPU workload by name", func() {
@@ -88,11 +88,23 @@ var _ = Describe("Registry", func() {
 		Expect(w.Name()).To(Equal("chaos-process"))
 	})
 
+	It("should return chaos-network workload by name", func() {
+		w, err := reg.Get("chaos-network", config.WorkloadConfig{
+			Enabled:  true,
+			VMCount:  1,
+			CPUCores: 1,
+			Memory:   "1Gi",
+		})
+		Expect(err).NotTo(HaveOccurred())
+		Expect(w.Name()).To(Equal("chaos-network"))
+	})
+
 	It("should return error for unknown name with available names", func() {
 		_, err := reg.Get("unknown", config.WorkloadConfig{})
 		Expect(err).To(HaveOccurred())
 		Expect(err.Error()).To(ContainSubstring("unknown"))
 		Expect(err.Error()).To(ContainSubstring("chaos-process"))
+		Expect(err.Error()).To(ContainSubstring("chaos-network"))
 		Expect(err.Error()).To(ContainSubstring("cpu"))
 		Expect(err.Error()).To(ContainSubstring("database"))
 		Expect(err.Error()).To(ContainSubstring("disk"))
@@ -103,7 +115,16 @@ var _ = Describe("Registry", func() {
 
 	It("should list all names sorted alphabetically", func() {
 		names := reg.List()
-		Expect(names).To(Equal([]string{"chaos-process", "cpu", "database", "disk", "memory", "network", "tps"}))
+		Expect(names).To(Equal([]string{
+			"chaos-network",
+			"chaos-process",
+			"cpu",
+			"database",
+			"disk",
+			"memory",
+			"network",
+			"tps",
+		}))
 	})
 
 	It("should return tps workload by name", func() {