Merge pull request #74 from steadybit/fix/check-ipv6-module

fix: check if ipv6 module is enabled
steadybit · Dec 20, 2023 · f813334 · f813334
2 parents f7cf225 + c0084f7
commit f813334
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Showing 6 changed files with 91 additions and 33 deletions.
diff --git a/go/action_kit_commons/network/bandwidth_test.go b/go/action_kit_commons/network/bandwidth_test.go
@@ -13,11 +13,12 @@ import (
 
 func TestLimitBandwidthOpts_TcCommands(t *testing.T) {
 	tests := []struct {
-		name    string
-		opts    LimitBandwidthOpts
-		wantAdd []byte
-		wantDel []byte
-		wantErr bool
+		name         string
+		opts         LimitBandwidthOpts
+		ipv6Disabled bool
+		wantAdd      []byte
+		wantDel      []byte
+		wantErr      bool
 	}{
 		{
 			name: "bandwidth less then 8bit not supported",
@@ -94,6 +95,13 @@ qdisc del dev eth0 root handle 1: htb default 30
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
+			ipv6Supported = func() bool {
+				return !tt.ipv6Disabled
+			}
+			defer func() {
+				ipv6Supported = defaultIpv6Supported
+			}()
+
 			gotAdd, err := tt.opts.TcCommands(ModeAdd)
 			if (err != nil) != tt.wantErr {
 				t.Errorf("TcCommands() error = %v, wantErr %v", err, tt.wantErr)

diff --git a/go/action_kit_commons/network/blackhole_test.go b/go/action_kit_commons/network/blackhole_test.go
@@ -13,13 +13,14 @@ import (
 
 func TestBlackholeOpts_IpCommands(t *testing.T) {
 	tests := []struct {
-		name      string
-		opts      BlackholeOpts
-		wantAddV4 []byte
-		wantDelV4 []byte
-		wantAddV6 []byte
-		wantDelV6 []byte
-		wantErr   bool
+		name         string
+		opts         BlackholeOpts
+		ipv6Disabled bool
+		wantAddV4    []byte
+		wantDelV4    []byte
+		wantAddV6    []byte
+		wantDelV6    []byte
+		wantErr      bool
 	}{
 		{
 			name: "blackhole",
@@ -91,6 +92,13 @@ rule del blackhole to ::/0 ipproto udp dport 123
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
+			ipv6Supported = func() bool {
+				return !tt.ipv6Disabled
+			}
+			defer func() {
+				ipv6Supported = defaultIpv6Supported
+			}()
+
 			gotAddV4, err := tt.opts.IpCommands(FamilyV4, ModeAdd)
 			if (err != nil) != tt.wantErr {
 				t.Errorf("TcCommands() error = %v, wantErr %v", err, tt.wantErr)

diff --git a/go/action_kit_commons/network/delay_test.go b/go/action_kit_commons/network/delay_test.go
@@ -14,11 +14,12 @@ import (
 
 func TestDelayOpts_TcCommands(t *testing.T) {
 	tests := []struct {
-		name    string
-		opts    DelayOpts
-		wantAdd []byte
-		wantDel []byte
-		wantErr bool
+		name         string
+		opts         DelayOpts
+		ipv6Disabled bool
+		wantAdd      []byte
+		wantDel      []byte
+		wantErr      bool
 	}{
 		{
 			name: "delay",
@@ -86,6 +87,13 @@ qdisc del dev eth0 root handle 1: prio
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
+			ipv6Supported = func() bool {
+				return !tt.ipv6Disabled
+			}
+			defer func() {
+				ipv6Supported = defaultIpv6Supported
+			}()
+
 			gotAdd, err := tt.opts.TcCommands(ModeAdd)
 			if (err != nil) != tt.wantErr {
 				t.Errorf("TcCommands() error = %v, wantErr %v", err, tt.wantErr)

diff --git a/go/action_kit_commons/network/network.go b/go/action_kit_commons/network/network.go
@@ -12,8 +12,10 @@ import (
 	"github.com/rs/zerolog/log"
 	"github.com/steadybit/action-kit/go/action_kit_commons/runc"
 	"github.com/steadybit/action-kit/go/action_kit_commons/utils"
+	"os"
 	"runtime/trace"
 	"strconv"
+	"strings"
 	"time"
 )
 
@@ -42,9 +44,12 @@ func generateAndRunCommands(ctx context.Context, r runc.Runc, sidecar SidecarOpt
 		return err
 	}
 
-	ipCommandsV6, err := opts.IpCommands(FamilyV6, mode)
-	if err != nil {
-		return err
+	var ipCommandsV6 []string
+	if ipv6Supported() {
+		ipCommandsV6, err = opts.IpCommands(FamilyV6, mode)
+		if err != nil {
+			return err
+		}
 	}
 
 	tcCommands, err := opts.TcCommands(mode)
@@ -56,19 +61,19 @@ func generateAndRunCommands(ctx context.Context, r runc.Runc, sidecar SidecarOpt
 	runLock.LockKey(netNsID)
 	defer func() { _ = runLock.UnlockKey(netNsID) }()
 
-	if ipCommandsV4 != nil {
+	if len(ipCommandsV4) > 0 {
 		if ipErr := executeIpCommands(ctx, r, sidecar, FamilyV4, ipCommandsV4); ipErr != nil {
 			err = errors.Join(err, FilterBatchErrors(ipErr, mode, ipCommandsV4))
 		}
 	}
 
-	if ipCommandsV6 != nil {
+	if len(ipCommandsV6) > 0 {
 		if ipErr := executeIpCommands(ctx, r, sidecar, FamilyV6, ipCommandsV6); ipErr != nil {
 			err = errors.Join(err, FilterBatchErrors(ipErr, mode, ipCommandsV6))
 		}
 	}
 
-	if tcCommands != nil {
+	if len(tcCommands) > 0 {
 		if tcErr := executeTcCommands(ctx, r, sidecar, tcCommands); tcErr != nil {
 			err = errors.Join(err, FilterBatchErrors(tcErr, mode, tcCommands))
 		}
@@ -77,6 +82,19 @@ func generateAndRunCommands(ctx context.Context, r runc.Runc, sidecar SidecarOpt
 	return err
 }
 
+var ipv6Supported = defaultIpv6Supported
+
+func defaultIpv6Supported() bool {
+	if content, err := os.ReadFile("/sys/module/ipv6/parameters/disable"); err == nil {
+		disabled := strings.TrimSpace(string(content)) == "1"
+		log.Trace().Bool("disabled", disabled).Msg("read ipv6 module parameters")
+		return !disabled
+	} else {
+		log.Warn().Err(err).Msg("Failed to read /sys/module/ipv6/parameters/disable. Assuming ipv6 is disabled.")
+		return false
+	}
+}
+
 func executeIpCommands(ctx context.Context, r runc.Runc, sidecar SidecarOpts, family Family, cmds []string) error {
 	defer trace.StartRegion(ctx, "network.executeIpCommands").End()
 	if len(cmds) == 0 {

diff --git a/go/action_kit_commons/network/packageCorruption_test.go b/go/action_kit_commons/network/packageCorruption_test.go
@@ -13,11 +13,12 @@ import (
 
 func TestCorruptPackagesOpts_TcCommands(t *testing.T) {
 	tests := []struct {
-		name    string
-		opts    CorruptPackagesOpts
-		wantAdd []byte
-		wantDel []byte
-		wantErr bool
+		name         string
+		opts         CorruptPackagesOpts
+		ipv6Disabled bool
+		wantAdd      []byte
+		wantDel      []byte
+		wantErr      bool
 	}{
 		{
 			name: "corrupt",
@@ -82,6 +83,13 @@ qdisc del dev eth0 root handle 1: prio
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
+			ipv6Supported = func() bool {
+				return !tt.ipv6Disabled
+			}
+			defer func() {
+				ipv6Supported = defaultIpv6Supported
+			}()
+
 			gotAdd, err := tt.opts.TcCommands(ModeAdd)
 			if (err != nil) != tt.wantErr {
 				t.Errorf("TcCommands() error = %v, wantErr %v", err, tt.wantErr)

diff --git a/go/action_kit_commons/network/packageLoss_test.go b/go/action_kit_commons/network/packageLoss_test.go
@@ -13,11 +13,12 @@ import (
 
 func TestPackageLossOpts_TcCommands(t *testing.T) {
 	tests := []struct {
-		name    string
-		opts    PackageLossOpts
-		wantAdd []byte
-		wantDel []byte
-		wantErr bool
+		name         string
+		opts         PackageLossOpts
+		ipv6Disabled bool
+		wantAdd      []byte
+		wantDel      []byte
+		wantErr      bool
 	}{
 		{
 			name: "loss",
@@ -82,6 +83,13 @@ qdisc del dev eth0 root handle 1: prio
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
+			ipv6Supported = func() bool {
+				return !tt.ipv6Disabled
+			}
+			defer func() {
+				ipv6Supported = defaultIpv6Supported
+			}()
+
 			gotAdd, err := tt.opts.TcCommands(ModeAdd)
 			if (err != nil) != tt.wantErr {
 				t.Errorf("TcCommands() error = %v, wantErr %v", err, tt.wantErr)