pkg/ns: remove namespace creation (and move to testutils)

Namespace creation had an unergonomic interface and isn't used, except
for testing code. Remove it; downstream users should really be creating
their own namespaces

plugins/meta/bandwidth/bandwidth_linux_test.go

@@ -52,10 +52,10 @@ var _ = Describe("bandwidth test", func() {
 		hostIfname = "host-veth"
 		containerIfname = "container-veth"
 
-		hostNs, err = ns.NewNS()
+		hostNs, err = testutils.NewNS()
 		Expect(err).NotTo(HaveOccurred())
 
-		containerNs, err = ns.NewNS()
+		containerNs, err = testutils.NewNS()
 		Expect(err).NotTo(HaveOccurred())
 
 		hostIP = net.IP{169, 254, 0, 1}
@@ -455,10 +455,10 @@ var _ = Describe("bandwidth test", func() {
 			containerWithoutTbfIFName := "ptp1"
 
 			var err error
-			containerWithTbfNS, err = ns.NewNS()
+			containerWithTbfNS, err = testutils.NewNS()
 			Expect(err).NotTo(HaveOccurred())
 
-			containerWithoutTbfNS, err = ns.NewNS()
+			containerWithoutTbfNS, err = testutils.NewNS()
 			Expect(err).NotTo(HaveOccurred())
 
 			By("create two containers, and use the bandwidth plugin on one of them")

plugins/meta/flannel/flannel_linux_test.go

@@ -37,7 +37,7 @@ var _ = Describe("Flannel", func() {
 
 	BeforeEach(func() {
 		var err error
-		originalNS, err = ns.NewNS()
+		originalNS, err = testutils.NewNS()
 		Expect(err).NotTo(HaveOccurred())
 	})
 
@@ -88,7 +88,7 @@ FLANNEL_IPMASQ=true
 		It("uses dataDir for storing network configuration", func() {
 			const IFNAME = "eth0"
 
-			targetNs, err := ns.NewNS()
+			targetNs, err := testutils.NewNS()
 			Expect(err).NotTo(HaveOccurred())
 			defer targetNs.Close()
 

plugins/meta/portmap/chain_test.go

@@ -20,6 +20,7 @@ import (
 	"runtime"
 
 	"github.com/containernetworking/plugins/pkg/ns"
+	"github.com/containernetworking/plugins/pkg/testutils"
 	"github.com/coreos/go-iptables/iptables"
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
@@ -40,7 +41,7 @@ var _ = Describe("chain tests", func() {
 		currNs, err := ns.GetCurrentNS()
 		Expect(err).NotTo(HaveOccurred())
 
-		testNs, err := ns.NewNS()
+		testNs, err := testutils.NewNS()
 		Expect(err).NotTo(HaveOccurred())
 
 		tlChainName := fmt.Sprintf("cni-test-%d", rand.Intn(10000000))

plugins/meta/portmap/portmap_integ_test.go

@@ -27,6 +27,7 @@ import (
 	"github.com/containernetworking/cni/libcni"
 	"github.com/containernetworking/cni/pkg/types/current"
 	"github.com/containernetworking/plugins/pkg/ns"
+	"github.com/containernetworking/plugins/pkg/testutils"
 	"github.com/coreos/go-iptables/iptables"
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
@@ -78,7 +79,7 @@ var _ = Describe("portmap integration tests", func() {
 		dirs := filepath.SplitList(os.Getenv("PATH"))
 		cniConf = &libcni.CNIConfig{Path: dirs}
 
-		targetNS, err = ns.NewNS()
+		targetNS, err = testutils.NewNS()
 		Expect(err).NotTo(HaveOccurred())
 		fmt.Fprintln(GinkgoWriter, "namespace:", targetNS.Path())
 

plugins/meta/tuning/tuning_test.go

@@ -33,7 +33,7 @@ var _ = Describe("tuning plugin", func() {
 	BeforeEach(func() {
 		// Create a new NetNS so we don't modify the host
 		var err error
-		originalNS, err = ns.NewNS()
+		originalNS, err = testutils.NewNS()
 		Expect(err).NotTo(HaveOccurred())
 
 		err = originalNS.Do(func(ns.NetNS) error {
@@ -79,7 +79,7 @@ var _ = Describe("tuning plugin", func() {
 	}
 }`)
 
-		targetNs, err := ns.NewNS()
+		targetNs, err := testutils.NewNS()
 		Expect(err).NotTo(HaveOccurred())
 		defer targetNs.Close()