Merge pull request #421 from aojea/portmapErrors2

Portmap doesn't fail if chain doesn't exist

go.mod

@@ -8,7 +8,7 @@ require (
 	github.com/alexflint/go-filemutex v0.0.0-20171022225611-72bdc8eae2ae
 	github.com/buger/jsonparser v0.0.0-20180808090653-f4dd9f5a6b44
 	github.com/containernetworking/cni v0.7.1
-	github.com/coreos/go-iptables v0.4.2
+	github.com/coreos/go-iptables v0.4.5
 	github.com/coreos/go-systemd v0.0.0-20180511133405-39ca1b05acc7
 	github.com/d2g/dhcp4 v0.0.0-20170904100407-a1d1b6c41b1c
 	github.com/d2g/dhcp4client v1.0.0

go.sum

@@ -10,6 +10,10 @@ github.com/containernetworking/cni v0.7.1 h1:fE3r16wpSEyaqY4Z4oFrLMmIGfBYIKpPrHK
 github.com/containernetworking/cni v0.7.1/go.mod h1:LGwApLUm2FpoOfxTDEeq8T9ipbpZ61X79hmU3w8FmsY=
 github.com/coreos/go-iptables v0.4.2 h1:KH0EwId05JwWIfb96gWvkiT2cbuOu8ygqUaB+yPAwIg=
 github.com/coreos/go-iptables v0.4.2/go.mod h1:/mVI274lEDI2ns62jHCDnCyBF9Iwsmekav8Dbxlm1MU=
+github.com/coreos/go-iptables v0.4.4 h1:5oOUvU7Fk53Hn/rkdJ0zcYGCffotqXpyi4ADCkO1TJ8=
+github.com/coreos/go-iptables v0.4.4/go.mod h1:/mVI274lEDI2ns62jHCDnCyBF9Iwsmekav8Dbxlm1MU=
+github.com/coreos/go-iptables v0.4.5 h1:DpHb9vJrZQEFMcVLFKAAGMUVX0XoRC0ptCthinRYm38=
+github.com/coreos/go-iptables v0.4.5/go.mod h1:/mVI274lEDI2ns62jHCDnCyBF9Iwsmekav8Dbxlm1MU=
 github.com/coreos/go-systemd v0.0.0-20180511133405-39ca1b05acc7 h1:u9SHYsPQNyt5tgDm3YN7+9dYrpK96E5wFilTFWIDZOM=
 github.com/coreos/go-systemd v0.0.0-20180511133405-39ca1b05acc7/go.mod h1:F5haX7vjVVG0kc13fIWeqUViNPyEJxv/OmvnBo0Yme4=
 github.com/d2g/dhcp4 v0.0.0-20170904100407-a1d1b6c41b1c h1:Xo2rK1pzOm0jO6abTPIQwbAmqBIOj132otexc1mmzFc=

pkg/utils/iptables.go

@@ -62,3 +62,60 @@ func ChainExists(ipt *iptables.IPTables, table, chain string) (bool, error) {
 	}
 	return false, nil
 }
+
+// DeleteRule idempotently delete the iptables rule in the specified table/chain.
+// It does not return an error if the referring chain doesn't exist
+func DeleteRule(ipt *iptables.IPTables, table, chain string, rulespec ...string) error {
+	if ipt == nil {
+		return errors.New("failed to ensure iptable chain: IPTables was nil")
+	}
+	if err := ipt.Delete(table, chain, rulespec...); err != nil {
+		eerr, eok := err.(*iptables.Error)
+		switch {
+		case eok && eerr.IsNotExist():
+			// swallow here, the chain was already deleted
+			return nil
+		case eok && eerr.ExitStatus() == 2:
+			// swallow here, invalid command line parameter because the referring rule is missing
+			return nil
+		default:
+			return fmt.Errorf("Failed to delete referring rule %s %s: %v", table, chain, err)
+		}
+	}
+	return nil
+}
+
+// DeleteChain idempotently deletes the specified table/chain.
+// It does not return an errors if the chain does not exist
+func DeleteChain(ipt *iptables.IPTables, table, chain string) error {
+	if ipt == nil {
+		return errors.New("failed to ensure iptable chain: IPTables was nil")
+	}
+
+	err := ipt.DeleteChain(table, chain)
+	eerr, eok := err.(*iptables.Error)
+	switch {
+	case eok && eerr.IsNotExist():
+		// swallow here, the chain was already deleted
+		return nil
+	default:
+		return err
+	}
+}
+
+// ClearChain idempotently clear the iptables rules in the specified table/chain.
+// If the chain does not exist, a new one will be created
+func ClearChain(ipt *iptables.IPTables, table, chain string) error {
+	if ipt == nil {
+		return errors.New("failed to ensure iptable chain: IPTables was nil")
+	}
+	err := ipt.ClearChain(table, chain)
+	eerr, eok := err.(*iptables.Error)
+	switch {
+	case eok && eerr.IsNotExist():
+		// swallow here, the chain was already deleted
+		return EnsureChain(ipt, table, chain)
+	default:
+		return err
+	}
+}

pkg/utils/iptables_test.go

@@ -67,6 +67,7 @@ var _ = Describe("chain tests", func() {
 		cleanup()
 	})
 
+	Describe("EnsureChain", func() {
 		It("creates chains idempotently", func() {
 			err := EnsureChain(ipt, TABLE, testChain)
 			Expect(err).NotTo(HaveOccurred())
@@ -76,3 +77,21 @@ var _ = Describe("chain tests", func() {
 			Expect(err).NotTo(HaveOccurred())
 		})
 	})
+
+	Describe("DeleteChain", func() {
+		It("delete chains idempotently", func() {
+			// Create chain
+			err := EnsureChain(ipt, TABLE, testChain)
+			Expect(err).NotTo(HaveOccurred())
+
+			// Delete chain
+			err = DeleteChain(ipt, TABLE, testChain)
+			Expect(err).NotTo(HaveOccurred())
+
+			// Delete it again!
+			err = DeleteChain(ipt, TABLE, testChain)
+			Expect(err).NotTo(HaveOccurred())
+		})
+	})
+
+})

plugins/meta/portmap/chain.go

@@ -70,7 +70,7 @@ func (c *chain) teardown(ipt *iptables.IPTables) error {
 	// flush the chain
 	// This will succeed *and create the chain* if it does not exist.
 	// If the chain doesn't exist, the next checks will fail.
-	if err := ipt.ClearChain(c.table, c.name); err != nil {
+	if err := utils.ClearChain(ipt, c.table, c.name); err != nil {
 		return err
 	}
 
@@ -90,17 +90,15 @@ func (c *chain) teardown(ipt *iptables.IPTables) error {
 				}
 				chainParts = chainParts[2:] // List results always include an -A CHAINNAME
 
-				if err := ipt.Delete(c.table, entryChain, chainParts...); err != nil {
-					return fmt.Errorf("Failed to delete referring rule %s %s: %v", c.table, entryChainRule, err)
+				if err := utils.DeleteRule(ipt, c.table, entryChain, chainParts...); err != nil {
+					return err
 				}
+
 			}
 		}
 	}
 
-	if err := ipt.DeleteChain(c.table, c.name); err != nil {
-		return err
-	}
-	return nil
+	return utils.DeleteChain(ipt, c.table, c.name)
 }
 
 // insertUnique will add a rule to a chain if it does not already exist.

plugins/meta/portmap/chain_test.go

@@ -18,6 +18,7 @@ import (
 	"fmt"
 	"math/rand"
 	"runtime"
+	"sync"
 
 	"github.com/containernetworking/plugins/pkg/ns"
 	"github.com/containernetworking/plugins/pkg/testutils"
@@ -32,6 +33,7 @@ const TABLE = "filter" // We'll monkey around here
 var _ = Describe("chain tests", func() {
 	var testChain chain
 	var ipt *iptables.IPTables
+	var testNs ns.NetNS
 	var cleanup func()
 
 	BeforeEach(func() {
@@ -41,7 +43,7 @@ var _ = Describe("chain tests", func() {
 		currNs, err := ns.GetCurrentNS()
 		Expect(err).NotTo(HaveOccurred())
 
-		testNs, err := testutils.NewNS()
+		testNs, err = testutils.NewNS()
 		Expect(err).NotTo(HaveOccurred())
 
 		tlChainName := fmt.Sprintf("cni-test-%d", rand.Intn(10000000))
@@ -195,4 +197,38 @@ var _ = Describe("chain tests", func() {
 			}
 		}
 	})
+
+	It("deletes chains idempotently in parallel", func() {
+		defer cleanup()
+		// number of parallel executions
+		N := 10
+		var wg sync.WaitGroup
+		err := testChain.setup(ipt)
+		Expect(err).NotTo(HaveOccurred())
+		errCh := make(chan error, N)
+		for i := 0; i < N; i++ {
+			wg.Add(1)
+			go func() {
+				defer wg.Done()
+				// teardown chain
+				errCh <- testNs.Do(func(ns.NetNS) error {
+					return testChain.teardown(ipt)
+				})
+			}()
+		}
+		wg.Wait()
+		close(errCh)
+		for err := range errCh {
+			Expect(err).NotTo(HaveOccurred())
+		}
+
+		chains, err := ipt.ListChains(TABLE)
+		Expect(err).NotTo(HaveOccurred())
+		for _, chain := range chains {
+			if chain == testChain.name {
+				Fail("Chain was not deleted")
+			}
+		}
+
+	})
 })

plugins/meta/portmap/portmap_integ_test.go

@@ -96,6 +96,7 @@ var _ = Describe("portmap integration tests", func() {
 		}
 	})
 
+	Describe("Creating an interface in a namespace with the ptp plugin", func() {
 		// This needs to be done using Ginkgo's asynchronous testing mode.
 		It("forwards a TCP port on ipv4", func(done Done) {
 			var err error
@@ -171,6 +172,18 @@ var _ = Describe("portmap integration tests", func() {
 			cmd.Stdout = GinkgoWriter
 			Expect(cmd.Run()).To(Succeed())
 
+			// dump ip routes output for debugging
+			cmd = exec.Command("ip", "route")
+			cmd.Stderr = GinkgoWriter
+			cmd.Stdout = GinkgoWriter
+			Expect(cmd.Run()).To(Succeed())
+
+			// dump ip addresses output for debugging
+			cmd = exec.Command("ip", "addr")
+			cmd.Stderr = GinkgoWriter
+			cmd.Stdout = GinkgoWriter
+			Expect(cmd.Run()).To(Succeed())
+
 			// Sanity check: verify that the container is reachable directly
 			contOK := testEchoServer(contIP.String(), containerPort, "")
 
@@ -210,6 +223,7 @@ var _ = Describe("portmap integration tests", func() {
 
 		}, TIMEOUT*9)
 	})
+})
 
 // testEchoServer returns true if we found an echo server on the port
 func testEchoServer(address string, port int, netns string) bool {

vendor/github.com/coreos/go-iptables/iptables/iptables.go

@@ -48,9 +48,13 @@ func (e *Error) Error() string {
 
 // IsNotExist returns true if the error is due to the chain or rule not existing
 func (e *Error) IsNotExist() bool {
-	return e.ExitStatus() == 1 &&
-		(e.msg == fmt.Sprintf("%s: Bad rule (does a matching rule exist in that chain?).\n", getIptablesCommand(e.proto)) ||
-			e.msg == fmt.Sprintf("%s: No chain/target/match by that name.\n", getIptablesCommand(e.proto)))
+	if e.ExitStatus() != 1 {
+		return false
+	}
+	cmdIptables := getIptablesCommand(e.proto)
+	msgNoRuleExist := fmt.Sprintf("%s: Bad rule (does a matching rule exist in that chain?).\n", cmdIptables)
+	msgNoChainExist := fmt.Sprintf("%s: No chain/target/match by that name.\n", cmdIptables)
+	return strings.Contains(e.msg, msgNoRuleExist) || strings.Contains(e.msg, msgNoChainExist)
 }
 
 // Protocol to differentiate between IPv4 and IPv6
@@ -101,7 +105,13 @@ func NewWithProtocol(proto Protocol) (*IPTables, error) {
 		return nil, err
 	}
 	vstring, err := getIptablesVersionString(path)
+	if err != nil {
+		return nil, fmt.Errorf("could not get iptables version: %v", err)
+	}
 	v1, v2, v3, mode, err := extractIptablesVersion(vstring)
+	if err != nil {
+		return nil, fmt.Errorf("failed to extract iptables version from [%s]: %v", vstring, err)
+	}
 
 	checkPresent, waitPresent, randomFullyPresent := getIptablesCommandSupport(v1, v2, v3)
 
@@ -348,18 +358,6 @@ func (ipt *IPTables) executeList(args []string) ([]string, error) {
 		rules = rules[:len(rules)-1]
 	}
 
-	// nftables mode doesn't return an error code when listing a non-existent
-	// chain. Patch that up.
-	if len(rules) == 0 && ipt.mode == "nf_tables" {
-		v := 1
-		return nil, &Error{
-			cmd:        exec.Cmd{Args: args},
-			msg:        fmt.Sprintf("%s: No chain/target/match by that name.\n", getIptablesCommand(ipt.proto)),
-			proto:      ipt.proto,
-			exitStatus: &v,
-		}
-	}
-
 	for i, rule := range rules {
 		rules[i] = filterRuleOutput(rule)
 	}
@@ -437,6 +435,7 @@ func (ipt *IPTables) runWithOutput(args []string, stdout io.Writer) error {
 		}
 		ul, err := fmu.tryLock()
 		if err != nil {
+			syscall.Close(fmu.fd)
 			return err
 		}
 		defer ul.Unlock()

vendor/modules.txt

@@ -32,7 +32,7 @@ github.com/containernetworking/cni/pkg/skel
 github.com/containernetworking/cni/pkg/version
 github.com/containernetworking/cni/pkg/types/020
 github.com/containernetworking/cni/libcni
-# github.com/coreos/go-iptables v0.4.2
+# github.com/coreos/go-iptables v0.4.5
 github.com/coreos/go-iptables/iptables
 # github.com/coreos/go-systemd v0.0.0-20180511133405-39ca1b05acc7
 github.com/coreos/go-systemd/activation