Golang Interface.Restore方法代码示例

// CleanupLeftovers removes all iptables rules and chains created by the Proxier
// It returns true if an error was encountered. Errors are logged.
func CleanupLeftovers(ipt utiliptables.Interface) (encounteredError bool) {
	// Unlink the services chain.
	args := []string{
		"-m", "comment", "--comment", "kubernetes service portals",
		"-j", string(kubeServicesChain),
	}
	tableChainsWithJumpServices := []struct {
		table utiliptables.Table
		chain utiliptables.Chain
	}{
		{utiliptables.TableFilter, utiliptables.ChainOutput},
		{utiliptables.TableNAT, utiliptables.ChainOutput},
		{utiliptables.TableNAT, utiliptables.ChainPrerouting},
	}
	for _, tc := range tableChainsWithJumpServices {
		if err := ipt.DeleteRule(tc.table, tc.chain, args...); err != nil {
			if !utiliptables.IsNotFoundError(err) {
				glog.Errorf("Error removing pure-iptables proxy rule: %v", err)
				encounteredError = true
			}
		}
	}

	// Unlink the postrouting chain.
	args = []string{
		"-m", "comment", "--comment", "kubernetes postrouting rules",
		"-j", string(kubePostroutingChain),
	}
	if err := ipt.DeleteRule(utiliptables.TableNAT, utiliptables.ChainPostrouting, args...); err != nil {
		if !utiliptables.IsNotFoundError(err) {
			glog.Errorf("Error removing pure-iptables proxy rule: %v", err)
			encounteredError = true
		}
	}

	// Flush and remove all of our chains.
	if iptablesSaveRaw, err := ipt.Save(utiliptables.TableNAT); err != nil {
		glog.Errorf("Failed to execute iptables-save for %s: %v", utiliptables.TableNAT, err)
		encounteredError = true
	} else {
		existingNATChains := getChainLines(utiliptables.TableNAT, iptablesSaveRaw)
		natChains := bytes.NewBuffer(nil)
		natRules := bytes.NewBuffer(nil)
		writeLine(natChains, "*nat")
		// Start with chains we know we need to remove.
		for _, chain := range []utiliptables.Chain{kubeServicesChain, kubeNodePortsChain, kubePostroutingChain, kubeMarkMasqChain} {
			if _, found := existingNATChains[chain]; found {
				chainString := string(chain)
				writeLine(natChains, existingNATChains[chain]) // flush
				writeLine(natRules, "-X", chainString)         // delete
			}
		}
		// Hunt for service and endpoint chains.
		for chain := range existingNATChains {
			chainString := string(chain)
			if strings.HasPrefix(chainString, "KUBE-SVC-") || strings.HasPrefix(chainString, "KUBE-SEP-") {
				writeLine(natChains, existingNATChains[chain]) // flush
				writeLine(natRules, "-X", chainString)         // delete
			}
		}
		writeLine(natRules, "COMMIT")
		natLines := append(natChains.Bytes(), natRules.Bytes()...)
		// Write it.
		err = ipt.Restore(utiliptables.TableNAT, natLines, utiliptables.NoFlushTables, utiliptables.RestoreCounters)
		if err != nil {
			glog.Errorf("Failed to execute iptables-restore for %s: %v", utiliptables.TableNAT, err)
			encounteredError = true
		}
	}
	{
		filterBuf := bytes.NewBuffer(nil)
		writeLine(filterBuf, "*filter")
		writeLine(filterBuf, fmt.Sprintf(":%s - [0:0]", kubeServicesChain))
		writeLine(filterBuf, fmt.Sprintf("-X %s", kubeServicesChain))
		writeLine(filterBuf, "COMMIT")
		// Write it.
		if err := ipt.Restore(utiliptables.TableFilter, filterBuf.Bytes(), utiliptables.NoFlushTables, utiliptables.RestoreCounters); err != nil {
			glog.Errorf("Failed to execute iptables-restore for %s: %v", utiliptables.TableFilter, err)
			encounteredError = true
		}
	}

	// Clean up the older SNAT rule which was directly in POSTROUTING.
	// TODO(thockin): Remove this for v1.3 or v1.4.
	args = []string{
		"-m", "comment", "--comment", "kubernetes service traffic requiring SNAT",
		"-m", "mark", "--mark", oldIptablesMasqueradeMark,
		"-j", "MASQUERADE",
	}
	if err := ipt.DeleteRule(utiliptables.TableNAT, utiliptables.ChainPostrouting, args...); err != nil {
		if !utiliptables.IsNotFoundError(err) {
			glog.Errorf("Error removing old-style SNAT rule: %v", err)
			encounteredError = true
		}
	}

	return encounteredError
}