Delegated Azure IPAM

azure-ipam/const.go

@@ -0,0 +1,19 @@
+package main
+
+import (
+	"time"
+)
+
+const (
+	pluginName    = "azure-ipam"
+	cnsBaseURL    = "" // fallback to default http://localhost:10090
+	cnsReqTimeout = 15 * time.Second
+)
+
+// plugin specific error codes
+// https://www.cni.dev/docs/spec/#error
+const (
+	ErrCreateIPConfigRequest uint = iota + 100
+	ErrRequestIPConfigFromCNS
+	ErrProcessIPConfigResponse
+)

azure-ipam/go.mod

@@ -0,0 +1,82 @@
+module github.com/Azure/azure-container-networking/azure-ipam
+
+go 1.18
+
+require (
+	github.com/pkg/errors v0.9.1
+	github.com/stretchr/testify v1.7.1
+	go.uber.org/zap v1.21.0
+)
+
+require (
+	code.cloudfoundry.org/clock v1.0.0 // indirect
+	github.com/Masterminds/semver v1.5.0 // indirect
+	github.com/Microsoft/go-winio v0.4.17 // indirect
+	github.com/Microsoft/hcsshim v0.8.23 // indirect
+	github.com/PuerkitoBio/purell v1.1.1 // indirect
+	github.com/PuerkitoBio/urlesc v0.0.0-20170810143723-de5bf2ad4578 // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/billgraziano/dpapi v0.4.0 // indirect
+	github.com/cespare/xxhash/v2 v2.1.2 // indirect
+	github.com/containerd/cgroups v1.0.1 // indirect
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/emicklei/go-restful v2.9.5+incompatible // indirect
+	github.com/go-logr/logr v1.2.0 // indirect
+	github.com/go-openapi/jsonpointer v0.19.5 // indirect
+	github.com/go-openapi/jsonreference v0.19.5 // indirect
+	github.com/go-openapi/swag v0.19.14 // indirect
+	github.com/gofrs/uuid v4.2.0+incompatible // indirect
+	github.com/gogo/protobuf v1.3.2 // indirect
+	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
+	github.com/golang/protobuf v1.5.2 // indirect
+	github.com/google/gnostic v0.5.7-v3refs // indirect
+	github.com/google/go-cmp v0.5.8 // indirect
+	github.com/google/gofuzz v1.2.0 // indirect
+	github.com/google/uuid v1.3.0 // indirect
+	github.com/imdario/mergo v0.3.12 // indirect
+	github.com/josharian/intern v1.0.0 // indirect
+	github.com/json-iterator/go v1.1.12 // indirect
+	github.com/mailru/easyjson v0.7.6 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.2-0.20181231171920-c182affec369 // indirect
+	github.com/microsoft/ApplicationInsights-Go v0.4.4 // indirect
+	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
+	github.com/modern-go/reflect2 v1.0.2 // indirect
+	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/prometheus/client_golang v1.12.2 // indirect
+	github.com/prometheus/client_model v0.2.0 // indirect
+	github.com/prometheus/common v0.32.1 // indirect
+	github.com/prometheus/procfs v0.7.3 // indirect
+	github.com/sirupsen/logrus v1.8.1 // indirect
+	github.com/spf13/pflag v1.0.5 // indirect
+	go.opencensus.io v0.23.0 // indirect
+	golang.org/x/net v0.0.0-20220520000938-2e3eb7b945c2 // indirect
+	golang.org/x/oauth2 v0.0.0-20220411215720-9780585627b5 // indirect
+	golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a // indirect
+	golang.org/x/term v0.0.0-20210927222741-03fcf44c2211 // indirect
+	golang.org/x/text v0.3.7 // indirect
+	golang.org/x/time v0.0.0-20220210224613-90d013bbcef8 // indirect
+	google.golang.org/appengine v1.6.7 // indirect
+	google.golang.org/protobuf v1.28.0 // indirect
+	gopkg.in/inf.v0 v0.9.1 // indirect
+	gopkg.in/yaml.v2 v2.4.0 // indirect
+	gopkg.in/yaml.v3 v3.0.0 // indirect
+	k8s.io/api v0.24.1 // indirect
+	k8s.io/apimachinery v0.24.1 // indirect
+	k8s.io/client-go v0.24.1 // indirect
+	k8s.io/klog/v2 v2.60.1 // indirect
+	k8s.io/kube-openapi v0.0.0-20220328201542-3ee0da9b0b42 // indirect
+	k8s.io/utils v0.0.0-20220210201930-3a6ce19ff2f9 // indirect
+	sigs.k8s.io/controller-runtime v0.12.1 // indirect
+	sigs.k8s.io/json v0.0.0-20211208200746-9f7c6b3444d2 // indirect
+	sigs.k8s.io/structured-merge-diff/v4 v4.2.1 // indirect
+	sigs.k8s.io/yaml v1.3.0 // indirect
+)
+
+require (
+	github.com/Azure/azure-container-networking v1.4.27
+	github.com/containernetworking/cni v1.1.1
+	github.com/containernetworking/plugins v1.1.1
+	go.uber.org/atomic v1.9.0 // indirect
+	go.uber.org/multierr v1.8.0 // indirect
+)

azure-ipam/internal/buildinfo/buildinfo.go

@@ -0,0 +1,6 @@
+package buildinfo
+
+// this will be populate by the Go compiler via
+// the -ldflags, which insert dynamic information
+// into the binary at build time
+var Version string

azure-ipam/ipam.go

@@ -0,0 +1,173 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"io"
+	"net"
+
+	"github.com/Azure/azure-container-networking/azure-ipam/internal/buildinfo"
+	"github.com/Azure/azure-container-networking/azure-ipam/ipconfig"
+	"github.com/Azure/azure-container-networking/cns"
+	cniSkel "github.com/containernetworking/cni/pkg/skel"
+	cniTypes "github.com/containernetworking/cni/pkg/types"
+	types100 "github.com/containernetworking/cni/pkg/types/100"
+	"github.com/pkg/errors"
+	"go.uber.org/zap"
+)
+
+// IPAMPlugin is the struct for the delegated azure-ipam plugin
+// https://www.cni.dev/docs/spec/#section-4-plugin-delegation
+type IPAMPlugin struct {
+	Name      string
+	Version   string
+	Options   map[string]interface{}
+	logger    *zap.Logger
+	cnsClient cnsClient
+	out       io.Writer // indicate the output channel for the plugin
+}
+
+type cnsClient interface {
+	RequestIPAddress(context.Context, cns.IPConfigRequest) (*cns.IPConfigResponse, error)
+	ReleaseIPAddress(context.Context, cns.IPConfigRequest) error
+}
+
+// NewPlugin constructs a new IPAM plugin instance with given logger and CNS client
+func NewPlugin(logger *zap.Logger, c cnsClient, out io.Writer) (*IPAMPlugin, error) {
+	plugin := &IPAMPlugin{
+		Name:      pluginName,
+		Version:   buildinfo.Version,
+		logger:    logger,
+		out:       out,
+		cnsClient: c,
+	}
+	return plugin, nil
+}
+
+//
+// CNI implementation
+// https://github.com/containernetworking/cni/blob/master/SPEC.md
+//
+
+// CmdAdd handles CNI add commands.
+func (p *IPAMPlugin) CmdAdd(args *cniSkel.CmdArgs) error {
+	p.logger.Info("ADD called", zap.Any("args", args))
+
+	// Parsing network conf
+	nwCfg, err := parseNetConf(args.StdinData)
+	if err != nil {
+		p.logger.Error("Failed to parse CNI network config from stdin", zap.Error(err), zap.Any("argStdinData", args.StdinData))
+		return cniTypes.NewError(cniTypes.ErrDecodingFailure, err.Error(), "failed to parse CNI network config from stdin")
+	}
+	p.logger.Debug("Parsed network config", zap.Any("netconf", nwCfg))
+
+	// Create ip config request from args
+	req, err := ipconfig.CreateIPConfigReq(args)
+	if err != nil {
+		p.logger.Error("Failed to create CNS IP config request", zap.Error(err))
+		return cniTypes.NewError(ErrCreateIPConfigRequest, err.Error(), "failed to create CNS IP config request")
+	}
+	p.logger.Debug("Created CNS IP config request", zap.Any("request", req))
+
+	p.logger.Debug("Making request to CNS")
+	// if this fails, the caller plugin should execute again with cmdDel before returning error.
+	// https://www.cni.dev/docs/spec/#delegated-plugin-execution-procedure
+	resp, err := p.cnsClient.RequestIPAddress(context.TODO(), req)
+	if err != nil {
+		p.logger.Error("Failed to request IP address from CNS", zap.Error(err), zap.Any("request", req))
+		return cniTypes.NewError(ErrRequestIPConfigFromCNS, err.Error(), "failed to request IP address from CNS")
+	}
+	p.logger.Debug("Received CNS IP config response", zap.Any("response", resp))
+
+	// Get Pod IP and gateway IP from ip config response
+	podIPNet, gwIP, err := ipconfig.ProcessIPConfigResp(resp)
+	if err != nil {
+		p.logger.Error("Failed to interpret CNS IPConfigResponse", zap.Error(err), zap.Any("response", resp))
+		return cniTypes.NewError(ErrProcessIPConfigResponse, err.Error(), "failed to interpret CNS IPConfigResponse")
+	}
+	p.logger.Debug("Parsed pod IP and gateway IP", zap.String("podIPNet", podIPNet.String()), zap.String("gwIP", gwIP.String()))
+
+	cniResult := &types100.Result{
+		IPs: []*types100.IPConfig{
+			{
+				Address: net.IPNet{
+					IP:   net.ParseIP(podIPNet.Addr().String()),
+					Mask: net.CIDRMask(podIPNet.Bits(), 32), // nolint
+				},
+				Gateway: net.ParseIP(gwIP.String()),
+			},
+		},
+		Routes: []*cniTypes.Route{
+			{
+				Dst: net.IPNet{
+					IP:   net.IPv4zero,
+					Mask: net.IPv4Mask(0, 0, 0, 0),
+				},
+				GW: net.ParseIP(gwIP.String()),
+			},
+		},
+	}
+
+	// Get versioned result
+	versionedCniResult, err := cniResult.GetAsVersion(nwCfg.CNIVersion)
+	if err != nil {
+		p.logger.Error("Failed to interpret CNI result with netconf CNI version", zap.Error(err), zap.Any("cniVersion", nwCfg.CNIVersion))
+		return cniTypes.NewError(cniTypes.ErrIncompatibleCNIVersion, err.Error(), "failed to interpret CNI result with netconf CNI version")
+	}
+
+	p.logger.Info("ADD success", zap.Any("result", versionedCniResult))
+
+	// Write result to output channel
+	err = versionedCniResult.PrintTo(p.out)
+	if err != nil {
+		p.logger.Error("Failed to print CNI result to output channel", zap.Error(err), zap.Any("result", versionedCniResult))
+		return cniTypes.NewError(cniTypes.ErrIOFailure, err.Error(), "failed to print CNI result to output channel")
+	}
+
+	return nil
+}
+
+// CmdDel handles CNI delete commands.
+func (p *IPAMPlugin) CmdDel(args *cniSkel.CmdArgs) error {
+	p.logger.Info("DEL called", zap.Any("args", args))
+
+	// Create ip config request from args
+	req, err := ipconfig.CreateIPConfigReq(args)
+	if err != nil {
+		p.logger.Error("Failed to create CNS IP config request", zap.Error(err))
+		return cniTypes.NewError(cniTypes.ErrTryAgainLater, err.Error(), "failed to create CNS IP config request")
+	}
+	p.logger.Debug("Created CNS IP config request", zap.Any("request", req))
+
+	p.logger.Debug("Making request to CNS")
+	// cnsClient enforces it own timeout
+	if err := p.cnsClient.ReleaseIPAddress(context.TODO(), req); err != nil {
+		p.logger.Error("Failed to release IP address from CNS", zap.Error(err), zap.Any("request", req))
+		return cniTypes.NewError(cniTypes.ErrTryAgainLater, err.Error(), "failed to release IP address from CNS")
+	}
+
+	p.logger.Info("DEL success")
+
+	return nil
+}
+
+// CmdCheck handles CNI check command - not implemented
+func (p *IPAMPlugin) CmdCheck(args *cniSkel.CmdArgs) error {
+	p.logger.Info("CHECK called")
+	return nil
+}
+
+// Parse network config from given byte array
+func parseNetConf(b []byte) (*cniTypes.NetConf, error) {
+	netConf := &cniTypes.NetConf{}
+	err := json.Unmarshal(b, netConf)
+	if err != nil {
+		return nil, errors.Wrapf(err, "failed to unmarshal net conf")
+	}
+
+	if netConf.CNIVersion == "" {
+		netConf.CNIVersion = "0.2.0" // default CNI version
+	}
+
+	return netConf, nil
+}