calico.go

// Copyright 2015 Tigera Inc
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package main

import (
	"encoding/json"
	goerrors "errors"
	"flag"
	"fmt"
	"os"
	"runtime"

	"net"

	log "github.com/Sirupsen/logrus"
	"github.com/containernetworking/cni/pkg/ipam"
	"github.com/containernetworking/cni/pkg/skel"
	"github.com/containernetworking/cni/pkg/types"
	"github.com/containernetworking/cni/pkg/types/current"
	cniSpecVersion "github.com/containernetworking/cni/pkg/version"
	"github.com/projectcalico/cni-plugin/k8s"
	. "github.com/projectcalico/cni-plugin/utils"
	"github.com/projectcalico/libcalico-go/lib/api"
	"github.com/projectcalico/libcalico-go/lib/errors"
	cnet "github.com/projectcalico/libcalico-go/lib/net"
)

var nodename string

func init() {
	// This ensures that main runs only on main thread (thread group leader).
	// since namespace ops (unshare, setns) are done for a single thread, we
	// must ensure that the goroutine does not jump from OS thread to thread
	runtime.LockOSThread()

	nodename, _ = os.Hostname()
}

func updateNodename(conf NetConf, logger *log.Entry) {
	if conf.Hostname != "" {
		nodename = conf.Hostname
		logger.Warn("Configuration option 'hostname' is deprecated, use 'nodename' instead.")
	}
	if conf.Nodename != "" {
		nodename = conf.Nodename
	}
}

func cmdAdd(args *skel.CmdArgs) error {
	// Unmarshal the network config, and perform validation
	conf := NetConf{}
	if err := json.Unmarshal(args.StdinData, &conf); err != nil {
		return fmt.Errorf("failed to load netconf: %v", err)
	}

	cniVersion := conf.CNIVersion

	ConfigureLogging(conf.LogLevel)

	workload, orchestrator, err := GetIdentifiers(args)
	if err != nil {
		return err
	}

	logger := CreateContextLogger(workload)

	// Allow the nodename to be overridden by the network config
	updateNodename(conf, logger)

	logger.WithFields(log.Fields{
		"Orchestrator": orchestrator,
		"Node":         nodename,
	}).Info("Extracted identifiers")

	logger.WithFields(log.Fields{"NetConfg": conf}).Info("Loaded CNI NetConf")
	calicoClient, err := CreateClient(conf)
	if err != nil {
		return err
	}

	// Always check if there's an existing endpoint.
	endpoints, err := calicoClient.WorkloadEndpoints().List(api.WorkloadEndpointMetadata{
		Node:         nodename,
		Orchestrator: orchestrator,
		Workload:     workload})
	if err != nil {
		return err
	}

	logger.Debugf("Retrieved endpoints: %v", endpoints)

	var endpoint *api.WorkloadEndpoint
	if len(endpoints.Items) == 1 {
		endpoint = &endpoints.Items[0]
	}

	fmt.Fprintf(os.Stderr, "Calico CNI checking for existing endpoint: %v\n", endpoint)

	// Collect the result in this variable - this is ultimately what gets "returned" by this function by printing
	// it to stdout.
	var result *current.Result

	// If running under Kubernetes then branch off into the kubernetes code, otherwise handle everything in this
	// function.
	if orchestrator == "k8s" {
		if result, err = k8s.CmdAddK8s(args, conf, nodename, calicoClient, endpoint); err != nil {
			return err
		}
	} else {
		// Default CNI behavior - use the CNI network name as the Calico profile.
		profileID := conf.Name

		if endpoint != nil {
			// There is an existing endpoint - no need to create another.
			// This occurs when adding an existing container to a new CNI network
			// Find the IP address from the endpoint and use that in the response.
			// Don't create the veth or do any networking.
			// Just update the profile on the endpoint. The profile will be created if needed during the
			// profile processing step.
			fmt.Fprintf(os.Stderr, "Calico CNI appending profile: %s\n", profileID)
			endpoint.Spec.Profiles = append(endpoint.Spec.Profiles, profileID)
			result, err = CreateResultFromEndpoint(endpoint)
			logger.WithField("result", result).Debug("Created result from endpoint")
			if err != nil {
				return err
			}
		} else {
			// There's no existing endpoint, so we need to do the following:
			// 1) Call the configured IPAM plugin to get IP address(es)
			// 2) Configure the Calico endpoint
			// 3) Create the veth, configuring it on both the host and container namespace.

			// 1) Run the IPAM plugin and make sure there's an IP address returned.
			logger.WithFields(log.Fields{"paths": os.Getenv("CNI_PATH"),
				"type": conf.IPAM.Type}).Debug("Looking for IPAM plugin in paths")
			ipamResult, err := ipam.ExecAdd(conf.IPAM.Type, args.StdinData)
			logger.WithField("IPAM result", ipamResult).Info("Got result from IPAM plugin")
			if err != nil {
				return err
			}

			// Convert IPAM result into current Result.
			// IPAM result has a bunch of fields that are optional for an IPAM plugin
			// but required for a CNI plugin, so this is to populate those fields.
			// See CNI Spec doc for more details.
			result, err = current.NewResultFromResult(ipamResult)
			if err != nil {
				ReleaseIPAllocation(logger, conf.IPAM.Type, args.StdinData)
				return err
			}

			if len(result.IPs) == 0 {
				ReleaseIPAllocation(logger, conf.IPAM.Type, args.StdinData)
				return goerrors.New("IPAM plugin returned missing IP config")
			}

			// Parse endpoint labels passed in by Mesos, and store in a map.
			labels := map[string]string{}
			for _, label := range conf.Args.Mesos.NetworkInfo.Labels.Labels {
				labels[label.Key] = label.Value
			}

			// 2) Create the endpoint object
			endpoint = api.NewWorkloadEndpoint()
			endpoint.Metadata.Name = args.IfName
			endpoint.Metadata.Node = nodename
			endpoint.Metadata.Orchestrator = orchestrator
			endpoint.Metadata.Workload = workload
			endpoint.Metadata.Labels = labels
			endpoint.Spec.Profiles = []string{profileID}

			logger.WithField("endpoint", endpoint).Debug("Populated endpoint (without nets)")
			if err = PopulateEndpointNets(endpoint, result); err != nil {
				// Cleanup IP allocation and return the error.
				ReleaseIPAllocation(logger, conf.IPAM.Type, args.StdinData)
				return err
			}
			logger.WithField("endpoint", endpoint).Info("Populated endpoint (with nets)")

			fmt.Fprintf(os.Stderr, "Calico CNI using IPs: %s\n", endpoint.Spec.IPNetworks)

			// 3) Set up the veth
			hostVethName, contVethMac, err := DoNetworking(args, conf, result, logger, "")
			if err != nil {
				// Cleanup IP allocation and return the error.
				ReleaseIPAllocation(logger, conf.IPAM.Type, args.StdinData)
				return err
			}

			logger.WithFields(log.Fields{
				"HostVethName":     hostVethName,
				"ContainerVethMac": contVethMac,
			}).Info("Networked namespace")

			mac, err := net.ParseMAC(contVethMac)
			if err != nil {
				// Cleanup IP allocation and return the error.
				ReleaseIPAllocation(logger, conf.IPAM.Type, args.StdinData)
				return err
			}

			endpoint.Spec.MAC = &cnet.MAC{HardwareAddr: mac}
			endpoint.Spec.InterfaceName = hostVethName
		}

		// Write the endpoint object (either the newly created one, or the updated one with a new ProfileIDs).
		if _, err := calicoClient.WorkloadEndpoints().Apply(endpoint); err != nil {
			// Cleanup IP allocation and return the error.
			ReleaseIPAllocation(logger, conf.IPAM.Type, args.StdinData)
			return err
		}

		logger.WithField("endpoint", endpoint).Info("Wrote endpoint to datastore")
	}

	// Handle profile creation - this is only done if there isn't a specific policy handler.
	if conf.Policy.PolicyType == "" {
		logger.Debug("Handling profiles")
		// Start by checking if the profile already exists. If it already exists then there is no work to do.
		// The CNI plugin never updates a profile.
		exists := true
		_, err = calicoClient.Profiles().Get(api.ProfileMetadata{Name: conf.Name})
		if err != nil {
			_, ok := err.(errors.ErrorResourceDoesNotExist)
			if ok {
				exists = false
			} else {
				// Cleanup IP allocation and return the error.
				ReleaseIPAllocation(logger, conf.IPAM.Type, args.StdinData)
				return err
			}
		}

		if !exists {
			// The profile doesn't exist so needs to be created. The rules vary depending on whether k8s is being used.
			// Under k8s (without full policy support) the rule is permissive and allows all traffic.
			// Otherwise, incoming traffic is only allowed from profiles with the same tag.
			fmt.Fprintf(os.Stderr, "Calico CNI creating profile: %s\n", conf.Name)
			var inboundRules []api.Rule
			if orchestrator == "k8s" {
				inboundRules = []api.Rule{{Action: "allow"}}
			} else {
				inboundRules = []api.Rule{{Action: "allow", Source: api.EntityRule{Tag: conf.Name}}}
			}

			profile := &api.Profile{
				Metadata: api.ProfileMetadata{
					Name: conf.Name,
					Tags: []string{conf.Name},
				},
				Spec: api.ProfileSpec{
					EgressRules:  []api.Rule{{Action: "allow"}},
					IngressRules: inboundRules,
				},
			}

			logger.WithField("profile", profile).Info("Creating profile")

			if _, err := calicoClient.Profiles().Create(profile); err != nil {
				// Cleanup IP allocation and return the error.
				ReleaseIPAllocation(logger, conf.IPAM.Type, args.StdinData)
				return err
			}
		}
	}

	// Set Gateway to nil. Calico-IPAM doesn't set it, but host-local does.
	// We modify IPs subnet received from the IPAM plugin (host-local),
	// so Gateway isn't valid anymore. It is also not used anywhere by Calico.
	for _, ip := range result.IPs {
		ip.Gateway = nil
	}

	// Print result to stdout, in the format defined by the requested cniVersion.
	return types.PrintResult(result, cniVersion)
}

func cmdDel(args *skel.CmdArgs) error {
	conf := NetConf{}
	if err := json.Unmarshal(args.StdinData, &conf); err != nil {
		return fmt.Errorf("failed to load netconf: %v", err)
	}

	ConfigureLogging(conf.LogLevel)

	workload, orchestrator, err := GetIdentifiers(args)
	if err != nil {
		return err
	}

	logger := CreateContextLogger(workload)

	// Allow the nodename to be overridden by the network config
	updateNodename(conf, logger)

	logger.WithFields(log.Fields{
		"Workload":     workload,
		"Orchestrator": orchestrator,
		"Node":         nodename,
	}).Info("Extracted identifiers")

	calicoClient, err := CreateClient(conf)
	if err != nil {
		return err
	}

	wep := api.WorkloadEndpointMetadata{
		Name:         args.IfName,
		Node:         nodename,
		Orchestrator: orchestrator,
		Workload:     workload,
	}

	// Handle k8s specific bits of handling the DEL.
	if orchestrator == "k8s" {
		return k8s.CmdDelK8s(calicoClient, wep, args, conf, logger)
	}

	// Release the IP address by calling the configured IPAM plugin.
	ipamErr := CleanUpIPAM(conf, args, logger)

	// Delete the WorkloadEndpoint object from the datastore.
	if err = calicoClient.WorkloadEndpoints().Delete(wep); err != nil {
		if _, ok := err.(errors.ErrorResourceDoesNotExist); ok {
			// Log and proceed with the clean up if WEP doesn't exist.
			logger.WithField("endpoint", wep).Info("Endpoint object does not exist, no need to clean up.")
		} else {
			return err
		}
	}

	// Clean up namespace by removing the interfaces.
	err = CleanUpNamespace(args, logger)
	if err != nil {
		return err
	}

	// Return the IPAM error if there was one. The IPAM error will be lost if there was also an error in cleaning up
	// the device or endpoint, but crucially, the user will know the overall operation failed.
	return ipamErr
}

// VERSION is filled out during the build process (using git describe output)
var VERSION string

func main() {
	// Display the version on "-v", otherwise just delegate to the skel code.
	// Use a new flag set so as not to conflict with existing libraries which use "flag"
	flagSet := flag.NewFlagSet("Calico", flag.ExitOnError)

	version := flagSet.Bool("v", false, "Display version")
	err := flagSet.Parse(os.Args[1:])
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}
	if *version {
		fmt.Println(VERSION)
		os.Exit(0)
	}

	if err := AddIgnoreUnknownArgs(); err != nil {
		os.Exit(1)
	}

	skel.PluginMain(cmdAdd, cmdDel, cniSpecVersion.All)
}