k3s/pkg/agent/flannel/setup.go
Manuel Buil 243fd14cf1 Change Replace with ReplaceAll function
strings has a specific function to replace all matches. We should use that one instead of strings.Replace(string, old, new string, -1)

Signed-off-by: Manuel Buil <mbuil@suse.com>
2021-06-07 09:52:26 +02:00

172 lines
4.5 KiB
Go

package flannel
import (
"context"
"fmt"
"os"
"path/filepath"
"strings"
"time"
"github.com/rancher/k3s/pkg/agent/util"
"github.com/rancher/k3s/pkg/daemons/config"
"github.com/rancher/k3s/pkg/version"
"github.com/sirupsen/logrus"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
v1 "k8s.io/client-go/kubernetes/typed/core/v1"
)
const (
cniConf = `{
"name":"cbr0",
"cniVersion":"0.3.1",
"plugins":[
{
"type":"flannel",
"delegate":{
"hairpinMode":true,
"forceAddress":true,
"isDefaultGateway":true
}
},
{
"type":"portmap",
"capabilities":{
"portMappings":true
}
}
]
}
`
flannelConf = `{
"Network": "%CIDR%",
"Backend": %backend%
}
`
vxlanBackend = `{
"Type": "vxlan"
}`
hostGWBackend = `{
"Type": "host-gw"
}`
ipsecBackend = `{
"Type": "ipsec",
"UDPEncap": true,
"PSK": "%psk%"
}`
wireguardBackend = `{
"Type": "extension",
"PreStartupCommand": "wg genkey | tee %flannelConfDir%/privatekey | wg pubkey",
"PostStartupCommand": "export SUBNET_IP=$(echo $SUBNET | cut -d'/' -f 1); ip link del flannel.1 2>/dev/null; echo $PATH >&2; wg-add.sh flannel.1 && wg set flannel.1 listen-port 51820 private-key %flannelConfDir%/privatekey && ip addr add $SUBNET_IP/32 dev flannel.1 && ip link set flannel.1 up && ip route add $NETWORK dev flannel.1",
"ShutdownCommand": "ip link del flannel.1",
"SubnetAddCommand": "read PUBLICKEY; wg set flannel.1 peer $PUBLICKEY endpoint $PUBLIC_IP:51820 allowed-ips $SUBNET persistent-keepalive 25",
"SubnetRemoveCommand": "read PUBLICKEY; wg set flannel.1 peer $PUBLICKEY remove"
}`
)
func Prepare(ctx context.Context, nodeConfig *config.Node) error {
if err := createCNIConf(nodeConfig.AgentConfig.CNIConfDir); err != nil {
return err
}
return createFlannelConf(nodeConfig)
}
func Run(ctx context.Context, nodeConfig *config.Node, nodes v1.NodeInterface) error {
nodeName := nodeConfig.AgentConfig.NodeName
for {
node, err := nodes.Get(ctx, nodeName, metav1.GetOptions{})
if err == nil && node.Spec.PodCIDR != "" {
break
}
if err == nil {
logrus.Info("Waiting for node " + nodeName + " CIDR not assigned yet")
} else {
logrus.Infof("Waiting for node %s: %v", nodeName, err)
}
time.Sleep(2 * time.Second)
}
logrus.Info("Node CIDR assigned for: " + nodeName)
go func() {
err := flannel(ctx, nodeConfig.FlannelIface, nodeConfig.FlannelConf, nodeConfig.AgentConfig.KubeConfigKubelet)
logrus.Fatalf("flannel exited: %v", err)
}()
return nil
}
func createCNIConf(dir string) error {
if dir == "" {
return nil
}
p := filepath.Join(dir, "10-flannel.conflist")
return util.WriteFile(p, cniConf)
}
func createFlannelConf(nodeConfig *config.Node) error {
if nodeConfig.FlannelConf == "" {
return nil
}
if nodeConfig.FlannelConfOverride {
logrus.Infof("Using custom flannel conf defined at %s", nodeConfig.FlannelConf)
return nil
}
confJSON := strings.ReplaceAll(flannelConf, "%CIDR%", nodeConfig.AgentConfig.ClusterCIDR.String())
var backendConf string
switch nodeConfig.FlannelBackend {
case config.FlannelBackendVXLAN:
backendConf = vxlanBackend
case config.FlannelBackendHostGW:
backendConf = hostGWBackend
case config.FlannelBackendIPSEC:
backendConf = strings.ReplaceAll(ipsecBackend, "%psk%", nodeConfig.AgentConfig.IPSECPSK)
if err := setupStrongSwan(nodeConfig); err != nil {
return err
}
case config.FlannelBackendWireguard:
backendConf = strings.ReplaceAll(wireguardBackend, "%flannelConfDir%", filepath.Dir(nodeConfig.FlannelConf))
default:
return fmt.Errorf("Cannot configure unknown flannel backend '%s'", nodeConfig.FlannelBackend)
}
confJSON = strings.ReplaceAll(confJSON, "%backend%", backendConf)
return util.WriteFile(nodeConfig.FlannelConf, confJSON)
}
func setupStrongSwan(nodeConfig *config.Node) error {
// if data dir env is not set point to root
dataDir := os.Getenv(version.ProgramUpper + "_DATA_DIR")
if dataDir == "" {
dataDir = "/"
}
dataDir = filepath.Join(dataDir, "etc", "strongswan")
info, err := os.Lstat(nodeConfig.AgentConfig.StrongSwanDir)
// something exists but is not a symlink, return
if err == nil && info.Mode()&os.ModeSymlink == 0 {
return nil
}
if err == nil {
target, err := os.Readlink(nodeConfig.AgentConfig.StrongSwanDir)
// current link is the same, return
if err == nil && target == dataDir {
return nil
}
}
// clean up strongswan old link
os.Remove(nodeConfig.AgentConfig.StrongSwanDir)
// make new strongswan link
return os.Symlink(dataDir, nodeConfig.AgentConfig.StrongSwanDir)
}