constellation/internal/cloud/gcp/client.go
Malte Poll 26e9c67a00 Move cloud metadata packages and kubernetes resources marshaling to internal
Decouples cloud provider metadata packages from kubernetes related code

Signed-off-by: Malte Poll <mp@edgeless.systems>
2022-08-29 16:07:55 +02:00

425 lines
14 KiB
Go

package gcp
import (
"context"
"errors"
"fmt"
"net"
"regexp"
"strings"
compute "cloud.google.com/go/compute/apiv1"
"github.com/edgelesssys/constellation/internal/cloud/metadata"
"github.com/edgelesssys/constellation/internal/gcpshared"
"google.golang.org/api/iterator"
computepb "google.golang.org/genproto/googleapis/cloud/compute/v1"
"google.golang.org/protobuf/proto"
)
const (
gcpSSHMetadataKey = "ssh-keys"
constellationUIDMetadataKey = "constellation-uid"
)
var zoneFromRegionRegex = regexp.MustCompile("([a-z]*-[a-z]*[0-9])")
// Client implements the gcp.API interface.
type Client struct {
instanceAPI
subnetworkAPI
metadataAPI
forwardingRulesAPI
}
// NewClient creates a new Client.
func NewClient(ctx context.Context) (*Client, error) {
insAPI, err := compute.NewInstancesRESTClient(ctx)
if err != nil {
return nil, err
}
subnetAPI, err := compute.NewSubnetworksRESTClient(ctx)
if err != nil {
return nil, err
}
forwardingRulesAPI, err := compute.NewForwardingRulesRESTClient(ctx)
if err != nil {
return nil, err
}
return &Client{
instanceAPI: &instanceClient{insAPI},
subnetworkAPI: &subnetworkClient{subnetAPI},
forwardingRulesAPI: &forwardingRulesClient{forwardingRulesAPI},
metadataAPI: &metadataClient{},
}, nil
}
// RetrieveInstances returns list of instances including their ips and metadata.
func (c *Client) RetrieveInstances(ctx context.Context, project, zone string) ([]metadata.InstanceMetadata, error) {
uid, err := c.UID()
if err != nil {
return nil, err
}
req := &computepb.ListInstancesRequest{
Project: project,
Zone: zone,
}
instanceIterator := c.instanceAPI.List(ctx, req)
instances := []metadata.InstanceMetadata{}
for {
resp, err := instanceIterator.Next()
if err == iterator.Done {
break
}
if err != nil {
return nil, fmt.Errorf("retrieving instance list from compute API client: %w", err)
}
metadata := extractInstanceMetadata(resp.Metadata, "", false)
// skip instances not belonging to the current constellation
if instanceUID, ok := metadata[constellationUIDMetadataKey]; !ok || instanceUID != uid {
continue
}
instance, err := convertToCoreInstance(resp, project, zone)
if err != nil {
return nil, err
}
instances = append(instances, instance)
}
return instances, nil
}
// RetrieveInstance returns a an instance including ips and metadata.
func (c *Client) RetrieveInstance(ctx context.Context, project, zone, instanceName string) (metadata.InstanceMetadata, error) {
instance, err := c.getComputeInstance(ctx, project, zone, instanceName)
if err != nil {
return metadata.InstanceMetadata{}, err
}
return convertToCoreInstance(instance, project, zone)
}
// RetrieveProjectID retrieves the GCP projectID containing the current instance.
func (c *Client) RetrieveProjectID() (string, error) {
value, err := c.metadataAPI.ProjectID()
if err != nil {
return "", fmt.Errorf("requesting GCP projectID failed %w", err)
}
return value, nil
}
// RetrieveZone retrieves the GCP zone containing the current instance.
func (c *Client) RetrieveZone() (string, error) {
value, err := c.metadataAPI.Zone()
if err != nil {
return "", fmt.Errorf("requesting GCP zone failed %w", err)
}
return value, nil
}
func (c *Client) RetrieveInstanceName() (string, error) {
value, err := c.metadataAPI.InstanceName()
if err != nil {
return "", fmt.Errorf("requesting GCP instanceName failed %w", err)
}
return value, nil
}
func (c *Client) RetrieveInstanceMetadata(attr string) (string, error) {
value, err := c.metadataAPI.InstanceAttributeValue(attr)
if err != nil {
return "", fmt.Errorf("requesting GCP instance metadata: %w", err)
}
return value, nil
}
// SetInstanceMetadata modifies a key value pair of metadata for the instance specified by project, zone and instanceName.
func (c *Client) SetInstanceMetadata(ctx context.Context, project, zone, instanceName, key, value string) error {
instance, err := c.getComputeInstance(ctx, project, zone, instanceName)
if err != nil {
return fmt.Errorf("retrieving instance metadata: %w", err)
}
if instance == nil || instance.Metadata == nil {
return fmt.Errorf("retrieving instance metadata returned invalid results")
}
// convert instance metadata to map to handle duplicate keys correctly
metadataMap := extractInstanceMetadata(instance.Metadata, key, false)
metadataMap[key] = value
// convert instance metadata back to flat list
metadata := flattenInstanceMetadata(metadataMap, instance.Metadata.Fingerprint, instance.Metadata.Kind)
if err := c.updateInstanceMetadata(ctx, project, zone, instanceName, metadata); err != nil {
return fmt.Errorf("setting instance metadata %v: %v: %w", key, value, err)
}
return nil
}
// UnsetInstanceMetadata modifies a key value pair of metadata for the instance specified by project, zone and instanceName.
func (c *Client) UnsetInstanceMetadata(ctx context.Context, project, zone, instanceName, key string) error {
instance, err := c.getComputeInstance(ctx, project, zone, instanceName)
if err != nil {
return fmt.Errorf("retrieving instance metadata: %w", err)
}
if instance == nil || instance.Metadata == nil {
return fmt.Errorf("retrieving instance metadata returned invalid results")
}
// convert instance metadata to map to handle duplicate keys correctly
// and skip the key to be removed
metadataMap := extractInstanceMetadata(instance.Metadata, key, true)
// convert instance metadata back to flat list
metadata := flattenInstanceMetadata(metadataMap, instance.Metadata.Fingerprint, instance.Metadata.Kind)
if err := c.updateInstanceMetadata(ctx, project, zone, instanceName, metadata); err != nil {
return fmt.Errorf("unsetting instance metadata key %v: %w", key, err)
}
return nil
}
// RetrieveSubnetworkAliasCIDR returns the alias CIDR of the subnetwork specified by project, zone and subnetworkName.
func (c *Client) RetrieveSubnetworkAliasCIDR(ctx context.Context, project, zone, instanceName string) (string, error) {
instance, err := c.getComputeInstance(ctx, project, zone, instanceName)
if err != nil {
return "", err
}
if instance == nil || instance.NetworkInterfaces == nil || len(instance.NetworkInterfaces) == 0 || instance.NetworkInterfaces[0].Subnetwork == nil {
return "", fmt.Errorf("retrieving instance network interfaces failed")
}
subnetworkURL := *instance.NetworkInterfaces[0].Subnetwork
subnetworkURLFragments := strings.Split(subnetworkURL, "/")
subnetworkName := subnetworkURLFragments[len(subnetworkURLFragments)-1]
// convert:
// zone --> region
// europe-west3-b --> europe-west3
region := zoneFromRegionRegex.FindString(zone)
if region == "" {
return "", fmt.Errorf("invalid zone %s", zone)
}
req := &computepb.GetSubnetworkRequest{
Project: project,
Region: region,
Subnetwork: subnetworkName,
}
subnetwork, err := c.subnetworkAPI.Get(ctx, req)
if err != nil {
return "", fmt.Errorf("retrieving subnetwork alias CIDR failed: %w", err)
}
if subnetwork == nil || len(subnetwork.SecondaryIpRanges) == 0 || (subnetwork.SecondaryIpRanges[0]).IpCidrRange == nil {
return "", fmt.Errorf("retrieving subnetwork alias CIDR returned invalid results")
}
return *(subnetwork.SecondaryIpRanges[0]).IpCidrRange, nil
}
// RetrieveLoadBalancerEndpoint returns the endpoint of the load balancer with the constellation-uid tag.
func (c *Client) RetrieveLoadBalancerEndpoint(ctx context.Context, project, zone string) (string, error) {
uid, err := c.UID()
if err != nil {
return "", err
}
region := zoneFromRegionRegex.FindString(zone)
if region == "" {
return "", fmt.Errorf("invalid zone %s", zone)
}
req := &computepb.ListForwardingRulesRequest{
Project: project,
Region: region,
}
iter := c.forwardingRulesAPI.List(ctx, req)
for {
resp, err := iter.Next()
if err == iterator.Done {
break
}
if err != nil {
return "", fmt.Errorf("retrieving load balancer IP failed: %w", err)
}
if resp.Labels["constellation-uid"] == uid {
if len(resp.Ports) == 0 {
return "", errors.New("load balancer with searched UID has no ports")
}
return net.JoinHostPort(*resp.IPAddress, resp.Ports[0]), nil
}
}
return "", fmt.Errorf("retrieving load balancer IP failed: load balancer not found")
}
// Close closes the instanceAPI client.
func (c *Client) Close() error {
if err := c.subnetworkAPI.Close(); err != nil {
return err
}
if err := c.forwardingRulesAPI.Close(); err != nil {
return err
}
return c.instanceAPI.Close()
}
func (c *Client) getComputeInstance(ctx context.Context, project, zone, instanceName string) (*computepb.Instance, error) {
instanceGetReq := &computepb.GetInstanceRequest{
Project: project,
Zone: zone,
Instance: instanceName,
}
instance, err := c.instanceAPI.Get(ctx, instanceGetReq)
if err != nil {
return nil, fmt.Errorf("retrieving compute instance: %w", err)
}
return instance, nil
}
// updateInstanceMetadata updates all instance metadata key-value pairs.
func (c *Client) updateInstanceMetadata(ctx context.Context, project, zone, instanceName string, metadata *computepb.Metadata) error {
setMetadataReq := &computepb.SetMetadataInstanceRequest{
Project: project,
Zone: zone,
Instance: instanceName,
MetadataResource: metadata,
}
if _, err := c.instanceAPI.SetMetadata(ctx, setMetadataReq); err != nil {
return fmt.Errorf("updating instance metadata: %w", err)
}
return nil
}
// UID retrieves the current instances uid.
func (c *Client) UID() (string, error) {
// API endpoint: http://metadata.google.internal/computeMetadata/v1/instance/attributes/constellation-uid
uid, err := c.RetrieveInstanceMetadata(constellationUIDMetadataKey)
if err != nil {
return "", fmt.Errorf("retrieving constellation uid: %w", err)
}
return uid, nil
}
// extractVPCIP extracts the primary private IP from a list of interfaces.
func extractVPCIP(interfaces []*computepb.NetworkInterface) string {
for _, interf := range interfaces {
if interf == nil || interf.NetworkIP == nil || interf.Name == nil || *interf.Name != "nic0" {
continue
}
// return private IP from the default interface
return *interf.NetworkIP
}
return ""
}
// extractPublicIP extracts a public IP from a list of interfaces.
func extractPublicIP(interfaces []*computepb.NetworkInterface) string {
for _, interf := range interfaces {
if interf == nil || interf.AccessConfigs == nil || interf.Name == nil || *interf.Name != "nic0" {
continue
}
// return public IP from the default interface
// GCP only supports one type of access config, so returning the first IP should result in a valid public IP
for _, accessConfig := range interf.AccessConfigs {
if accessConfig == nil || accessConfig.NatIP == nil {
continue
}
return *accessConfig.NatIP
}
}
return ""
}
// extractAliasIPRanges extracts alias interface IPs from a list of interfaces.
func extractAliasIPRanges(interfaces []*computepb.NetworkInterface) []string {
ips := []string{}
for _, interf := range interfaces {
if interf == nil || interf.AliasIpRanges == nil {
continue
}
for _, aliasIP := range interf.AliasIpRanges {
if aliasIP == nil || aliasIP.IpCidrRange == nil {
continue
}
ips = append(ips, *aliasIP.IpCidrRange)
}
}
return ips
}
// extractSSHKeys extracts SSH keys from GCP instance metadata.
// reference: https://cloud.google.com/compute/docs/connect/add-ssh-keys .
func extractSSHKeys(metadata map[string]string) map[string][]string {
sshKeysRaw, ok := metadata[gcpSSHMetadataKey]
if !ok {
// ignore missing metadata entry
return map[string][]string{}
}
sshKeyLines := strings.Split(sshKeysRaw, "\n")
keys := map[string][]string{}
for _, sshKeyRaw := range sshKeyLines {
keyParts := strings.SplitN(sshKeyRaw, ":", 2)
if len(keyParts) != 2 {
continue
}
username := keyParts[0]
keyParts = strings.SplitN(keyParts[1], " ", 3)
if len(keyParts) < 2 {
continue
}
keyValue := fmt.Sprintf("%s %s", keyParts[0], keyParts[1])
keys[username] = append(keys[username], keyValue)
}
return keys
}
// convertToCoreInstance converts a *computepb.Instance to a core.Instance.
func convertToCoreInstance(in *computepb.Instance, project string, zone string) (metadata.InstanceMetadata, error) {
if in.Name == nil {
return metadata.InstanceMetadata{}, fmt.Errorf("retrieving instance from compute API client returned invalid instance Name: %v", in.Name)
}
mdata := extractInstanceMetadata(in.Metadata, "", false)
return metadata.InstanceMetadata{
Name: *in.Name,
ProviderID: gcpshared.JoinProviderID(project, zone, *in.Name),
Role: extractRole(mdata),
VPCIP: extractVPCIP(in.NetworkInterfaces),
PublicIP: extractPublicIP(in.NetworkInterfaces),
AliasIPRanges: extractAliasIPRanges(in.NetworkInterfaces),
SSHKeys: extractSSHKeys(mdata),
}, nil
}
// extractInstanceMetadata will extract the list of instance metadata key-value pairs into a map.
// If "skipKey" is true, "key" will be skipped.
func extractInstanceMetadata(in *computepb.Metadata, key string, skipKey bool) map[string]string {
metadataMap := map[string]string{}
for _, item := range in.Items {
if item == nil || item.Key == nil || item.Value == nil {
continue
}
if skipKey && *item.Key == key {
continue
}
metadataMap[*item.Key] = *item.Value
}
return metadataMap
}
// flattenInstanceMetadata takes a map of metadata key-value pairs and returns a flat list of computepb.Items inside computepb.Metadata.
func flattenInstanceMetadata(metadataMap map[string]string, fingerprint, kind *string) *computepb.Metadata {
metadata := &computepb.Metadata{
Fingerprint: fingerprint,
Kind: kind,
Items: make([]*computepb.Items, len(metadataMap)),
}
i := 0
for mapKey, mapValue := range metadataMap {
metadata.Items[i] = &computepb.Items{Key: proto.String(mapKey), Value: proto.String(mapValue)}
i++
}
return metadata
}