|
| 1 | +package networking |
| 2 | + |
| 3 | +import ( |
| 4 | + "context" |
| 5 | + "fmt" |
| 6 | + |
| 7 | + awssdk "github.com/aws/aws-sdk-go-v2/aws" |
| 8 | + ec2sdk "github.com/aws/aws-sdk-go-v2/service/ec2" |
| 9 | + ec2types "github.com/aws/aws-sdk-go-v2/service/ec2/types" |
| 10 | + "k8s.io/apimachinery/pkg/util/sets" |
| 11 | + "sigs.k8s.io/aws-load-balancer-controller/v3/pkg/aws/services" |
| 12 | +) |
| 13 | + |
| 14 | +const ec2FilterNameDomain = "domain" |
| 15 | + |
| 16 | +//go:generate mockgen -destination=eip_resolver_mocks.go -package=networking sigs.k8s.io/aws-load-balancer-controller/v3/pkg/networking EIPResolver |
| 17 | + |
| 18 | +// EIPResolver resolves Elastic IP allocation IDs for NLB subnet mappings. |
| 19 | +type EIPResolver interface { |
| 20 | + ResolveForSubnets(ctx context.Context, tagFilters map[string]string, subnets []ec2types.Subnet) ([]string, error) |
| 21 | +} |
| 22 | + |
| 23 | +// NewDefaultEIPResolver constructs a new defaultEIPResolver. |
| 24 | +func NewDefaultEIPResolver(ec2Client services.EC2) *defaultEIPResolver { |
| 25 | + return &defaultEIPResolver{ |
| 26 | + ec2Client: ec2Client, |
| 27 | + } |
| 28 | +} |
| 29 | + |
| 30 | +type defaultEIPResolver struct { |
| 31 | + ec2Client services.EC2 |
| 32 | +} |
| 33 | + |
| 34 | +var _ EIPResolver = &defaultEIPResolver{} |
| 35 | + |
| 36 | +func (r *defaultEIPResolver) ResolveForSubnets(ctx context.Context, tagFilters map[string]string, subnets []ec2types.Subnet) ([]string, error) { |
| 37 | + if len(tagFilters) == 0 { |
| 38 | + return nil, fmt.Errorf("EIP discovery tags must not be empty") |
| 39 | + } |
| 40 | + if len(subnets) == 0 { |
| 41 | + return nil, fmt.Errorf("subnets must not be empty for EIP discovery") |
| 42 | + } |
| 43 | + |
| 44 | + addresses, err := r.listAddressesByTagFilters(ctx, tagFilters) |
| 45 | + if err != nil { |
| 46 | + return nil, fmt.Errorf("failed to list EIPs by discovery tags: %w", err) |
| 47 | + } |
| 48 | + |
| 49 | + addressesByAZ := make(map[string][]ec2types.Address) |
| 50 | + for _, addr := range addresses { |
| 51 | + az := awssdk.ToString(addr.NetworkBorderGroup) |
| 52 | + if az == "" { |
| 53 | + return nil, fmt.Errorf("discovered EIP %s has empty network border group", awssdk.ToString(addr.AllocationId)) |
| 54 | + } |
| 55 | + addressesByAZ[az] = append(addressesByAZ[az], addr) |
| 56 | + } |
| 57 | + |
| 58 | + allocationIDs := make([]string, 0, len(subnets)) |
| 59 | + for _, subnet := range subnets { |
| 60 | + subnetAZ := awssdk.ToString(subnet.AvailabilityZone) |
| 61 | + addrsInAZ := addressesByAZ[subnetAZ] |
| 62 | + if len(addrsInAZ) == 0 { |
| 63 | + return nil, fmt.Errorf("no EIP found for subnet %s in availability zone %s matching discovery tags", awssdk.ToString(subnet.SubnetId), subnetAZ) |
| 64 | + } |
| 65 | + if len(addrsInAZ) > 1 { |
| 66 | + return nil, fmt.Errorf("multiple EIPs found for availability zone %s matching discovery tags", subnetAZ) |
| 67 | + } |
| 68 | + addr := addrsInAZ[0] |
| 69 | + if err := validateDiscoveredEIP(addr); err != nil { |
| 70 | + return nil, err |
| 71 | + } |
| 72 | + allocationIDs = append(allocationIDs, awssdk.ToString(addr.AllocationId)) |
| 73 | + } |
| 74 | + |
| 75 | + return allocationIDs, nil |
| 76 | +} |
| 77 | + |
| 78 | +func validateDiscoveredEIP(addr ec2types.Address) error { |
| 79 | + if addr.AllocationId == nil || awssdk.ToString(addr.AllocationId) == "" { |
| 80 | + return fmt.Errorf("discovered EIP has empty allocation ID") |
| 81 | + } |
| 82 | + if addr.AssociationId != nil && awssdk.ToString(addr.AssociationId) != "" { |
| 83 | + owner := awssdk.ToString(addr.NetworkInterfaceOwnerId) |
| 84 | + if owner != "" && owner != "amazon-elb" { |
| 85 | + return fmt.Errorf("EIP %s is associated with another resource", awssdk.ToString(addr.AllocationId)) |
| 86 | + } |
| 87 | + } |
| 88 | + return nil |
| 89 | +} |
| 90 | + |
| 91 | +func (r *defaultEIPResolver) listAddressesByTagFilters(ctx context.Context, tagFilters map[string]string) ([]ec2types.Address, error) { |
| 92 | + req := &ec2sdk.DescribeAddressesInput{ |
| 93 | + Filters: []ec2types.Filter{ |
| 94 | + { |
| 95 | + Name: awssdk.String(ec2FilterNameDomain), |
| 96 | + Values: []string{"vpc"}, |
| 97 | + }, |
| 98 | + }, |
| 99 | + } |
| 100 | + for _, key := range sets.StringKeySet(tagFilters).List() { |
| 101 | + req.Filters = append(req.Filters, ec2types.Filter{ |
| 102 | + Name: awssdk.String("tag:" + key), |
| 103 | + Values: []string{tagFilters[key]}, |
| 104 | + }) |
| 105 | + } |
| 106 | + return r.ec2Client.DescribeAddressesAsList(ctx, req) |
| 107 | +} |
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