func()

in pkg/providers/subnet/subnet.go [82:132]

• 46 lines of code
• 9 McCabe index (conditional complexity)

func (p *DefaultProvider) List(ctx context.Context, nodeClass *v1.EC2NodeClass) ([]ec2types.Subnet, error) {
	p.Lock()
	defer p.Unlock()
	filterSets := getFilterSets(nodeClass.Spec.SubnetSelectorTerms)
	if len(filterSets) == 0 {
		return []ec2types.Subnet{}, nil
	}
	hash, err := hashstructure.Hash(filterSets, hashstructure.FormatV2, &hashstructure.HashOptions{SlicesAsSets: true})
	if err != nil {
		return nil, err
	}
	if subnets, ok := p.cache.Get(fmt.Sprint(hash)); ok {
		// Ensure what's returned from this function is a shallow-copy of the slice (not a deep-copy of the data itself)
		// so that modifications to the ordering of the data don't affect the original
		return append([]ec2types.Subnet{}, subnets.([]ec2types.Subnet)...), nil
	}
	// Ensure that all the subnets that are returned here are unique
	subnets := map[string]ec2types.Subnet{}
	for _, filters := range filterSets {
		paginator := ec2.NewDescribeSubnetsPaginator(p.ec2api, &ec2.DescribeSubnetsInput{
			Filters:    filters,
			MaxResults: lo.ToPtr(int32(500)),
		})
		for paginator.HasMorePages() {
			output, err := paginator.NextPage(ctx)
			if err != nil {
				return nil, serrors.Wrap(fmt.Errorf("describing subnets with filters, %w", err), "filters", pretty.Concise(filters))
			}
			for i := range output.Subnets {
				subnets[lo.FromPtr(output.Subnets[i].SubnetId)] = output.Subnets[i]
				p.availableIPAddressCache.SetDefault(lo.FromPtr(output.Subnets[i].SubnetId), lo.FromPtr(output.Subnets[i].AvailableIpAddressCount))
				p.associatePublicIPAddressCache.SetDefault(lo.FromPtr(output.Subnets[i].SubnetId), lo.FromPtr(output.Subnets[i].MapPublicIpOnLaunch))
				// subnets can be leaked here, if a subnets is never called received from ec2
				// we are accepting it for now, as this will be an insignificant amount of memory
				delete(p.inflightIPs, lo.FromPtr(output.Subnets[i].SubnetId)) // remove any previously tracked IP addresses since we just refreshed from EC2
			}
		}
	}
	p.cache.SetDefault(fmt.Sprint(hash), lo.Values(subnets))
	if p.cm.HasChanged(fmt.Sprintf("subnets/%s", nodeClass.Name), lo.Keys(subnets)) {
		log.FromContext(ctx).
			WithValues("subnets", lo.Map(lo.Values(subnets), func(s ec2types.Subnet, _ int) v1.Subnet {
				return v1.Subnet{
					ID:     lo.FromPtr(s.SubnetId),
					Zone:   lo.FromPtr(s.AvailabilityZone),
					ZoneID: lo.FromPtr(s.AvailabilityZoneId),
				}
			})).V(1).Info("discovered subnets")
	}
	return lo.Values(subnets), nil
}