package common import ( "context" "fmt" "log" "math/rand" "sort" "github.com/aws/aws-sdk-go/service/ec2" "github.com/hashicorp/packer/helper/multistep" "github.com/hashicorp/packer/packer" ) // StepNetworkInfo queries AWS for information about // VPC's and Subnets that is used throughout the AMI creation process. // // Produces (adding them to the state bag): // vpc_id string - the VPC ID // subnet_id string - the Subnet ID // availability_zone string - the AZ name type StepNetworkInfo struct { VpcId string VpcFilter VpcFilterOptions SubnetId string SubnetFilter SubnetFilterOptions AvailabilityZone string SecurityGroupIds []string SecurityGroupFilter SecurityGroupFilterOptions } type subnetsSort []*ec2.Subnet func (a subnetsSort) Len() int { return len(a) } func (a subnetsSort) Swap(i, j int) { a[i], a[j] = a[j], a[i] } func (a subnetsSort) Less(i, j int) bool { return *a[i].AvailableIpAddressCount < *a[j].AvailableIpAddressCount } // Returns the most recent AMI out of a slice of images. func mostFreeSubnet(subnets []*ec2.Subnet) *ec2.Subnet { sortedSubnets := subnets sort.Sort(subnetsSort(sortedSubnets)) return sortedSubnets[len(sortedSubnets)-1] } func (s *StepNetworkInfo) Run(ctx context.Context, state multistep.StateBag) multistep.StepAction { ec2conn := state.Get("ec2").(*ec2.EC2) ui := state.Get("ui").(packer.Ui) // VPC if s.VpcId == "" && !s.VpcFilter.Empty() { params := &ec2.DescribeVpcsInput{} params.Filters = buildEc2Filters(s.VpcFilter.Filters) s.VpcFilter.Filters["state"] = "available" log.Printf("Using VPC Filters %v", params) vpcResp, err := ec2conn.DescribeVpcs(params) if err != nil { err := fmt.Errorf("Error querying VPCs: %s", err) state.Put("error", err) ui.Error(err.Error()) return multistep.ActionHalt } if len(vpcResp.Vpcs) != 1 { err := fmt.Errorf("Exactly one VPC should match the filter, but %d VPC's was found matching filters: %v", len(vpcResp.Vpcs), params) state.Put("error", err) ui.Error(err.Error()) return multistep.ActionHalt } s.VpcId = *vpcResp.Vpcs[0].VpcId ui.Message(fmt.Sprintf("Found VPC ID: %s", s.VpcId)) } // Subnet if s.SubnetId == "" && !s.SubnetFilter.Empty() { params := &ec2.DescribeSubnetsInput{} s.SubnetFilter.Filters["state"] = "available" if s.VpcId != "" { s.SubnetFilter.Filters["vpc-id"] = s.VpcId } if s.AvailabilityZone != "" { s.SubnetFilter.Filters["availabilityZone"] = s.AvailabilityZone } params.Filters = buildEc2Filters(s.SubnetFilter.Filters) log.Printf("Using Subnet Filters %v", params) subnetsResp, err := ec2conn.DescribeSubnets(params) if err != nil { err := fmt.Errorf("Error querying Subnets: %s", err) state.Put("error", err) ui.Error(err.Error()) return multistep.ActionHalt } if len(subnetsResp.Subnets) == 0 { err := fmt.Errorf("No Subnets was found matching filters: %v", params) state.Put("error", err) ui.Error(err.Error()) return multistep.ActionHalt } if len(subnetsResp.Subnets) > 1 && !s.SubnetFilter.Random && !s.SubnetFilter.MostFree { err := fmt.Errorf("Your filter matched %d Subnets. Please try a more specific search, or set random or most_free to true.", len(subnetsResp.Subnets)) state.Put("error", err) ui.Error(err.Error()) return multistep.ActionHalt } var subnet *ec2.Subnet switch { case s.SubnetFilter.MostFree: subnet = mostFreeSubnet(subnetsResp.Subnets) case s.SubnetFilter.Random: subnet = subnetsResp.Subnets[rand.Intn(len(subnetsResp.Subnets))] default: subnet = subnetsResp.Subnets[0] } s.SubnetId = *subnet.SubnetId ui.Message(fmt.Sprintf("Found Subnet ID: %s", s.SubnetId)) } // Try to find AZ and VPC Id from Subnet if they are not yet found/given if s.SubnetId != "" && (s.AvailabilityZone == "" || s.VpcId == "") { log.Printf("[INFO] Finding AZ and VpcId for the given subnet '%s'", s.SubnetId) resp, err := ec2conn.DescribeSubnets(&ec2.DescribeSubnetsInput{SubnetIds: []*string{&s.SubnetId}}) if err != nil { err := fmt.Errorf("Describing the subnet: %s returned error: %s.", s.SubnetId, err) state.Put("error", err) ui.Error(err.Error()) return multistep.ActionHalt } if s.AvailabilityZone == "" { s.AvailabilityZone = *resp.Subnets[0].AvailabilityZone log.Printf("[INFO] AvailabilityZone found: '%s'", s.AvailabilityZone) } if s.VpcId == "" { s.VpcId = *resp.Subnets[0].VpcId log.Printf("[INFO] VpcId found: '%s'", s.VpcId) } } state.Put("vpc_id", s.VpcId) state.Put("availability_zone", s.AvailabilityZone) state.Put("subnet_id", s.SubnetId) return multistep.ActionContinue } func (s *StepNetworkInfo) Cleanup(multistep.StateBag) {}