builder/amazon: Update Session Manger connectivity

* Update security group creation step skip ingress rules if using session manager
* Update create ssm tunnel step to dynamically set a session port
* Add SSHPort function to common to return session-manager tunnel port
* Update SSHHost to return proper host for session-manager

builder/amazon/common/run_config.go

@@ -441,6 +441,7 @@ func (c *RunConfig) Prepare(ctx *interpolate.Context) []error {
 		c.SSHInterface != "private_ip" &&
 		c.SSHInterface != "public_dns" &&
 		c.SSHInterface != "private_dns" &&
+		c.SSHInterface != "session_manager" &&
 		c.SSHInterface != "" {
 		errs = append(errs, fmt.Errorf("Unknown interface type: %s", c.SSHInterface))
 	}

builder/amazon/common/ssh.go

@@ -28,6 +28,10 @@ func SSHHost(e ec2Describer, sshInterface string, host string) func(multistep.St
 			return host, nil
 		}
 
+		if sshInterface == "session_manager" {
+			return "127.0.0.1", nil
+		}
+
 		const tries = 2
 		// <= with current structure to check result of describing `tries` times
 		for j := 0; j <= tries; j++ {
@@ -85,3 +89,20 @@ func SSHHost(e ec2Describer, sshInterface string, host string) func(multistep.St
 		return "", errors.New("couldn't determine address for instance")
 	}
 }
+
+// SSHPort returns a function that can be given to the SSH communicator
+// for determining the SSH port to use when connecting to an instance.
+func SSHPort(sshInterface string, port int) func(multistep.StateBag) (int, error) {
+	return func(state multistep.StateBag) (int, error) {
+		if sshInterface != "session_manager" {
+			return port, nil
+		}
+
+		port, ok := state.GetOk("sessionPort")
+		if !ok {
+			return 0, fmt.Errorf("no local port defined for session-manager")
+		}
+		return port.(int), nil
+
+	}
+}

builder/amazon/common/step_create_ssm_tunnel.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"net"
 	"strconv"
 	"time"
 
@@ -12,6 +11,7 @@ import (
 	"github.com/aws/aws-sdk-go/aws/session"
 	"github.com/aws/aws-sdk-go/service/ec2"
 	"github.com/aws/aws-sdk-go/service/ssm"
+	"github.com/hashicorp/packer/common/net"
 	"github.com/hashicorp/packer/common/retry"
 	"github.com/hashicorp/packer/helper/communicator"
 	"github.com/hashicorp/packer/helper/multistep"
@@ -22,37 +22,34 @@ type StepCreateSSMTunnel struct {
 	CommConfig *communicator.Config
 	AWSSession *session.Session
 	InstanceID string
-	DstPort    string
-	SrcPort    string
+	DstPort    int
 
 	ssmSession *ssm.StartSessionOutput
-	tunnel     net.Listener
 }
 
 func (s *StepCreateSSMTunnel) Run(ctx context.Context, state multistep.StateBag) multistep.StepAction {
 	ui := state.Get("ui").(packer.Ui)
-	/*
-		p, _ := strconv.Atoi(s.SrcPort)
-		//TODO dynamically setup local port
 	// Find an available TCP port for our HTTP server
-		l, err := packernet.ListenRangeConfig{
-			Min:     p,
-			Max:     p,
+	l, err := net.ListenRangeConfig{
+		Min:     8000,
+		Max:     9000,
 		Addr:    "0.0.0.0",
 		Network: "tcp",
 	}.Listen(ctx)
-
 	if err != nil {
-			err := fmt.Errorf("Error finding port: %s", err)
+		err := fmt.Errorf("error finding an available port to initiate a session tunnel: %s", err)
 		state.Put("error", err)
 		ui.Error(err.Error())
 		return multistep.ActionHalt
 	}
-	*/
+
+	dst, src := strconv.Itoa(s.DstPort), strconv.Itoa(l.Port)
 	params := map[string][]*string{
-		"portNumber":      []*string{aws.String(s.DstPort)},
-		"localPortNumber": []*string{aws.String(strconv.Itoa(8081))},
+		"portNumber":      []*string{aws.String(dst)},
+		"localPortNumber": []*string{aws.String(src)},
 	}
+	l.Close()
+
 	instance, ok := state.Get("instance").(*ec2.Instance)
 	if !ok {
 		err := fmt.Errorf("error encountered in obtaining target instance id for SSM tunnel")
@@ -62,15 +59,14 @@ func (s *StepCreateSSMTunnel) Run(ctx context.Context, state multistep.StateBag)
 	}
 
 	s.InstanceID = aws.StringValue(instance.InstanceId)
-
 	ssmconn := ssm.New(s.AWSSession)
 	input := ssm.StartSessionInput{
 		DocumentName: aws.String("AWS-StartPortForwardingSession"),
 		Parameters:   params,
 		Target:       aws.String(s.InstanceID),
 	}
+
 	var output *ssm.StartSessionOutput
-	var err error
 	err = retry.Config{
 		Tries:       11,
 		ShouldRetry: func(err error) bool { return isAWSErr(err, "TargetNotConnected", "") },
@@ -81,36 +77,41 @@ func (s *StepCreateSSMTunnel) Run(ctx context.Context, state multistep.StateBag)
 	})
 
 	if err != nil {
-		err = fmt.Errorf("error encountered in starting session: %s", err)
+		err = fmt.Errorf("error encountered in starting session for instance %q: %s", s.InstanceID, err)
 		ui.Error(err.Error())
 		state.Put("error", err)
 		return multistep.ActionHalt
 	}
 	s.ssmSession = output
 
-	sessJson, err := json.Marshal(s.ssmSession)
+	// AWS session-manager-plugin requires a valid session be passed in JSON
+	sessionDetails, err := json.Marshal(s.ssmSession)
 	if err != nil {
 		ui.Error(err.Error())
-		state.Put("error", err)
+		state.Put("error encountered in reading session details", err)
 		return multistep.ActionHalt
 	}
 
-	paramsJson, err := json.Marshal(input)
+	sessionParameters, err := json.Marshal(input)
 	if err != nil {
 		ui.Error(err.Error())
-		state.Put("error", err)
+		state.Put("error encountered in reading session parameter details", err)
 		return multistep.ActionHalt
 	}
 
 	driver := SSMDriver{Ui: ui}
-	// sessJson, region, "StartSession", profile, paramJson, endpoint
-	if err := driver.StartSession(string(sessJson), "us-east-1", "packer", string(paramsJson), ssmconn.Endpoint); err != nil {
-		err = fmt.Errorf("error encountered in creating a connection to the SSM agent: %s", err)
+	// sessionDetails, region, "StartSession", profile, paramJson, endpoint
+	region := aws.StringValue(s.AWSSession.Config.Region)
+	// how to best get Profile name
+	if err := driver.StartSession(string(sessionDetails), region, "default", string(sessionParameters), ssmconn.Endpoint); err != nil {
+		err = fmt.Errorf("error encountered in establishing a tunnel with the session-manager-plugin: %s", err)
 		ui.Error(err.Error())
 		state.Put("error", err)
 		return multistep.ActionHalt
 	}
 
+	state.Put("sessionPort", l.Port)
+
 	return multistep.ActionContinue
 }
 

builder/amazon/common/step_security_group.go

@@ -21,7 +21,7 @@ type StepSecurityGroup struct {
 	SecurityGroupFilter    SecurityGroupFilterOptions
 	SecurityGroupIds       []string
 	TemporarySGSourceCidrs []string
-	SkipSSHGroupCreation   bool
+	SkipSSHRuleCreation    bool
 
 	createdGroupId string
 }
@@ -77,10 +77,7 @@ func (s *StepSecurityGroup) Run(ctx context.Context, state multistep.StateBag) m
 		return multistep.ActionContinue
 	}
 
-	if s.SkipSSHGroupCreation {
-		return multistep.ActionContinue
-	}
-
+	// TODO move to some prevalidation step for
 	port := s.CommConfig.Port()
 	if port == 0 {
 		if s.CommConfig.Type != "none" {
@@ -115,15 +112,15 @@ func (s *StepSecurityGroup) Run(ctx context.Context, state multistep.StateBag) m
 			GroupIds: []*string{aws.String(s.createdGroupId)},
 		},
 	)
-	if err == nil {
-		log.Printf("[DEBUG] Found security group %s", s.createdGroupId)
-	} else {
+	if err != nil {
 		err := fmt.Errorf("Timed out waiting for security group %s: %s", s.createdGroupId, err)
 		log.Printf("[DEBUG] %s", err.Error())
 		state.Put("error", err)
 		return multistep.ActionHalt
 	}
 
+	log.Printf("[DEBUG] Found security group %s", s.createdGroupId)
+
 	// map the list of temporary security group CIDRs bundled with config to
 	// types expected by EC2.
 	groupIpRanges := []*ec2.IpRange{}
@@ -134,6 +131,13 @@ func (s *StepSecurityGroup) Run(ctx context.Context, state multistep.StateBag) m
 		groupIpRanges = append(groupIpRanges, &ipRange)
 	}
 
+	// Set some state data for use in future steps
+	state.Put("securityGroupIds", []string{s.createdGroupId})
+
+	if s.SkipSSHRuleCreation {
+		return multistep.ActionContinue
+	}
+
 	// Authorize the SSH access for the security group
 	groupRules := &ec2.AuthorizeSecurityGroupIngressInput{
 		GroupId: groupResp.GroupId,
@@ -159,9 +163,6 @@ func (s *StepSecurityGroup) Run(ctx context.Context, state multistep.StateBag) m
 		return multistep.ActionHalt
 	}
 
-	// Set some state data for use in future steps
-	state.Put("securityGroupIds", []string{s.createdGroupId})
-
 	return multistep.ActionContinue
 }
 

builder/amazon/ebs/builder.go

@@ -11,7 +11,6 @@ package ebs
 import (
 	"context"
 	"fmt"
-	"strconv"
 
 	"github.com/aws/aws-sdk-go/service/ec2"
 	"github.com/aws/aws-sdk-go/service/iam"
@@ -240,6 +239,7 @@ func (b *Builder) Run(ctx context.Context, ui packer.Ui, hook packer.Hook) (pack
 			SecurityGroupIds:       b.config.SecurityGroupIds,
 			CommConfig:             &b.config.RunConfig.Comm,
 			TemporarySGSourceCidrs: b.config.TemporarySGSourceCidrs,
+			SkipSSHRuleCreation:    b.config.SSHInterface == "session_manager",
 		},
 		&awscommon.StepIamInstanceProfile{
 			IamInstanceProfile:                        b.config.IamInstanceProfile,
@@ -258,8 +258,7 @@ func (b *Builder) Run(ctx context.Context, ui packer.Ui, hook packer.Hook) (pack
 		},
 		&awscommon.StepCreateSSMTunnel{
 			AWSSession: session,
-			DstPort:    strconv.Itoa(22),
-			SrcPort:    "8081",
+			DstPort:    b.config.Comm.SSHPort,
 		},
 		&communicator.StepConnect{
 			Config: &b.config.RunConfig.Comm,
@@ -268,6 +267,10 @@ func (b *Builder) Run(ctx context.Context, ui packer.Ui, hook packer.Hook) (pack
 				b.config.SSHInterface,
 				b.config.Comm.Host(),
 			),
+			SSHPort: awscommon.SSHPort(
+				b.config.SSHInterface,
+				b.config.Comm.Port(),
+			),
 			SSHConfig: b.config.RunConfig.Comm.SSHConfigFunc(),
 		},
 		&common.StepProvision{},