resource,iac: return errors when collecting ops

We want to be able to bubble up errors when collecting ops as opposed to
panicing in the middle

cmd/iac.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"sync"
 
+	"github.com/samsarahq/go/oops"
 	"github.com/santiago-labs/telophasecli/cmd/runner"
 	"github.com/santiago-labs/telophasecli/resource"
 	"github.com/santiago-labs/telophasecli/resourceoperation"
@@ -27,7 +28,10 @@ func runIAC(
 				return
 			}
 
-			ops := resourceoperation.CollectAccountOps(ctx, consoleUI, cmd, &acct, stacks)
+			ops, err := resourceoperation.CollectAccountOps(ctx, consoleUI, cmd, &acct, stacks)
+			if err != nil {
+				panic(oops.Wrapf(err, "error collecting account ops for acct: %s", acct.AccountID))
+			}
 
 			if len(ops) == 0 {
 				consoleUI.Print("No stacks to deploy\n", acct)

resource/account.go

@@ -67,7 +67,7 @@ func (a Account) AllTags() []string {
 	return tags
 }
 
-func (a Account) AllBaselineStacks() []Stack {
+func (a Account) AllBaselineStacks() ([]Stack, error) {
 	var stacks []Stack
 	if a.Parent != nil {
 		stacks = append(stacks, a.Parent.AllBaselineStacks()...)
@@ -81,32 +81,36 @@ func (a Account) AllBaselineStacks() []Stack {
 	var returnStacks []Stack
 	for i := range stacks {
 		if stacks[i].Region == "all" {
-			returnStacks = append(returnStacks, a.GenerateStacks(stacks[i])...)
+			generatedStacks, err := a.GenerateStacks(stacks[i])
+			if err != nil {
+				return nil, err
+			}
+			returnStacks = append(returnStacks, generatedStacks...)
 			continue
 		}
 		returnStacks = append(returnStacks, stacks[i])
 	}
 
-	return returnStacks
+	return returnStacks, nil
 }
 
-func (a Account) GenerateStacks(stack Stack) []Stack {
+func (a Account) GenerateStacks(stack Stack) ([]Stack, error) {
 	// We only generate multiple stacks if the region is "all"
 	if stack.Region != "all" {
-		return []Stack{stack}
+		return []Stack{stack}, nil
 	}
 
 	sess, err := awssess.DefaultSession()
 	if err != nil {
-		panic(fmt.Sprintf("error starting sess: %s", err))
+		return nil, oops.Wrapf(err, "error starting sess")
 	}
 	acctClient := account.New(sess)
 	output, err := acctClient.ListRegions(&account.ListRegionsInput{
 		AccountId:  &a.AccountID,
 		MaxResults: aws.Int64(50),
 	})
 	if err != nil {
-		panic(oops.Wrapf(err, "listing regions for account: (%s)", a.AccountID))
+		return nil, oops.Wrapf(err, "listing regions for account: (%s)", a.AccountID)
 	}
 
 	var stacks []Stack
@@ -121,13 +125,18 @@ func (a Account) GenerateStacks(stack Stack) []Stack {
 		}
 	}
 
-	return stacks
+	return stacks, nil
 }
 
-func (a Account) FilterBaselineStacks(stackNames string) []Stack {
+func (a Account) FilterBaselineStacks(stackNames string) ([]Stack, error) {
 	var matchingStacks []Stack
 	targetStackNames := strings.Split(stackNames, ",")
-	for _, stack := range a.AllBaselineStacks() {
+	baselineStacks, err := a.AllBaselineStacks()
+	if err != nil {
+		return nil, err
+	}
+
+	for _, stack := range baselineStacks {
 		acctStackNames := strings.Split(stack.Name, ",")
 		var matchingStackNames []string
 		for _, name := range acctStackNames {
@@ -146,7 +155,7 @@ func (a Account) FilterBaselineStacks(stackNames string) []Stack {
 			})
 		}
 	}
-	return matchingStacks
+	return matchingStacks, nil
 }
 
 func (a Account) FilterServiceControlPolicies(stackNames string) []Stack {

resourceoperation/account.go

@@ -50,13 +50,21 @@ func CollectAccountOps(
 	operation int,
 	acct *resource.Account,
 	stackFilter string,
-) []ResourceOperation {
+) ([]ResourceOperation, error) {
 
 	var acctStacks []resource.Stack
 	if stackFilter != "" && stackFilter != "*" {
-		acctStacks = append(acctStacks, acct.FilterBaselineStacks(stackFilter)...)
+		baselineStacks, err := acct.FilterBaselineStacks(stackFilter)
+		if err != nil {
+			return nil, err
+		}
+		acctStacks = append(acctStacks, baselineStacks...)
 	} else {
-		acctStacks = append(acctStacks, acct.AllBaselineStacks()...)
+		baselineStacks, err := acct.AllBaselineStacks()
+		if err != nil {
+			return nil, err
+		}
+		acctStacks = append(acctStacks, baselineStacks...)
 	}
 
 	var ops []ResourceOperation
@@ -68,7 +76,7 @@ func CollectAccountOps(
 		}
 	}
 
-	return ops
+	return ops, nil
 }
 
 func (ao *accountOperation) AddDependent(op ResourceOperation) {