fix stack delete behavior to not attempt to delete configured lambda roles. (Closes #787) (#788)

* Corrections to CONTRIBUTING.md

Running `make test` fails unless the `-modtime` option to `go-bindata` is available.
The jteeuwen fork lacks such an option.
My assumption is that at some point this project migrated from the jteeuwen fork to the shuLhan fork and failed to update the contributing docs.

Also, a minor typo correction.

* Don't attempt to delete a configured lambda role (fixes #787)

This makes the behavior of delete stack match create stack (if there's a role configured, skip doing anything regarding the role).

Author: davidmc24

CONTRIBUTING.md

@@ -7,7 +7,7 @@ Before contributing to Up you'll need a few things:
 The following are optional:
 
 - Install [pointlander/peg](https://github.com/pointlander/peg) if you're working on the log grammar
-- Install [jteeuwen/go-bindata](https://github.com/jteeuwen/go-bindata) if you need to bake `up-proxy` into `up`
+- Install [shuLhan/go-bindata](https://github.com/shuLhan/go-bindata) if you need to bake `up-proxy` into `up`
 
 ## Setup
 
@@ -43,7 +43,7 @@ Although Up is not provided as a library it is structured as if it was, for orga
 - [config](config) – Configuration structures and validation for `up.json`
 - [cmd](cmd) – Commands, where `up` is the CLI and `up-proxy` is serving requests in production
 
-Note that this is just a first past, and the code / layout will be refactored. View [Godoc](http://godoc.org/github.com/apex/up) for more details of the internals.
+Note that this is just a first pass, and the code / layout will be refactored. View [Godoc](http://godoc.org/github.com/apex/up) for more details of the internals.
 
 ## Proxy
 

platform/lambda/lambda.go

@@ -814,6 +814,12 @@ func (p *Platform) roleName() string {
 func (p *Platform) deleteRole(region string) error {
 	name := fmt.Sprintf("%s-function", p.config.Name)
 	c := iam.New(session.New(aws.NewConfig().WithRegion(region)))
+	
+	// role is provided
+	if s := p.config.Lambda.Role; s != "" {
+		log.Debugf("using role from config %s; not deleting", s)
+		return nil
+	}
 
 	_, err := c.DeleteRolePolicy(&iam.DeleteRolePolicyInput{
 		RoleName:   &name,

platform/lambda/lambda_test.go

@@ -6,6 +6,9 @@ import (
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/service/acm"
 	"github.com/tj/assert"
+	
+	"github.com/apex/up/config"
+	"github.com/apex/up/platform/event"
 )
 
 func TestGetCert(t *testing.T) {
@@ -55,3 +58,29 @@ func TestGetCert(t *testing.T) {
 	arn = getCert(certs, "staging.v1.api.example.com")
 	assert.Empty(t, arn)
 }
+
+func TestCreateRole(t *testing.T) {
+	t.Run("doesn't attempt to create configured role", func(t *testing.T) {
+		c := &config.Config{
+			Lambda: config.Lambda{
+				Role: "custom-role-name",
+			},
+		}
+		events := make(event.Events)
+		p := New(c, events)
+		assert.NoError(t, p.createRole(), "createRole")
+	})
+}
+
+func TestDeleteRole(t *testing.T) {
+	t.Run("doesn't attempt to delete configured role", func(t *testing.T) {
+		c := &config.Config{
+			Lambda: config.Lambda{
+				Role: "custom-role-name",
+			},
+		}
+		events := make(event.Events)
+		p := New(c, events)
+		assert.NoError(t, p.deleteRole("us-west-2"), "deleteRole")
+	})
+}