Set Load Balancer internal/external per process instead of per applic…

…ation

Introduces EMPIRE_X_EXPOSURE which needs to be either `internal` or `internet-facing` (kept AWS terminology here).

If that environment variable is not set, we fallback to the default selection via application (where you use `domain-add`).

Fixes remind101#1076

.gitignore

@@ -4,3 +4,5 @@ build
 *.dump
 *.key
 *.cert
+\#*\#
+.\#*

procfile/README.md

@@ -78,3 +78,12 @@ This allows you to set process specific environment variables. If these are set
 environment:
   EMPIRE_X_LOAD_BALANCER_TYPE: "alb"
 ```
+
+We support the following environment variables per process:
+
+Name | Default value | Available options | Description
+---- | ------------- | -----------
+`EMPIRE_X_LOAD_BALANCER_TYPE` | `elb` | `alb`, `elb`| Determines whether you will use an ALB or ELB
+`EMPIRE_X_EXPOSURE` | not set | `public` | Sets whether your ALB or ELB will be a public one, the default is internal.
+`EMPIRE_X_TASK_DEFINITION_TYPE` | not set | `custom` | Determines whether we use the Custom::ECSTaskDefinition (better explanation needed)
+`EMPIRE_X_TASK_ROLE_ARN` | not set | any IAM role ARN | Sets the IAM role for that app/process. **Your ECS cluster MUST have this enabled!**

releases.go

@@ -367,12 +367,12 @@ func newSchedulerProcess(release *Release, name string, p Process) (*twelvefacto
 	)
 	// For `web` processes defined in the standard procfile, we'll
 	// generate a default exposure setting and also set the PORT
-	// environment variable for backwards compatability.
+	// environment variable for backwards compatibility.
 	if name == webProcessType && len(p.Ports) == 0 {
 		exposure = standardWebExposure(release.App)
 		env["PORT"] = "8080"
 	} else {
-		exposure, err = processExposure(release.App, name, p)
+		exposure, err = processExposure(release.App, name, p, env)
 		if err != nil {
 			return nil, err
 		}
@@ -437,7 +437,7 @@ func standardWebExposure(app *App) *twelvefactor.Exposure {
 	}
 }
 
-func processExposure(app *App, name string, process Process) (*twelvefactor.Exposure, error) {
+func processExposure(app *App, name string, process Process, env map[string]string) (*twelvefactor.Exposure, error) {
 	// No ports == not exposed
 	if len(process.Ports) == 0 {
 		return nil, nil
@@ -474,8 +474,16 @@ func processExposure(app *App, name string, process Process) (*twelvefactor.Expo
 			Protocol:  protocol,
 		})
 	}
+
+	external := app.Exposure == exposePublic
+	if v, ok := env["EMPIRE_X_EXPOSURE"]; ok {
+		if v == exposePublic {
+			external = true
+		}
+	}
+
 	return &twelvefactor.Exposure{
-		External: app.Exposure == exposePublic,
+		External: external,
 		Ports:    ports,
 	}, nil
 }