Add support for --profile for selecting IAM credentials (#131)

env.go

@@ -36,9 +36,9 @@ import (
  This priority also applies to AWS_* system variables
 */
 
-func getEnvironmentVariables(logicalID string, function *cloudformation.AWSServerlessFunction, overrideFile string) map[string]string {
+func getEnvironmentVariables(logicalID string, function *cloudformation.AWSServerlessFunction, overrideFile string, profile string) map[string]string {
 
-	env := getEnvDefaults(function)
+	env := getEnvDefaults(function, profile)
 	osenv := getEnvFromOS()
 	overrides := getEnvOverrides(logicalID, overrideFile)
 
@@ -69,9 +69,9 @@ func getEnvironmentVariables(logicalID string, function *cloudformation.AWSServe
 
 }
 
-func getEnvDefaults(function *cloudformation.AWSServerlessFunction) map[string]string {
+func getEnvDefaults(function *cloudformation.AWSServerlessFunction, profile string) map[string]string {
 
-	creds := getSessionOrDefaultCreds()
+	creds := getSessionOrDefaultCreds(profile)
 
 	// Variables available in Lambda execution environment for all functions (AWS_* variables)
 	env := map[string]string{
@@ -123,7 +123,7 @@ func getEnvOverrides(logicalID string, filename string) map[string]string {
 
 }
 
-func getSessionOrDefaultCreds() map[string]string {
+func getSessionOrDefaultCreds(profile string) map[string]string {
 
 	region := "us-east-1"
 	key := "defaultkey"
@@ -135,8 +135,10 @@ func getSessionOrDefaultCreds() map[string]string {
 		"secret": secret,
 	}
 
+	opts := session.Options{}
+	opts.Profile = profile
 	// Obtain AWS credentials and pass them through to the container runtime via env variables
-	if sess, err := session.NewSession(); err == nil {
+	if sess, err := session.NewSessionWithOptions(opts); err == nil {
 		if creds, err := sess.Config.Credentials.Get(); err == nil {
 			if *sess.Config.Region != "" {
 				result["region"] = *sess.Config.Region

env_test.go

@@ -23,7 +23,7 @@ var _ = Describe("Environment Variables", func() {
 		It("return defaults with those defined in the template", func() {
 
 			for name, function := range functions {
-				variables := getEnvironmentVariables(name, &function, "")
+				variables := getEnvironmentVariables(name, &function, "", "")
 				Expect(variables).To(HaveLen(9))
 				Expect(variables).To(HaveKey("AWS_SAM_LOCAL"))
 				Expect(variables).To(HaveKey("AWS_REGION"))
@@ -46,7 +46,7 @@ var _ = Describe("Environment Variables", func() {
 				os.Setenv("AWS_SECRET_ACCESS_KEY", "secret")
 				os.Unsetenv("AWS_SESSION_TOKEN")
 
-				variables := getEnvironmentVariables(name, &function, "")
+				variables := getEnvironmentVariables(name, &function, "", "")
 				Expect(variables).To(HaveLen(9))
 				Expect(variables).To(HaveKey("AWS_SAM_LOCAL"))
 				Expect(variables).To(HaveKey("AWS_REGION"))
@@ -72,7 +72,7 @@ var _ = Describe("Environment Variables", func() {
 				os.Setenv("AWS_SECRET_ACCESS_KEY", "secret")
 				os.Setenv("AWS_SESSION_TOKEN", "token")
 
-				variables := getEnvironmentVariables(name, &function, "")
+				variables := getEnvironmentVariables(name, &function, "", "")
 				Expect(variables).To(HaveLen(10))
 				Expect(variables).To(HaveKey("AWS_SAM_LOCAL"))
 				Expect(variables).To(HaveKey("AWS_REGION"))
@@ -96,19 +96,19 @@ var _ = Describe("Environment Variables", func() {
 
 		It("overides template with environment variables", func() {
 			for name, function := range functions {
-				variables := getEnvironmentVariables(name, &function, "")
+				variables := getEnvironmentVariables(name, &function, "", "")
 				Expect(variables["TABLE_NAME"]).To(Equal(""))
 
 				os.Setenv("TABLE_NAME", "ENV_TABLE")
-				variables = getEnvironmentVariables(name, &function, "")
+				variables = getEnvironmentVariables(name, &function, "", "")
 				Expect(variables["TABLE_NAME"]).To(Equal("ENV_TABLE"))
 				os.Unsetenv("TABLE_NAME")
 			}
 		})
 
 		It("overrides template and environment with customer overrides", func() {
 			for name, function := range functions {
-				variables := getEnvironmentVariables(name, &function, "test/environment-overrides.json")
+				variables := getEnvironmentVariables(name, &function, "test/environment-overrides.json", "")
 				Expect(variables["TABLE_NAME"]).To(Equal("OVERRIDE_TABLE"))
 			}
 			os.Unsetenv("TABLE_NAME")

invoke.go

@@ -121,7 +121,7 @@ func invoke(c *cli.Context) {
 		event = string(pb)
 	}
 
-	stdoutTxt, stderrTxt, err := runt.Invoke(event)
+	stdoutTxt, stderrTxt, err := runt.Invoke(event, c.String("profile"))
 	if err != nil {
 		log.Fatalf("Could not invoke function: %s\n", err)
 	}

main.go

@@ -115,6 +115,10 @@ func main() {
 							Usage:  "Optional. Specify whether SAM should skip pulling down the latest Docker image. Default is false.",
 							EnvVar: "SAM_SKIP_PULL_IMAGE",
 						},
+						cli.StringFlag{
+							Name: "profile",
+							Usage: "Optional. Specify which AWS credentials profile to use.",
+						},
 					},
 				},
 				cli.Command{
@@ -171,6 +175,10 @@ func main() {
 							Usage:  "Optional. Specify whether SAM should skip pulling down the latest Docker image. Default is false.",
 							EnvVar: "SAM_SKIP_PULL_IMAGE",
 						},
+						cli.StringFlag{
+							Name: "profile",
+							Usage: "Optional. Specify which AWS credentials profile to use.",
+						},
 					},
 				},
 				cli.Command{

runtime.go

@@ -40,8 +40,8 @@ import (
 
 // Invoker is a simple interface to help with testing runtimes
 type Invoker interface {
-	Invoke(string) (io.Reader, io.Reader, error)
-	InvokeHTTP() func(http.ResponseWriter, *http.Request)
+	Invoke(string, string) (io.Reader, io.Reader, error)
+	InvokeHTTP(string) func(http.ResponseWriter, *http.Request)
 	CleanUp()
 }
 
@@ -253,7 +253,7 @@ func (r *Runtime) getHostConfig() (*container.HostConfig, error) {
 // Invoke runs a Lambda function within the runtime with the provided event
 // payload and returns a pair of io.Readers for it's stdout (callback results)
 // and stderr (runtime logs).
-func (r *Runtime) Invoke(event string) (io.Reader, io.Reader, error) {
+func (r *Runtime) Invoke(event string, profile string) (io.Reader, io.Reader, error) {
 
 	log.Printf("Invoking %s (%s)\n", r.Function.Handler, r.Name)
 
@@ -293,7 +293,7 @@ func (r *Runtime) Invoke(event string) (io.Reader, io.Reader, error) {
 		Cmd:          []string{r.Function.Handler, event},
 		Env: func() []string {
 			result := []string{}
-			for k, v := range getEnvironmentVariables(r.LogicalID, &r.Function, r.EnvOverrideFile) {
+			for k, v := range getEnvironmentVariables(r.LogicalID, &r.Function, r.EnvOverrideFile, profile) {
 				result = append(result, k+"="+v)
 			}
 			return result
@@ -477,7 +477,7 @@ func (r *Runtime) CleanUp() {
 
 // InvokeHTTP invokes a Lambda function, and implements the Go http.HandlerFunc interface
 // so it can be connected straight into most HTTP packages/frameworks etc.
-func (r *Runtime) InvokeHTTP() func(http.ResponseWriter, *http.Request) {
+func (r *Runtime) InvokeHTTP(profile string) func(http.ResponseWriter, *http.Request) {
 
 	return func(w http.ResponseWriter, req *http.Request) {
 		var wg sync.WaitGroup
@@ -501,7 +501,7 @@ func (r *Runtime) InvokeHTTP() func(http.ResponseWriter, *http.Request) {
 			return
 		}
 
-		stdoutTxt, stderrTxt, err := r.Invoke(eventJSON)
+		stdoutTxt, stderrTxt, err := r.Invoke(eventJSON, profile)
 		if err != nil {
 			msg := fmt.Sprintf("Error invoking %s runtime: %s", r.Function.Runtime, err)
 			log.Println(msg)

start.go

@@ -91,7 +91,7 @@ func start(c *cli.Context) {
 		}
 
 		// Add this AWS::Serverless::Function to the HTTP router
-		if err := mux.AddFunction(&function, runt.InvokeHTTP()); err != nil {
+		if err := mux.AddFunction(&function, runt.InvokeHTTP(c.String("profile"))); err != nil {
 			if err == router.ErrNoEventsFound {
 				log.Printf("Ignoring %s (%s) as no API event sources are defined", name, function.Handler)
 			}