Add credentials profile command line option

Fixes #18

Author: clareliguori

README.md

@@ -33,6 +33,7 @@ USAGE:
 GLOBAL OPTIONS:
    --image value, -i value                 Name of the source container image. For example, 'my-docker-image:latest'. The Docker image must be pulled locally already.
    --region value, -r value                AWS region (default: "us-east-1")
+   --profile value, -p value               AWS credentials profile. Credentials will default to the same chain as the AWS CLI: environment variables, default profile, container credentials, EC2 instance credentials
    --output-directory value, -o value      Destination directory for command output (default: "./output")
    --layer-namespace value, -n value       Prefix for the layers published to Lambda (default: "img2lambda")
    --dry-run, -d                           Conduct a dry-run: Repackage the image, but only write the Lambda layers to local disk (do not publish to Lambda)

img2lambda/cli/main.go

@@ -42,6 +42,11 @@ func createApp() (*cli.App, *types.CmdOptions) {
 			Value:       "us-east-1",
 			Destination: &opts.Region,
 		},
+		cli.StringFlag{
+			Name:        "profile, p",
+			Usage:       "AWS credentials profile. Credentials will default to the same chain as the AWS CLI: environment variables, default profile, container credentials, EC2 instance credentials",
+			Destination: &opts.Profile,
+		},
 		cli.StringFlag{
 			Name:        "output-directory, o",
 			Usage:       "Destination directory for command output",

img2lambda/clients/clients.go

@@ -15,9 +15,10 @@ var userAgentHandler = request.NamedHandler{
 	Fn:   request.MakeAddToUserAgentHandler("aws-lambda-container-image-converter", version.Version),
 }
 
-func NewLambdaClient(region string) *lambda.Lambda {
-	sess := session.Must(session.NewSession())
-
+func NewLambdaClient(region string, profile string) *lambda.Lambda {
+	sess := session.Must(session.NewSessionWithOptions(session.Options{
+		Profile: profile,
+	}))
 	sess.Handlers.Build.PushBackNamed(userAgentHandler)
 
 	client := lambda.New(sess, &aws.Config{Region: aws.String(region)})

img2lambda/types/types.go

@@ -15,6 +15,7 @@ type LambdaLayer struct {
 type CmdOptions struct {
 	Image              string   // Name of the container image
 	Region             string   // AWS region
+	Profile            string   // AWS credentials profile
 	OutputDir          string   // Output directory for the Lambda layers
 	DryRun             bool     // Dry-run (will not register with Lambda)
 	LayerNamespace     string   // Prefix for published Lambda layers
@@ -36,7 +37,7 @@ type PublishOptions struct {
 func ConvertToPublishOptions(opts *CmdOptions) *PublishOptions {
 	return &PublishOptions{
 		SourceImageName:    opts.Image,
-		LambdaClient:       clients.NewLambdaClient(opts.Region),
+		LambdaClient:       clients.NewLambdaClient(opts.Region, opts.Profile),
 		LayerPrefix:        opts.LayerNamespace,
 		ResultsDir:         opts.OutputDir,
 		Description:        opts.Description,