Add aws_profile option to docker-push ecr_login

An aws_profile option is added to the AWS ECR login credentials
configuration to allow using shared AWS credentials stored in
a non-default profile.

Signed-off-by: Aaron Browne <aaron0browne@gmail.com>

builder/docker/ecr_login.go

@@ -19,6 +19,7 @@ type AwsAccessConfig struct {
 	AccessKey string `mapstructure:"aws_access_key"`
 	SecretKey string `mapstructure:"aws_secret_key"`
 	Token     string `mapstructure:"aws_token"`
+	Profile   string `mapstructure:"aws_profile"`
 }
 
 // Config returns a valid aws.Config object for access to AWS services, or
@@ -38,7 +39,10 @@ func (c *AwsAccessConfig) config(region string) (*aws.Config, error) {
 			SessionToken:    c.Token,
 		}},
 		&credentials.EnvProvider{},
-		&credentials.SharedCredentialsProvider{Filename: "", Profile: ""},
+		&credentials.SharedCredentialsProvider{
+			Filename: "",
+			Profile:  c.Profile,
+		},
 		&ec2rolecreds.EC2RoleProvider{
 			Client: ec2metadata.New(session),
 		},

website/source/docs/builders/docker.html.md

@@ -162,6 +162,9 @@ You must specify (only) one of `commit`, `discard`, or `export_path`.
     probably don't need it. This will also be read from the `AWS_SESSION_TOKEN`
     environmental variable.
 
+-   `aws_profile` (string) - The AWS shared credentials profile used to communicate with AWS.
+    [Learn how to set this.](/docs/builders/amazon.html#specifying-amazon-credentials)
+
 -   `changes` (array of strings) - Dockerfile instructions to add to the commit.
     Example of instructions are `CMD`, `ENTRYPOINT`, `ENV`, and `EXPOSE`. Example:
     `[ "USER ubuntu", "WORKDIR /app", "EXPOSE 8080" ]`

website/source/docs/post-processors/docker-push.html.md

@@ -30,6 +30,9 @@ This post-processor has only optional configuration:
     probably don't need it. This will also be read from the `AWS_SESSION_TOKEN`
     environmental variable.
 
+-   `aws_profile` (string) - The AWS shared credentials profile used to communicate with AWS.
+    [Learn how to set this.](/docs/builders/amazon.html#specifying-amazon-credentials)
+
 -   `ecr_login` (boolean) - Defaults to false. If true, the post-processor
     will login in order to push the image to
     [Amazon EC2 Container Registry (ECR)](https://aws.amazon.com/ecr/).