Docker multi arch build and push

README.md

Conditional Docker Build and Push with terraform

How to use

Save your dockerfile in a folder called images, this terraform code will build and push a multi-archtecture image to ECR. Whenever you update the Dockerfile and associated image tag, the null resource will be triggered to "re-create" subsequently updating the image in ECR.

But I've made a change and want to keep the same tag

Then simply run terraform apply -replace=null_resource.build_and_push ,- don't forget to use the full resource address if this code is inside a module. E.g module.name.null_resource.build_and_push.

ecr.tf

data "aws_ecr_authorization_token" "token" {

}

resource "aws_ecr_repository" "this" {

  name                 = "image"
  image_tag_mutability = "MUTABLE"

}

locals {
  image_tag = "go-1.21.5" # Changing this tag will force a build and push on the next deploy
}

resource "terraform_data" "this" {
  input = local.image_tag
}

resource "null_resource" "build_and_push" {
  provisioner "local-exec" {
    command = <<EOF
      docker login ${data.aws_ecr_authorization_token.token.proxy_endpoint} -u AWS -p ${nonsensitive(data.aws_ecr_authorization_token.token.password)}
      cd images
      docker buildx create --name image
      docker buildx build --builder image \
        --platform linux/amd64,linux/arm64 \
        --tag ${aws_ecr_repository.ukssbuilder.repository_url}:${local.image_tag} \
        --push  \
        --file Dockerfile .
      EOF
  }

  lifecycle {
    replace_triggered_by = [terraform_data.image_tag]
  }

}