# Docker Bake definition.
#
# One place that knows how to build every target variant, so that `docker buildx
# bake`, the GitHub Actions workflow and a developer's terminal all produce the same
# image from the same inputs.
#
#   docker buildx bake                 # build the default tag
#   docker buildx bake --push          # build and push
#   docker buildx bake --print         # show what would run
#   docker buildx bake --set *.platform=linux/arm64

variable "VERSION" {
  default = "dev"
}

variable "COMMIT" {
  default = "unknown"
}

variable "BUILD_DATE" {
  default = "unknown"
}

variable "REGISTRY" {
  default = "ghcr.io/urpi"
}

variable "IMAGE" {
  default = "${REGISTRY}/go-bananas"
}

variable "TAGS" {
  default = "${IMAGE}:${VERSION}"
}

# `platforms` is a list rather than a single value so that one invocation produces
# a manifest list covering both architectures.
group "default" {
  targets = ["image"]
}

target "_common" {
  context    = "."
  dockerfile = "Dockerfile"
  args = {
    VERSION    = VERSION
    COMMIT     = COMMIT
    BUILD_DATE = BUILD_DATE
  }
  labels = {
    "org.opencontainers.image.title"       = "go-bananas"
    "org.opencontainers.image.description" = "Runtime design-token service"
    "org.opencontainers.image.version"     = VERSION
    "org.opencontainers.image.revision"    = COMMIT
    "org.opencontainers.image.created"     = BUILD_DATE
    "org.opencontainers.image.source"      = "https://github.com/urpi/go-bananas"
  }
}

target "image" {
  inherits = ["_common"]
  tags     = ["${IMAGE}:${VERSION}", "${IMAGE}:latest"]
  platforms = ["linux/amd64", "linux/arm64"]
  output   = ["type=image"]
}

target "image-push" {
  inherits = ["_common"]
  tags     = split("\n", TAGS)
  platforms = ["linux/amd64", "linux/arm64"]
  output   = ["type=image,push=true"]
}

# A local single-architecture image for `docker compose up` and for a quick look
# on a laptop, where a manifest list only adds a layer of indirection.
target "dev" {
  inherits = ["_common"]
  tags     = ["go-bananas:dev"]
  platforms = ["linux/amd64"]
  output   = ["type=docker"]
  cache-to = ["type=gha,mode=max"]
}

# The cache-only target, for warming a CI runner before the real build.
target "cache" {
  inherits = ["_common"]
  platforms = ["linux/amd64"]
  cache-to = ["type=gha,mode=max"]
  cache-from = ["type=gha"]
}