Tiltfile

# -*- mode: Python -*-

# For more on Extensions, see: https://docs.tilt.dev/extensions.html
load('ext://restart_process', 'custom_build_with_restart')

load('./bazel.Tiltfile', 'bazel_sourcefile_deps')

# Records the current time, then kicks off a server update.
# Normally, you would let Tilt do deploys automatically, but this
# shows you how to set up a custom workflow that measures it.
local_resource(
    'deploy',
    'python record-start-time.py',
)

# Use Bazel to generate the Kubernetes YAML
for f in bazel_sourcefile_deps('//deployments:example-go'):
  watch_file(f)
k8s_yaml(local('bazel run //deployments:example-go'))

# Use Bazel to build the image

# The go_image BUILD rule
image_target='//:example-go-image'
binary_target='//:example-go'

# Where go_binary puts the binary. We query Bazel's action graph and parse the response.
# The path is not necessarily predictable across bazel rulesets, or even across releases
# of the same ruleset. Even configuration flags passed to Bazel can affect the path.
# See https://github.com/bazelbuild/rules_go/blob/dea7cd1/README.rst#how-do-i-access-go_binary-executables-from-go_test
action_graph = decode_json(local([
  'bazel',
  'aquery',
  '--output',
  'jsonproto',
  # Needed for compat with Bazel 3 and 4, see https://github.com/bazelbuild/bazel/issues/10358
  '--noincompatible_proto_output_v2',
  binary_target,
], quiet=True))

# If the image_target is a go_binary, it will have a GoLink action
go_link_actions = [action for action in action_graph['actions'] if action['mnemonic'] == 'GoLink']
# In our example this isn't used, but if your image were a nodejs_image you'd need the whole Bazel "runfiles"
# which is constructed as a symlink tree
symlink_tree_actions = [action for action in action_graph['actions'] if action['mnemonic'] == 'SymlinkTree']

if len(go_link_actions) == 1:
  outputIDs = [outputID for action in go_link_actions for outputID in action['outputIds']]
  binary_target_local = [a['execPath'] for a in action_graph['artifacts'] if a['id'] in outputIDs][0]

  # Where go_image puts the Go binary in the container. You can determine this
  # by shelling into the container with `kubectl exec -it [pod name] -- sh`
  container_workdir = '/app/example-go-image.binary.runfiles/__main__/'
  binary_target_container = container_workdir + 'example-go-image.binary_/example-go-image.binary'

elif len(symlink_tree_actions) > 0:
  outputIDs = [outputID for action in symlink_tree_actions for outputID in action['outputIds']]
  outputFiles = [a['execPath'] for a in action_graph['artifacts'] if a['id'] in outputIDs]
  # translate from the MANIFEST file path to the first-party monorepo outputs
  # the tilt-example-bazel here is the name in our WORKSPACE
  #   bazel-out/k8-fastbuild/bin/path/to.runfiles/MANIFEST
  # -> 
  #   bazel-out/k8-fastbuild/bin/path/to.runfiles/tilt-example-bazel
  binary_target_local = outputFiles[0][:-len('/MANIFEST')] + '/tilt-example-bazel'
  binary_target_container = '/'

# Where go_image puts the image in Docker (bazel/path/to/target:name)
bazel_image='bazel:example-go-image'

local_resource(
  name='example-go-compile',
  cmd='bazel build --platforms=@io_bazel_rules_go//go/toolchain:linux_amd64 {binary_target}'.format(binary_target=binary_target),
  deps=bazel_sourcefile_deps(binary_target))

custom_build_with_restart(
  ref='example-go-image',
  command=(
    'bazel run --platforms=@io_bazel_rules_go//go/toolchain:linux_amd64 {image_target} -- --norun && ' +
    'docker tag {bazel_image} $EXPECTED_REF').format(image_target=image_target, bazel_image=bazel_image),
  deps=['web', binary_target_local],
  entrypoint=binary_target_container,
  live_update=[
    sync('web', container_workdir + 'web'),
    sync(binary_target_local, binary_target_container)
  ],
)

k8s_resource('example-go', port_forwards=8000, resource_deps=['deploy', 'example-go-compile'])