Circlefile

# ABOUT THIS FILE
#
# In conjunction with a properly configured Circle CI build, this file
# will deploy a static build from Circle to a remote host of your
# choosing for every branch that is pushed to Github.
#
# To use it, add the following command to your circle.yml file:
#
# make -ef Circlefile deploy
#
# Note that this file is actually a *Makefile* masquerading as a
# "Circlefile". That's why to run these tasks you'll need to pass the
# '-f' flag and identify this file explicitly.
#
# By default, variables defined within a Makefile override environment
# variable values. This file is designed with the opposite principle in
# mind -- i.e. that the sane defaults are set explicitly here, any of
# which can be overridden via environment variables.
#
# To ensure this behavior, make sure to run this file with the `-e`
# flag.


# REQUIRED ENVIRONMENT VARIABLES
#
# The following environment variables must be defined in order for the
# make tasks in this file to execute properly. Most of these are
# already defined by Circle CI during each build.
#
# CIRCLEFILE_GITHUB_ACCESS_TOKEN
# An access token for this projects repository that has permission
# to get/post to the Github Status API. Set this value in the Circle
# CI admin under Project Settings > Tweaks > Environment Variables
#
# CIRCLE_PROJECT_USERNAME
# The username or organization name of the project being tested, i.e.
# "foo" in circleci.com/gh/foo/bar/123. Available by default in
# Circle CI build.
#
# CIRCLE_PROJECT_REPONAME
# The repository name of the project being tested, i.e. "bar" in
# circleci.com/gh/foo/bar/123. Available by default in Circle CI
# build.
#
# CIRCLE_BRANCH
# The name of the branch being tested, e.g. 'master'. Available by
# default in Circle CI build.
#
# CIRCLE_SHA1
# The SHA1 of the commit being tested. Available by default in
# Circle CI build.


# VARIABLES
#
# Note: Run make with the '-e' flag to ensure environment variables
# take precedence over these definitions.

CIRCLEFILE_BUILD_DIR := build
CIRCLEFILE_PROJECT_SUBFOLDER := $(CIRCLE_PROJECT_REPONAME)

CIRCLEFILE_DEPLOY_HOST := sandbox.instrument.com
CIRCLEFILE_DEPLOY_URL := http://$(CIRCLEFILE_DEPLOY_HOST)/$(CIRCLEFILE_PROJECT_SUBFOLDER)/$(CIRCLE_BRANCH)

CIRCLEFILE_RSYNC_SSH_USER := instrument
CIRCLEFILE_RSYNC_SSH_HOST := $(CIRCLEFILE_RSYNC_SSH_USER)@$(CIRCLEFILE_DEPLOY_HOST)
CIRCLEFILE_RSYNC_ROOT_DIR := /opt/hosted/$(CIRCLEFILE_PROJECT_SUBFOLDER)
CIRCLEFILE_RSYNC_DEST_DIR := $(CIRCLEFILE_RSYNC_ROOT_DIR)/$(CIRCLE_BRANCH)

GITHUB_STATUS_API_URL := https://api.github.com/repos/$(CIRCLE_PROJECT_USERNAME)/$(CIRCLE_PROJECT_REPONAME)/statuses/$(CIRCLE_SHA1)?access_token=$(CIRCLEFILE_GITHUB_ACCESS_TOKEN)
GITHUB_STATUS_DESCRIPTION := A build has been deployed to sandbox. Check it!
GITHUB_STATUS_STATE := success
GITHUB_STATUS_CONTEXT := sandbox/deploy
GITHUB_LIST_BRANCHES_API_URL := https://api.github.com/repos/$(CIRCLE_PROJECT_USERNAME)/$(CIRCLE_PROJECT_REPONAME)/branches?access_token=$(CIRCLEFILE_GITHUB_ACCESS_TOKEN)

TEMPDIR := $(shell mktemp -d /tmp/tmp.XXXXXXXXXX)


# TARGETS

# rsync the build to the appropriate destination on the remote host
rsync:
	@echo 'Rsyncing the build to $(CIRCLEFILE_DEPLOY_HOST)...'
	@# Ensure a destination directory exists
	@ssh $(CIRCLEFILE_RSYNC_SSH_HOST) 'mkdir -p $(CIRCLEFILE_RSYNC_DEST_DIR)'
	@#
	@# Do the rsync
	@rsync --delete -av -e 'ssh' $(CIRCLEFILE_BUILD_DIR)/ $(CIRCLEFILE_RSYNC_SSH_HOST):$(CIRCLEFILE_RSYNC_DEST_DIR)
	@#
	@# Add a .gitbranch file to the root, which we look for later to identify deleted branches that need
	@# to be pruned
	@ssh $(CIRCLEFILE_RSYNC_SSH_HOST) 'echo $(CIRCLE_BRANCH) > $(CIRCLEFILE_RSYNC_DEST_DIR)/.gitbranch'

# POST a message (default success) to Github, which will show on the pull request
update_github_status: $(TEMPDIR)/status.json
	@echo "Updating the status on Github to $(GITHUB_STATUS_STATE)"
	@curl -X POST --data @$< $(GITHUB_STATUS_API_URL)

# Clean all branches from remote that are not in the Github repo (i.e. because they have been deleted).
# This ensure the remote host doesn't fill up with dead branches
clean_remote: $(TEMPDIR)/branches_to_prune.txt
	@echo "Clean all deleted branches from $(CIRCLEFILE_RSYNC_ROOT_DIR) on $(CIRCLEFILE_DEPLOY_HOST)"
	@# Walking through each branch that needs to be pruned, we verify that .gitbranch exists in it
	@# then delete
	@cat $^ | xargs -I{} ssh $(CIRCLEFILE_RSYNC_SSH_HOST) 'test -e $(CIRCLEFILE_RSYNC_ROOT_DIR)/{}/.gitbranch && rm -rf $(CIRCLEFILE_RSYNC_ROOT_DIR)/{}'

# Build the list of branches to prune, by comparing the branches that are on the remote host with the
# branches that still exist on Github
$(TEMPDIR)/branches_to_prune.txt: $(TEMPDIR)/branches_in_git.txt $(TEMPDIR)/branches_on_host.txt
	@comm -13 $^ > $@

# Build the list of branches on the remote host
$(TEMPDIR)/branches_on_host.txt:
	@# Recursively search from the project root. Folders with .gitbranch in them indicate a branch
	@ssh $(CIRCLEFILE_RSYNC_SSH_HOST) 'cd $(CIRCLEFILE_RSYNC_ROOT_DIR) && find . -name '.gitbranch' -type f | cut -c 3-' | sed "s/\/\.gitbranch$$//" | sort > $@

# Parse the JSON file of git branches into a single column, sorted file
$(TEMPDIR)/branches_in_git.txt: $(TEMPDIR)/branches.json
	@cat $< | python -c 'import sys, json; [sys.stdout.write(b["name"]+"\n") for b in json.load(sys.stdin)]' | sort > $@

# Build a JSON file of all branches in the Github repo (via the Github API)
$(TEMPDIR)/branches.json:
	@curl -s $(GITHUB_LIST_BRANCHES_API_URL) > $@

# Build the JSON file that gets POSTed to the Github Status API update
$(TEMPDIR)/status.json:
	@echo '{' >> $@
	@echo '  "state": "$(GITHUB_STATUS_STATE)", ' >> $@
	@echo '  "target_url": "$(CIRCLEFILE_DEPLOY_URL)", ' >> $@
	@echo '  "description": "$(GITHUB_STATUS_DESCRIPTION)", ' >> $@
	@echo '  "context": "$(GITHUB_STATUS_CONTEXT)" ' >> $@
	@echo '}' >> $@

# Rsync the files, update the github status, then run clean up on remote
deploy: rsync update_github_status clean_remote


# SPECIAL TARGETS

# Ensures these targets will execute even if there happens to be a file
# of the same name as the target in the directory
.PHONY : rsync update_github_status

# Targets here are explicitly treated as intermediary, meaning they are deleted (rm)
# automatically when the make task is complete
.INTERMEDIATE: $(TEMPDIR)/status.json $(TEMPDIR)/branches.json $(TEMPDIR)/branches_in_git.txt $(TEMPDIR)/branches_on_host.txt $(TEMPDIR)/branches_to_prune.txt