vendor: add buildkit

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

vendor/github.com/containerd/continuity/Makefile

@@ -0,0 +1,82 @@
+#   Copyright The containerd Authors.
+
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+
+#       http://www.apache.org/licenses/LICENSE-2.0
+
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+
+# Set an output prefix, which is the local directory if not specified
+PREFIX?=$(shell pwd)
+
+# Used to populate version variable in main package.
+VERSION=$(shell git describe --match 'v[0-9]*' --dirty='.m' --always)
+
+GO_LDFLAGS=-ldflags "-X `go list ./version`.Version=$(VERSION)"
+
+PACKAGES=$(shell go list ./... | grep -v /vendor/)
+
+.PHONY: clean all fmt vet lint build test binaries setup
+.DEFAULT: default
+# skip lint at the moment
+all: AUTHORS clean fmt vet fmt build test binaries
+
+AUTHORS: .mailmap .git/HEAD
+	 git log --format='%aN <%aE>' | sort -fu > $@
+
+# This only needs to be generated by hand when cutting full releases.
+version/version.go:
+	./version/version.sh > $@
+
+${PREFIX}/bin/continuity: version/version.go $(shell find . -type f -name '*.go')
+	@echo "+ $@"
+	@go build  -o $@ ${GO_LDFLAGS}  ${GO_GCFLAGS} ./cmd/continuity
+
+setup:
+	@echo "+ $@"
+	@go get -u github.com/golang/lint/golint
+
+generate:
+	go generate $(PACKAGES)
+
+# Depends on binaries because vet will silently fail if it can't load compiled
+# imports
+vet: binaries
+	@echo "+ $@"
+	@go vet $(PACKAGES)
+
+fmt:
+	@echo "+ $@"
+	@test -z "$$(gofmt -s -l . | grep -v Godeps/_workspace/src/ | grep -v vendor/ | tee /dev/stderr)" || \
+		echo "+ please format Go code with 'gofmt -s'"
+
+lint:
+	@echo "+ $@"
+	@test -z "$$(golint $(PACKAGES) | grep -v Godeps/_workspace/src/ | grep -v vendor/ |tee /dev/stderr)"
+
+build:
+	@echo "+ $@"
+	@go build -v ${GO_LDFLAGS} $(PACKAGES)
+
+test:
+	@echo "+ $@"
+	@go test $(PACKAGES)
+
+test-compile:
+	@echo "+ $@"
+	@for pkg in $(PACKAGES); do go test -c $$pkg; done
+
+binaries: ${PREFIX}/bin/continuity
+	@echo "+ $@"
+	@if [ x$$GOOS = xwindows ]; then echo "+ continuity -> continuity.exe"; mv ${PREFIX}/bin/continuity ${PREFIX}/bin/continuity.exe; fi
+
+clean:
+	@echo "+ $@"
+	@rm -rf "${PREFIX}/bin/continuity" "${PREFIX}/bin/continuity.exe"
+