Update Makefile to support compile journald support

.gitignore

@@ -1 +1,2 @@
 /bin/node-problem-detector
+/Dockerfile

Dockerfile.in

@@ -12,8 +12,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-FROM alpine:3.4
+FROM @BASEIMAGE@
 MAINTAINER Random Liu <lantaol@google.com>
+
+# Avoid symlink of /etc/localtime.
+RUN test -h /etc/localtime && rm -f /etc/localtime && cp /usr/share/zoneinfo/UTC /etc/localtime || true
+
 ADD ./bin/node-problem-detector /node-problem-detector
 ADD config /config
 ENTRYPOINT ["/node-problem-detector", "--kernel-monitor=/config/kernel-monitor.json"]

Makefile

@@ -1,24 +1,73 @@
-.PHONY: all build-container build-tar build push-container push-tar push clean vet fmt version
+# Copyright 2017 The Kubernetes 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.
+
+# Build the node-problem-detector image.
+
+.PHONY: all build-container build-tar build push-container push-tar push clean vet fmt version Dockerfile
 
 all: build
 
-VERSION := $(shell git describe --tags --dirty)
+# VERSION is the version of the binary.
+VERSION:=$(shell git describe --tags --dirty)
 
-TAG ?= $(VERSION)
+# TAG is the tag of the container image, default to binary version.
+TAG?=$(VERSION)
 
-UPLOAD_PATH ?= gs://kubernetes-release
+# PROJ is the image project.
+PROJ?=gcr.io/google_containers
+
+# UPLOAD_PATH is the cloud storage path to upload release tar.
+UPLOAD_PATH?=gs://kubernetes-release
 # Trim the trailing '/' in the path
-UPLOAD_PATH := $(shell echo $(UPLOAD_PATH) | sed '$$s/\/*$$//')
+UPLOAD_PATH:=$(shell echo $(UPLOAD_PATH) | sed '$$s/\/*$$//')
 
-PROJ ?= google_containers
+# PKG is the package name of node problem detector repo.
+PKG:=k8s.io/node-problem-detector
 
-PKG := k8s.io/node-problem-detector
+# PKG_SOURCES are all the go source code.
+PKG_SOURCES:=$(shell find pkg cmd -name '*.go')
 
-PKG_SOURCES := $(shell find pkg cmd -name '*.go')
+# TARBALL is the name of release tar. Include binary version by default.
+TARBALL:=node-problem-detector-$(VERSION).tar.gz
 
-TARBALL := node-problem-detector-$(VERSION).tar.gz
+# IMAGE is the image name of the node problem detector container image.
+IMAGE:=$(PROJ)/node-problem-detector:$(TAG)
 
-IMAGE := gcr.io/$(PROJ)/node-problem-detector:$(TAG)
+# ENABLE_JOURNALD enables build journald support or not. Building journald support needs libsystemd-dev
+# or libsystemd-journal-dev.
+# TODO(random-liu): Build NPD inside container.
+ENABLE_JOURNALD?=1
+
+# TODO(random-liu): Support different architectures.
+BASEIMAGE:=alpine:3.4
+
+# Disable cgo by default to make the binary statically linked.
+CGO_ENABLED:=0
+
+# NOTE that enable journald will increase the image size.
+ifeq ($(ENABLE_JOURNALD), 1)
+	# Enable journald build tag.
+	BUILD_TAGS:=-tags journald
+	# Use fedora because it has newer systemd version (229) and support +LZ4. +LZ4 is needed
+	# on some os distros such as GCI.
+	BASEIMAGE:=fedora
+	# Enable cgo because sdjournal needs cgo to compile. The binary will be dynamically
+	# linked if CGO_ENABLED is enabled. This is fine because fedora already has necessary
+	# dynamic library. We can not use `-extldflags "-static"` here, because go-systemd uses
+	# dlopen, and dlopen will not work properly in a statically linked application.
+	CGO_ENABLED:=1
+endif
 
 vet:
 	go list ./... | grep -v "./vendor/*" | xargs go vet
@@ -30,14 +79,17 @@ version:
 	@echo $(VERSION)
 
 ./bin/node-problem-detector: $(PKG_SOURCES)
-	GOOS=linux go build -o bin/node-problem-detector \
-	     -ldflags '-w -extldflags "-static" -X $(PKG)/pkg/version.version=$(VERSION)' \
-	     cmd/node_problem_detector.go
+	CGO_ENABLED=$(CGO_ENABLED) GOOS=linux go build -o bin/node-problem-detector \
+	     -ldflags '-w -X $(PKG)/pkg/version.version=$(VERSION)' \
+	     $(BUILD_TAGS) cmd/node_problem_detector.go
+
+Dockerfile: Dockerfile.in
+	sed -e 's|@BASEIMAGE@|$(BASEIMAGE)|g' $< >$@
 
 test: vet fmt
-	go test -timeout=1m -v -race ./pkg/...
+	go test -timeout=1m -v -race ./pkg/... $(BUILD_TAGS)
 
-build-container: ./bin/node-problem-detector
+build-container: ./bin/node-problem-detector Dockerfile
 	docker build -t $(IMAGE) .
 
 build-tar: ./bin/node-problem-detector

node-problem-detector.yaml

@@ -12,6 +12,7 @@ spec:
       - name: node-problem-detector
         command:
         - /node-problem-detector
+        - --logtostderr
         - --kernel-monitor=/config/kernel-monitor.json
         image: gcr.io/google_containers/node-problem-detector:v0.2
         imagePullPolicy: Always