*: add pause binary as a build target

Take the pause binary's source code (from kubernetes/pause) and make it
part of the build setup for cri-o. This is necessary to remove the
Docker requirement for setting up the pause container, at least until
the storage API is set up so that we can make this far more flexible
(namely that we can pull the image from a registry or other transport,
even from an archive).

Signed-off-by: Aleksa Sarai <asarai@suse.de>

.gitignore

@@ -2,5 +2,7 @@
 /ocic
 conmon/conmon
 conmon/conmon.o
+pause/pause
+pause/pause.o
 /docs/ocid.8
 vendor/src/github.com/kubernetes-incubator/cri-o

Makefile

@@ -34,6 +34,9 @@ ${OCID_LINK}:
 conmon:
 	make -C $@
 
+pause:
+	make -C $@
+
 ocid: ${OCID_LINK}
 	go build -o ocid ./cmd/server/
 
@@ -44,6 +47,7 @@ clean:
 	rm -f ocic ocid
 	rm -f ${OCID_LINK}
 	rm -f conmon/conmon.o conmon/conmon
+	rm -f pause/pause.o pause/pause
 	rm -f docs/*.1 docs/*.8
 	find . -name \*~ -delete
 	find . -name \#\* -delete
@@ -64,7 +68,7 @@ integration: ocidimage
 localintegration: binaries
 	./test/test_runner.sh ${TESTFLAGS}
 
-binaries: ${OCID_LINK} ocid ocic conmon
+binaries: ${OCID_LINK} ocid ocic conmon pause
 
 MANPAGES_MD = $(wildcard docs/*.md)
 
@@ -82,12 +86,13 @@ install: binaries docs
 	install -D -m 755 ocid ${INSTALLDIR}/ocid
 	install -D -m 755 ocic ${INSTALLDIR}/ocic
 	install -D -m 755 conmon/conmon $(PREFIX)/libexec/ocid/conmon
+	install -D -m 755 pause/pause $(PREFIX)/libexec/ocid/pause
 	install -d $(PREFIX)/share/man/man8
 	install -m 644 $(basename $(MANPAGES_MD)) $(PREFIX)/share/man/man8
 
 uninstall:
 	rm -f ${INSTALLDIR}/{ocid,ocic}
-	rm -f $(PREFIX)/libexec/ocid/conmon
+	rm -f $(PREFIX)/libexec/ocid/{conmon,pause}
 	for i in $(basename $(MANPAGES_MD)); do \
 		rm -f $(PREFIX)/share/man/man8/$$(basename $${i}); \
 	done
@@ -118,13 +123,14 @@ install.tools: .install.gitvalidation .install.gometalinter .install.md2man
 
 .PHONY: \
 	binaries \
+	clean \
 	conmon \
 	default \
 	docs \
-	ocid \
-	ocic \
-	clean \
-	lint \
 	help \
 	install \
+	lint \
+	ocic \
+	ocid \
+	pause \
 	uninstall

pause/.gitignore

@@ -0,0 +1,3 @@
+/.container-*
+/.push-*
+/bin

pause/Makefile

@@ -0,0 +1,13 @@
+src = $(wildcard *.c)
+obj = $(src:.c=.o)
+
+override LIBS +=
+override CFLAGS += -Os -Wall -Wextra -static
+
+pause: $(obj)
+	$(CC) -o $@ $^ $(CFLAGS) $(LIBS)
+	strip $@
+
+.PHONY: clean
+clean:
+	rm -f $(obj) pause

pause/pause.c

@@ -0,0 +1,36 @@
+/*
+Copyright 2016 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.
+*/
+
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+static void sigdown(int signo) {
+	psignal(signo, "shutting down, got signal");
+	exit(0);
+}
+
+int main() {
+	if (signal(SIGINT, sigdown) == SIG_ERR)
+		return 1;
+	if (signal(SIGTERM, sigdown) == SIG_ERR)
+		return 2;
+	signal(SIGKILL, sigdown);
+	for (;;) pause();
+	fprintf(stderr, "error: infinite loop terminated\n");
+	return 42;
+}