Add a version string to pause.c

build/pause/Makefile

@@ -18,14 +18,15 @@ REGISTRY ?= k8s.gcr.io
 IMAGE = $(REGISTRY)/pause-$(ARCH)
 LEGACY_AMD64_IMAGE = $(REGISTRY)/pause
 
-TAG = 3.0
+TAG = 3.1
+REV = $(shell git describe --contains --always --match='v*')
 
 # Architectures supported: amd64, arm, arm64, ppc64le and s390x
 ARCH ?= amd64
 
 ALL_ARCH = amd64 arm arm64 ppc64le s390x
 
-CFLAGS = -Os -Wall -Werror -static
+CFLAGS = -Os -Wall -Werror -static -DVERSION=v$(TAG)-$(REV)
 KUBE_CROSS_IMAGE ?= k8s.gcr.io/kube-cross
 KUBE_CROSS_VERSION ?= $(shell cat ../build-image/cross/VERSION)
 
@@ -37,7 +38,7 @@ ifeq ($(ARCH),amd64)
 endif
 
 ifeq ($(ARCH),arm)
-	TRIPLE ?= arm-linux-gnueabi
+	TRIPLE ?= arm-linux-gnueabihf
 endif
 
 ifeq ($(ARCH),arm64)

build/pause/pause.c

@@ -17,20 +17,37 @@ limitations under the License.
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
+#define STRINGIFY(x) #x
+#define VERSION_STRING(x) STRINGIFY(x)
+
+#ifndef VERSION
+#define VERSION HEAD
+#endif
+
 static void sigdown(int signo) {
   psignal(signo, "Shutting down, got signal");
   exit(0);
 }
 
 static void sigreap(int signo) {
-  while (waitpid(-1, NULL, WNOHANG) > 0);
+  while (waitpid(-1, NULL, WNOHANG) > 0)
+    ;
 }
 
-int main() {
+int main(int argc, char **argv) {
+  int i;
+  for (i = 1; i < argc; ++i) {
+    if (!strcasecmp(argv[i], "-v")) {
+      printf("pause.c %s\n", VERSION_STRING(VERSION));
+      return 0;
+    }
+  }
+
   if (getpid() != 1)
     /* Not an error because pause sees use outside of infra containers. */
     fprintf(stderr, "Warning: pause should be the first process\n");