tools/alpine: Add iucode_tool to base

The iucode_tool is used to convert the Intel CPU microcode
binaries into a cpio archive. There is no alpine package
for it, so compile it from source.

This is for x86_64 only and on other archs we create a empty
file.

Signed-off-by: Rolf Neugebauer <rolf.neugebauer@docker.com>

tools/alpine/Dockerfile

@@ -53,6 +53,26 @@ RUN apk add --no-cache btrfs-progs-dev gcc libc-dev linux-headers make
 RUN cd $GOPATH/src/github.com/containerd/containerd && \
   make binaries EXTRA_FLAGS="-buildmode pie" EXTRA_LDFLAGS='-extldflags "-fno-PIC -static"' BUILD_TAGS="static_build"
 
+# Checkout and compile iucode-tool for Intel CPU microcode
+# On non-x86_64 create a dummy file to copy below.
+ENV IUCODE_REPO=https://gitlab.com/iucode-tool/iucode-tool
+ENV IUCODE_COMMIT=v2.2
+WORKDIR /
+ADD iucode-tool.patch /
+RUN set -e && \
+    mkdir /iucode_tool && \
+    if [ $(uname -m) = "x86_64" ]; then \
+        apk add --no-cache automake autoconf argp-standalone git gcc make musl-dev patch && \
+        git clone ${IUCODE_REPO} && \
+        cd /iucode-tool && \
+        git checkout ${IUCODE_COMMIT} && \
+        patch -p 1 < /iucode-tool.patch && \
+        ./autogen.sh && \
+        ./configure && \
+        make && \
+        cp iucode_tool /iucode_tool; \
+    fi
+
 FROM alpine:3.7
 
 COPY --from=mirror /etc/apk/repositories /etc/apk/repositories
@@ -62,6 +82,7 @@ COPY --from=mirror /mirror /mirror/
 COPY --from=mirror /go/bin /go/bin/
 COPY --from=mirror /Dockerfile /Dockerfile
 COPY --from=mirror /go/src/github.com/containerd/containerd /go/src/github.com/containerd/containerd/
+COPY --from=mirror /iucode_tool /usr/bin/
 
 RUN apk update && apk upgrade -a
 

tools/alpine/iucode-tool.patch

@@ -0,0 +1,12 @@
+diff --git a/iucode_tool.c b/iucode_tool.c
+index 460087c..8825ed6 100644
+--- a/iucode_tool.c
++++ b/iucode_tool.c
+@@ -31,6 +31,7 @@
+ #include <dirent.h>
+ #include <time.h>
+ #include <cpuid.h>
++#include <limits.h>
+ 
+ #include "intel_microcode.h"
+