diff --git a/.dockerignore b/.dockerignore
index 2e11fc7..6d290c9 100644
--- a/.dockerignore
+++ b/.dockerignore
@@ -1,7 +1,4 @@
-.git
-*.o
-gmid
-gg
-regress
-Makefile.local
-config.h
+**
+!*.c
+!Makefile
+!configure
diff --git a/Dockerfile b/contrib/Dockerfile
similarity index 92%
rename from Dockerfile
rename to contrib/Dockerfile
index 4ab92c1..e70e19c 100644
--- a/Dockerfile
+++ b/contrib/Dockerfile
@@ -7,3 +7,4 @@ RUN make static
 FROM alpine
 RUN apk update && apk upgrade
 COPY --from=builder /build/gmid /bin/gmid
+ENTRYPOINT ["gmid"]
diff --git a/contrib/README b/contrib/README
index be29c44..b2d39b0 100644
--- a/contrib/README
+++ b/contrib/README
@@ -1,6 +1,10 @@
 This directory is for additional contributed files which may be
 useful.
 
+Dockerfile
+
+	Sample Dockerfile to build alpine-based gmid images.
+
 gmid.service
 
 	Simple systemd service file.