Fix container test image

The test container is failing to execute ping on environments that
do not allow containers to run as root user (e.g. OpenShift 4.6).
This commit fixes the issue by ensuring iputils package from Alpine
is installed. Also, it upgrades packages versions.

Change-Id: I1f429110c888103734ce6657fea729529389eb1f

test_container/Dockerfile

@@ -1,5 +1,7 @@
-FROM scratch
+FROM alpine:3.12
+
 ADD rootfs.tar.xz /
+RUN apk update && apk add iputils
 RUN adduser -S kuryr
 
 USER kuryr

test_container/Dockerfile.builder

@@ -1,4 +1,4 @@
-FROM alpine:3.8
+FROM alpine:3.12
 
 RUN apk add --no-cache \
 		bash \
@@ -13,7 +13,7 @@ RUN apk add --no-cache \
 		perl \
 		tzdata
 
-ENV BUSYBOX_VERSION 1.29.0
+ENV BUSYBOX_VERSION 1.31.1
 
 RUN set -ex; \
 	tarball="busybox-${BUSYBOX_VERSION}.tar.bz2"; \

test_container/curl_builder.sh

@@ -1,10 +1,10 @@
 #!/usr/bin/env bash
 
 # Names of latest versions of each package
-export VERSION_MUSL=musl-1.1.18
+export VERSION_MUSL=musl-1.2.0
 export VERSION_ZLIB=zlib-1.2.11
-export VERSION_LIBRESSL=libressl-2.6.3
+export VERSION_LIBRESSL=libressl-3.2.1
-export VERSION_CURL=curl-7.58.0
+export VERSION_CURL=curl-7.72.0
 
 # URLs to the source directories
 export SOURCE_MUSL=http://www.musl-libc.org/releases/