cachebust for apt sources

We don't want to cache docker images once we've done an `apt-get
update`.  Subsequent `apt-get install` steps, if added or modified, can
use the cached `apt-get update` information which may be wildly out of
date.

Author: ethomson

Makefile

@@ -12,19 +12,19 @@ push: all
 	docker push libgit2/docurium:${TAG}
 
 trusty-amd64:
-	docker build -t libgit2/trusty-amd64:${TAG} --build-arg BASE=ubuntu:trusty -f trusty.Dockerfile .
+	docker build --build-arg CACHEBUST=$(CACHEBUST) -t libgit2/trusty-amd64:${TAG} --build-arg BASE=ubuntu:trusty -f trusty.Dockerfile .
 
 bionic-x86:
-	docker build -t libgit2/bionic-x86:${TAG} --build-arg BASE=multiarch/ubuntu-core:x86-bionic -f bionic.Dockerfile .
+	docker build --build-arg CACHEBUST=$(CACHEBUST) -t libgit2/bionic-x86:${TAG} --build-arg BASE=multiarch/ubuntu-core:x86-bionic -f bionic.Dockerfile .
 
 bionic-arm64:
-	docker build -t libgit2/bionic-arm64:${TAG} --build-arg BASE=multiarch/ubuntu-core:arm64-bionic -f bionic.Dockerfile .
+	docker build --build-arg CACHEBUST=$(CACHEBUST) -t libgit2/bionic-arm64:${TAG} --build-arg BASE=multiarch/ubuntu-core:arm64-bionic -f bionic.Dockerfile .
 
 bionic-arm32:
-	docker build -t libgit2/bionic-arm32:${TAG} --build-arg BASE=multiarch/ubuntu-core:armhf-bionic -f bionic.Dockerfile .
+	docker build --build-arg CACHEBUST=$(CACHEBUST) -t libgit2/bionic-arm32:${TAG} --build-arg BASE=multiarch/ubuntu-core:armhf-bionic -f bionic.Dockerfile .
 
 xenial-ppc64el:
-	docker build -t libgit2/xenial-ppc64el:${TAG} --build-arg BASE=multiarch/ubuntu-core:ppc64el-xenial -f xenial.Dockerfile .
+	docker build --build-arg CACHEBUST=$(CACHEBUST) -t libgit2/xenial-ppc64el:${TAG} --build-arg BASE=multiarch/ubuntu-core:ppc64el-xenial -f xenial.Dockerfile .
 
 docurium:
 	docker build --build-arg CACHEBUST=$(CACHEBUST) -t libgit2/docurium:${TAG} -f docurium.Dockerfile .

bionic.Dockerfile

@@ -1,5 +1,6 @@
 ARG BASE
 FROM $BASE
+ARG CACHEBUST=1
 RUN apt-get update
 RUN apt-get -y install pkgconf clang git cmake curl libssl-dev libcurl4 libcurl4-openssl-dev libssh2-1-dev libz-dev valgrind openssh-client openssh-server
 RUN if [ "$ARCH" != "armhf" -a "$ARCH" != "arm64" ]; then apt-get -y install openjdk-11-jre-headless; fi

centos.Dockerfile

@@ -0,0 +1,12 @@
+FROM multiarch/centos:7-ppc64-iso
+ARG CACHEBUST=1
+RUN yum install -y git cmake gcc make openssl-devel openssh-server \
+    git-daemon java-1.8.0-openjdk-headless
+WORKDIR "/tmp"
+RUN curl https://www.libssh2.org/download/libssh2-1.8.0.tar.gz -o libssh2-1.8.0.tar.gz
+RUN tar xvf libssh2-1.8.0.tar.gz
+WORKDIR "/tmp/libssh2-1.8.0"
+RUN ./configure
+RUN make
+RUN make install
+ENV PKG_CONFIG_PATH /usr/local/lib/pkgconfig

docurium.Dockerfile

@@ -1,4 +1,5 @@
 FROM debian:jessie-slim
+ARG CACHEBUST=1
 RUN apt-get update
 RUN apt install -y cmake pkg-config ruby ruby-dev llvm libclang-3.5-dev libssl-dev python-pygments
 ARG CACHEBUST=1

fedora.Dockerfile

@@ -0,0 +1,12 @@
+FROM multiarch/fedora:25-ppc64
+ARG CACHEBUST=1
+RUN yum install -y git cmake gcc make openssl-devel openssh-server \
+    git-daemon java-1.8.0-openjdk-headless
+WORKDIR "/tmp"
+RUN curl https://www.libssh2.org/download/libssh2-1.8.0.tar.gz -o libssh2-1.8.0.tar.gz
+RUN tar xvf libssh2-1.8.0.tar.gz
+WORKDIR "/tmp/libssh2-1.8.0"
+RUN ./configure
+RUN make
+RUN make install
+ENV PKG_CONFIG_PATH /usr/local/lib/pkgconfig

trusty.Dockerfile

@@ -1,5 +1,6 @@
 ARG BASE
 FROM $BASE
+ARG CACHEBUST=1
 
 RUN apt-get update
 RUN apt-get install -y curl apt-transport-https

xenial.Dockerfile

@@ -1,5 +1,6 @@
 ARG BASE
 FROM $BASE
+ARG CACHEBUST=1
 RUN apt-get update
 RUN apt-get -y install pkgconf clang git cmake curl libssl-dev libcurl3 libcurl3-gnutls libcurl4-gnutls-dev valgrind openssh-client openssh-server openjdk-8-jre
 RUN mkdir /var/run/sshd