Add docker image for running debos

Docker allows for an easy way to get a reproducible build environment,
add a docker file containing debos which can be used for image builds.

Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Reviewed-by: Héctor Orón Martínez <hector.oron@collabora.co.uk>
Differential Revision: https://phabricator.apertis.org/D7243

README

@@ -35,3 +35,29 @@ Create SDK image from prepared ospack:
 ```
 debos --scratchsize 10G -t type:sdk -t suite:17.12 apertis-image-sdk.yaml
 ```
+
+Building in docker
+==================
+
+To ease testing on a wide variaty of host systems (and building in Jenkins) a
+docker file is provided which sets up the build environment. To build using
+that:
+
+* build the docker image:
+```
+docker build -t apertis-image-builder apertis-image-builder
+```
+
+* Run the image build in docker e.g:
+```
+docker run --device /dev/kvm  -w /recipes \
+  -u $(id -u) \
+  --group-add=$(getent group kvm | cut -d : -f 3) \
+  -i -v $(pwd):/recipes -t apertis-image-builder \
+  debos apertis-ospack.yaml
+```
+
+The image build will be run in the build docker image using your uid with the
+additional kvm group (for debian based systems) to ensure debos/fakemachine can
+use hardware virtualisation. For fedora/Redhat based systems the group-add is
+likely not needed.

apertis-image-builder/Dockerfile

+FROM debian:stretch-slim
+
+ARG DEBIAN_FRONTEND=noninteractive
+
+ENV HOME=/recipes
+ENV GOPATH=/usr/local/go
+ENV PATH=$PATH:/usr/local/go/bin
+
+# Always install procps in case the docker file gets used in jenkins
+RUN apt update && apt-get install  --no-install-recommends -y procps
+
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends apt-transport-https \
+                                               ca-certificates
+
+RUN mkdir -p /etc/apt/sources.list.d
+COPY apertis-tools.list /etc/apt/sources.list.d
+RUN mkdir -p /etc/apt/trusted.gpg.d/
+COPY collabora-obs-archive-keyring.gpg /etc/apt/trusted.gpg.d
+
+RUN mkdir -p /etc/apt/preferences.d
+COPY parted-apertis /etc/apt/preferences.d
+
+# Bits needed to run fakemachine
+RUN apt-get update  && \
+    apt-get install --no-install-recommends -y qemu-system-x86 \
+                                               busybox \
+                                               linux-image-amd64 \
+                                               systemd \
+                                               dbus
+
+# Bits needed to build debos
+RUN apt-get update  && \
+    apt-get install --no-install-recommends -y golang-go \
+                                               git \
+                                               libostree-dev \
+                                               gcc \
+                                               libc6-dev \
+                                               pkg-config
+
+# Bits to build the image
+RUN apt-get update  && \
+    apt-get install --no-install-recommends -y parted \
+                                               e2fsprogs \
+                                               dosfstools \
+                                               qemu-user-static \
+                                               binfmt-support \
+                                               python3 \
+                                               bmap-tools \
+                                               rsync \
+                                               systemd-container \
+                                               openssh-client \
+                                               debootstrap \
+                                               libnss-wrapper \
+                                               ostree
+
+# build debos
+RUN go get github.com/go-debos/debos/cmd/debos && \
+    go install github.com/go-debos/debos/cmd/debos

apertis-image-builder/apertis-tools.list

+deb https://repositories.apertis.org/debian/ stretch tools
+

apertis-image-builder/parted-apertis

+Package: parted
+Pin: release o=Apertis
+Pin-Priority: 1000