Create a sysroot flavour of the Oak Containers system image

The idea is to use the .tar that is generated by this as the sysroot for
bazel in the future. This is not in use right now, though, as I've yet
to set up the toolchain that'd use this sysroot.

Bug: b/364256351
Change-Id: If78714221b3ff2999fd5bd58ad7f15b78950010a

oak_containers/system_image/build-base.sh

@@ -67,27 +67,35 @@ function build_nvidia_base {
   build_base "oak-containers-sysimage-nvidia-base" "nvidia_base_image.Dockerfile" "nvidia-base-image.tar"
 }
 
+function build_sysroot {
+  build_base "oak-sysroot" "sysroot.Dockerfile" "sysroot.tar"
+}
+
 if [ -z "${1:-}" ]
 then
   set +o xtrace
   echo ""
-  echo "Building both vanilla and nvidia base images."
+  echo "Building both vanilla and nvidia base images and the sysroot."
   echo ""
-  echo "If you want to build just one of the base image types, use:"
+  echo "If you want to build just one of the base image types, use one of the following:"
   echo "./scripts/build-bash.sh vanilla"
-  echo "or"
   echo "./scripts/build-bash.sh nvidia"
+  echo "./scripts/build-bash.sh sysroot"
   echo ""
   sleep 1
   set -o xtrace
   build_vanilla_base
   build_nvidia_base
+  build_sysroot
 elif [ "$1" == "vanilla" ]
 then
   build_vanilla_base
 elif [ "$1" == "nvidia" ]
 then
   build_nvidia_base
+elif [ "$1" == "sysroot" ]
+then
+  build_sysroot
 fi
 
 set +o xtrace

oak_containers/system_image/sysroot.Dockerfile

@@ -0,0 +1,25 @@
+# The expectation is that we build `base_image.Dockerfile` before this one.
+# hadolint ignore=DL3007
+FROM oak-containers-sysimage-base:latest
+
+ARG LINUX_KERNEL_VERSION
+
+SHELL ["/bin/bash", "-o", "pipefail", "-c"]
+
+RUN apt-get --yes update \
+    && apt-get install --yes --no-install-recommends \
+    libc6-dev flex bison build-essential bc cpio libncurses5-dev libelf-dev libssl-dev dwarves debhelper-compat rsync \
+    kmod \
+    # Cleanup
+    && apt-get clean \
+    && rm --recursive --force /var/lib/apt/lists/*
+
+COPY target/linux-${LINUX_KERNEL_VERSION}.tar.xz /tmp
+COPY target/minimal.config /tmp
+
+RUN tar --directory=/tmp --extract --file /tmp/linux-${LINUX_KERNEL_VERSION}.tar.xz \
+    && cp /tmp/minimal.config /tmp/linux-${LINUX_KERNEL_VERSION}/.config \
+    && make --directory=/tmp/linux-${LINUX_KERNEL_VERSION} bindeb-pkg \
+    && dpkg --install /tmp/linux-headers-${LINUX_KERNEL_VERSION}_${LINUX_KERNEL_VERSION}-1_amd64.deb \
+    && rm -rf /tmp/linux-${LINUX_KERNEL_VERSION} /tmp/linux-${LINUX_KERNEL_VERSION}.tar.xz /tmp/minimal.config
+