examples/bls: improve Containerfiles caching

Run the "install packages into the base image" section as the first
thing that happens, before the cfsctl binary gets copied in.

This means that we have to regenerate the initramfs, which is duplicated
work, but it enables caching of the package installation, which takes
much longer and involves downloading updated packages (which drift with
time).  This helps a lot with iterative local testing, and the bls
images are the ones that I usually use for that.

Also enable package caching for Arch and Debian by adding the
appropriate bind mounts.  Use `apt-get` instead of CLI-API-unstable
`apt`.  Use the new `kernel-install add-all` verb where applicable.

We leave Ubuntu out of this change for now: I keep ending up with two
initramfs files generated and I'm not sure how to workaround the weird
use of dracut there.  We can circle back to this later.

Signed-off-by: Allison Karlitskaya <[email protected]>

Author: allisonkarlitskaya

examples/bls/Containerfile

@@ -1,5 +1,4 @@
 FROM fedora:42
-COPY extra /
 RUN --mount=type=cache,target=/var/cache/libdnf5 <<EOF
     set -eux
 
@@ -12,9 +11,15 @@ RUN --mount=type=cache,target=/var/cache/libdnf5 <<EOF
         strace \
         util-linux \
         systemd
+EOF
 
+# --- Everything above this line should hopefully stay cached ---
+
+COPY cfsctl /usr/bin
+COPY extra /
+RUN --mount=type=cache,target=/var/cache/libdnf5 <<EOF
+    kernel-install add-all
     systemctl enable systemd-networkd
     passwd -d root
     mkdir /sysroot
 EOF
-COPY cfsctl /usr/bin

examples/bls/Containerfile.arch

@@ -1,11 +1,8 @@
 FROM archlinux AS base
-COPY extra /
-RUN <<EOF
+RUN --mount=type=cache,target=/var/cache/pacman/pkg \
+    --mount=type=cache,target=/var/lib/pacman/sync <<EOF
     set -eux
 
-    touch /etc/machine-id
-    echo 'root=/dev/vda2' > /etc/kernel/cmdline
-
     pacman -Syu --noconfirm
     pacman -Sy --noconfirm \
         btrfs-progs \
@@ -16,11 +13,19 @@ RUN <<EOF
         openssh \
         skopeo \
         strace
+EOF
+
+# --- Everything above this line should hopefully stay cached ---
 
-    kernel-install add "$(ls /usr/lib/modules)" /usr/lib/modules/"$(ls /usr/lib/modules)"/vmlinuz
+COPY cfsctl /usr/bin
+COPY extra /
+RUN <<EOF
+    touch /etc/machine-id
+    echo 'root=/dev/vda2' > /etc/kernel/cmdline
+
+    kernel-install add-all
 
     systemctl enable systemd-networkd systemd-resolved sshd
     passwd -d root
     mkdir /sysroot
 EOF
-COPY cfsctl /usr/bin

examples/bls/Containerfile.rawhide

@@ -1,5 +1,4 @@
 FROM fedora:rawhide
-COPY extra /
 RUN --mount=type=cache,target=/var/cache/libdnf5 <<EOF
     set -eux
 
@@ -12,9 +11,15 @@ RUN --mount=type=cache,target=/var/cache/libdnf5 <<EOF
         strace \
         systemd \
         util-linux
+EOF
+
+# --- Everything above this line should hopefully stay cached ---
 
+COPY cfsctl /usr/bin
+COPY extra /
+RUN <<EOF
     systemctl enable systemd-networkd
     passwd -d root
+    kernel-install add-all
     mkdir /sysroot
 EOF
-COPY cfsctl /usr/bin

examples/bls/Containerfile.rhel9

@@ -1,13 +1,7 @@
 # FROM docker.io/redhat/ubi9  missing: dosfstools, kernel
 FROM quay.io/centos/centos:9
-COPY extra /
 RUN --mount=type=cache,target=/var/cache/dnf <<EOF
     set -eux
-    mkdir -p /etc/kernel
-    touch /etc/kernel/cmdline
-
-    echo layout=bls | tee /etc/kernel/install.conf
-
     dnf --setopt keepcache=1 install --allowerasing -y \
         NetworkManager \
         composefs \
@@ -19,9 +13,21 @@ RUN --mount=type=cache,target=/var/cache/dnf <<EOF
         strace \
         systemd \
         util-linux
+EOF
+
+# --- Everything above this line should hopefully stay cached ---
+
+COPY cfsctl /usr/bin
+COPY extra /
+RUN <<EOF
+    set -eux
+    mkdir -p /etc/kernel
+    touch /etc/kernel/cmdline
+
+    echo layout=bls | tee /etc/kernel/install.conf
+    kernel-install add $(ls /usr/lib/modules) /usr/lib/modules/*/vmlinuz
 
     systemctl enable tmp.mount
     passwd -d root
     mkdir /sysroot
 EOF
-COPY cfsctl /usr/bin