Improve containerized builds

- "Tiered" configuration simplifies management and allows more targeted
  overrides, symlinking configs in `/etc/zfsbootmenu` in the container:

  1. First tier comes from `etc/zfsbootmenu` (global defaults)

  2. Second tier comes from `etc/zbm-builder` (container defaults)

  3. Third tier comes from the build root (build specific)

  Configurations in later tiers override those with conflicting names in
  earlier tiers.

- Tiered configuration now includes mkinitcpio configuration, allowing
  containers to build mkinitcpio images

- Container configuration for mkinitcpio supports dracut-style snippets
  in `mkinitcpio.conf.d`

- The builder now looks for an `rc.d` subdirectory in the build root and
  will invoke every executable file therein before generating images to
  provide a means to "terraform" the build container

- The `zbm-builder.sh` wrapper now supports a configuration file to
  allow defaults to be specified; this requires a two-pass getopts to
  find and load the configuration file before parsing remaining options

- A new option to `zbm-builder.sh`, `-R`, will remove any existing host
  files (`hostid` and `zpool.cache`) from the build root to make sure
  they are always up to date with the host versions

- The container entrypoint now configures `generate-zbm` to write its
  output directly to the desired output directory rather than staging in
  a temporary output directory, allowing `generate-zbm` to manage
  version rollovers as it does in host installations

- Remove superfluous arguments from container entrypoint to manage
  `hostid`, `zpool.cache` and `config.yaml`; the files either exist in
  the build root or the container will use defaults

- Drop `docker-compose.yml` and now-obsolete `config.yaml.default`

- Update documentation to better reflect current build procedure

etc/zbm-builder/config.yaml

@@ -0,0 +1,17 @@
+Global:
+  # Set InitCPIO to true to use mkinitcpio for ZBM images
+  #InitCPIO: true
+  # The build container *forces* Global.ManageImages
+Components:
+  # Enable only current kernel/initramfs components and a backup
+  Enabled: true
+  Versions: false
+  # The ZBM build container *forces* Components.ImageDir
+EFI:
+  # Enable only current EFI executable and a backup file
+  Enabled: true
+  Versions: false
+  # The ZBM build container *forces* EFI.ImageDir
+Kernel:
+  # Set ZBM command-line options for the EFI bundle here
+  CommandLine: zfsbootmenu ro quiet loglevel=4 nomodeset

etc/zbm-builder/mkinitcpio.conf

@@ -0,0 +1,42 @@
+# This is a specialization of the ZFSBootMenu mkinitcpio.conf file for use in
+# the ghcr.io/zbm-dev/zbm-builder container. Most documentation has been
+# omitted. For a description of this file, see the manual pages
+#
+# - zfsbootmenu(7)
+# - mkinitcpio(5)
+#
+# As well as a more thoroughly commented version at the location
+# etc/zfsbootmenu/mkinitcpio.conf in the zfsbootmenu git repository.
+
+# No specific customizations for container builds
+MODULES=()
+BINARIES=()
+FILES=()
+
+# Because generate-zbm adds the required 'zfsbootmenu' hook, omit it here.
+HOOKS=(base udev autodetect modconf block filesystems keyboard)
+
+# In containers, it is helpful to allow some dynamic configuration. In
+# particular, the zbm-builder.sh helper script that configures and runs the
+# build container will automatically create configuration entries in the
+# subdirectories
+#
+#     dracut.conf.d
+#     mkinitcpio.conf.d
+#
+# of the build directory for any hook found in the subdirectories
+#
+#     hooks.early_setup.d
+#     hooks.setup.d
+#     hooks.teardown.d
+#
+# of the same build directory. Support for mkinitcpio.conf.d mimics similar
+# support for dracut.conf.d built directly into dracut.
+#
+# Note that, inside the container, the build directory will be mounted at
+# /build, so reference those paths here.
+for _zbm_hook in /build/mkinitcpio.conf.d/*; do
+	[ -r "${_zbm_hook}" ] || continue
+	. "${_zbm_hook}"
+done
+unset _zbm_hook

releng/docker/README.md

@@ -63,22 +63,20 @@ specific commit based on the contents of `/etc/zbm-commit-hash`.
 
 When running a container from the ZFSBootMenu builder image, it is generally
 expected that some compatible volume (generally, a local directory) will be
-bind-mounted as a volume at the path `/zbm` inside the container. This volume
+bind-mounted as a volume at the path `/build` inside the container. The volume
-may either be empty or contain a pre-existing ZFSBootMenu source tree.
+may either be empty or contain a custom ZFSBootMenu configuration and will
-Specifically, if the volume is not empty, it must contain the following
+contain build products (a UEFI bundle, separate kernel and initramfs
-components of the ZFSBootMenu repository:
+components, or both) in a `build` subdirectory.
 
-- `dracut`, the Dracut module that populates an image with ZFSBootMenu;
+The container entrypoint expects to run `generate-zbm` directly from a
-
+ZFSBootMenu source repository that is available at `/zbm` within the container.
-- `zfsbootmenu`, the core ZFSBootMenu components;
+If the entrypoint finds `/zbm` nonexistent or devoid of files, it will fetch a
-
+copy of the upstream source repository and unpack it where expected. (The tag,
-- `bin/generate-zbm`, the executable script that creates ZFSBootMenu images;
+commit or branch to fetch can be specified at runtime or a default will be
-
+chosen as encoded in the container image.) Any pre-existing and non-empty
-If the build script finds the volume mounted at `/zbm` empty, it will fetch an
+`/zbm` within the container must contain a copy of the source repository. This
-archive of the official ZFSBootMenu repository on github.com. This makes the
+is useful, *e.g.*, to bind-mount a local clone of the repository into the
-image capable of producing default images without needing a local clone of the
+container.
-repository. The specific commit, tag or branch to fetch can be specified at
-container run time.
 
 ## Command-Line Arguments and Environment Variables
 
@@ -88,43 +86,20 @@ command-line argument to see a summary of build options and their default
 options. The options are:
 
 - `$BUILDROOT` specifies a default root for image builds. The build root is
-  expected to hold a default default configuration file and output directory,
+  expected to hold configuration files and, optionally, an output directory,
-  as well as optional hostid and pool cache files. If an output directory,
+  hostid and pool cache files. The value of `$BUILDROOT` is `/build` by
-  specific configuration and (when appropriate) hostid or pool cache are
+  default.
-  specified, then `$BUILDROOT` is not relevant.
 
   The environment variable or default can be overridden with the `-b` option.
 
-- `$ZBMCONF` specifies the in-container path to a specific configuration file.
+- `$ZBMOUTPUT` specifies an alternative output directory for ZFSBootMenu build
-  The build script will override any `ImageDir` paths and remove any
+  products. The container *always* overrides configurations to store build
-  `Global.BootMountPoint` option but otherwise uses the configuration as-is.A
+  products (UEFI bundles and kernel components, as configured) in a temporary
-
+  directory; these products will be copied to `$ZBMOUTPUT` after successful
-  The environment variable or default can be overridded with the `-c` option.
+  image creation. The value of `$ZBMOUTPUT` is `${BUILDROOT}/build` by default.
-
-- `$ZBMOUTPUT` specifies the in-container path to an output directory. As noted
-  above, the build script overrides any `ImageDir` path in a configuration,
-  pointing it instead to a temporary output directory. After the script
-  successfully runs `generate-zbm`, it will copy any artifacts from the
-  temporary build directory to `$ZBMOUTPUT`.
 
   The environment variable or default can be overridded with the `-o` option.
 
-- `$HOSTID` specifies the in-container path to a hostid file. If this file is
-  specified, it will be copied to `/etc/hostid` inside the container for
-  inclusion in ZFSBootMenu images. If not, any `/etc/hostid` in the container
-  will be removed. (Note: unless the `zfsbootmenu` dracut module is configured
-  with `release_mode=1`, the module may still create an `/etc/hostid` with
-  potentially arbitrary contents in output images.
-
-  The environment variable or default can be overridded with the `-H` option.
-
-- `$POOLCACHE` specifies the in-container path to a ZFS pool cache file. If
-  this file is specified, it will be copied to `/etc/zfs/zpool.cache` inside
-  the container for inclusion in ZFSBootMenu images. If not, any
-  `/etc/zfs/zpool.cache` in the container will be removed.
-
-  The environment variable or default can be overridded with the `-C` option.
-
 - `$ZBMTAG` specifies any "commit-ish" label recognized by `git` as a pointer
   to a specific git commit. This can be a branch name (to grab the head of that
   branch), tag or commit hash. If `/zbm` in the container is not pre-populated,
@@ -136,56 +111,133 @@ options. The options are:
 
   The environment variable or default can be overridded with the `-t` option.
 
-An additional command-line argument, `-e`, allows the ZFSBootMenu configuration
+A couple of additional arguments may only be set from the command line:
-to be modified with `yq-go eval` statements at container run time. Do not use
+
-this unless you review the build script and understand, without documentation,
+- `-e <statement>` provides a statement that will be evaluated via `yq-go eval`
-what will happen!
+  to modify the `generate-zbm` configuration file immediately before an image
+  is built. This option may be specified more than once.
+
+  > Do not use this unless you review the build script and understand, without
+  > documentation, what will happen!
+
+- `-p <package>` specifies a Void Linux package to install in the container
+  before images are generated. This option may be specified more than once.
+
+## ZFSBootMenu Configuration and Execution
+
+After the ZFSBootMenu container entrypoint fetches (or identifies) a copy of
+the ZFSBootMenu source repository, it "installs" the copy into the container by
+symlinking key components of the source repository into the container
+filesystem:
+
+- If the source repository is sufficiently new, a symbolic link
+
+      /usr/share/zfsbootmenu -> /zbm/zfsbootmenu
+
+  will point to the core ZFSBootMenu library.
+
+- For newer versions of ZFSBootMenu, the symbolic link
+
+      /usr/lib/dracut/modules.d/90zfsbootmenu -> /zbm/dracut
+
+  will point to the dracut module; for older versions, the link
+
+      /usr/lib/dracut/modules.d/90zfsbootmenu -> /zbm/90zfsbootmenu
+
+  will serve the same purpose.
+
+- If the ZFSBootMenu repository contains a mkinitcpio module, a family of links
+
+      /usr/lib/initcpio/hooks/* -> /zbm/initcpio/hooks/*
+      /usr/lib/initcpio/install/* -> /zbm/initcpio/install/*
+
+  for each file in `/zbm/initcpio/{hooks,install}` will be made to make
+  `mkinitcpio` aware of the ZFSBootMenu module.
+
+Configuration files are handled in a multi-pass approach that synthesizes a
+composite configuration from increasingly specific sources. In the first pass,
+generic upstream configurations are linked *if the source exists*:
+
+    /etc/zfsbootmenu/config.yaml -> /zbm/etc/zfsbootmenu/config.yaml
+    /etc/zfsbootmenu/mkinitcpio.conf -> /zbm/etc/zfsbootmenu/mkinitcpio.conf
+    /etc/zfsbootmenu/dracut.conf.d/* -> /zbm/etc/zfsbootmenu/dracut.conf.d/*
+    /etc/zfsbootmenu/mkinitcpio.conf.d/* -> /zbm/etc/zfsbootmenu/mkinitcpio.conf.d/*
+
+Next, container-specific defaults are linked *if the source exists*:
+
+    /etc/zfsbootmenu/config.yaml -> /zbm/etc/zbm-builder/config.yaml
+    /etc/zfsbootmenu/mkinitcpio.conf -> /zbm/etc/zbm-builder/mkinitcpio.conf
+    /etc/zfsbootmenu/dracut.conf.d/* -> /zbm/etc/zbm-builder/dracut.conf.d/*
+    /etc/zfsbootmenu/mkinitcpio.conf.d/* -> /zbm/etc/zbm-builder/mkinitcpio.conf.d/*
+
+Finally, build-specific configurations are linked *if the source exists*:
+
+    /etc/zfsbootmenu/config.yaml -> ${BUILDROOT}/config.yaml
+    /etc/zfsbootmenu/mkinitcpio.conf -> ${BUILDROOT}/mkinitcpio.conf
+    /etc/zfsbootmenu/dracut.conf.d/* -> ${BUILDROOT}/dracut.conf.d/*
+    /etc/zfsbootmenu/mkinitcpio.conf.d/* -> ${BUILDROOT}/mkinitcpio.conf.d/*
+
+Conflicting links will *replace* any links made by earlier passes. This allows
+each level of configurations to mask or augment earlier defaults.
+
+> NOTE: `mkinitcpio` does not natively support configuration snippets in
+> `/etc/zfsbootmenu/mkinitcpio.conf.d`. ZFSBootMenu includes a default
+> `mkinitcpio.conf` that manually sources these snippets to emulate the
+> standard configuration behavior of dracut.
+
+In addition, host-specific files are linked if each exists:
+
+    /etc/hostid -> ${BUILDROOT}/hostid
+    /etc/zfs/zpool.cache -> ${BUILDROOT}/zfs/zpool.cache
+
+When launched, the container entrypoint will run any executable files it finds
+in `${BUILDROOT}/rc.d`. This provides a means to "terraform" the build
+container before running `generate-zbm` and can be a useful way to, *e.g.*:
+
+- Modify the `FONT` variable defined in `/etc/rc.conf`, which will be parsed by
+  `mkinitcpio` to set a default console font in ZFSBootMenu images.
+
+- Create additional links to directories in `$BUILDROOT`, such as
+
+      /etc/initcpio -> ${BUILDROOT}/initcpio
+
+  to provide additional `mkinitcpio` modules or
+
+      /etc/dropbear -> ${BUILDROOT}/dropbear
+
+  to provide host keys and configuration for the `dropbear` `mkinitcpio`
+  module.
 
 ## Build Examples
 
 To use the previously created `zbm` image to produce ZFSBootMenu files from the
-default configuration using a local ZFSBootMenu repository `/sw/zfsbootmenu`,
+default configuration, simply run
-simply run
 
 ```sh
-podman run -v /sw/zfsbootmenu:/zbm zbm
+podman run -v .:/build zbm
 ```
 
 After some console output, the container should terminate and the directory
-`/sw/zfsbootmenu/releng/docker/build` should contain the UEFI bundle
+`./build` should contain the UEFI bundle `vmlinuz.EFI` as well as the
-`vmlinuz.EFI` as well as the components `vmlinuz-bootmenu` (a stock Void Linux
+components `vmlinuz-bootmenu` (a stock Void Linux kernel) and corresponding
-kernel) and corresponding ZFSBootMenu initramfs `initramfs-bootmenu.img`.
+ZFSBootMenu initramfs `initramfs-bootmenu.img`.
 
-In the default configuration, the ZFSBootMenu images probably contain an
+To provide the hostid and pool cache files to the build container and run from
-arbitrary `/etc/hostid` that likely does not agree with the corresponding file
+the `/etc/zfsbootmenu/build` directory, copy the desired files and run the
-on the host. To make sure that the hostid within the images remains consistent
+container with the appropriate volume mount:
-with the build host, first copy the file from the host to the `releng/docker`
-directory:
 
 ```sh
-cp /etc/hostid /sw/zfsbootmenu/releng/docker/hostid
+cp /etc/hostid /etc/zfs/zpool.cache /etc/zfsbootmenu/build
-podman run -v /sw/zfsbootmenu:/zbm zbm
+podman run -v /etc/zfsbootmenu/build:/build zbm
 ```
 
-To create an image from the current `master` branch without having a local
+To create an image from a local repository available at `/sw/zfsbootmenu` and
-repository, store the output images in `/boot/efi/EFI/zfsbootmenu` and include
+again use a build root of `/etc/zfsbootmenu/build`, run
-the hostid of the current system, assuming a `zbm` builder container is tagged
-locally:
 
 ```sh
-mkdir -p /boot/efi/EFI/zfsbootmenu
+podman run -v /etc/zfsbootmenu/build:/build -v /sw/zfsbootmenu:/zbm:ro zbm
-podman run -v /boot/efi/EFI/zfsbootmenu:/output \
-    -v /etc/hostid:/hostid:ro zbm -o /output -H /hostid
 ```
 
-# Using Docker Compose
+Because the build container does not modify the repository found in `/zbm`, it
-
+is possible to mount that volume read-only (as indicated by the `:ro` suffix)
-The file `docker-compose.yml` defines a Docker Compose service that will create
+without consequence.
-a ZFSBootMenu builder image and mount the parent repository (at path `../..`)
-at `/zbm` in the build container. To use this service, simply run
-
-```sh
-docker-compose up
-```
-
-from this directory.

releng/docker/build-init.sh

@@ -24,22 +24,10 @@ Usage: $0 [options]
      Specify path for build root
      (Default: /build)
 
-  -c <configuration>
-     Specify path to generate-zbm(5) configuration
-     (Default: \${BUILDROOT}/config.yaml or \${BUILDROOT}/config.yaml.default)
-
   -o <output-directory>
      Specify path to output directory
      (Default: \${BUILDROOT}/build)
 
-  -H <hostid>
-     Specify path to hostid file
-     (Default: \${BUILDROOT}/hostid)
-
-  -C <cache>
-     Specify path to zpool.cache file
-     (Default: \${BUILDROOT}/zpool.cache)
-
   -p <package>
      Install the named Void Linux package in the container
      before building. May be specified more than once to
@@ -66,23 +54,14 @@ EOF
 PACKAGES=()
 CONFIGEVALS=()
 GENARGS=()
-while getopts "hc:b:o:H:C:t:e:p:" opt; do
+while getopts "hb:o:t:e:p:" opt; do
   case "${opt}" in
-    c)
-      ZBMCONF="${OPTARG}"
-      ;;
     b)
       BUILDROOT="${OPTARG}"
       ;;
     o)
       ZBMOUTPUT="${OPTARG}"
       ;;
-    H)
-      HOSTID="${OPTARG}"
-      ;;
-    C)
-      POOLCACHE="${OPTARG}"
-      ;;
     t)
       ZBMTAG="${OPTARG}"
       ;;
@@ -175,18 +154,6 @@ mkdir -p /usr/lib/dracut/modules.d
 ln -Tsf "${dracutmod}" /usr/lib/dracut/modules.d/90zfsbootmenu \
   || error "unable to link dracut module"
 
-# generate-zbm configures dracut to look in /etc/zfsbootmenu/dracut.conf.d.
-# Rather than override the default, just link to the in-repo defaults
-dconfd="/etc/zfsbootmenu/dracut.conf.d"
-if [ ! -d "${dconfd}" ]; then
-  mkdir -p "${dconfd}" || error "unable to create dracut configuration directory"
-
-  for cfile in /zbm/etc/zfsbootmenu/dracut.conf.d/*; do
-    [ -e "${cfile}" ] || continue
-    ln -Tsf "${cfile}" "${dconfd}/${cfile##*/}" || error "unable to link ${cfile}"
-  done
-fi
-
 # Make sure the build root exists
 : "${BUILDROOT:=/build}"
 mkdir -p "${BUILDROOT}" || error "unable to create directory '${BUILDROOT}'"
@@ -195,78 +162,72 @@ mkdir -p "${BUILDROOT}" || error "unable to create directory '${BUILDROOT}'"
 : "${ZBMOUTPUT:=${BUILDROOT}/build}"
 mkdir -p "${ZBMOUTPUT}" || error "unable to create directory '${ZBMOUTPUT}'"
 
-# Pick a default configuration if one was not provided
-if [ -z "${ZBMCONF}" ]; then
-  if [ -r "${BUILDROOT}/config.yaml" ]; then
-    ZBMCONF="${BUILDROOT}/config.yaml"
-  else
-    ZBMCONF="${BUILDROOT}/config.yaml.default"
-  fi
-fi
-
-# Configuration must exist
-[ -r "${ZBMCONF}" ] || error "missing configuration '${ZBMCONF}'"
-cp "${ZBMCONF}" "${ZBMWORKDIR}/config.yaml"
-
-# ZBMCONF now points to local copy
-ZBMCONF="${ZBMWORKDIR}/config.yaml"
-
-GENARGS+=( "--config" "${ZBMCONF}" )
-
 # Add forced overrides to the end of CONFIGEVALS
 CONFIGEVALS+=(
   ".Global.ManageImages = true"
-  ".Components.ImageDir = \"${ZBMWORKDIR}/build/components\""
+  ".Components.ImageDir = \"${ZBMOUTPUT}\""
-  ".EFI.ImageDir = \"${ZBMWORKDIR}/build\""
+  ".EFI.ImageDir = \"${ZBMOUTPUT}\""
   "del(.Global.BootMountPoint)"
 )
 
-mkdir -p "${ZBMWORKDIR}/build" || error "unable to create build directory"
+# Use provided hostid and zpool.cache files
-
+if [ -r "${BUILDROOT}/hostid" ]; then
-# Apply CONFIGEVALS to override configuration
+  ln -Tsf "${BUILDROOT}/hostid" /etc/hostid \
-for ceval in "${CONFIGEVALS[@]}"; do
+    || error "failed to link hostid"
-  yq-go eval "${ceval}" -i "${ZBMCONF}" || error "failed to apply '${ceval}' to config"
-done
-
-# Make sure a hostid and cache, if provided, exist
-if [ -z "${HOSTID}" ]; then
-  [ -r "${BUILDROOT}/hostid" ] && HOSTID="${BUILDROOT}/hostid"
-elif [ ! -r "${HOSTID}" ]; then
-  error "missing hostid '${HOSTID}'"
-fi
-
-if [ -z "${POOLCACHE}" ]; then
-  [ -r "${BUILDROOT}/zpool.cache" ] && POOLCACHE="${BUILDROOT}/zpool.cache"
-elif [ ! -r "${POOLCACHE}" ]; then
-  error "missing pool cache '${POOLCACHE}'"
-fi
-
-# Copy the hostid in place if specified, otherwise remove any hostid
-if [ -n "${HOSTID}" ]; then
-  cp "${HOSTID}" "/etc/hostid" || error "unable to copy hostid"
 else
   rm -f /etc/hostid
 fi
 
-# Copy the pool cache in place if specified, otherwise remove any cache
+if [ -r "${BUILDROOT}/zpool.cache" ]; then
-if [ -n "${POOLCACHE}" ]; then
   mkdir -p /etc/zfs
-  cp "${POOLCACHE}" /etc/zfs/zpool.cache || error "unable to copy pool cache"
+  ln -Tsf "${BUILDROOT}/zpool.cache" /etc/zfs/zpool.cache \
+    || error "failed to link zpool.cache"
 else
   rm -f /etc/zfs/zpool.cache
 fi
 
-# If a custom dracut.conf.d exists, link to its contents in the default location
+# Link all configuration files in standard location;
-if [ -d "${BUILDROOT}/dracut.conf.d" ]; then
+# go from most generic to most specificj
-  for cfile in "${BUILDROOT}"/dracut.conf.d/*; do
+mkdir -p /etc/zfsbootmenu
-    [ -e "${cfile}" ] || continue
+confroots=(
-    ln -Tsf "${cfile}" "${dconfd}/${cfile##*/}" || error "unable to link ${cfile}"
+  "/zbm/etc/zfsbootmenu"
+  "/zbm/etc/zbm-builder"
+  "${BUILDROOT}"
+)
+for confroot in "${confroots[@]}"; do
+  for cfile in "config.yaml" "mkinitcpio.conf"; do
+    [ -e "${confroot}/${cfile}" ] || continue
+    ln -Tsf "${confroot}/${cfile}" "/etc/zfsbootmenu/${cfile}" \
+      || error "unable to link mkinitcpio.conf"
   done
-fi
 
-/zbm/bin/generate-zbm "${GENARGS[@]}" || error "failed to build images"
+  for confd in "dracut.conf.d" "mkinitcpio.conf.d"; do
-
+    mkdir -p "/etc/zfsbootmenu/${confd}"
-for f in "${ZBMWORKDIR}"/build/*; do
+    for cfile in "${confroot}/${confd}"/*; do
-  [ "${f}" != "${ZBMWORKDIR}/build/*" ] || error "no images to copy to output"
+      [ -e "${cfile}" ] || continue
-  cp -R "${f}" "${ZBMOUTPUT}"
+      ln -Tsf "${cfile}" "/etc/zfsbootmenu/${confd}/${cfile##*/}" \
+        || error "unable to link ${cfile}"
+    done
+  done
 done
+
+# If a custom rc.d exists, run every executable file therein
+for rfile in "${BUILDROOT}"/rc.d/*; do
+  [ -x "${rfile}" ] || continue
+  "${rfile}" || error "failed to run RC script ${rfile##*/}"
+done
+
+# Copy default configuration to temporary directory for modifications
+ZBMCONF="${ZBMWORKDIR}/config.yaml"
+cp "/etc/zfsbootmenu/config.yaml" "${ZBMCONF}" \
+  || error "failed to copy configuration to working directory"
+
+GENARGS+=( "--config" "${ZBMCONF}" )
+
+# Apply CONFIGEVALS to override configuration in working directory
+for ceval in "${CONFIGEVALS[@]}"; do
+  yq-go eval "${ceval}" -i "${ZBMCONF}" \
+    || error "failed to apply '${ceval}' to config"
+done
+
+exec /zbm/bin/generate-zbm "${GENARGS[@]}"

releng/docker/config.yaml.default

@@ -1,22 +0,0 @@
-Global:
-  # Enable image creation
-  ManageImages: true
-  # Make sure to look for dracut configuration in the repo
-  DracutConfDir: /zbm/etc/zfsbootmenu/dracut.conf.d
-Components:
-  # zbm-build.sh overwrites this anyway
-  ImageDir: /zbm/releng/docker/build
-  Enabled: true
-  # Disable versioning, this is usually a one-off creation
-  Versions: false
-  syslinux:
-    Enabled: false
-EFI:
-  # zbm-build.sh overwrites this anyway
-  ImageDir: /zbm/releng/docker/build
-  Versions: false
-  Enabled: true
-Kernel:
-  # For the EFI bundle, turn off modesetting to avoid initializing GPUs
-  # Also set loglevel=4 to provide some helpful warning output
-  CommandLine: zfsbootmenu ro loglevel=4 nomodeset

releng/docker/docker-compose.yml

@@ -1,9 +0,0 @@
-# This builds the ZFSBootMenu builder and then runs it to create images
-version: "2"
-services:
-    zfsbootmenu-compiler:
-        build: "."
-        # Mount the current repo (../..) where the builder expects it
-        # Outputs will be stored in ../../releng/docker/build
-        volumes:
-            - "../..:/zbm"

zbm-builder.sh

@@ -11,6 +11,15 @@ sanitise_path() {
   return 1
 }
 
+boolean_enabled() {
+  local val="${1:-}"
+
+  case "${val}" in
+    [Yy][Ee][Ss]|[Yy]|[Oo][Nn]|1) return 0 ;;
+    *) return 1 ;;
+  esac
+}
+
 usage() {
   cat << EOF
 Build ZFSBootMenu images in an OCI container using podman or docker.
@@ -39,6 +48,8 @@ OPTIONS:
      Build specific ZFSBootMenu commit or tag (e.g. v1.12.0, d5594589)
      (Default: current upstream master)
 
+  -R Remove any existing zpool.cache and hostid in the build directory
+
   -C Do not include host /etc/zfs/zpool.cache in image
      (If ./zpool.cache exists, this switch will be ignored)
 
@@ -63,6 +74,7 @@ EOF
 
 SKIP_HOSTID=
 SKIP_CACHE=
+REMOVE_HOST_FILES=
 
 # By default, use the latest upstream build container image
 BUILD_IMG="ghcr.io/zbm-dev/zbm-builder:latest"
@@ -80,24 +92,64 @@ BUILD_ARGS=()
 # Volume mounts for the container manager
 VOLUME_ARGS=()
 
+# Optional configuration file
+CONFIG=
+
 if command -v podman >/dev/null 2>&1; then
   PODMAN="podman"
 else
   PODMAN="docker"
 fi
 
-while getopts "b:dhi:l:t:p:v:CH" opt; do
+CMDOPTS="b:dhi:l:t:p:v:c:CHR"
+
+# First pass to get build directory and configuration file
+while getopts "${CMDOPTS}" opt; do
   case "${opt}" in
     b)
       BUILD_DIRECTORY="${OPTARG}"
       ;;
-    d)
+    c)
-      PODMAN=docker
+      CONFIG="${OPTARG}"
       ;;
     h)
       usage
       exit 0
       ;;
+  esac
+done
+
+# Make sure the build directory is identifiable
+if ! BUILD_DIRECTORY="$( sanitise_path "${BUILD_DIRECTORY}" )"; then
+  echo "ERROR: build directory does not exist"
+  exit 1
+fi
+
+# If a configuration wasn't specified, use a default it one exists
+if [ -z "${CONFIG}" ] && [ -r "${BUILD_DIRECTORY}/zbm-builder.conf" ]; then
+  CONFIG="${BUILD_DIRECTORY}/zbm-builder.conf"
+fi
+
+# Read the optional configuration
+if [ -n "${CONFIG}" ]; then
+  if [ -r "${CONFIG}" ]; then
+    # shellcheck disable=SC1090
+    source "${CONFIG}"
+  else
+    echo "ERROR: non-existent configuration specified"
+    exit 1
+  fi
+fi
+
+OPTIND=1
+while getopts "${CMDOPTS}" opt; do
+  case "${opt}" in
+    # These have already been parsed in first pass
+    b|c|h)
+      ;;
+    d)
+      PODMAN=docker
+      ;;
     i)
       BUILD_IMG="${OPTARG}"
       ;;
@@ -113,6 +165,9 @@ while getopts "b:dhi:l:t:p:v:CH" opt; do
     H)
       SKIP_HOSTID="yes"
       ;;
+    R)
+      REMOVE_HOST_FILES="yes"
+      ;;
     p)
       BUILD_ARGS+=( "-p" "${OPTARG}" )
       ;;
@@ -132,11 +187,6 @@ if ! command -v "${PODMAN}" >/dev/null 2>&1; then
 fi
 
 # Always mount a build directory at /build
-if ! BUILD_DIRECTORY="$( sanitise_path "${BUILD_DIRECTORY}" )"; then
-  echo "ERROR: build directory does not exist"
-  exit 1
-fi
-
 VOLUME_ARGS+=( "-v" "${BUILD_DIRECTORY}:/build" )
 
 # Only mount a local repo at /zbm if specified
@@ -154,9 +204,21 @@ if [ -n "${BUILD_TAG}" ]; then
   BUILD_ARGS+=( "-t" "${BUILD_TAG}" )
 fi
 
+if boolean_enabled "${REMOVE_HOST_FILES}"; then
+  # Remove existing host files
+  for host_file in "hostid" "zpool.cache"; do
+    [ -e "${BUILD_DIRECTORY}/${host_file}" ] || continue
+    if ! rm "${BUILD_DIRECTORY}/${host_file}"; then
+      echo "ERROR: failed to remove file '${host_file}' from build directory"
+      exit 1
+    fi
+    echo "Removed file '${host_file}' by user request"
+  done
+fi
+
 # If no local hostid is available, copy the system hostid if desired
 if ! [ -r "${BUILD_DIRECTORY}"/hostid ]; then
-  if [ "${SKIP_HOSTID}" != "yes" ] && [ -r /etc/hostid ]; then
+  if ! boolean_enabled "${SKIP_HOSTID}" && [ -r /etc/hostid ]; then
     if ! cp /etc/hostid "${BUILD_DIRECTORY}"/hostid; then
       echo "ERROR: unable to copy /etc/hostid"
       echo "Copy a hostid file to ./hostid or use -H to disable"
@@ -167,7 +229,7 @@ fi
 
 # If no local zpool.cache is available, copy the system cache if desired
 if ! [ -r "${BUILD_DIRECTORY}"/zpool.cache ]; then
-  if [ "${SKIP_CACHE}" != "yes" ] && [ -r /etc/zfs/zpool.cache ]; then
+  if ! boolean_enabled "${SKIP_CACHE}" && [ -r /etc/zfs/zpool.cache ]; then
     if ! cp /etc/zfs/zpool.cache "${BUILD_DIRECTORY}"/zpool.cache; then
       echo "ERROR: unable to copy /etc/zfs/zpool.cache"
       echo "Copy a zpool cache to ./zpool.cache or use -C to disable"
@@ -178,7 +240,6 @@ fi
 
 # If no config is specified, use in-tree default but force EFI and components
 if ! [ -r "${BUILD_DIRECTORY}"/config.yaml ]; then
-  BUILD_ARGS+=( "-c" "/zbm/etc/zfsbootmenu/config.yaml" )
   BUILD_ARGS+=( "-e" ".EFI.Enabled=true" )
   BUILD_ARGS+=( "-e" ".Components.Enabled=true" )
 fi