feat(installer): delete dracut path; the Flatcar kernel already carries its initramfs (#128)

docs/skills/avoid-over-engineering.md

@@ -53,7 +53,7 @@ existing repo convention already does the job.
 | "A forwarding recipe is harmless." | It duplicates the command surface and rots when the real recipe changes. |
 | "I don't need to re-validate after a tiny cut." | `just validate` is the merge contract. Run it every time. |
 | "This build dep isn't named in the commands, so it's unused." | `manual`/`script` element commands run in a sandbox that still needs `/bin/sh` and coreutils. Cutting the dep that supplies them breaks the build even if `make` itself is never called. |
-| "The tool I depend on doesn't need grep/sed/gzip/etc." | Build tools like `dracut` and archive pipelines invoke `grep`, `sed`, `gzip`, `kmod` (`depmod`), and `ldconfig` internally. If the sandbox doesn't have them, the tool fails with opaque "command not found" (exitcode 127) or missing-library errors. |
+| "The tool I depend on doesn't need grep/sed/gzip/etc." | Archive pipelines and build tools invoke `grep`, `sed`, `gzip`, `kmod` (`depmod`), and `ldconfig` internally. If the sandbox doesn't have them, the tool fails with opaque "command not found" (exitcode 127) or missing-library errors. |
 
 ## Red Flags
 

docs/skills/ddi-installer-build.md

@@ -101,7 +101,7 @@ The release process is driven by `.github/workflows/build.yml`:
 | Rationalization | Reality |
 |---|---|
 | "A bash script is simpler." | A bash script cannot run the systemd-native interactive installer TUI. Use `systemd-sysinstall`. |
-| "Kernel image is at `/boot/vmlinuz`." | FSDK installs kernels into `/usr/lib/modules/<kver>/vmlinuz`. Toolchains (dracut, ukify, PXE export) must point to `/usr/lib/modules/<kver>/vmlinuz`. |
+| "Kernel image is at `/boot/vmlinuz`." | FSDK installs kernels into `/usr/lib/modules/<kver>/vmlinuz`. Toolchains (ukify, PXE export) must point to `/usr/lib/modules/<kver>/vmlinuz`. |
 | "Initrd archive tools (gzip, cpio) are in base-stack." | In FSDK 26.08, gzip and cpio are standalone components; elements packing or unpacking initrds must explicitly declare `components/gzip.bst` and `components/cpio.bst` in `build-depends`. |
 | "Use knuckle instead." | knuckle is deprecated in favor of native `systemd-sysinstall` (systemd 261+). |
 | "Hardcode `root=/dev/vda2` for QEMU." | Bare metal has different device names. Always use PARTUUID. |

docs/skills/ddi-installer.md

@@ -163,8 +163,7 @@ offline installation.
 | Rationalization | Reality |
 |---|---|
 | "A bash script is simpler." | A bash script cannot run the systemd-native interactive installer TUI. Use `systemd-sysinstall`. |
-| "Kernel image is at `/boot/vmlinuz`." | FSDK installs kernels into `/usr/lib/modules/<kver>/vmlinuz`. Toolchains (dracut, ukify, PXE export) must point to `/usr/lib/modules/<kver>/vmlinuz`. |
-| "dracut finds glibc libraries automatically." | In FSDK 26.08, glibc libraries live under `/usr/lib/x86_64-linux-gnu`. `dracut-install` requires `/etc/ld.so.conf` to include `/usr/lib/x86_64-linux-gnu` and `ldconfig` to generate `/etc/ld.so.cache` before dracut runs. |
+| "Kernel image is at `/boot/vmlinuz`." | FSDK installs kernels into `/usr/lib/modules/<kver>/vmlinuz`. Toolchains (ukify, PXE export) must point to `/usr/lib/modules/<kver>/vmlinuz`. |
 | "Initrd archive tools (gzip, cpio) are in base-stack." | In FSDK 26.08, gzip and cpio are standalone components; elements packing or unpacking initrds must explicitly declare `components/gzip.bst` and `components/cpio.bst` in `build-depends`. |
 | "Use knuckle instead." | knuckle is deprecated in favor of native `systemd-sysinstall` (systemd 261+). |
 | "Hardcode `root=/dev/vda2` for QEMU." | Bare metal has different device names. Always use PARTUUID. |

elements/oci/bluefin-server-installer.bst

@@ -31,14 +31,10 @@ description: |
 build-depends:
   # Toolchain for assembly
   - base/base-stack.bst
-  - freedesktop-sdk.bst:components/dracut.bst
   - freedesktop-sdk.bst:components/kmod.bst
   - freedesktop-sdk.bst:components/cpio.bst      # newc cpio archive creation
   - freedesktop-sdk.bst:components/findutils.bst # find for cpio pipe
   - freedesktop-sdk.bst:components/gzip.bst      # gzip for initrd cpio
-  # grep/sed are required by dracut/dracut-install even though our commands don't name them.
-  - freedesktop-sdk.bst:components/grep.bst
-  - freedesktop-sdk.bst:components/sed.bst
   - freedesktop-sdk.bst:components/zstd.bst       # compress initrd + final disk
   # ukify assembles the UKI (kernel + initrd + cmdline -> .efi)
   - freedesktop-sdk.bst:components/systemd-ukify.bst
@@ -87,7 +83,7 @@ config:
       mkdir -p /layer/boot
       mkdir -p /target-root/boot/EFI/Linux /tmp /var/tmp
 
-    # ── Step 1b: Generate target OS UKI (dracut + ukify) ────────────────
+    # ── Step 1b: Generate target OS UKI (ukify) ─────────────────────────
     - |
       set -eux
       TARGET_KVER="$(basename "$(find /target-root/usr/lib/modules -mindepth 1 -maxdepth 1 -type d | head -n1)")"
@@ -105,38 +101,8 @@ config:
 
       depmod -b /target-root "${TARGET_KVER}" || true
 
-      # Configure dynamic linker search paths so ldconfig indexes FSDK libraries
-      # (e.g. libc.so.6, libgcc_s.so.1, libkmod.so) for dracut-install
-      printf '/usr/lib/x86_64-linux-gnu\n/usr/lib/x86_64-linux-gnu/systemd\n' > /etc/ld.so.conf
-      if [ -d /etc/ld.so.conf.d ]; then
-        echo 'include /etc/ld.so.conf.d/*.conf' >> /etc/ld.so.conf
-      fi
-      ldconfig
-
-      # Build target-root linker cache and stage it at /etc/ld.so.cache for dracut
-      mkdir -p /target-root/tmp /target-root/etc
-      printf '/usr/lib/x86_64-linux-gnu\n/usr/lib/x86_64-linux-gnu/systemd\n' > /target-root/tmp/ld.so.conf
-      if [ -d /target-root/etc/ld.so.conf.d ]; then
-        echo 'include /etc/ld.so.conf.d/*.conf' >> /target-root/tmp/ld.so.conf
-      fi
-      ldconfig -r /target-root -f /tmp/ld.so.conf
-      rm -f /target-root/tmp/ld.so.conf
-      cp /target-root/etc/ld.so.cache /etc/ld.so.cache
-
-      # Run dracut in generic (non-hostonly) mode and explicitly add XFS, VirtIO, and NVMe storage drivers.
-      dracut -v --reproducible --no-machineid --no-hostonly \
-        --add-drivers "virtio virtio_blk virtio_pci virtio_scsi nvme nvme_core xfs erofs overlay zfs spl" \
-        --filesystems "xfs vfat zfs" \
-        --install /etc/ld.so.cache \
-        --kmoddir "/target-root/usr/lib/modules/${TARGET_KVER}" \
-        --kernel-image "${TARGET_KERNEL}" \
-        --kver "${TARGET_KVER}" \
-        --kernel-cmdline "rw console=ttyS0,115200 console=tty0 quiet loglevel=3 audit=0" \
-        /tmp/bluefin-server-target.initramfs
-
       ukify build \
         --linux="${TARGET_KERNEL}" \
-        --initrd=/tmp/bluefin-server-target.initramfs \
         --cmdline="rw console=ttyS0,115200 console=tty0 quiet loglevel=3 audit=0" \
         --output=/target-root/boot/EFI/Linux/bluefin-server.efi
       cp /target-root/boot/EFI/Linux/bluefin-server.efi /layer/usr/lib/bluefin-server/bluefin-server.efi
@@ -184,16 +150,6 @@ config:
       #!/bin/bash
       set -euo pipefail
 
-      # Ensure storage controller modules and filesystems are loaded before probing devices
-      modprobe -q nvme || true
-      modprobe -q nvme_core || true
-      modprobe -q usb-storage || true
-      modprobe -q uas || true
-      modprobe -q ahci || true
-      modprobe -q sd_mod || true
-      modprobe -q xfs || true
-      udevadm trigger --subsystem-match=block || true
-      udevadm settle --timeout=15 || true
       # Auto-detect target disk for unattended install (any raw disk of type "disk" that is not the installer, is not read-only, and has size > 0)
       TARGET_DISK=""
       INSTALLER_PART="$(readlink -f /dev/disk/by-partlabel/bluefin-installer-data 2>/dev/null || true)"
@@ -293,8 +249,6 @@ config:
       mkdir -p /layer/etc/systemd/system/systemd-sysinstall.service.d
       cat > /layer/etc/systemd/system/systemd-sysinstall.service.d/override.conf << 'EOF'
       [Unit]
-      After=systemd-udev-settle.service
-      Wants=systemd-udev-settle.service
       SuccessAction=poweroff
       FailureAction=poweroff
 

tests/unit/test_installer_contract.py

@@ -101,25 +101,37 @@ def test_ddi_generates_module_indexes_for_runtime_filesystem_drivers() -> None:
     assert "> /layer/etc/hosts" in ddi_element
 
 
-def test_target_initramfs_preloads_sysext_filesystem_drivers() -> None:
+def test_target_uki_build_does_not_invoke_dracut() -> None:
     installer_element = INSTALLER_ELEMENT.read_text(encoding="utf-8")
-
-    assert (
-        '--add-drivers "virtio virtio_blk virtio_pci virtio_scsi nvme nvme_core xfs erofs overlay zfs spl"'
-        in installer_element
+    data = yaml.safe_load(installer_element)
+    dep_names = [
+        dep if isinstance(dep, str) else dep.get("filename", "")
+        for dep in data.get("build-depends", [])
+    ]
+    commands = data.get("config", {}).get("commands", [])
+    commands_text = "\n".join(
+        cmd if isinstance(cmd, str) else "\n".join(cmd) for cmd in commands
     )
 
+    assert "freedesktop-sdk.bst:components/dracut.bst" not in dep_names
+    assert "freedesktop-sdk.bst:components/grep.bst" not in dep_names
+    assert "freedesktop-sdk.bst:components/sed.bst" not in dep_names
+    assert "dracut" not in commands_text
+    assert "--add-drivers" not in commands_text
+    assert "ld.so.cache" not in commands_text
+    target_uki_cmd = commands[1] if len(commands) > 1 else ""
+    assert '--linux="${TARGET_KERNEL}"' in target_uki_cmd
+    assert "--initrd" not in target_uki_cmd
+
 
-def test_installer_loads_storage_drivers_and_settles_udev() -> None:
+def test_installer_omits_module_force_load_and_udev_settle_workarounds() -> None:
     installer_element = INSTALLER_ELEMENT.read_text(encoding="utf-8")
 
-    assert "modprobe -q nvme || true" in installer_element
-    assert "modprobe -q nvme_core || true" in installer_element
-    assert "modprobe -q usb-storage || true" in installer_element
-    assert "modprobe -q uas || true" in installer_element
-    assert "udevadm settle --timeout=15 || true" in installer_element
-    assert "After=systemd-udev-settle.service" in installer_element
-    assert "Wants=systemd-udev-settle.service" in installer_element
+    assert "modprobe -q nvme" not in installer_element
+    assert "modprobe -q usb-storage" not in installer_element
+    assert "udevadm settle --timeout=15" not in installer_element
+    assert "After=systemd-udev-settle.service" not in installer_element
+    assert "Wants=systemd-udev-settle.service" not in installer_element
 
 def test_interactive_installer_uses_local_virtual_console() -> None:
     installer_element = INSTALLER_ELEMENT.read_text(encoding="utf-8")