refactor: ♻️ start rewrite

BREAKING CHANGE: everything

README.md

@@ -1,9 +1 @@
 # snap-pac-uki
-Pacman hooks creating unified kernel images for snapshots created by snap-pac.
-
-## Limits
-- only works on the "root" snap-pac config
-- puts all UKIs into `/boot/EFI/Linux/`
-- kernel parameters are extracted from a file called `/boot/loader/entries/00-arch.conf`
-- expects that the default subvolume is mounted via kernel command line
-- expects that the default subvolume is called `@`

hooks/01_snap-pac-uki_pre.hook

@@ -1,12 +0,0 @@
-[Trigger]
-Operation = Upgrade
-Operation = Install
-Operation = Remove
-Type = Package
-Target = *
-
-[Action]
-Description = Performing pre UKI creation...
-When = PreTransaction
-Exec = /usr/share/libalpm/scripts/snap-pac-uki_create.fish
-AbortOnFail

hooks/zzy_snap-pac-uki_post.hook

@@ -1,11 +0,0 @@
-[Trigger]
-Operation = Upgrade
-Operation = Install
-Operation = Remove
-Type = Package
-Target = *
-
-[Action]
-Description = Performing post UKI creation...
-When = PostTransaction
-Exec = /usr/share/libalpm/scripts/snap-pac-uki_create.fish

hooks/zzz_snap-pac-uki_cleanup.hook

@@ -1,11 +0,0 @@
-[Trigger]
-Operation = Upgrade
-Operation = Install
-Operation = Remove
-Type = Package
-Target = *
-
-[Action]
-Description = Performing UKI cleanup...
-When = PostTransaction
-Exec = /usr/share/libalpm/scripts/snap-pac-uki_cleanup.fish

install.fish

@@ -1,4 +0,0 @@
-#!/bin/fish
-
-cp ./hooks/* /usr/share/libalpm/hooks/
-cp ./scripts/* /usr/share/libalpm/scripts/

scripts/snap-pac-uki_cleanup.fish

@@ -1,17 +0,0 @@
-#!/bin/fish
-
-# get snapshots
-set -l config "root"
-set -l snapshot_ids (snapper -c $config --jsonout ls | jq ".$config | .[] | .number")
-
-
-# get current ukis
-set -l ukis (ls /boot/EFI/Linux/ | grep '^snap-pac-uki-[1-9][0-9]*\.efi$' | grep -o "[1-9][0-9]*")
-
-for x in $ukis
-    if not contains $x $snapshot_ids
-        set -l path "/boot/EFI/Linux/snap-pac-uki-$x.efi"
-        rm $path
-        echo "==> removed UKI: $path"
-    end
-end

scripts/snap-pac-uki_create.fish

@@ -1,46 +1,103 @@
 #!/bin/fish
 
-# get id and type of last snapshot
+function error -d "prints an error and terminates the program" -a error
-set -l config "root"
+    echo $error
-set -l snapshot (snapper -c $config --jsonout ls | jq -c ".$config | last")
-set -l id (echo $snapshot | jq ".number")
 
-if not contains (echo $snapshot | jq -r ".type") "pre" "post"
+    exit 1
-    echo "==> last snapshot type is neither 'pre' nor 'post'; no UKI creation"
-    exit
 end
 
+function checkdeps -d "check for depenencies"
+    set -l deps "jq" "snapper"
 
-# check if UKI already exists
+    for dep in $deps
-set -l ukis (ls /boot/EFI/Linux/ | grep '^snap-pac-uki-[1-9][0-9]*\.efi$' | grep -o "[1-9][0-9]*")
+        which $dep >/dev/null 2>/dev/null
-
+        if test $status != "0"
-if contains $id $ukis
+            error "didn't find depenecy: $dep"
-    echo "==> UKI already exists; no UKI creation"
+        end
-    exit
+    end
 end
 
+function load_config -d "loads the config from a config file" -a cfg
+    # set default values
+    set -g BUILD_PATH "/tmp/snap-pac-uki"
+    set -g EFI_DIR "/efi/EFI/Linux/"
+    set -g SNAPPER_CONFIG "root"
+    set -g SNAPSHOT_SUBVOL "@snapshots"
 
-# prepare uki creation
+    # load file
-set -l buildpath "/tmp/snap-pac-uki/$id"
+    set -l cfg (jq -c <$cfg)
-mkdir -p $buildpath
-rm -rf "$buildpath/*"
-cd $buildpath
 
-sed "s/BUILD_ID=.*/BUILD_ID=\"Snapshot $id\"/" </usr/lib/os-release >./os-release
+    # parse config
+    set -l cfgs "build_path" "efi_dir" "kernel_cmd" "fallback_cmd" "snapper_config" "snapshot_subvol"
+    for c in $cfgs
+        echo $cfg | jq -e ".$c" >/dev/null
 
-grep options /boot/loader/entries/00-arch.conf | \
+        switch $status
-    string sub -s 9 | \
+            case "0"
-    sed ':a;N;$!ba;s/\n/ /g' | \
+                set -g (echo $c | sed "s/./\U&/g") (echo $cfg | jq -r ".$c")
-    sed "s/subvol=@/subvol=@snapshots\\/$id\\/snapshot/" >./kernel-parameters
+            case "4"
+                error "failed to parse option: $c"
+        end
+    end
 
+    # check for mandatory options
+    set -l mandatory_cfgs "kernel_cmd" "fallback_cmd"
+    for mc in $mandatory_cfgs
+        set -gq (echo $mc | sed "s/./\U&/g")
 
-# create uki
+        if test $status != 0
-set -l ukipath "/boot/EFI/Linux/snap-pac-uki-$id.efi"
+            error "missing config parameter: $mc"
-objcopy \
+        end
-    --add-section .osrel="./os-release" --change-section-vma .osrel=0x20000 \
+    end
-    --add-section .cmdline="./kernel-parameters" --change-section-vma .cmdline=0x30000 \
+end
+
+function get_last_snapshot -d "reads the last snapper snapshot id"
+    set -g SNAPSHOT_ID (snapper -c $SNAPPER_CONFIG --jsonout ls | jq ".$SNAPPER_CONFIG | last | .number")
+    echo $SNAPSHOT_ID
+end
+
+function create_uki -d "creates a new uki" -a fallback
+    # prepare directory
+    set -l bp "$BUILD_PATH/$SNAPSHOT_ID"
+    mkdir -p $bp
+    rm -rf "$bp/*"
+
+    # os-release
+    sed "s/BUILD_ID=.*/BUILD_ID=\"Snapshot $SNAPSHOT_ID\"/" </usr/lib/os-release >"$bp/os-release"
+
+    # kernel cmd
+    echo $KERNEL_CMD | sed "s/SNAPSHOT/$SNAPSHOT_SUBVOL\\/$SNAPSHOT_ID\\/snapshot/" >"$bp/kernel-cmd"
+
+    # create uki
+    objcopy \
+        --add-section .osrel="$bp/os-release" --change-section-vma .osrel=0x20000 \
+        --add-section .cmdline="$bp/kernel-cmd" --change-section-vma .cmdline=0x30000 \
         --add-section .splash="/usr/share/systemd/bootctl/splash-arch.bmp" --change-section-vma .splash=0x40000 \
         --add-section .linux="/boot/vmlinuz-linux" --change-section-vma .linux=0x2000000 \
-    --add-section .initrd="/boot/initramfs-linux.img" --change-section-vma .initrd=0x3000000 \
+        --add-section .initrd="/boot/initramfs-linux$fallback.img" --change-section-vma .initrd=0x3000000 \
-    "/usr/lib/systemd/boot/efi/linuxx64.efi.stub" $ukipath
+        "/usr/lib/systemd/boot/efi/linuxx64.efi.stub" "$bp/arch-linux-$SNAPSHOT_ID$fallback.efi"
-echo "==> created UKI: $ukipath"
+end
+
+function copy_current -d "copies new ukis to efi"
+    # copy to "current"
+    cp "$BUILD_PATH/$SNAPSHOT_ID/arch-linux-$SNAPSHOT_ID.efi" "$EFI_DIR/arch-linux-current.efi"
+    cp "$BUILD_PATH/$SNAPSHOT_ID/arch-linux-$SNAPSHOT_ID-fallback.efi" "$EFI_DIR/arch-linux-fallback.efi"
+
+    # copy to "snapshots"
+    cp "$BUILD_PATH/$SNAPSHOT_ID/arch-linux-$SNAPSHOT_ID.efi" $EFI_DIR
+end
+
+function main -d "the main function"
+    checkdeps
+    load_config "/etc/snap-pac-uki.json"
+
+    get_last_snapshot
+    create_uki
+    create_uki "-fallback"
+
+    copy_current
+
+    exit 0
+end
+
+main

uninstall.fish

@@ -1,9 +0,0 @@
-#!/bin/fish
-
-for x in (ls ./hooks)
-    rm "/usr/share/libalpm/hooks/$x"
-end
-
-for x in (ls ./scripts)
-    rm "/usr/share/libalpm/scripts/$x"
-end