refactor(os): Fix function numbering (#19)

README.md

@@ -109,6 +109,30 @@ In cases where a variable is both exported prior to script execution and specifi
 
 Known options are as follows.
 
+### Kernel downgrade
+
+By default we install newest `linux` and `linux-headers` packages into a `chroot`. Once we're in that `chroot` we then install newest [AUR zfs-dkms package](https://aur.archlinux.org/packages/zfs-dkms). You may want to override `linux` and `linux-headers` versions we're installing to ensure you end up with a compatible mix between them and `zfs-dkms`.
+
+For example:
+```
+export ARCHZBM_KERNEL_VER=6.5.9.arch2
+```
+
+In our `chroot` this will trigger execution of:
+```
+downgrade --ala-only 'linux=6.5.9.arch2' 'linux-headers=6.5.9.arch2' --ignore always
+```
+
+Where `downgrade` is the [AUR downgrade package](https://aur.archlinux.org/packages/downgrade). This will downgrade `linux` and `linux-headers` and will add a setting to your `/etc/pacman.conf`:
+```
+[options]
+IgnorePkg = linux linux-headers
+```
+
+Setting `ARCHZBM_KERNEL_VER` to an empty string `''` or keeping it undefined are both valid and will retain newest versions instead of downgrading.
+
+Also read [Kernel selection](#kernel-selection) for details.
+
 ### Compression
 
 By default we create a zpool with ZFS property `compression=on`. If the `lz4_compress` pool feature is active this will by default enable `compression=lz4`. See `man 7 zfsprops` for example in ZFS 2.1.9 for details. See `zpool get feature@lz4_compress <pool>` to check this feature's status on your `<pool>`.
@@ -296,6 +320,24 @@ When it comes to the point that your SSH client sends an are-your-still-there me
 
 This effectively configures your SSH client to remain connected even through somewhat lossy hops to the Dropbear daemon; and to cleanly disconnect 3 seconds and some change after you've executed whatever you needed to do in ZFSBootMenu.
 
+# Kernel selection
+
+This script compiles ZFS via Arch Linux' [Dynamic Kernel Module Support](https://wiki.archlinux.org/title/Dynamic_Kernel_Module_Support) (DKMS). Not all kernels allow for successful compilation, in some instances a particularly recent kernel version may change APIs to such a degree that ZFS compilation simply fails.
+
+We strongly suggest to that you:
+
+- Firstly, refer to a resource such as the [Arch Linux Archive package version list](https://archive.archlinux.org/packages/l/linux/) to find out what newest kernel version this script will install.
+- Secondly, research if newest [AUR zfs-dkms package](https://aur.archlinux.org/packages/zfs-dkms) is compatible with that kernel. Two reasonable points of contact are AUR and its comments section for `zfs-dkms` where users quickly report issues; and the [github.com/openzfs/zfs issues list](https://github.com/openzfs/zfs/issues).
+
+An example for this is that `linux-6.6.1.arch1-1-x86_64` released on Wednesday, November 8, 2023 at a time when newest `zfs-dkms` package version [was 2.2.0](https://aur.archlinux.org/cgit/aur.git/commit/?h=zfs-dkms&id=da1b6372c57b16f2781a7fda2b95971bb392c5ee) which did not compile against `linux` 6.6.x.
+
+You'd then set for example:
+```
+export ARCHZBM_KERNEL_VER=6.5.9.arch2
+```
+
+Where any 6.5.x version is known to work well with `zfs-dkms`. See also [Kernel downgrade](#kernel-downgrade) for details on how to configure this.
+
 # Flavor choices
 
 We make the following opinionated flavor choices. Feel free to change them to your liking.

setup.sh

@@ -68,6 +68,10 @@ function setup_env_vars () {
     echo '----------------------------------------'
     echo
 
+    read -u3 -p 'Please type kernel version to use, leave empty for latest, confirm with <Enter>: ' -s ARCHZBM_KERNEL_VER
+    echo
+    echo
+
     echo 'Do you want compressed datasets?'
     select arg_compressed in "Compressed" "Uncompressed"; do
         case "${arg_compressed}" in
@@ -278,6 +282,48 @@ function setup_env_vars () {
         fi
     fi
 
+    if [[ "${want_ssh_in_zbm}" ]]; then
+        echo 'Do you want to define OS root user'"'"'s SSH pub key?'
+        select arg_root_pub_keys in 'Yes (let me specify)' 'Yes (use ZBM pub keys)' 'No (don'"'"'t enable sshd.service)'; do
+            case "${arg_root_pub_keys}" in
+                'Yes (let me specify)')
+                    want_custom_pub_keys_in_os='true'
+                    break
+                    ;;
+                'Yes (use ZBM pub keys)')
+                    ARCHZBM_OS_SSH_AUTH_KEYS="${ARCHZBM_SSH_AUTH_KEYS}"
+                    break
+                    ;;
+                'No (don'"'"'t enable sshd.service)')
+                    break
+                    ;;
+            esac
+        done <&3 && echo
+
+        if [[ "${want_custom_pub_keys_in_os}" ]]; then
+            read -u3 -p 'Please type SSH pub keys on one line separated by double-commas (,,) and confirm with <Enter>: ' ARCHZBM_OS_SSH_AUTH_KEYS
+            echo
+        fi
+    else
+        echo 'Do you want to define OS root user'"'"'s SSH pub key?'
+        select arg_root_pub_keys in 'Yes (let me specify)' 'No (don'"'"'t enable sshd.service)'; do
+            case "${arg_root_pub_keys}" in
+                'Yes (let me specify)')
+                    want_own_pub_key_in_os='true'
+                    break
+                    ;;
+                'No (don'"'"'t enable sshd.service)')
+                    break
+                    ;;
+            esac
+        done <&3 && echo
+
+        if [[ "${want_own_pub_key_in_os}" ]]; then
+            read -u3 -p 'Please type SSH pub keys on one line separated by double-commas (,,) and confirm with <Enter>: ' ARCHZBM_OS_SSH_AUTH_KEYS
+            echo
+        fi
+    fi
+
     if [[ "${want_dns_and_ntp}" ]]; then
         read -u3 -p 'Specify one or more comma-separated DNS IPs: ' ARCHZBM_OS_DNS_IP
         echo
@@ -301,7 +347,7 @@ function setup_env_vars () {
         fi
     fi
 
-    for env_var in 'ARCHZBM_ZFSPROPS_NO_COMPRESSION' 'ARCHZBM_ZFSPROPS_NO_ENCRYPTION' 'ARCHZBM_ZPOOL_PASSWORD' 'ARCHZBM_ROOT_PASSWORD' 'ARCHZBM_NET_AUTOCONF' 'ARCHZBM_NET_DEVICE' 'ARCHZBM_NET_CLIENT_IP' 'ARCHZBM_NET_NETMASK' 'ARCHZBM_NET_GATEWAY_IP' 'ARCHZBM_SSH_PORT' 'ARCHZBM_SSH_KEEPALIVE_INTVL' 'ARCHZBM_SSH_AUTH_KEYS' 'ARCHZBM_OS_CLIENT_IP' 'ARCHZBM_OS_GATEWAY_IP' 'ARCHZBM_OS_DNS_IP' 'ARCHZBM_OS_NTP_IP'; do
+    for env_var in 'ARCHZBM_KERNEL_VER' 'ARCHZBM_ZFSPROPS_NO_COMPRESSION' 'ARCHZBM_ZFSPROPS_NO_ENCRYPTION' 'ARCHZBM_ZPOOL_PASSWORD' 'ARCHZBM_ROOT_PASSWORD' 'ARCHZBM_NET_AUTOCONF' 'ARCHZBM_NET_DEVICE' 'ARCHZBM_NET_CLIENT_IP' 'ARCHZBM_NET_NETMASK' 'ARCHZBM_NET_GATEWAY_IP' 'ARCHZBM_SSH_PORT' 'ARCHZBM_SSH_KEEPALIVE_INTVL' 'ARCHZBM_SSH_AUTH_KEYS' 'ARCHZBM_OS_CLIENT_IP' 'ARCHZBM_OS_GATEWAY_IP' 'ARCHZBM_OS_SSH_AUTH_KEYS' 'ARCHZBM_OS_DNS_IP' 'ARCHZBM_OS_NTP_IP'; do
         if [[ "${!env_var}" ]]; then
             printf -- '%s='"'"'%s'"'"'\n' \
                 "${env_var}" "${!env_var}" \
@@ -312,7 +358,7 @@ function setup_env_vars () {
     printf -- '%s\n' \
         'Done, please rerun script now with just' \
         '... | bash' \
-        'so without the '"'"'setup'"'"' argument's
+        'so without the '"'"'setup'"'"' argument'
     exit 77
 }
 
@@ -1047,7 +1093,6 @@ EFI:
   ImageDir: /efi/EFI/ZBM
   Versions: false
   Enabled: true
-  Stub: /usr/share/zfsbootmenu/stubs/linuxx64.efi.stub/linuxx64.efi.stub  # workaround: https://github.com/zbm-dev/zfsbootmenu/discussions/501
 Kernel:
   CommandLine: ro loglevel=0 zbm.import_policy=hostid
   Prefix: vmlinuz
@@ -1261,6 +1306,13 @@ function install_os_in_chroot () {
     unleash_makepkg                             #2.5
     add_motd_getting_started_msg                #2.6
     get_aur_helper                              #2.7
+    if [[ "${ARCHZBM_KERNEL_VER}" ]]; then
+        paru_install 'downgrade'
+        yes | downgrade --ala-only \
+            'linux='"${ARCHZBM_KERNEL_VER}" \
+            'linux-headers='"${ARCHZBM_KERNEL_VER}" \
+            --ignore always
+    fi
     paru_install 'zfs-dkms' 'zfs-utils' 'jq'
     hwclock --systohc
     mkinitcpio -P
@@ -1312,8 +1364,8 @@ EOF
         [[ "${ARCHZBM_OS_NTP_IP}" ]]; then
 
         cat >> '/mnt/etc/systemd/network/50-wired.network' <<EOF
-Address="${ARCHZBM_OS_CLIENT_IP}"
-Gateway="${ARCHZBM_OS_GATEWAY_IP}"
+Address=${ARCHZBM_OS_CLIENT_IP}
+Gateway=${ARCHZBM_OS_GATEWAY_IP}
 EOF
 
         if [[ "${ARCHZBM_OS_DNS_IP}" ]]; then
@@ -1324,7 +1376,7 @@ EOF
         fi
         for dns_addr in "${dns_addresses[@]}"; do
             cat >> '/mnt/etc/systemd/network/50-wired.network' <<EOF
-DNS="${dns_addr}"
+DNS=${dns_addr}
 EOF
         done
 
@@ -1332,7 +1384,7 @@ EOF
             mapfile -t ntp_addresses < <(<<<"${ARCHZBM_OS_NTP_IP}" tr ',' '\n' | sed '/^$/d')
             for ntp_addr in "${ntp_addresses[@]}"; do
                 cat >> '/mnt/etc/systemd/network/50-wired.network' <<EOF
-NTP="${ntp_addr}"
+NTP=${ntp_addr}
 EOF
             done
         fi
@@ -1356,29 +1408,50 @@ EOF
     systemctl disable 'systemd-networkd-wait-online' --root='/mnt'
 }
 
-function configure_dns () {
+function configure_sshd () {
     #3.4
+    local pub_key_line
+
+    cat >> '/mnt/etc/ssh/sshd_config.d/40-defaults.conf' <<"EOF"
+PasswordAuthentication no
+PermitRootLogin yes
+EOF
+
+    while IFS= read -r pub_key_line; do
+        printf -- '%s\n' "${pub_key_line}" >> '/mnt/root/.ssh/authorized_keys'
+    done < <(<<<"${ARCHZBM_OS_SSH_AUTH_KEYS}" sed -r -e 's/,,/\n/g')
+
+    systemctl enable 'sshd.service' --root='/mnt'
+}
+
+function configure_dns () {
+    #3.5
     rm '/mnt/etc/resolv.conf'
     ln -s '/run/systemd/resolve/stub-resolv.conf' '/mnt/etc/resolv.conf'
 
     # Optionally you may want /etc/systemd/network/50-wired.network to use
     # UseDNS=no and hardcode DNS server(s) here:
     # sed -i 's/^#DNS=.*/DNS=1.1.1.1/' /mnt/etc/systemd/resolved.conf
-    systemctl enable 'systemd-resolved' --root='/mnt'
+    systemctl enable 'systemd-resolved.service' --root='/mnt'
+}
+
+function configure_ntp () {
+    #3.6
+    systemctl enable 'systemd-timesyncd.service' --root='/mnt'
 }
 
 function configure_reflector () {
-    #3.5
+    #3.7
     systemctl enable 'reflector.service' 'reflector.timer' --root='/mnt'
 }
 
 function configure_zfs () {
-    #3.6
-    systemctl enable 'zfs-import-cache' 'zfs-mount' 'zfs-import.target' 'zfs.target' --root='/mnt'
+    #3.8
+    systemctl enable 'zfs-import-cache.service' 'zfs-mount.service' 'zfs-import.target' 'zfs.target' --root='/mnt'
 }
 
 function configure_zfs_mount_gen () {
-    #3.7
+    #3.9
     mkdir -p '/mnt/etc/zfs/zfs-list.cache'
     touch '/mnt/etc/zfs/zfs-list.cache/'"${zpool_name}"
     zfs list -H -o name,mountpoint,canmount,atime,relatime,devices,exec,readonly,setuid,nbmand | sed 's/\/mnt//' > '/mnt/etc/zfs/zfs-list.cache/'"${zpool_name}"
@@ -1386,7 +1459,7 @@ function configure_zfs_mount_gen () {
 }
 
 function set_new_uefi_boot_entries () {
-    #3.8
+    #3.10
     declare -a uefi_images
     mapfile -t uefi_images < \
         <(find '/mnt/efi/EFI/ZBM' -type f -iname '*.efi' -print0 | \
@@ -1429,7 +1502,7 @@ function set_new_uefi_boot_entries () {
 }
 
 function umount_all () {
-    #3.9
+    #3.11
     if [[ "${part_schema}" = 'mbr' ]]; then
         umount '/mnt/boot/syslinux'
     else
@@ -1441,16 +1514,20 @@ function umount_all () {
 
 function finalize_os_setup () {
     #3.1
-    set_root_pw                                 #3.2
-    configure_networking                        #3.3
-    configure_dns                               #3.4
-    configure_reflector                         #3.5
-    configure_zfs                               #3.6
-    configure_zfs_mount_gen                     #3.7
-    if [[ "${part_schema}" = 'gpt' ]]; then
-        set_new_uefi_boot_entries               #3.8
+    set_root_pw                                     #3.2
+    configure_networking                            #3.3
+    if [[ "${ARCHZBM_OS_SSH_AUTH_KEYS}" ]]; then
+        configure_sshd                              #3.4
     fi
-    umount_all                                  #3.9
+    configure_dns                                   #3.5
+    configure_ntp                                   #3.6
+    configure_reflector                             #3.7
+    configure_zfs                                   #3.8
+    configure_zfs_mount_gen                         #3.9
+    if [[ "${part_schema}" = 'gpt' ]]; then
+        set_new_uefi_boot_entries                   #3.10
+    fi
+    umount_all                                      #3.11
 }
 
 function main () {
@@ -1458,29 +1535,29 @@ function main () {
         arg_parse "${@}"
     fi
     if we_are_changerooted; then
-        install_os_in_chroot                    #2.2
+        install_os_in_chroot                        #2.2
     else
-        no_kernel_update_in_iso                 #1.1
-        set_ntp                                 #1.2
-        resize_cow_space                        #1.3
-        update_pacman_db                        #1.4
-        install_pkgs 'jq'                       #1.5
-        install_zfs                             #1.6
-        uefi_or_bios                            #1.7
-        load_settings_file                      #1.8
-        setup_zpool                             #1.9
-        mount_system                            #1.10
-        copy_zpool_cache                        #1.11
-        install_archlinux                       #1.12
-        gen_fstab                               #1.13
-        set_hostname                            #1.14
-        set_locale                              #1.15
-        add_zfs_hook_to_initramfs               #1.16
-        set_initramfs_build_list                #1.17
-        add_zfs_files_to_new_os                 #1.18
-        enter_chroot                            #2.1
+        no_kernel_update_in_iso                     #1.1
+        set_ntp                                     #1.2
+        resize_cow_space                            #1.3
+        update_pacman_db                            #1.4
+        install_pkgs 'jq'                           #1.5
+        install_zfs                                 #1.6
+        uefi_or_bios                                #1.7
+        load_settings_file                          #1.8
+        setup_zpool                                 #1.9
+        mount_system                                #1.10
+        copy_zpool_cache                            #1.11
+        install_archlinux                           #1.12
+        gen_fstab                                   #1.13
+        set_hostname                                #1.14
+        set_locale                                  #1.15
+        add_zfs_hook_to_initramfs                   #1.16
+        set_initramfs_build_list                    #1.17
+        add_zfs_files_to_new_os                     #1.18
+        enter_chroot                                #2.1
         # We're done in chroot
-        finalize_os_setup                       #3.1
+        finalize_os_setup                           #3.1
     fi
 }