refactor(iso): Trust that ZFS partition selection works, remove if-else clause (#1)

setup.sh

@@ -65,22 +65,21 @@ function get_parts () {
 }
 
 function we_have_exactly_one_part () {
-    declare parttype parts_list parts_count
+    local parttype parts_list parts_count
     parttype="${1:?}"
     parts_list="${2:?}"
     parts_count="$(wc -l <<<"${parts_list}")"
     if [[ "$(wc -c <<<"${parts_list}")" -gt '1' ]]; then
         case "${parts_count}" in
             0)
-                printf -- '%s\n' 'No '"${parttype}"' partition found. Exiting 1 ...'
+                printf -- '%s\n' 'No '"${parttype^^}"' partition found. Exiting 1 ...'
                 exit 1
                 ;;
             1)
                 return 0
                 ;;
             *)
-                printf -- '%s\n' 'Multiple '"${parttype}"' partitions found. We expect exactly one. Cowardly exiting 1 ...'
-                exit 1
+                return 1
                 ;;
         esac
         printf -- '%s\n' 'Partition list does not look valid. Cowardly exiting 1 ...'
@@ -88,6 +87,46 @@ function we_have_exactly_one_part () {
     fi
 }
 
+function get_drive_id () {
+    declare drive_id
+    drive_id="$(find -L /dev/disk/by-id -samefile "${1:?}")"
+    if [[ "$(wc -l <<<"${drive_id}")" -eq '1' ]] && [[ "$(wc -c <<<"${drive_id}")" -gt '1' ]]; then
+        printf -- '%s' "${drive_id}"
+        return 0
+    fi
+    printf -- '%s\n' 'Not exactly one '"'${1:?}'"' partition entry in /dev/disk/by-id, exiting 1 ...'
+    exit 1
+}
+
+function select_part () {
+    local parts enriched_parts enriched_parts_count part_number part_type
+    declare part
+    part_type="${1:?}" # 'efi' or 'zfs'
+    parts="$(get_parts "${part_type}")"
+
+    if we_have_exactly_one_part "${part_type}" "${parts}"; then
+        part="${parts}"
+    else
+        printf -- '%s\n' 'Which '"${part_type^^}"' partition do you want us to use?'
+        while IFS= read -r found_part; do
+            enriched_parts+=("'${found_part}'"' (aka ID '"'$(get_drive_id "${found_part}")'"')')
+        done <<<"${parts}"
+        enriched_parts_count="${#enriched_parts[@]}"
+        select part in "${enriched_parts[@]}"; do
+            part_number="${REPLY}"
+            if [[ "${part_number}" -le "${enriched_parts_count}" ]]; then
+                part="$(sed "${REPLY}q;d" <<<"${parts}")"
+                printf -- '%s\n' 'You'"'"'ve selected '"'${part}'"' ...'
+                break
+            else
+                printf -- '%s\n' 'Invalid option, please choose between 1 and '"${enriched_parts_count}"
+            fi
+        done
+    fi
+    printf -- '%s' "${part}"
+    return 0
+}
+
 function no_zpool_exists () {
     declare zpool_list
     zpool_list="$(zpool list -H)"
@@ -95,17 +134,6 @@ function no_zpool_exists () {
     return 1
 }
 
-function zpool_drive_id () {
-    declare drive_id
-    drive_id="$(find -L /dev/disk/by-id -samefile "${1:?}")"
-    if [[ "$(wc -l <<<"${drive_id}")" -eq '1' ]]; then
-        printf -- '%s' "${drive_id}"
-        return 0
-    fi
-    printf -- '%s\n' 'More than zpool partition entry in /dev/disk/by-id, exiting 1 ...'
-    exit 1
-}
-
 function set_zpool_password () {
     # May or may not have a newline at the end, ZFS doesn't care
     printf -- '%s' 'password' > '/etc/zfs/'"${zpool_name}"'.key'
@@ -162,7 +190,7 @@ function export_pool () {
 function setup_zpool () {
     declare zpool_drive drive_by_id
     zpool_drive="${1:?}"
-    drive_by_id="$(zpool_drive_id "${zpool_drive}")"
+    drive_by_id="$(get_drive_id "${zpool_drive}")"
 
     set_zpool_password
     if no_zpool_exists; then
@@ -182,12 +210,9 @@ function mount_system () {
     zfs mount "${zpool_name}"'/root/'"${zfs_arch_dataset_name}"
     zfs mount -a
 
-    declare efi_part
-    efi_part="$(get_parts 'efi')"
-    if we_have_exactly_one_part 'efi' "${efi_part}"; then
-        mkdir -p '/mnt/efi'
-        mount "${efi_part}" '/mnt/efi'
-    fi
+    local efi_part="$(select_part 'efi')"
+    mkdir -p '/mnt/efi'
+    mount "${efi_part}" '/mnt/efi'
 }
 
 function copy_zpool_cache () {
@@ -544,26 +569,25 @@ function main () {
     else
         set_ntp
         update_pacman_db
+
         install_pkgs 'jq'
-        declare zfs_part
-        zfs_part="$(get_parts 'zfs')"
-        if we_have_exactly_one_part 'zfs' "${zfs_part}"; then
-            printf -- 'Creating zpool on partition '"'"'%s'"'"' ...\n' "${zfs_part}"
-            install_zfs
-            setup_zpool "${zfs_part}"
-            mount_system
-            copy_zpool_cache
-            install_archlinux
-            gen_fstab
-            set_hostname
-            set_locale
-            add_zfs_hook_to_initramfs
-            set_initramfs_build_list
-            add_zfs_files_to_new_os
-            enter_chroot
-            # We're done in chroot
-            finalize_os_setup
-        fi
+        local zfs_part
+        zfs_part="$(select_part 'zfs')"
+
+        install_zfs
+        setup_zpool "${zfs_part}"
+        mount_system
+        copy_zpool_cache
+        install_archlinux
+        gen_fstab
+        set_hostname
+        set_locale
+        add_zfs_hook_to_initramfs
+        set_initramfs_build_list
+        add_zfs_files_to_new_os
+        enter_chroot
+        # We're done in chroot
+        finalize_os_setup
     fi
 }