guix-install.sh: Add unique requirement for sysv init system

This improves the installer's ability to detect that all requirements are
present regardless of init system. It also avoids performing the requirement
check twice (printing excessively to the console) and provides a framework for
adding new init system specific requirements if it's needed in the future.

* etc/guix-install.sh (add_init_sys_require): Create.
(SYSV_INIT_REQUIRE): Create.
(main_install): Reorder installer steps so all requirements are checked in one
pass.

Change-Id: Ic541c1b90499d504642b7ab4ae595501b1a37b0d
Signed-off-by: Ludovic Courtès <ludo@gnu.org>

1 files changed, 21 insertions, 1 deletions

diff --git a/etc/guix-install.sh b/etc/guix-install.sh
index d61e36ef9b4..9d9c294d75e 100755
--- a/etc/guix-install.sh
+++ b/etc/guix-install.sh
@@ -15,6 +15,7 @@
 # Copyright © 2020 David A. Redick <david.a.redick@gmail.com>
 # Copyright © 2024 Janneke Nieuwenhuizen <janneke@gnu.org>
 # Copyright © 2024 Tomas Volf <~@wolfsden.cz>
+# Copyright © 2024 Richard Sent <richard@freakingpenguin.com>
 #
 # This file is part of GNU Guix.
 #
@@ -81,6 +82,12 @@ REQUIRE=(
     "xz"
 )
 
+# Add variables using form FOO_INIT_REQUIRE when init system FOO dependencies
+# should be checked.
+SYSV_INIT_REQUIRE=(
+    "daemonize"
+)
+
 PAS=$'[ \033[32;1mPASS\033[0m ] '
 ERR=$'[ \033[31;1mFAIL\033[0m ] '
 WAR=$'[ \033[33;1mWARN\033[0m ] '
@@ -148,6 +155,18 @@ chk_require()
     _msg "${PAS}verification of required commands completed"
 }
 
+add_init_sys_require()
+{ # Add the elements of FOO_INIT_SYS to REQUIRE
+    local init_require="${INIT_SYS}_REQUIRE[@]"
+    if [[ ! -z "$init_require" ]]; then
+        # Have to add piecemeal because ${!foo[@]} performs direct array key
+        # expansion, not indirect plain array expansion.
+        for r in "${!init_require}"; do
+            REQUIRE+=("$r")
+        done
+    fi
+}
+
 chk_gpg_keyring()
 { # Check whether the Guix release signing public key is present.
     _debug "--- [ ${FUNCNAME[0]} ] ---"
@@ -794,9 +813,10 @@ main_install()
     _msg "Starting installation ($(date))"
 
     chk_term
+    chk_init_sys
+    add_init_sys_require
     chk_require "${REQUIRE[@]}"
     chk_gpg_keyring
-    chk_init_sys
     chk_sys_arch
     chk_sys_nscd