[rpms/fedora-packager] epel10.2: fkinit: Add support for ~/.fedora.upn

[Neal Gompa <ngompa@fedoraproject.org>]

            A new commit has been pushed.

            Repo   : rpms/fedora-packager
            Branch : epel10.2
            Commit : 45ef3873ef4778f42b2c3bd67ef6e18556541c5e
            Author : Neal Gompa <ngompa@fedoraproject.org>
            Date   : 2025-06-10T06:33:59-04:00
            Stats  : +5/-1 in 1 file(s)
            URL    : https://src.fedoraproject.org/rpms/fedora-packager/c/45ef3873ef4778f42b2c3bd67ef6e18556541c5e?branch=epel10.2

            Log:
            fkinit: Add support for ~/.fedora.upn

This is the known file for setting the FAS user for Fedora infrastructure
client tools to use when the local Unix user does not match the FAS user.

Adding support for this with fkinit makes it easier to use in containerized
environments.

---
diff --git a/fkinit b/fkinit
index d2add1a..d8b1e17 100755
--- a/fkinit
+++ b/fkinit
@@ -36,7 +36,7 @@ print_help()
 {
 	printf '%s\n' "Acquire a Kerberos ticket-granting ticket for Fedora"
 	printf 'Usage: %s [-u|--user <arg>] [--(no-)staging] [-h|--help]\n' "$0"
-	printf '\t%s\n' "-u, --user: Fedora account name (default: '$USER')"
+	printf '\t%s\n' "-u, --user: Fedora account name (default: value in ~/.fedora.upn if exists, otherwise '$USER')"
 	printf '\t%s\n' "--staging, --no-staging: Use the staging infrastructure (off by default)"
 	printf '\t%s\n' "-h, --help: Prints help"
 	printf '\n%s\n' "If the environment variable \$FKINIT_OTP is set, it will be read for the one-time password instead of prompting for it."
@@ -97,6 +97,10 @@ set -e
 armorcache=$(mktemp)
 trap finalize EXIT
 
+if [ -f "$HOME/.fedora.upn" ] && [ -z "$_arg_user" ]; then
+	$_arg_user=$(<"$HOME/.fedora.upn")
+fi
+
 if [ "$_arg_staging" == "on" ]; then
     domain=STG.FEDORAPROJECT.ORG
 else