abuild-keygen: use -a to add the needed config setting

So basicly, running 'abuild-keygen -a -i' will be all you need to do to
be able to use abuild-sign and install the signed packages.

abuild-keygen.in

@@ -20,6 +20,7 @@ usage() {
 	echo "abuild-keygen $abuild_ver"
 	echo "usage: abuild-keygen [-ih]"
 	echo "options:"
+	echo " -a  Set PACKAGER_PRIVKEY=<generated key> in $abuild_userconf"
 	echo " -i  Install public key into /etc/apk/keys using sudo"
 	echo " -h  Show this help"
 	echo ""
@@ -46,8 +47,9 @@ else
 	default_name="$USER"
 fi
 
-while getopts "hi" opt; do
+while getopts "ahi" opt; do
 	case $opt in
+	a) append_config=yes;;
 	h) usage;;
 	i) install_pubkey=yes;
 	esac
@@ -69,7 +71,7 @@ pubkey="$privkey.pub"
 
 # generate the private key in a subshell with stricter umask
 (
-umask 0077
+umask 0007
 openssl genrsa -out "$privkey" 2048
 )
 openssl rsa -in "$privkey" -pubout -out "$pubkey"
@@ -87,7 +89,22 @@ else
 	echo "$privkey"
 fi
 
+if [ -n "$append_config" ]; then
+	if [ -f "$abuild_userconf" ]; then
+		# comment out the existing values
+		sed -i -e 's/^\(PACKAGER_PRIVKEY=.*\)/\#\1/' "$abuild_userconf"
+	fi
+	echo "PACKAGER_PRIVKEY=\"$privkey\"" >> "$abuild_userconf"
+else
+	echo ""
+	echo "You might want add following line to $abuild_userconf:"
+	echo ""
+	echo "PACKAGER_PRIVKEY=\"$privkey\""
+	echo ""
+fi
+
 echo ""
-echo "Please remember to make a safe backup of $privkey"
+echo "Please remember to make a safe backup of your private key:"
+echo "$privkey"
 echo ""