refactoring for more flexible config

Makefile

@@ -11,6 +11,7 @@ MAN1FILES =
 MAN8FILES = overlay-boot.8 overlay-go.8 overlay-stop.8
 HTMLDOC = $(MAN8FILES:%=%.html)
 VARLIBFILES = overlay-boot overlay-go overlay-stop functions reaper
+VARLIBFILES += overlay-init overlay-postmount overlay-premount
 
 all: asm/reaper
 

functions

@@ -31,7 +31,7 @@ subhost_config() {
     config UPPER "$BASE/root"
     config WORK "$BASE/work"
     config LOWER "/"
-    config START "!networking ssh"
+    config START "networking ssh"
     config PREMOUNT "$PROGRAMDIR/overlay-premount"
     config POSTMOUNT "$PROGRAMDIR/overlay-postmount"
     config INIT "$PROGRAMDIR/overlay-init"

overlay-boot

@@ -4,6 +4,7 @@
 # configuration file named on the command line.
 # See "man overlay-boot" for details.
 
+set -x
 PROGRAMDIR="$(dirname $(realpath $0))"
 . $PROGRAMDIR/functions
 

overlay-boot.8.adoc

@@ -178,6 +178,7 @@ EXAMPLES
 ./opt/subhost/mta/mta.conf
 ****
 BASE=.
+CABLES= =
 START= rsyslog newtorking ssh postfix
 ****
 
@@ -185,5 +186,11 @@ The above example assumes a directory +/opt/subhost/mta+ that contains
 the configuration file +mta.conf+ and directories +root+, +work+ and
 +live+. *overlay-boot* will set up an overlay mount on +live+ with
 +root+ as UPPER, +work+ as WORK and +/+ as LOWER, i.e. an overlay of
-the main host filesystem.
+the main host filesystem. Further, the running subhost will feature a
+virtual cable to the main host, where the subhost end is named +eth0+
+and the main host end is named +mta0+, and upon start, an +ifup mta0+
+is attempted at the host end while the subhost end is handled via its
+neworking service.
+
+