service distinctly separate from the main host while sharing files
wherever sensible.
-A subhost is started by identifyinf its configuration file on the
+A subhost is started by identifying its configuration file on the
command line for *overlay-boot*. The configuration file is a plain
text file with a small collection of "variables" that tell how the
subhost is set up. When all is good, *overlay-boot* spawns a
The subhost execution environment may be "entered" to perform
adminstrative tasks with *overlay-go*, and it is later stopped with
-*overlay-stop*.
+*overlay-stop*.
OPTIONS
-------
Networking
----------
-*overlay-boot* sets up a nework namespace named by the subhost NAME,
-and uses the CABLES variable to set up +veth+ virtual cables. The host
-end of such cables are named by NAME followed by a number from 0 and
-up while the subhost end are named by +eth+ followed by the same
-number.
+*overlay-boot* sets up a nework namespace named by the subhost
++$NAME+, and uses the +$CABLES+ variable to set up +veth+ virtual
+cables. The host end of such cables are named by +$NAME+ followed by a
+number from 0 and up while the subhost end are named by +eth+ followed
+by the same number.
-As mentioned above, CABLES consists of a space separated list of cable
-specifiers, each consisting of a bridge interface name and a with an
-equal sign ("=") between them. The equal sign is required while either
-or both of the bridge and MAC address may be left empty.
+As mentioned above, +$CABLES+ consists of a space separated list of
+cable specifiers, each consisting of a bridge interface name and a
+with an equal sign ("=") between them. The equal sign is required
+while either or both of the bridge and MAC address may be left empty.
The bridge interface name, if given, will be given control of the host
end cable interface. A cable specification with empty bridge name part
----
BASE=.
CABLES= =
-START= rsyslog networking ssh postfix
+START= rsyslog networking ssh saslauthd postfix dovecot
----
****
is attempted at the host end while the subhost end is handled via its
neworking service.
+./opt/subhost/tiny/tiny.conf
+****
+----
+BASE=.
+CABLES= =
+START= none
+LOWER=!mkdir -p base work root live ; echo base
+WORK= work
+UPPER= root
+LIVE= live
+----
+****
+The +tiny+ subhost would be for overlaying a separate +debootstrap+
+root filesystem, without any services (since +START+ is empty). This
+gets started with a +dummy_service+ to hold the overlay for access via
++overlay-go+. The +dummy_service+ sets up and listens on a pipe at
++/run/dummy_service+, and exits when anything is written to that.
+
+SEE ALSO
+--------
+*overlay-stop*, *overlay-go*