From: Richard Jones <rjones@redhat.com>
Date: Wed, 1 Apr 2009 14:53:01 +0000 (+0100)
Subject: Use febootstrap-run properly.
X-Git-Tag: 1.5~3
X-Git-Url: http://git.annexia.org/?a=commitdiff_plain;h=2aecd64fe51659409760a2c1e15145325f09b7e6;p=febootstrap.git

Use febootstrap-run properly.
Better documentation for febootstrap-run.
---

diff --git a/examples/guestfs-test.sh b/examples/guestfs-test.sh
index f487f50..8092ff2 100755
--- a/examples/guestfs-test.sh
+++ b/examples/guestfs-test.sh
@@ -41,7 +41,9 @@ echo -n "After minimization:  "; du -sh guestfs
 
 # Create the /init which will scan for and enable all LVM volume groups.
 
-( cd guestfs && cat > init <<'__EOF__'
+create_init ()
+{
+  cat > /init <<'__EOF__'
 #!/bin/sh
 PATH=/sbin:/usr/sbin:$PATH
 MAKEDEV mem null port zero core full ram tty console fd \
@@ -54,8 +56,10 @@ lvm vgscan --ignorelockingfailure
 lvm vgchange -ay --ignorelockingfailure
 /bin/bash -i
 __EOF__
-chmod +x init
-)
+  chmod +x init
+}
+export -f create_init
+../febootstrap-run ./guestfs -- bash -c create_init
 
 # Convert the filesystem to an initrd image.
 
diff --git a/examples/minimal-filesystem.sh b/examples/minimal-filesystem.sh
index 678d612..497d209 100755
--- a/examples/minimal-filesystem.sh
+++ b/examples/minimal-filesystem.sh
@@ -35,15 +35,19 @@ echo -n "After minimization:  "; du -sh minimal
 # Create the /init which is just a simple script to give users an
 # interactive shell.
 
-( cd minimal && cat > init <<'__EOF__'
+create_init ()
+{
+  cat > /init <<'__EOF__'
 #!/bin/sh
 echo; echo; echo
 echo "Welcome to the minimal filesystem example"
 echo; echo; echo
 /bin/bash -i
 __EOF__
-chmod +x init
-)
+  chmod +x /init
+}
+export -f create_init
+../febootstrap-run ./minimal -- bash -c create_init
 
 # Convert the filesystem to an initrd image.
 
diff --git a/febootstrap-run.pod b/febootstrap-run.pod
index c5e713c..9072f5a 100644
--- a/febootstrap-run.pod
+++ b/febootstrap-run.pod
@@ -37,6 +37,35 @@ contents still happen).
 
 =back
 
+=head1 EXAMPLES
+
+One way to create a new file with specific ownership and permissions
+from a script is to create new content for a file as C<root/file.new>:
+
+ #!/bin/bash
+
+ echo blah > root/file.new
+
+then "install" it with the correct ownership and permissions.
+
+ febootstrap-run root -- install -m 0644 -o root -g root /file.new /file
+ rm root/file.new
+
+(This requires that the C</usr/bin/install> command from coreutils
+exists inside the root.)
+
+Another way to do complex operations from a script is to export a
+function:
+
+ #!/bin/bash
+
+ do_stuff ()
+ {
+     # complex operations inside the root
+ }
+ export -f do_stuff
+ febootstrap-run root -- bash -c do_stuff
+
 =head1 ENVIRONMENT VARIABLES
 
 Some L<fakechroot(1)> environment variables are applicable.  In