[OE-core] [RFC PATCH] bind: add support for read-only rootfs

[Phil Blundell]

On Thu, 2013-11-21 at 08:42 -0600, Mark Hatle wrote:
> On 11/21/13, 6:12 AM, Phil Blundell wrote:
> > On Thu, 2013-11-21 at 00:59 -0600, Mark Hatle wrote:
> >> +# When using a read-only rootfs additional setup may be required
> >> +# uncomment the following line to make bind start in read-only rootfs
> >> +#ALLOW_ROOTFS_READ_ONLY="yes"
> >
> > If the filesystem is read-only then it's going to be fairly difficult
> > for the user to uncomment this line on the target.
> 
> A post image process script would be capable of un-commenting that line (or 
> simply replacing the file with a specific image specific configuration.)

That's true, but I still don't understand why this ought to be
necessary.  Why should it not just default to being enabled?

> >> ++	[ `is_on_read_only_partition /etc/bind` = "yes" ] && bind_mount /var/volatile/bind/etc /etc/bind
> >> ++	[ `is_on_read_only_partition /var/named` = "yes" ] && bind_mount /var/volatile/bind/named /var/named
> >
> > Is it really necessary to mount a tmpfs at /etc/bind?  Can't those files
> > just be relocated somewhere else?
> 
> My understanding is both locations need to be RW for bind to work properly.  In 
> a normal READONLY filesystem configuration, neither is RW by default.

What files does it need to write to /etc/bind?

p.