Patchwork [1/4] image.bbclass: add a hook funtion to support readonly rootfs

From: Chen Qi <Qi.Chen@windriver.com>

read_only_rootfs_hook: this funtion is invoked only if 'read-only-rootfs'
is in IMAGE_FEATURES. It tweaks some basic files and makes populate-
volatile.sh script run at rootfs time.

For now, it has real effect only if the init system is sysvinit.

[YOCTO #3406]

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
---
 meta/classes/image.bbclass |   18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

On 19 February 2013 08:38,  <Qi.Chen@windriver.com> wrote:
> From: Chen Qi <Qi.Chen@windriver.com>
>
> read_only_rootfs_hook: this funtion is invoked only if 'read-only-rootfs'
> is in IMAGE_FEATURES. It tweaks some basic files and makes populate-
> volatile.sh script run at rootfs time.
>
> For now, it has real effect only if the init system is sysvinit.
>
> [YOCTO #3406]
>
> Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
> ---
>  meta/classes/image.bbclass |   18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
>
> diff --git a/meta/classes/image.bbclass b/meta/classes/image.bbclass
> index dd78acb..7d533b6 100644
> --- a/meta/classes/image.bbclass
> +++ b/meta/classes/image.bbclass
> @@ -233,6 +233,24 @@ run_intercept_scriptlets () {
>         fi
>  }
>
> +# A hook function to support read-only-rootfs IMAGE_FEATURES
> +# Currently, it only supports sysvinit system.
> +read_only_rootfs_hook () {
> +       if ${@base_contains("DISTRO_FEATURES", "sysvinit", "true", "false", d)}; then
> +               # Tweak the mount option in fstab
> +               sed -i '/rootfs/ s/defaults/ro/' ${IMAGE_ROOTFS}/etc/fstab

to be cautious i would say
sed -i -e '/^[#[:space:]]*rootfs/s/defaults/ro/' ${IMAGE_ROOTFS}/etc/fstab
for ro rootfs fs_passno should be set to 0, too, imo:
sed -i -e '/^[#[:space:]]*rootfs/{s/defaults/ro/;s/\([[:space:]]*[[:digit:]]\)\([[:space:]]*\)[[:digit:]]$/\1\20/}'
${IMAGE_ROOTFS}/etc/fstab

> +               # Change the value of ROOTFS_READ_ONLY in /etc/default/rcS to yes
> +               if [ -e ${IMAGE_ROOTFS}/etc/default/rcS ]; then
> +                       sed -i 's/ROOTFS_READ_ONLY=no/ROOTFS_READ_ONLY=yes/' ${IMAGE_ROOTFS}/etc/default/rcS
> +               fi
> +               # Run populate-volatile.sh at rootfs time to set up basic files
> +               # and directories to support read-only rootfs.
> +               if [ -e ${IMAGE_ROOTFS}/etc/init.d/populate-volatile.sh ]; then

-x if you want to execute it below.
> +                       ${IMAGE_ROOTFS}/etc/init.d/populate-volatile.sh
> +               fi
> +       fi
> +}
> +
>  fakeroot do_rootfs () {
>         #set -x
>         # When use the rpm incremental image generation, don't remove the rootfs

On 02/19/2013 07:39 PM, Bernhard Reutner-Fischer wrote:
> On 19 February 2013 08:38,  <Qi.Chen@windriver.com> wrote:
>> From: Chen Qi <Qi.Chen@windriver.com>
>>
>> read_only_rootfs_hook: this funtion is invoked only if 'read-only-rootfs'
>> is in IMAGE_FEATURES. It tweaks some basic files and makes populate-
>> volatile.sh script run at rootfs time.
>>
>> For now, it has real effect only if the init system is sysvinit.
>>
>> [YOCTO #3406]
>>
>> Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
>> ---
>>   meta/classes/image.bbclass |   18 ++++++++++++++++++
>>   1 file changed, 18 insertions(+)
>>
>> diff --git a/meta/classes/image.bbclass b/meta/classes/image.bbclass
>> index dd78acb..7d533b6 100644
>> --- a/meta/classes/image.bbclass
>> +++ b/meta/classes/image.bbclass
>> @@ -233,6 +233,24 @@ run_intercept_scriptlets () {
>>          fi
>>   }
>>
>> +# A hook function to support read-only-rootfs IMAGE_FEATURES
>> +# Currently, it only supports sysvinit system.
>> +read_only_rootfs_hook () {
>> +       if ${@base_contains("DISTRO_FEATURES", "sysvinit", "true", "false", d)}; then
>> +               # Tweak the mount option in fstab
>> +               sed -i '/rootfs/ s/defaults/ro/' ${IMAGE_ROOTFS}/etc/fstab
> to be cautious i would say
> sed -i -e '/^[#[:space:]]*rootfs/s/defaults/ro/' ${IMAGE_ROOTFS}/etc/fstab
> for ro rootfs fs_passno should be set to 0, too, imo:
> sed -i -e '/^[#[:space:]]*rootfs/{s/defaults/ro/;s/\([[:space:]]*[[:digit:]]\)\([[:space:]]*\)[[:digit:]]$/\1\20/}'
> ${IMAGE_ROOTFS}/etc/fstab

Thank you for your suggestion.

Version 2 has been sent out.

Best Regards,
Chen Qi

>> +               # Change the value of ROOTFS_READ_ONLY in /etc/default/rcS to yes
>> +               if [ -e ${IMAGE_ROOTFS}/etc/default/rcS ]; then
>> +                       sed -i 's/ROOTFS_READ_ONLY=no/ROOTFS_READ_ONLY=yes/' ${IMAGE_ROOTFS}/etc/default/rcS
>> +               fi
>> +               # Run populate-volatile.sh at rootfs time to set up basic files
>> +               # and directories to support read-only rootfs.
>> +               if [ -e ${IMAGE_ROOTFS}/etc/init.d/populate-volatile.sh ]; then
> -x if you want to execute it below.
>> +                       ${IMAGE_ROOTFS}/etc/init.d/populate-volatile.sh
>> +               fi
>> +       fi
>> +}
>> +
>>   fakeroot do_rootfs () {
>>          #set -x
>>          # When use the rpm incremental image generation, don't remove the rootfs
>