[Buildroot] Startup files numbering policy

[Buildroot] Startup files numbering policy

[Benoît Thébaudeau]

Hi all,

So far, BuildRoot has always used arbitrary Sxx numbers for the startup files in
/etc/init.d/, e.g. S91smb in the samba package. Depending on each board needs,
these numbers might be more or less appropriate for the startup order. Do you
plan to add a mechanism to choose non-default custom numbering for those
scripts, or do you have a policy such as "It's up to each board to run
post-build scripts for such adjustments."?

Best regards,
Beno?t

[Buildroot] Startup files numbering policy

[Thomas Petazzoni]

Dear Beno?t Th?baudeau,

On Tue, 21 May 2013 21:31:02 +0200 (CEST), Beno?t Th?baudeau wrote:

> So far, BuildRoot has always used arbitrary Sxx numbers for the startup files in
> /etc/init.d/, e.g. S91smb in the samba package. Depending on each board needs,
> these numbers might be more or less appropriate for the startup order. Do you
> plan to add a mechanism to choose non-default custom numbering for those
> scripts, or do you have a policy such as "It's up to each board to run
> post-build scripts for such adjustments."?

I don't think we will want a mechanism to customize that, a post-build
script is definitely appropriate.

However, we could clarify, adjust and/or document the current numbering
policy, in order to make it clearer and more usable.

What specific problems do you have with the current numbering? Would a
change in the numbering policy solve those problems?

So far, in the projects I've done, I don't remember having issues with
the numbering policy used by Buildroot. I just added my own scripts, at
different levels, and the scripts installed by Buildroot were living
enough "free" numbers at various stages in the initialization to do
whatever I needed. But it is very well possible that I didn't come
across the cases you have in your project.

Best regards,

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[Buildroot] Startup files numbering policy

[Benoît Thébaudeau]

Dear Thomas Petazzoni,

On Tuesday, May 21, 2013 10:17:07 PM, Thomas Petazzoni wrote:
> Dear Beno?t Th?baudeau,
> 
> On Tue, 21 May 2013 21:31:02 +0200 (CEST), Beno?t Th?baudeau wrote:
> 
> > So far, BuildRoot has always used arbitrary Sxx numbers for the startup
> > files in
> > /etc/init.d/, e.g. S91smb in the samba package. Depending on each board
> > needs,
> > these numbers might be more or less appropriate for the startup order. Do
> > you
> > plan to add a mechanism to choose non-default custom numbering for those
> > scripts, or do you have a policy such as "It's up to each board to run
> > post-build scripts for such adjustments."?
> 
> I don't think we will want a mechanism to customize that, a post-build
> script is definitely appropriate.
> 
> However, we could clarify, adjust and/or document the current numbering
> policy, in order to make it clearer and more usable.
> 
> What specific problems do you have with the current numbering? Would a
> change in the numbering policy solve those problems?
> 
> So far, in the projects I've done, I don't remember having issues with
> the numbering policy used by Buildroot. I just added my own scripts, at
> different levels, and the scripts installed by Buildroot were living
> enough "free" numbers at various stages in the initialization to do
> whatever I needed. But it is very well possible that I didn't come
> across the cases you have in your project.

I don't have the exact use case in mind, but I have encountered this issue at
least once on a project with many startup scripts. The board needed many custom
startup scripts in its target skeleton, and in the end there was a collision
with BuildRoot's predefined startup script numbers that broke the expected
startup order. It was also unclear how to number the board-specific startup
scripts before launching the 1st build, and without a list there is always the
risk of a collision when enabling a new package.

I don't think that changing the current script numbering would be a solution,
because that could cause an issue for someone else. There could perhaps be a
document listing the numbering of the startup scripts installed by all BuildRoot
packages. That would make it clear how to assign a new startup script number,
what to expect from BuildRoot, and how to perform custom adjustments (i.e.
post-build script).

Best regards,
Beno?t

[Buildroot] Startup files numbering policy

[Thomas Petazzoni]

Dear Beno?t Th?baudeau,

On Tue, 21 May 2013 23:10:40 +0200 (CEST), Beno?t Th?baudeau wrote:

> I don't have the exact use case in mind, but I have encountered this issue at
> least once on a project with many startup scripts. The board needed many custom
> startup scripts in its target skeleton, and in the end there was a collision
> with BuildRoot's predefined startup script numbers that broke the expected
> startup order. It was also unclear how to number the board-specific startup
> scripts before launching the 1st build, and without a list there is always the
> risk of a collision when enabling a new package.

Ok.

> I don't think that changing the current script numbering would be a solution,
> because that could cause an issue for someone else. There could perhaps be a
> document listing the numbering of the startup scripts installed by all BuildRoot
> packages. That would make it clear how to assign a new startup script number,
> what to expect from BuildRoot, and how to perform custom adjustments (i.e.
> post-build script).

Isn't:

$ find package/ -name 'S[0-9][0-9]*'

a good enough documentation for this?

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[Buildroot] Startup files numbering policy

[Benoît Thébaudeau]

Dear Thomas Petazzoni,

On Tuesday, May 21, 2013 11:24:48 PM, Thomas Petazzoni wrote:
> Dear Beno?t Th?baudeau,
> 
> On Tue, 21 May 2013 23:10:40 +0200 (CEST), Beno?t Th?baudeau wrote:
> 
> > I don't have the exact use case in mind, but I have encountered this issue
> > at
> > least once on a project with many startup scripts. The board needed many
> > custom
> > startup scripts in its target skeleton, and in the end there was a
> > collision
> > with BuildRoot's predefined startup script numbers that broke the expected
> > startup order. It was also unclear how to number the board-specific startup
> > scripts before launching the 1st build, and without a list there is always
> > the
> > risk of a collision when enabling a new package.
> 
> Ok.
> 
> > I don't think that changing the current script numbering would be a
> > solution,
> > because that could cause an issue for someone else. There could perhaps be
> > a
> > document listing the numbering of the startup scripts installed by all
> > BuildRoot
> > packages. That would make it clear how to assign a new startup script
> > number,
> > what to expect from BuildRoot, and how to perform custom adjustments (i.e.
> > post-build script).
> 
> Isn't:
> 
> $ find package/ -name 'S[0-9][0-9]*'
> 
> a good enough documentation for this?

Maybe. This is what I had done. I mostly wanted to know if you would add a
mechanism for that, which you answered. E.g., PTXdist has a config option with a
default value giving the file name to use for each startup script.

Best regards,
Beno?t

[Buildroot] Startup files numbering policy

[Thomas Petazzoni]

Dear Beno?t Th?baudeau,

On Wed, 22 May 2013 00:08:40 +0200 (CEST), Beno?t Th?baudeau wrote:

> Maybe. This is what I had done. I mostly wanted to know if you would add a
> mechanism for that, which you answered. E.g., PTXdist has a config option with a
> default value giving the file name to use for each startup script.

I'm not sure we want to have a config option for each and every init
script. Especially since with systemd, you have a unit file rather than
an init script, so we would have to handle this as well.

I think having a default sane numbering is good enough, since we allow
the users to customize whatever they want using post-build scripts.

Note that I'm not saying the current numbering is perfect, it could be
clarified, with a bit documentation saying "from number X to Y, it's
basic services that are not network dependent", "from Y to Z, it's this
type of services, etc.". I'm just talking about the general approach of
just having a default numbering, and leaving the rest of the
customization to post-build scripts.

Best regards,

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com