Re: [RFC v2][PATCH 2/3] build-rep: Add helper class

[Henning Schild <henning.schild@siemens.com>]

Am Thu, 11 Jan 2018 14:19:38 +0300
schrieb Alexander Smirnov <asmirnov@ilbers.de>:

> Add class that helps to implement build reproducibility. It implements
> anonymous function that will get all the Debian dependencies that are
> needed for current Isar tree.
> 
> Until build reproducibility will be fully implemented, it's disabled
> by default. To enable it just set ISAR_BUILD_REP to "1" in local.conf.
> 
> Signed-off-by: Alexander Smirnov <asmirnov@ilbers.de>
> ---
>  meta-isar/conf/local.conf.sample                 |  6 +++++
>  meta-isar/recipes-app/hello/hello.bb             |  2 ++
>  meta/classes/build-rep.bbclass                   | 32
> ++++++++++++++++++++++++
> meta/classes/dpkg-base.bbclass                   |  2 ++
> meta/classes/image.bbclass                       |  2 ++
> meta/recipes-devtools/buildchroot/buildchroot.bb |  2 ++ 6 files
> changed, 46 insertions(+) create mode 100644
> meta/classes/build-rep.bbclass
> 
> diff --git a/meta-isar/conf/local.conf.sample
> b/meta-isar/conf/local.conf.sample index 660958f..45b8995 100644
> --- a/meta-isar/conf/local.conf.sample
> +++ b/meta-isar/conf/local.conf.sample
> @@ -162,3 +162,9 @@ BB_NUMBER_THREADS = "4"
>  #
>  # Number of attempts to try to get reprepro lock for access to apt
> cache REPREPRO_LOCK_ATTEMPTS = "16"
> +
> +# Isar build reproducibility feature creates local repository which
> contains +# copies for all the upstream Debian packages that could be
> used to build +# your Isar tree. So fetching them once will guarantee
> that all the next Isar +# builds will be identically.
> +ISAR_BUILD_REP ?= "0"
> diff --git a/meta-isar/recipes-app/hello/hello.bb
> b/meta-isar/recipes-app/hello/hello.bb index 44b8bc3..fafda2e 100644
> --- a/meta-isar/recipes-app/hello/hello.bb
> +++ b/meta-isar/recipes-app/hello/hello.bb
> @@ -16,3 +16,5 @@ SRCREV = "ad7065ecc4840cc436bfcdac427386dbba4ea719"
>  SRC_DIR = "git"
>  
>  inherit dpkg
> +
> +DEBIAN_DEPENDS = "debhelper (>= 9), autotools-dev"

If i understand it correctly, this approach is an absolute NoGo.

DEBIAN_DEPENDS as it is used today are runtime deps of pre-built
packages. Here you include build-deps of a package that Isar needs to
build. And you do so by introducing a copy of a string that is already
included in the sources /debian/-folder. In fact you would have to
put build and runtime deps into that one variable. And what about
packages where the content depends on DISTRO_ARCH and friends?

I think we first need a working solution of two "inherit dpkg" packages
actually depending on each-other. After that we will need a real build
of the Image to fill the cache. That is the only reliable way to make
sure that the repo will contain the runtime and the build deps of all
packages. More "sed"-guesswork is not going to do that trick and is
only getting us 95% of what we need. And maintaining copies of stuff
that is in /debian/ should not be considered.

Henning

> diff --git a/meta/classes/build-rep.bbclass
> b/meta/classes/build-rep.bbclass new file mode 100644
> index 0000000..ede5a93
> --- /dev/null
> +++ b/meta/classes/build-rep.bbclass
> @@ -0,0 +1,32 @@
> +# This software is a part of ISAR.
> +# Copyright (C) 2017 Siemens AG
> +
> +python __anonymous() {
> +    rep = d.getVar('ISAR_BUILD_REP', True) or "0"
> +    if rep == "0":
> +        return
> +
> +    depsdir = d.getVar('BASE_APT_DIR', True)
> +    if depsdir is None:
> +        return
> +
> +    depsdir += '/deps/'
> +
> +    pn = d.getVar('PN', True)
> +
> +    if not os.path.exists(depsdir):
> +        os.makedirs(depsdir, exist_ok=True)
> +
> +    if d.getVar('DEBIAN_DEPENDS', True):
> +        with open(depsdir + '/' +  pn + '.depends', 'w') as the_file:
> +            the_file.write(d.getVar('DEBIAN_DEPENDS', True))
> +            the_file.close
> +    elif d.getVar('BUILDCHROOT_PREINSTALL', True):
> +        with open(depsdir + '/' +  pn + '.preinst', 'w') as the_file:
> +            the_file.write(d.getVar('BUILDCHROOT_PREINSTALL', True))
> +            the_file.close
> +    elif d.getVar('IMAGE_PREINSTALL', True):
> +        with open(depsdir + '/' +  pn + '.preinst', 'w') as the_file:
> +            the_file.write(d.getVar('IMAGE_PREINSTALL', True))
> +            the_file.close
> +}
> diff --git a/meta/classes/dpkg-base.bbclass
> b/meta/classes/dpkg-base.bbclass index 4d220da..bf66e78 100644
> --- a/meta/classes/dpkg-base.bbclass
> +++ b/meta/classes/dpkg-base.bbclass
> @@ -3,6 +3,8 @@
>  
>  DEBIAN_DEPENDS ?= ""
>  
> +inherit build-rep
> +
>  # Add dependency from buildchroot creation
>  do_build[depends] = "buildchroot:do_build"
>  
> diff --git a/meta/classes/image.bbclass b/meta/classes/image.bbclass
> index e2cb01b..67f5af8 100644
> --- a/meta/classes/image.bbclass
> +++ b/meta/classes/image.bbclass
> @@ -5,6 +5,8 @@ IMAGE_INSTALL ?= ""
>  IMAGE_TYPE    ?= "ext4-img"
>  IMAGE_ROOTFS   = "${WORKDIR}/rootfs"
>  
> +inherit build-rep
> +
>  def get_image_name(d, name_link):
>      S = d.getVar("IMAGE_ROOTFS", True)
>      path_link = os.path.join(S, name_link)
> diff --git a/meta/recipes-devtools/buildchroot/buildchroot.bb
> b/meta/recipes-devtools/buildchroot/buildchroot.bb index
> 51f9d5d..da18231 100644 ---
> a/meta/recipes-devtools/buildchroot/buildchroot.bb +++
> b/meta/recipes-devtools/buildchroot/buildchroot.bb @@ -16,6 +16,8 @@
> SRC_URI = "file://multistrap.conf.in \ file://build.sh"
>  PV = "1.0"
>  
> +inherit build-rep
> +
>  BUILDCHROOT_PREINSTALL ?= "gcc \
>                             make \
>                             build-essential \