Re: [PATCH 2/2] ci: Add compat arch support

[Jan Kiszka <jan.kiszka@siemens.com>]

On 09.09.20 15:44, Henning Schild wrote:
> On Tue, 8 Sep 2020 10:53:58 +0200
> "[ext] Jan Kiszka" <jan.kiszka@siemens.com> wrote:
> 
>> On 04.09.20 14:47, [ext] Jan Kiszka wrote:
>>> From: Jan Kiszka <jan.kiszka@siemens.com>
>>>
>>> Build hello-isar and libisar for the compat arch if that is enabled.
>>> Set ISAR_ENABLE_COMPAT_ARCH for all supported combinations in CI.
>>>
>>> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
>>> ---
>>>  meta-isar/recipes-app/hello-isar/hello-isar.bb | 3 +++
>>>  meta-isar/recipes-app/libhello/libhello.bb     | 3 +++
>>>  scripts/ci_build.sh                            | 6 ++++++
>>>  3 files changed, 12 insertions(+)
>>>
>>> diff --git a/meta-isar/recipes-app/hello-isar/hello-isar.bb
>>> b/meta-isar/recipes-app/hello-isar/hello-isar.bb index
>>> 144a433e..8c3ba8b2 100644 ---
>>> a/meta-isar/recipes-app/hello-isar/hello-isar.bb +++
>>> b/meta-isar/recipes-app/hello-isar/hello-isar.bb @@ -20,4 +20,7 @@
>>> SRC_URI = " \ file://yet-another-change.txt;apply=yes;striplevel=0"
>>>  SRCREV = "a18c14cc11ce6b003f3469e89223cffb4016861d"
>>>  
>>> +# NOTE: This is just to test 32-bit building on 64-bit archs.
>>> +PACKAGE_ARCH_compat-arch = "${COMPAT_DISTRO_ARCH}"
>>> +
>>>  inherit dpkg
>>> diff --git a/meta-isar/recipes-app/libhello/libhello.bb
>>> b/meta-isar/recipes-app/libhello/libhello.bb index
>>> ab271b58..5c44de50 100644 ---
>>> a/meta-isar/recipes-app/libhello/libhello.bb +++
>>> b/meta-isar/recipes-app/libhello/libhello.bb @@ -13,4 +13,7 @@ PV =
>>> "0.1-98f2e41" SRC_URI =
>>> "git://github.com/ilbers/libhello.git;protocol=https;destsuffix=${P}"
>>> SRCREV = "98f2e41e7d05ab8d19b0c5d160b104b725c8fd93" 
>>> +# NOTE: This is just to test 32-bit building on 64-bit archs.
>>> +PACKAGE_ARCH_compat-arch = "${COMPAT_DISTRO_ARCH}"
>>> +
>>>  inherit dpkg
>>> diff --git a/scripts/ci_build.sh b/scripts/ci_build.sh
>>> index d2c707b8..461fd5cc 100755
>>> --- a/scripts/ci_build.sh
>>> +++ b/scripts/ci_build.sh
>>> @@ -139,6 +139,12 @@ if [ ! -d "$BUILD_DIR" ]; then
>>>  fi
>>>  source isar-init-build-env "$BUILD_DIR"
>>>  
>>> +cat >>conf/local.conf <<EOF
>>> +ISAR_ENABLE_COMPAT_ARCH_amd64 = "1"
>>> +ISAR_ENABLE_COMPAT_ARCH_arm64 = "1"
>>> +ISAR_ENABLE_COMPAT_ARCH_debian-stretch_amd64 = "0"
>>> +EOF
>>> +
>>>  if [ -n "$CROSS_BUILD" ]; then
>>>      sed -i -e 's/ISAR_CROSS_COMPILE ?= "0"/ISAR_CROSS_COMPILE ?=
>>> "1"/g' conf/local.conf fi
>>>   
>>
>> This triggers a problem:
>>
>> In a multiconfig setup like our CI, building the 32-bit package from
>> both the native 32-bit arch as well as the 64-bit arch now races. If
>> the 64-bit arch tries to install its self-built compat package, that
>> may just be under re-deployment by the 32-bit arch, and the build
>> fails.
>>
>> Options:
>>  - somehow express that both archs provide the same package (though
>> that may defeat the purpose of testing the compat build)
> 
> The purpose is that people want to use compat because they have just
> one image.

Well, one could imagine building a legacy application for both an old
ARMv7 device as well as for a new ARMv8 design. All that in one build
run (mc:...). Then the user would have to express that
my_beloved_legacy_app is actually a dependency that only needs to be
built once, and it would not matter if that is done by the armhf
buildchroot or via compat by the arm64 one.

> 
>>  - split isar-apt per arch, not just per distro
> 
> But would the compat not need to include both now, and the mc enemy
> would still mess with one of them?

We would have isar-apt/apt/debian-buster-armhf, debian-buster-arm64
etc., but all of them able to carry packages for any arch.

> 
> - better/more locking around isar-apt readers and writers
> 

Nope, that would only paper over the fact that a package is built twice
and the one to be used would be chosen by chance. Bad for reliable testing.

Jan

>> Suggestions?
> 
> Well one thing ... but i do not want to repeat myself ... 
> 
> Henning
> 
>> Jan
>>
> 

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