Re: [Tarantool-patches] [PATCH v2] build: enable CentOS 8 packaging

[Alexander Turenko <alexander.turenko@tarantool.org>]

Please, look into the changes I proposed below. They are about style,
nothing intruisive.

I also pushed them to avtikhon/gh-4543-centos8-more-full-ci branch to
look into CI and ease reading of the resulting changeset.

CI is green:

https://gitlab.com/tarantool/tarantool/pipelines/94633088
https://travis-ci.org/tarantool/tarantool/builds/609234538

If you're okay, I'll push the patch.

WBR, Alexander Turenko.

> build: enable CentOS 8 packaging
>
> Enabled packages build rules for CentOS 8.

Aren't this duplicate of the header? (See the proposal below.)

> For now CentOS 8 uses 'python2-' prefix for Python 2 modules
> rather the 'python-', changed CentOS 8 packages installation
> rules to use python2 packages instead of python.
> 
> Found that old packages like python-gevent and python-greenlet
> were completely removed from CentOS 8. To fix it the sources
> if these packages were downloaded from https://cbs.centos.org/
> and rebuilt, to make them available the binaries were saved
> at the PackageCloud packpack backport repository.
> 
> Met the issue with app-tap/pwd.test.lua test from the commit
> 7732daded14f86a314d44486e306e17bbc6ab293 (lua: treat ENOENT as
> success in getpwall/getgrall), temporary blocked the test (till
> the fix will be pushed) with the new issue:
> https://github.com/tarantool/tarantool/issues/4592

$ git show 7732daded14f86a314d44486e306e17bbc6ab293
fatal: bad object 7732daded14f86a314d44486e306e17bbc6ab293

It is part of a branch that was already deleted. Please, link only those
commits that are part of of long-term branches.

I would link only the issue here.

(See the proposal below.)

> 
> Found that libunwind library couldn't be installed from dependecies
> which was needed by backtrace feature. Decided to block it temporary
> till it will be enabled by issue:
> https://github.com/tarantool/tarantool/issues/4611

I would make it clear that it is available via EPEL, but does not via
the base repositories. (See the proposal below.)

> Added CentOS 8 into regular testing at gitlab-ci and travis-ci.
> 
> Closes #4543
> ---

My variant of the commit message is below. Please, let me know whether
you are okay with it. I left all points you highlighted and tried to
make its description more easy to understand w/o much context.

 | travis-ci/gitlab-ci: add CentOS 8
 |
 | Added build + test jobs in GitLab-CI and build + test + deploy jobs on
 | Travis-CI for CentOS 8.
 |
 | Updated testing dependencies in the RPM spec to follow the new Python 2
 | package naming scheme that was introduced in CentOS 8: it uses
 | 'python2-' prefix rather then 'python-'.
 |
 | CentOS 8 does not provide python2-gevent and python2-greenlet packages,
 | so they were pushed to https://packagecloud.io/packpack/backports
 | repository. This repository is enabled in our build image
 | (packpack/packpack:el-8) by default. Those dependencies are build-time,
 | so nothing was changed for a user. The source RPM packages were gathered
 | from https://cbs.centos.org.
 |
 | Disabled app-tap/pwd.test.lua on CentOS 8 due to systemd-nss issue,
 | which was not worked around properly. Filed #4592 to resolved it in the
 | future.
 |
 | Eliminated libunwind runtime dependency (and libunwind-devel build
 | dependency) on CentOS 8, because the base system does not provide it.
 | fiber.info() backtraces and printing of a backtrace after a crash will
 | not be available on this system. Hopefully we'll fix it in the future,
 | filed #4611 on this.
 |
 | Closes #4543

Also added a docbot comment to the issue.

> 
> Github: https://github.com/tarantool/tarantool/tree/avtikhon/gh-4543-centos8-full-ci
> Issue: https://github.com/tarantool/tarantool/issues/4543
> 
>  .gitlab-ci.yml            |  6 ++++++
>  .travis.yml               |  3 +++
>  rpm/tarantool.spec        | 13 ++++++++++++-
>  test/app-tap/pwd.skipcond | 11 +++++++++++
>  4 files changed, 32 insertions(+), 1 deletion(-)
>  create mode 100644 test/app-tap/pwd.skipcond
> 
> diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
> index cd5f2806f..cf13c382e 100644
> --- a/.gitlab-ci.yml
> +++ b/.gitlab-ci.yml
> @@ -152,6 +152,12 @@ centos_7:
>      OS: 'el'
>      DIST: '7'
>  
> +centos_8:
> +  <<: *deploy_test_definition
> +  variables:
> +    OS: 'el'
> +    DIST: '8'
> +
>  fedora_28:
>    <<: *deploy_test_definition
>    variables:
> diff --git a/.travis.yml b/.travis.yml
> index db7d80bd2..d48ef39e0 100644
> --- a/.travis.yml
> +++ b/.travis.yml
> @@ -43,6 +43,9 @@ jobs:
>        - name: "CentOS 7 build + test + deploy RPM"
>          env: OS=el DIST=7
>          if: branch = "master"
> +      - name: "CentOS 8 build + test + deploy RPM"
> +        env: OS=el DIST=8
> +        if: branch = "master"
>        - name: "Fedora 28 build + test + deploy RPM"
>          env: OS=fedora DIST=28
>          if: branch = "master"
> diff --git a/rpm/tarantool.spec b/rpm/tarantool.spec
> index b837214a6..416b4ebb4 100644
> --- a/rpm/tarantool.spec
> +++ b/rpm/tarantool.spec
> @@ -63,12 +63,18 @@ BuildRequires: libunwind-devel
>  %endif
>  
>  # For tests
> -%if (0%{?fedora} >= 22 || 0%{?rhel} >= 7)
> +%if (0%{?fedora} >= 22 || 0%{?rhel} == 7)
>  BuildRequires: python >= 2.7
>  BuildRequires: python-six >= 1.9.0
>  BuildRequires: python-gevent >= 1.0
>  BuildRequires: python-yaml >= 3.0.9
>  %endif
> +%if (0%{?rhel} >= 8)

I removed parentheses around the condition.

> +BuildRequires: python2 >= 2.7
> +BuildRequires: python2-six >= 1.9.0
> +BuildRequires: python2-gevent >= 1.0
> +BuildRequires: python2-yaml >= 3.0.9
> +%endif
>  
>  Name: tarantool
>  # ${major}.${major}.${minor}.${patch}, e.g. 1.6.8.175
> @@ -125,14 +131,19 @@ C and Lua/C modules.
>  
>  %build
>  # RHBZ #1301720: SYSCONFDIR an LOCALSTATEDIR must be specified explicitly
> +# gh-4611: temporary blocked the backtrace on CentOS 8 till completely enabled
>  %cmake . -DCMAKE_BUILD_TYPE=RelWithDebInfo \
>           -DCMAKE_INSTALL_LOCALSTATEDIR:PATH=%{_localstatedir} \
>           -DCMAKE_INSTALL_SYSCONFDIR:PATH=%{_sysconfdir} \
> +%if (0%{?rhel} >= 8)
> +         -DENABLE_BACKTRACE:BOOL=OFF \
> +%else
>  %if %{with backtrace}
>           -DENABLE_BACKTRACE:BOOL=ON \
>  %else
>           -DENABLE_BACKTRACE:BOOL=OFF \
>  %endif
> +%endif

Look at the code above:

 | %bcond_without backtrace # enabled by default
 | 
 | %if %{with backtrace}
 | BuildRequires: libunwind-devel

It would be better to set %{with backtrace} to appropriate value here
and avoid the unnecessary build dependency.

I changed it in the following way:

 | diff --git a/rpm/tarantool.spec b/rpm/tarantool.spec
 | index 416b4ebb4..41dbaf726 100644
 | --- a/rpm/tarantool.spec
 | +++ b/rpm/tarantool.spec
 | @@ -44,7 +44,14 @@ Requires(preun): chkconfig
 |  Requires(preun): initscripts
 |  %endif
 |  
 | -%bcond_without backtrace # enabled by default
 | +%if 0%{?rhel} >= 8
 | +# gh-4611: Disable backtraces on CentOS 8 by default due to lack
 | +# of libunwind package in the base system.
 | +%bcond_with backtrace
 | +%else
 | +# Enable backtraces by default.
 | +%bcond_without backtrace
 | +%endif
 |  
 |  %if %{with backtrace}
 |  BuildRequires: libunwind-devel
 | @@ -131,19 +138,14 @@ C and Lua/C modules.
 |  
 |  %build
 |  # RHBZ #1301720: SYSCONFDIR an LOCALSTATEDIR must be specified explicitly
 | -# gh-4611: temporary blocked the backtrace on CentOS 8 till completely enabled
 |  %cmake . -DCMAKE_BUILD_TYPE=RelWithDebInfo \
 |           -DCMAKE_INSTALL_LOCALSTATEDIR:PATH=%{_localstatedir} \
 |           -DCMAKE_INSTALL_SYSCONFDIR:PATH=%{_sysconfdir} \
 | -%if (0%{?rhel} >= 8)
 | -         -DENABLE_BACKTRACE:BOOL=OFF \
 | -%else
 |  %if %{with backtrace}
 |           -DENABLE_BACKTRACE:BOOL=ON \
 |  %else
 |           -DENABLE_BACKTRACE:BOOL=OFF \
 |  %endif
 | -%endif
 |  %if %{with systemd}
 |           -DWITH_SYSTEMD:BOOL=ON \
 |           -DSYSTEMD_UNIT_DIR:PATH=%{_unitdir} \

BTW, I was wonder how it works w/o libunwind runtime dependency. The
answer is here if you are interesting:
https://rpm.org/user_doc/more_dependencies.html#automatic-dependencies

After this change I found that packpack passes `--with backtrace` into
rpmbuild and fixed it in https://github.com/packpack/packpack/pull/114

After this I found another problem and fixed it in a separate commit:

 | commit 41359c8b6e4e1dac20fbd211ea64f2fc3b9abf16
 | Author: Alexander Turenko <alexander.turenko@tarantool.org>
 | Date:   Fri Nov 8 14:12:24 2019 +0300
 |
 |     build: don't pass LDFLAGS from environment to curl
 |     
 |     After ea5929db4d400f5013a1c521870b9e14a8edcf85 ('build: fix OpenSSL
 |     linking problems on FreeBSD') we set CFLAGS explicitly (possibly to an
 |     empty value) when invoking a configure script for curl. When this
 |     parameter is set the script does not use a value of environment variable
 |     CFLAGS.
 |     
 |     Before this commit LDFLAGS environment variable can affect build of curl
 |     submodule. This can lead to a problem when a user or a tool set CFLAGS
 |     and LDFLAGS both and some linker flag assumes that some compilation flag
 |     is present. Here we set empty LDFLAGS explicitly to avoid using of the
 |     environment variable.
 |     
 |     A distributive build tool such as rpmbuild or emerge usually sets CFLAGS
 |     and LDFLAGS. The problem with incompatible compiler / linker options has
 |     been reveal under rpmbuild on CentOS 8 with hardened build enabled
 |     (which is so when backtraces are disabled).
 |     
 |     It is not clear whether we should follow environment variables or values
 |     determined by CMake for CFLAGS, CPPFLAGS and LDFLAGS when building a
 |     submodule (such as luajit and curl). Let's decide about this later.
 |     
 |     Part of #4543.
 |
 | diff --git a/cmake/BuildLibCURL.cmake b/cmake/BuildLibCURL.cmake
 | index 12062ec8b..6d40ab045 100644
 | --- a/cmake/BuildLibCURL.cmake
 | +++ b/cmake/BuildLibCURL.cmake
 | @@ -57,9 +57,20 @@ macro(curl_build)
 |  
 |                  # Pass -isysroot=<SDK_PATH> option on Mac OS, see
 |                  # above.
 | +                # Note: Passing of CPPFLAGS / CFLAGS explicitly
 | +                # discards using of corresponsing environment
 | +                # variables.
 |                  CPPFLAGS=${LIBCURL_CPPFLAGS}
 |                  CFLAGS=${LIBCURL_CFLAGS}
 |  
 | +                # Pass empty LDFLAGS to discard using of
 | +                # corresponding environment variable.
 | +                # It is possible that a linker flag assumes that
 | +                # some compilation flag is set. We don't pass
 | +                # CFLAGS from environment, so we should not do it
 | +                # for LDFLAGS too.
 | +                LDFLAGS=
 | +
 |                  --prefix <INSTALL_DIR>
 |                  --enable-static
 |                  --enable-shared

>  %if %{with systemd}
>           -DWITH_SYSTEMD:BOOL=ON \
>           -DSYSTEMD_UNIT_DIR:PATH=%{_unitdir} \
> diff --git a/test/app-tap/pwd.skipcond b/test/app-tap/pwd.skipcond
> new file mode 100644
> index 000000000..cebc6706c
> --- /dev/null
> +++ b/test/app-tap/pwd.skipcond
> @@ -0,0 +1,11 @@
> +import subprocess
> +
> +# Disabled at CentOS 8 build due to issue #4592.
> +try:
> +    if subprocess.check_output(["rpm --eval '%{centos_ver}'"], \
> +            shell=True).strip() == '8':
> +        self.skip = 1

Made fixes suggested by flake8:

test/app-tap/pwd.skipcond:5:64: E502 the backslash is redundant between brackets
test/app-tap/pwd.skipcond:6:13: E128 continuation line under-indented for visual indent

Eliminated using of shell=True: we can split arguments ourself, there is
no problem with it.

 | diff --git a/test/app-tap/pwd.skipcond b/test/app-tap/pwd.skipcond
 | index cebc6706c..cf97461bc 100644
 | --- a/test/app-tap/pwd.skipcond
 | +++ b/test/app-tap/pwd.skipcond
 | @@ -1,9 +1,9 @@
 |  import subprocess
 |  
 | -# Disabled at CentOS 8 build due to issue #4592.
 | +# Disable the test on CentOS 8 until gh-4592 will be resolved.
 |  try:
 | -    if subprocess.check_output(["rpm --eval '%{centos_ver}'"], \
 | -            shell=True).strip() == '8':
 | +    cmd = ['rpm', '--eval', '%{centos_ver}']
 | +    if subprocess.check_output(cmd).strip() == '8':
 | 		 self.skip = 1
 |  except:
 | 	 pass

> +except:
> +    pass
> +
> +# vim: set ft=python:
> -- 
> 2.17.1
>