Streamline useradd/groupadd calls in RPM spec files

Summary

Replace RPM useradd/groupadd shell script fragments in spec files with dedicated RPM macros.

Owner

Name: Harald Hoyer
Name: Kay Sievers

Current status

Targeted release: Fedora 30
Tracker bug: <will be assigned by the Wrangler>

Detailed Description

Storing the user and group information a RPM package provides in structured data, opens the possibility to process this data with external tools in a programmatic way, instead of running opaque shell scripts at package installation time.

This is part of a long-term effort to gradually convert RPM shell scripts to information available in the RPM database or the /usr filesystem. Ideally, the operating system image creation process will create a /usr tree which contains all the information to instantiate a new bootable system. The RPM scripts only run at package installation time and their result cannot be reliably reproduced on the already installed system, when the content of /etc and /var is programmatically recreated from the content in /usr.

Because the macros accept all the important useradd/groupadd CLI options, we can extend the macros, if

rpm gains native fields for user and group
systemd-sysusers gains more functionality
we move to a completely different mechanism
or we can provide compat macros for old Fedora/RHEL versions expanding to the old useradd/groupadd calls

Example test.spec file processing:

$ rpmbuild --define "_sourcedir $(pwd)" --define "_specdir $(pwd)" --define "_builddir $(pwd)" --define "_srcrpmdir $(pwd)" --define "_rpmdir $(pwd)" -ba test.spec && rpm -qp --scripts noarch/*.rpm && rpm -qp --provides  noarch/*.rpm

Executing(%prep): /bin/sh -e /var/tmp/rpm-tmp.XfQ6P6
+ umask 022
+ cd /home/kay
+ exit 0
Executing(%build): /bin/sh -e /var/tmp/rpm-tmp.KFSrt0
+ umask 022
+ cd /home/kay
+ exit 0
Executing(%install): /bin/sh -e /var/tmp/rpm-tmp.XC996T
+ umask 022
+ cd /home/kay
+ '[' /home/kay/rpmbuild/BUILDROOT/test-1-1.x86_64 '!=' / ']'
+ rm -rf /home/kay/rpmbuild/BUILDROOT/test-1-1.x86_64
++ dirname /home/kay/rpmbuild/BUILDROOT/test-1-1.x86_64
+ mkdir -p /home/kay/rpmbuild/BUILDROOT
+ mkdir /home/kay/rpmbuild/BUILDROOT/test-1-1.x86_64
+ mkdir -p /home/kay/rpmbuild/BUILDROOT/test-1-1.x86_64/usr/lib/sysusers.d/
+ cat
+ mkdir -p /home/kay/rpmbuild/BUILDROOT/test-1-1.x86_64/usr/lib/sysusers.d/
+ cat
+ mkdir -p /home/kay/rpmbuild/BUILDROOT/test-1-1.x86_64/usr/lib/sysusers.d/
+ cat
+ /usr/lib/rpm/check-buildroot
+ /usr/lib/rpm/redhat/brp-ldconfig
+ /usr/lib/rpm/brp-compress
+ /usr/lib/rpm/brp-strip /usr/bin/strip
+ /usr/lib/rpm/brp-strip-comment-note /usr/bin/strip /usr/bin/objdump
+ /usr/lib/rpm/brp-strip-static-archive /usr/bin/strip
+ /usr/lib/rpm/brp-python-bytecompile /usr/bin/python 1 1
+ /usr/lib/rpm/brp-python-hardlink
+ /usr/lib/rpm/redhat/brp-mangle-shebangs
Processing files: test-1-1.noarch
Provides: group(group1) group(group2) group(group3) group(group4) test = 1-1 user(user1) user(user2)
Requires(interp): /bin/sh
Requires(rpmlib): rpmlib(CompressedFileNames) <= 3.0.4-1 rpmlib(FileDigests) <= 4.6.0-1 rpmlib(PayloadFilesHavePrefix) <= 4.0-1
Requires(pre): /bin/sh
Processing files: test-sub-1-1.noarch
Provides: group(subgroup1) test-sub = 1-1
Requires(interp): /bin/sh
Requires(rpmlib): rpmlib(CompressedFileNames) <= 3.0.4-1 rpmlib(FileDigests) <= 4.6.0-1 rpmlib(PayloadFilesHavePrefix) <= 4.0-1
Requires(pre): /bin/sh
Processing files: foo-1-1.noarch
Provides: foo = 1-1 group(foo1)
Requires(interp): /bin/sh
Requires(rpmlib): rpmlib(CompressedFileNames) <= 3.0.4-1 rpmlib(FileDigests) <= 4.6.0-1 rpmlib(PayloadFilesHavePrefix) <= 4.0-1
Requires(pre): /bin/sh
Checking for unpackaged file(s): /usr/lib/rpm/check-files /home/kay/rpmbuild/BUILDROOT/test-1-1.x86_64
Wrote: /home/kay/test-1-1.src.rpm
Wrote: /home/kay/noarch/test-1-1.noarch.rpm
Wrote: /home/kay/noarch/test-sub-1-1.noarch.rpm
Wrote: /home/kay/noarch/foo-1-1.noarch.rpm
Executing(%clean): /bin/sh -e /var/tmp/rpm-tmp.4EIRZN
+ umask 022
+ cd /home/kay
+ /usr/bin/rm -rf /home/kay/rpmbuild/BUILDROOT/test-1-1.x86_64
+ exit 0

It has created the following RPMs:

$ tree noarch/
noarch/
├── foo-1-1.noarch.rpm
├── test-1-1.noarch.rpm
└── test-sub-1-1.noarch.rpm

$ rpm -ihv noarch/*
Verifying...                          ################################# [100%]
Preparing...                          ################################# [100%]
Creating group subgroup1 with gid 968.
Updating / installing...
   1:test-sub-1-1                     ################################# [ 33%]
Creating group group1 with gid 967.
Creating group group2 with gid 966.
Creating group group3 with gid 13.
Creating group group4 with gid 965.
Creating group user1 with gid 964.
Creating user user1 (User 1) with uid 964 and gid 964.
Creating group user2 with gid 963.
Creating user user2 (User 2) with uid 963 and gid 963.
   2:test-1-1                         ################################# [ 67%]
Creating group foo1 with gid 962.
   3:foo-1-1                          ################################# [100%]

The macros created sysusers files which are installed on the system:

$ cat /usr/lib/sysusers.d/test.conf
g	group1	11	-
g	group2	12	-
g	group3	13	-
g	group4	-	-
u	user1	100	"User 1"	/var/user1	/sbin/nologin
m	user1	group1
m	user1	group3
m	user1	group4
u	user2	-	"User 2"	/var/user2	/sbin/nologin
m	user2	group2
m	user2	group3
m	user2	group4

$ cat /usr/lib/sysusers.d/test-sub.conf 
g	subgroup1	-	-

$ cat /usr/lib/sysusers.d/foo.conf 
g	foo1	-	-

The macros added the scripts to the RPM package which run at installation time:

$ rpm -qp --scripts noarch/*.rpm
preinstall scriptlet (using /bin/sh):
systemd-sysusers --replace=/usr/lib/sysusers.d/foo.conf - <<EOF
g	foo1	-	-
EOF
preinstall scriptlet (using /bin/sh):
systemd-sysusers --replace=/usr/lib/sysusers.d/test.conf - <<EOF
g	group1	11	-
g	group2	12	-
g	group3	13	-
g	group4	-	-
u	user1	100	"User 1"	/var/user1	/sbin/nologin
m	user1	group1
m	user1	group3
m	user1	group4
u	user2	-	"User 2"	/var/user2	/sbin/nologin
m	user2	group2
m	user2	group3
m	user2	group4
EOF
preinstall scriptlet (using /bin/sh):
systemd-sysusers --replace=/usr/lib/sysusers.d/test-sub.conf - <<EOF
g	subgroup1	-	-
EOF

The macros added Provides: to the packages, for all provided users and groups, so other packages can depend on them and pin the packages which provide the users and groups:

$ rpm -qp --provides  noarch/*.rpm
foo = 1-1
group(foo1)
group(group1)
group(group2)
group(group3)
group(group4)
test = 1-1
user(user1)
user(user2)
group(subgroup1)
test-sub = 1-1

/usr/lib/rpm/macros.d/macros.sysusers:

#################################################################
# macros.sysusers
#################################################################
%sysusers_useradd(n:S:c:d:g:G:lmMNors:u:UZ:) %{lua:
    -- -n package name
    -- -S subpackage name
    -- -* useradd options
\
    local package = rpm.expand("%{?-S*}")
    local name = rpm.expand("%{?!-n*:%{name}}%{?-n*}")
    if package ~= "" then
        name = name .. "_" .. package
    end
\
    local group = rpm.expand("%{?-g*}")
    local gecko = rpm.expand("%{?-c*}%{?!-c*:-}")
    local home = rpm.expand("%{?-d*}%{!-d*:-}")
    local shell = rpm.expand("%{?-s*}%{!-s*:-}")
    local uid = rpm.expand("%{?-u*}%{!-u*:-}")
    local user = rpm.expand("%{1}")
    local moregroups = rpm.expand("%{?-G*}")
\
    -- Add an ASCII unit separator instead of a newline
    local newlines = "u\\t" .. user .. "\\t" .. uid .. "\\t" .. gecko .. "\\t" .. home .. "\\t" .. shell .. "\\31"
\
    if group ~= "" then
        newlines = newlines .. "m\\t" .. user .. "\\t" .. group .. "\\31"
    end
\
    for group in string.gmatch(moregroups, "[^,]+") do
        newlines = newlines .. "m\\t" .. user .. "\\t" .. group .. "\\31"
    end
\
    local oldlines = rpm.expand("%{?sysusers_useradd_" .. name .. "}")
    rpm.define("sysusers_useradd_" .. name .. " " .. oldlines .. newlines)
\
    print("Provides: user(" .. user .. ")\\n")
}

%sysusers_groupadd(n:S:g:rfoB:N:) %{lua:
    -- -n package name
    -- -S subpackage name
    -- -* groupadd options
\
    local package = rpm.expand("%{?-S*}")
    local name = rpm.expand("%{?!-n*:%{name}}%{?-n*}")
    if package ~= "" then
        name = name .. "_" .. package
    end
\
    local gid = rpm.expand("%{?-g*}%{!-g*:-}")
    local group = rpm.expand("%{1}")
\
    local oldlines = rpm.expand("%{?sysusers_useradd_" .. name .. "}")
    -- Add an ASCII unit separator instead of a newline
    local newline = "g\\t" .. group .. "\\t" .. gid .. "\\t-\\31"
    rpm.define("sysusers_useradd_" .. name .. " " .. oldlines .. newline)
\
    print("Provides: group(" .. group .. ")\\n")
}

%sysusers_pre(n:S:) %{lua:
    -- -n package name
    -- -S subpackage name
\
    local package = rpm.expand("%{?-S*}")
    local name = rpm.expand("%{?!-n*:%{name}}%{?-n*}")
    local filename = name
    if package ~= "" then
        filename = name .. "-" .. package
        name = name .. "_" .. package
    end
\
    print("systemd-sysusers --replace=" .. rpm.expand("%{_sysusersdir}/") .. filename .. ".conf - <<EOF\\n")
    local lines = rpm.expand("%{?sysusers_useradd_" .. name .. "}")
    -- Split string at the ASCII unit separator
    for line in string.gmatch(lines, "[^\\31]+") do
        print(line .. "\\n")
    end
    print("EOF\\n")
}

%sysusers_install(n:S:) %{lua:
    -- -n package name
    -- -S subpackage name
\
    local package = rpm.expand("%{?-S*}")
    local name = rpm.expand("%{?!-n*:%{name}}%{?-n*}")
    local filename = name
    if package ~= "" then
        filename = name .. "-" .. package
        name = name .. "_" .. package
    end
\
    print("mkdir -p " .. rpm.expand("%{buildroot}") .. rpm.expand("%{_sysusersdir}/") .. "\\n")
    print("cat >" .. rpm.expand("%{buildroot}") .. rpm.expand("%{_sysusersdir}/") .. filename .. ".conf <<EOF\\n")
    local lines = rpm.expand("%{?sysusers_useradd_" .. name .. "}")
    -- Split string at the ASCII unit separator
    for line in string.gmatch(lines, "[^\\31]+") do
        print(line .. "\\n")
    end
    print("EOF\\n")
}

%sysusers_files(n:S:) %{lua:
    -- -n package name
    -- -S subpackage name
\
    local package = rpm.expand("%{?-S*}")
    local name = rpm.expand("%{?!-n*:%{name}}%{?-n*}")
    local filename = name
    if package ~= "" then
       filename = name .. "-" .. package
       name = name .. "_" .. package
    end
\
    print(rpm.expand("%{_sysusersdir}/") .. filename .. ".conf\\n")
}

test.spec

#################################################################
# test.spec
#################################################################
Name:           test
Version:        1
Release:        1
Summary:        test
License:        MIT
BuildArch:      noarch

%define GROUPNAME1 group1
%define USERNAME1  user1

%sysusers_groupadd -g 11 %{GROUPNAME1}
%sysusers_groupadd -g 12 group2
%sysusers_groupadd -g 13 group3
%sysusers_groupadd group4
%sysusers_useradd -g group1 -G group3,group4 -u 100 -d /var/user1 -s /sbin/nologin -c %{quote:"User 1"} %{USERNAME1}
%sysusers_useradd -g group2 -G group3,group4 -d /var/user2 -s /sbin/nologin -c %{quote:"User 2"} user2

%description

%package sub
Summary:         sub
%sysusers_groupadd -S sub subgroup1
%description sub

%package -n foo
Summary:         foo
%sysusers_groupadd -n foo foo1
%description -n foo

%pre
%sysusers_pre

%pre sub
%sysusers_pre -S sub

%pre -n foo
%sysusers_pre -n foo

%prep

%build

%install
%sysusers_install
%sysusers_install -n foo
%sysusers_install -S sub

%files
%sysusers_files

%files sub
%sysusers_files -S sub

%files -n foo
%sysusers_files -n foo

Benefit to Fedora

As a long-term goal, with enough structured data in the installed system, it would carry the needed information to reset itself to a factory default. The system users are one piece of the puzzle to provide the infrastructure to do that.

Scope

Proposal owners:

There are currently 378 (2018-11-03) spec files in the Fedora repository which call useradd/groupadd. This feature is about the mass-conversion of all these spec files.

Other developers: N/A (not a System Wide Change)

Release engineering: #Releng issue number (a check of an impact with Release Engineering is needed)
- List of deliverables: N/A (not a System Wide Change)

Policies and guidelines: N/A (not a System Wide Change)

The packaging guidelines need to be updated to document the use of the sysusers macros instead of useradd/groupadd shell snippets.

Trademark approval: N/A (not needed for this Change)

Upgrade/compatibility impact

N/A (not a System Wide Change)

How To Test

N/A (not a System Wide Change)

User Experience

Dependencies

N/A (not a System Wide Change)

Contingency Plan

Contingency mechanism: (What to do? Who will do it?) N/A (not a System Wide Change)
Contingency deadline: N/A (not a System Wide Change)
Blocks release? N/A (not a System Wide Change), Yes/No
Blocks product? product

Documentation

N/A (not a System Wide Change)

Release Notes

Search

Changes/RPMStreamlineUseradd

Contents

Streamline useradd/groupadd calls in RPM spec files

Summary

Owner

Current status

Detailed Description

Benefit to Fedora

Scope

Upgrade/compatibility impact

How To Test

User Experience

Dependencies

Contingency Plan

Documentation

Release Notes