[PATCH] buildchroot: build debian packages as "builder" not "root"

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

We used to build packages as "root" and now do that as a regular user.
Not building as "root" allows us to find mistakes in debian/rules where
privileged operations are used while they should not (a sudo was
found in a rules-file). Further some build steps might actually expect
to not run as root (seen in openssl test suite).

Not building as root should increase overall quality and brings us
closer to how debian packages are build by others.

Signed-off-by: Henning Schild <henning.schild@siemens.com>
---
 meta/recipes-devtools/buildchroot/buildchroot-target.bb | 3 ++-
 meta/recipes-devtools/buildchroot/files/build.sh        | 6 ++++--
 meta/recipes-devtools/buildchroot/files/configscript.sh | 4 ++++
 3 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/meta/recipes-devtools/buildchroot/buildchroot-target.bb b/meta/recipes-devtools/buildchroot/buildchroot-target.bb
index 42f47fc..c342625 100644
--- a/meta/recipes-devtools/buildchroot/buildchroot-target.bb
+++ b/meta/recipes-devtools/buildchroot/buildchroot-target.bb
@@ -18,6 +18,7 @@ BUILDCHROOT_PREINSTALL ?= "gcc \
                            apt \
                            automake \
                            devscripts \
-                           equivs"
+                           equivs \
+                           adduser"
 
 do_build[depends] = "isar-apt:do_cache_config isar-bootstrap-target:do_bootstrap"
diff --git a/meta/recipes-devtools/buildchroot/files/build.sh b/meta/recipes-devtools/buildchroot/files/build.sh
index e74bc14..d98eb2e 100644
--- a/meta/recipes-devtools/buildchroot/files/build.sh
+++ b/meta/recipes-devtools/buildchroot/files/build.sh
@@ -14,5 +14,7 @@ for i in configure aclocal.m4 Makefile.am Makefile.in; do
     fi
 done
 
-# Build the package
-dpkg-buildpackage -a$target_arch -d --source-option=-I
+# Build the package as user "builder"
+chown -R builder:builder $1 # the sources
+chown builder:builder $1/.. # the output
+su - builder -c "cd $1; dpkg-buildpackage -a$target_arch -d --source-option=-I"
diff --git a/meta/recipes-devtools/buildchroot/files/configscript.sh b/meta/recipes-devtools/buildchroot/files/configscript.sh
index d591c2a..30660e7 100644
--- a/meta/recipes-devtools/buildchroot/files/configscript.sh
+++ b/meta/recipes-devtools/buildchroot/files/configscript.sh
@@ -9,3 +9,7 @@ debconf-set-selections <<END
 locales locales/locales_to_be_generated multiselect en_US.UTF-8 UTF-8
 locales locales/default_environment_locale select en_US.UTF-8
 END
+
+addgroup --quiet --system builder
+useradd --system --gid builder --no-create-home --home /home/builder --no-user-group --comment "Isar buildchroot build user" builder
+chown -R builder:builder /home/builder
-- 
2.19.1