Add sudo ability detection

Detect current capabilities with help of sudo tool. If addresses are
already configured, then just run tests. If they are not, use capsh to
detect ability to configure network.

bind9-next.spec

@@ -6,6 +6,8 @@
 # bcond_without is built by default, unless --without X is passed
 # bcond_with is built only when --with X is passed to build
 %bcond_with    SYSTEMTEST
+# Allow net configuration using sudo when SYSTEMTEST is enabled
+%bcond_without SUDO
 %bcond_without GSSTSIG
 %bcond_without JSON
 # FIXME: Not ready. Should it be worked on?
@@ -133,8 +135,12 @@ BuildRequires:  softhsm
 # bin/tests/system dependencies
 BuildRequires:  perl(Net::DNS) perl(Net::DNS::Nameserver) perl(Time::HiRes) perl(Getopt::Long)
 BuildRequires:  perl(English)
+BuildRequires:  python3-pytest
 # manual configuration requires this tool
 BuildRequires:  iproute
+%if %{with SUDO}
+BuildRequires:  libcap sudo
+%endif
 %endif
 %if %{with GSSTSIG}
 BuildRequires:  krb5-devel
@@ -479,13 +485,21 @@ export TSAN_OPTIONS="log_exe_name=true log_path=ThreadSanitizer exitcode=0"
 %if %{with SYSTEMTEST}
 # Runs system test if ip addresses are already configured
 # or it is able to configure them
+  SUDO=
   pushd build/bin/tests/system/
   if perl ./testsock.pl
   then
     CONFIGURED=already
   else
+    %if %{with SUDO}
+      if [ -x /usr/sbin/capsh ] && ! /usr/sbin/capsh --has-p=cap_net_admin; then
+        echo "Not running as privileged user, using sudo"
+        SUDO=sudo
+      fi
+    %endif
+
     CONFIGURED=
-    sh ./ifconfig.sh up
+    $SUDO sh ./ifconfig.sh up
     perl ./testsock.pl && CONFIGURED=build
   fi
   popd
@@ -498,7 +512,7 @@ export TSAN_OPTIONS="log_exe_name=true log_path=ThreadSanitizer exitcode=0"
     chown -R ${USER} . # Can be unknown user
     %make_build test 2>&1 | tee test.log
     e=$?
-    [ "$CONFIGURED" = build ] && sh ./ifconfig.sh down
+    [ "$CONFIGURED" = build ] && $SUDO sh ./ifconfig.sh down
     popd
     if [ "$e" -ne 0 ]; then
       echo "ERROR: this build of BIND failed 'make test'. Aborting."