Update docs and semantics of become key

tests/provision/connect/test.sh

@@ -30,11 +30,11 @@ rlJournalStart
         rlAssertGrep "Reboot finished" $rlRun_LOG
         rlAssertGrep "sudo /bin/bash -c reboot" $rlRun_LOG
 
-        # Test reboot without become (should fail for non-root user)
+        # Test reboot without become (should apply sudo as well, no a user script)
         provision_no_become="provision -h connect --guest localhost --port $guest_port --key $guest_key --user $guest_user"
-        rlRun -s "tmt -vv run --scratch -i $run_connect_no_become $provision_no_become reboot --step provision" 2
-        rlAssertGrep "fail: Command 'reboot' returned 1." $rlRun_LOG
-        rlAssertGrep "Call to Reboot failed: Access denied" $rlRun_LOG
+        rlRun -s "tmt -vv run --scratch -i $run_connect_no_become $provision_no_become reboot --step provision"
+        rlAssertGrep "Reboot finished" $rlRun_LOG
+        rlAssertGrep "sudo /bin/bash -c reboot" $rlRun_LOG
 
         rlRun "tmt run -i $run cleanup"
         rlRun "tmt run -i $run_connect cleanup"

tests/provision/reboot/test.sh

@@ -124,7 +124,7 @@ rlJournalStart
                 0 "Systemd soft-reboot"
             rlAssertGrep "reboot: Rebooting guest using systemd-soft mode." $rlRun_LOG
             rlAssertGrep "reboot: Reboot finished" $rlRun_LOG
-            rlAssertGrep "cmd: systemctl soft-reboot" $rlRun_LOG
+            rlAssertGrep "cmd: /bin/bash -c 'systemctl soft-reboot'" $rlRun_LOG
 
             rlRun -s "tmt -vv run -l reboot --systemd-soft --command 'systemctl soft-reboot'" \
                 0 "Systemd soft-reboot with custom command"

tests/test/check/test-journal.sh

@@ -145,10 +145,10 @@ rlJournalStart
                   rlAssertGrep "Configured persistent journal storage with sudo" $rlRun_LOG
                 fi
 
-                rlFileExists "$config_test/checks/journal.txt"
+                rlAssertExists "$config_test/checks/journal.txt"
 
                 rlRun -s "cat $config_test_check/output.txt"
-                rlAssertGrep "^\[Journal\]$" $rlRun_LOG
+                rlAssertGrep "\[Journal\]" $rlRun_LOG
                 rlAssertGrep "^Storage=persistent$" $rlRun_LOG
                 rlAssertGrep "^Compress=yes$" $rlRun_LOG
             rlPhaseEnd

tmt/guest/__init__.py

@@ -1309,8 +1309,9 @@ class GuestData(
         is_flag=True,
         option=('-b', '--become'),
         help="""
-             Whether to run tests and shell scripts in prepare and
-             finish steps with ``sudo``.
+             If set, user-provided commands - ``prepare`` and ``finish``
+             scripts and tests - will be invoked with elevated, superuser
+             privileges via passwordless ``sudo`` if necessary.
              """,
     )
 
@@ -3757,10 +3758,9 @@ def reboot(
                 f"Guest '{self.multihost_name}' does not support hard reboot."
             )
 
-        if self.become:
-            default_reboot_command = ShellScript(
-                f'sudo {default_reboot_command.to_shell_command()}'
-            )
+        default_reboot_command = ShellScript(
+            f'{self.facts.sudo_prefix} {default_reboot_command.to_shell_command()}'
+        )
 
         command = command or default_reboot_command
         waiting = waiting or default_reboot_waiting()

tmt/steps/context/pidfile.py

@@ -102,13 +102,8 @@
 OUTER_WRAPPER_TEMPLATE = jinja2.Template("""
 {% macro log_to_dmesg(msg) %}
     {%- if not GUEST.facts.is_superuser %}
-        {%- if GUEST.become %}
 # Logging test into kernel log
-sudo bash -c "echo \\\"{{ msg }}\\\" > /dev/kmsg"
-        {%- else %}
-# Not logging into kernel log: not a superuser, 'become' not enabled
-# echo \"{{ msg }}\" > /dev/kmsg
-        {%- endif %}
+{{ GUEST.facts.sudo_prefix }} bash -c "echo \\\"{{ msg }}\\\" > /dev/kmsg"
     {%- else %}
 # Logging test into kernel log
 echo "{{ msg }}" > /dev/kmsg

tmt/steps/prepare/shell.py

@@ -250,9 +250,7 @@ def _invoke_script(
             pull_options.exclude.append(str(script_log_filepath))
 
             if guest.become and not guest.facts.is_superuser:
-                command = tmt.utils.ShellScript(
-                    f'{guest.facts.sudo_prefix} {script.to_shell_command()}'
-                )
+                command = tmt.utils.ShellScript(f'sudo -E {script.to_shell_command()}')
             else:
                 command = script