systemd-analyze: option to exit with an error when 'verify' fails

The commit introduces a callback invoked from log_syntax_internal.
Use it from systemd-analyze to gather a list of units that contain
syntax warnings. A new command line option is added to make use of this.

The new option --recursive-errors takes in three possible modes:

1. yes - which is the default. systemd-analyze exits with an error when syntax warnings arise during verification of the
	 specified units or any of their dependencies.
3. no - systemd-analyze exits with an error when syntax warnings arise during verification of only the selected unit.
	Analyzing and loading any dependencies will be skipped.
4. one - systemd-analyze exits with an error when syntax warnings arise during verification
	 of only the selected units and their direct dependencies.

Below are two service unit files that I created for the purposes of testing:

1. First, we run the commands on a unit that does not have dependencies but has a non-existing key-value setting (i.e. foo = bar).

> cat <<EOF>testcase.service

[Unit]
foo = bar

[Service]
ExecStart = echo hello
EOF

OUTPUT:

maanya-goenka@debian:~/systemd (log-error)$ sudo build/systemd-analyze verify testcase.service
/home/maanya-goenka/systemd/testcase.service:2: Unknown key name 'foo' in section 'Unit', ignoring.
/usr/lib/systemd/system/plymouth-start.service:15: Unit configured to use KillMode=none. This is unsafe, as it disables systemd's process lifecycle management for the service. Please update your service to use a safer KillMode=, such as 'mixed' or 'control-group'. Support for KillMode=none is deprecated and will eventually be removed.
/usr/lib/systemd/system/dbus.socket:5: ListenStream= references a path below legacy directory /var/run/, updating /var/run/dbus/system_bus_socket → /run/dbus/system_bus_socket; please update the unit file accordingly.
/usr/lib/systemd/system/gdm.service:30: Standard output type syslog is obsolete, automatically updating to journal. Please update your unit file, and consider removing the setting altogether.
maanya-goenka@debian:~/systemd (log-error)$ echo $?
1

maanya-goenka@debian:~/systemd (log-error)$ sudo build/systemd-analyze verify --recursive-errors=yes testcase.service
/home/maanya-goenka/systemd/testcase.service:2: Unknown key name 'foo' in section 'Unit', ignoring.
/usr/lib/systemd/system/plymouth-start.service:15: Unit configured to use KillMode=none. This is unsafe, as it disables systemd's process lifecycle management for the service. Please update your service to use a safer KillMode=, such as 'mixed' or 'control-group'. Support for KillMode=none is deprecated and will eventually be removed.
/usr/lib/systemd/system/dbus.socket:5: ListenStream= references a path below legacy directory /var/run/, updating /var/run/dbus/system_bus_socket → /run/dbus/system_bus_socket; please update the unit file accordingly.
/usr/lib/systemd/system/gdm.service:30: Standard output type syslog is obsolete, automatically updating to journal. Please update your unit file, and consider removing the setting altogether.
maanya-goenka@debian:~/systemd (log-error)$ echo $?
1

maanya-goenka@debian:~/systemd (log-error)$ sudo build/systemd-analyze verify --recursive-errors=no testcase.service
/home/maanya-goenka/systemd/testcase.service:2: Unknown key name 'foo' in section 'Unit', ignoring.
maanya-goenka@debian:~/systemd (log-error)$ echo $?
1

maanya-goenka@debian:~/systemd (log-error)$ sudo build/systemd-analyze verify --recursive-errors=one testcase.service
/home/maanya-goenka/systemd/testcase.service:2: Unknown key name 'foo' in section 'Unit', ignoring.
/usr/lib/systemd/system/plymouth-start.service:15: Unit configured to use KillMode=none. This is unsafe, as it disables systemd's process lifecycle management for the service. Please update your service to use a safer KillMode=, such as 'mixed' or 'control-group'. Support for KillMode=none is deprecated and will eventually be removed.
/usr/lib/systemd/system/dbus.socket:5: ListenStream= references a path below legacy directory /var/run/, updating /var/run/dbus/system_bus_socket → /run/dbus/system_bus_socket; please update the unit file accordingly.
/usr/lib/systemd/system/gdm.service:30: Standard output type syslog is obsolete, automatically updating to journal. Please update your unit file, and consider removing the setting altogether.
maanya-goenka@debian:~/systemd (log-error)$ echo $?
1

2. Next, we run the commands on a unit that is syntactically valid but has a non-existing dependency (i.e. foo2.service)

> cat <<EOF>foobar.service

[Unit]
Requires = foo2.service

[Service]
ExecStart = echo hello
EOF

OUTPUT:

maanya-goenka@debian:~/systemd (log-error)$ sudo build/systemd-analyze verify foobar.service
/usr/lib/systemd/system/plymouth-start.service:15: Unit configured to use KillMode=none. This is unsafe, as it disables systemd's process lifecycle management for the service. Please update your service to use a safer KillMode=, such as 'mixed' or 'control-group'. Support for KillMode=none is deprecated and will eventually be removed.
/usr/lib/systemd/system/dbus.socket:5: ListenStream= references a path below legacy directory /var/run/, updating /var/run/dbus/system_bus_socket → /run/dbus/system_bus_socket; please update the unit file accordingly.
/usr/lib/systemd/system/gdm.service:30: Standard output type syslog is obsolete, automatically updating to journal. Please update your unit file, and consider removing the setting altogether.
foobar.service: Failed to create foobar.service/start: Unit foo2.service not found.
maanya-goenka@debian:~/systemd (log-error)$ echo $?
1

maanya-goenka@debian:~/systemd (log-error)$ sudo build/systemd-analyze verify --recursive-errors=yes foobar.service
/usr/lib/systemd/system/plymouth-start.service:15: Unit configured to use KillMode=none. This is unsafe, as it disables systemd's process lifecycle management for the service. Please update your service to use a safer KillMode=, such as 'mixed' or 'control-group'. Support for KillMode=none is deprecated and will eventually be removed.
/usr/lib/systemd/system/dbus.socket:5: ListenStream= references a path below legacy directory /var/run/, updating /var/run/dbus/system_bus_socket → /run/dbus/system_bus_socket; please update the unit file accordingly.
/usr/lib/systemd/system/gdm.service:30: Standard output type syslog is obsolete, automatically updating to journal. Please update your unit file, and consider removing the setting altogether.
foobar.service: Failed to create foobar.service/start: Unit foo2.service not found.
maanya-goenka@debian:~/systemd (log-error)$ echo $?
1

maanya-goenka@debian:~/systemd (log-error)$ sudo build/systemd-analyze verify --recursive-errors=no foobar.service
maanya-goenka@debian:~/systemd (log-error)$ echo $?
0

maanya-goenka@debian:~/systemd (log-error)$ sudo build/systemd-analyze verify --recursive-errors=one foobar.service
/usr/lib/systemd/system/plymouth-start.service:15: Unit configured to use KillMode=none. This is unsafe, as it disables systemd's process lifecycle management for the service. Please update your service to use a safer KillMode=, such as 'mixed' or 'control-group'. Support for KillMode=none is deprecated and will eventually be removed.
/usr/lib/systemd/system/dbus.socket:5: ListenStream= references a path below legacy directory /var/run/, updating /var/run/dbus/system_bus_socket → /run/dbus/system_bus_socket; please update the unit file accordingly.
/usr/lib/systemd/system/gdm.service:30: Standard output type syslog is obsolete, automatically updating to journal. Please update your unit file, and consider removing the setting altogether.
foobar.service: Failed to create foobar.service/start: Unit foo2.service not found.
maanya-goenka@debian:~/systemd (log-error)$ echo $?
1

2 files changed, 2 insertions, 1 deletions

diff --git a/shell-completion/bash/systemd-analyze b/shell-completion/bash/systemd-analyze
index 872518add0..1b9447a125 100644
--- a/shell-completion/bash/systemd-analyze
+++ b/shell-completion/bash/systemd-analyze
@@ -125,7 +125,7 @@ _systemd_analyze() {
 
     elif __contains_word "$verb" ${VERBS[VERIFY]}; then
         if [[ $cur = -* ]]; then
-            comps='--help --version --system --user --global --man=no --generators=yes --root --image'
+            comps='--help --version --system --user --global --man=no --generators=yes --root --image --recursive-errors=no --recursive-errors=yes --recursive-errors=one'
         else
             comps=$( compgen -A file -- "$cur" )
             compopt -o filenames
diff --git a/shell-completion/zsh/_systemd-analyze b/shell-completion/zsh/_systemd-analyze
index 88a09d84b9..0dd080afb7 100644
--- a/shell-completion/zsh/_systemd-analyze
+++ b/shell-completion/zsh/_systemd-analyze
@@ -89,6 +89,7 @@ _arguments \
     '--global[Show global user instance config]' \
     '--root=[Add support for root argument]:PATH' \
     '--image=[Add support for discrete images]:PATH' \
+    '--recursive-errors=[When verifying a unit, control dependency verification]:MODE' \
     '--no-pager[Do not pipe output into a pager]' \
     '--man=[Do (not) check for existence of man pages]:boolean:(1 0)' \
     '--order[When generating graph for dot, show only order]' \