Merge pull request #2151 from oxzi/check_by_ssh-ignore-stderr

check_by_ssh: Ignore output on stderr by default

2 files changed, 17 insertions, 8 deletions

diff --git a/plugins/check_by_ssh.c b/plugins/check_by_ssh.c
index 74b7a46f..a43c0d34 100644
--- a/plugins/check_by_ssh.c
+++ b/plugins/check_by_ssh.c
@@ -119,13 +119,14 @@ int main(int argc, char **argv) {
                 skip_stderr = config.skip_stderr;
         }
 
-        /* UNKNOWN or worse if (non-skipped) output found on stderr */
-        if (chld_err.lines > (size_t)skip_stderr) {
+        /* Allow UNKNOWN or WARNING state for (non-skipped) output found on stderr */
+        if (chld_err.lines > (size_t)skip_stderr && (config.unknown_on_stderr || config.warn_on_stderr)) {
                 printf(_("Remote command execution failed: %s\n"), chld_err.line[skip_stderr]);
-                if (config.warn_on_stderr) {
+                if (config.unknown_on_stderr) {
+                        return max_state_alt(result, STATE_UNKNOWN);
+                } else if (config.warn_on_stderr) {
                         return max_state_alt(result, STATE_WARNING);
                 }
-                return max_state_alt(result, STATE_UNKNOWN);
         }
 
         /* this is simple if we're not supposed to be passive.
@@ -191,12 +192,13 @@ check_by_ssh_config_wrapper process_arguments(int argc, char **argv) {
                 {"name", required_argument, 0, 'n'},
                 {"services", required_argument, 0, 's'},
                 {"identity", required_argument, 0, 'i'},
-                {"user", required_argument, 0, 'u'},
+                {"user", required_argument, 0, 'u'}, /* backwards compatibility */
                 {"logname", required_argument, 0, 'l'},
                 {"command", required_argument, 0, 'C'},
                 {"skip", optional_argument, 0, 'S'}, /* backwards compatibility */
                 {"skip-stdout", optional_argument, 0, 'S'},
                 {"skip-stderr", optional_argument, 0, 'E'},
+                {"unknown-on-stderr", no_argument, 0, 'e'},
                 {"warn-on-stderr", no_argument, 0, 'W'},
                 {"proto1", no_argument, 0, '1'},
                 {"proto2", no_argument, 0, '2'},
@@ -341,6 +343,9 @@ check_by_ssh_config_wrapper process_arguments(int argc, char **argv) {
                                 result.config.skip_stderr = atoi(optarg);
                         }
                         break;
+                case 'e': /* exit with unknown if there is an output on stderr */
+                        result.config.unknown_on_stderr = true;
+                        break;
                 case 'W': /* exit with warning if there is an output on stderr */
                         result.config.warn_on_stderr = true;
                         break;
@@ -468,8 +473,10 @@ void print_help(void) {
         printf("    %s\n", _("Ignore all or (if specified) first n lines on STDOUT [optional]"));
         printf(" %s\n", "-E, --skip-stderr[=n]");
         printf("    %s\n", _("Ignore all or (if specified) first n lines on STDERR [optional]"));
-        printf(" %s\n", "-W, --warn-on-stderr]");
-        printf("    %s\n", _("Exit with an warning, if there is an output on STDERR"));
+        printf(" %s\n", "-e, --unknown-on-stderr");
+        printf("    %s\n", _("Exit with UNKNOWN, if there is output on STDERR"));
+        printf(" %s\n", "-W, --warn-on-stderr");
+        printf("    %s\n", _("Exit with WARNING, if there is output on STDERR"));
         printf(" %s\n", "-f");
         printf("    %s\n", _("tells ssh to fork rather than create a tty [optional]. This will always "
                                                  "return OK if ssh is executed"));
@@ -522,7 +529,7 @@ void print_help(void) {
 void print_usage(void) {
         printf("%s\n", _("Usage:"));
         printf(" %s -H <host> -C <command> [-fqvU] [-1|-2] [-4|-6]\n"
-                   "       [-S [lines]] [-E [lines]] [-W] [-t timeout] [-i identity]\n"
+                   "       [-S [lines]] [-E [lines]] [-e|-W] [-t timeout] [-i identity]\n"
                    "       [-l user] [-n name] [-s servicelist] [-O outputfile]\n"
                    "       [-p port] [-o ssh-option] [-F configfile]\n",
                    progname);
diff --git a/plugins/check_by_ssh.d/config.h b/plugins/check_by_ssh.d/config.h
index 05435def..0e4b56d4 100644
--- a/plugins/check_by_ssh.d/config.h
+++ b/plugins/check_by_ssh.d/config.h
@@ -21,6 +21,7 @@ typedef struct {
         command_construct cmd;
 
         bool unknown_timeout;
+        bool unknown_on_stderr;
         bool warn_on_stderr;
         int skip_stdout;
         int skip_stderr;
@@ -46,6 +47,7 @@ check_by_ssh_config check_by_ssh_config_init() {
                         },
 
                 .unknown_timeout = false,
+                .unknown_on_stderr = false,
                 .warn_on_stderr = false,
                 .skip_stderr = 0,
                 .skip_stdout = 0,