Improve feedback from dinitctl when service load fails

Distinguish between service not found, service description error, and
other load errors. Suggest running dinitcheck or checking logs where
appropriate.

src/control.cc

@@ -148,7 +148,13 @@ bool control_conn_t::process_find_load(int pktType)
     service_record * record = nullptr;
     
     string serviceName = rbuf.extract_string(3, svcSize);
+
+    // Clear the packet from the buffer
+    rbuf.consume(chklen);
+    chklen = 0;
     
+    char fail_code = DINIT_RP_NOSERVICE;
+
     if (pktType == DINIT_CP_LOADSERVICE) {
         // LOADSERVICE
         try {
@@ -156,10 +162,17 @@ bool control_conn_t::process_find_load(int pktType)
         }
         catch (service_description_exc &sdexc) {
             log_service_load_failure(sdexc);
+            fail_code = DINIT_RP_SERVICE_DESC_ERR;
+        }
+        catch (service_not_found &snf) {
+            log(loglevel_t::ERROR, "Could not load service ", snf.service_name, ": ",
+                    snf.exc_description);
+            // fail_code = DINIT_RP_NOSERVICE;   (already set)
         }
         catch (service_load_exc &slexc) {
             log(loglevel_t::ERROR, "Could not load service ", slexc.service_name, ": ",
                     slexc.exc_description);
+            fail_code = DINIT_RP_SERVICE_LOAD_ERR;
         }
     }
     else {
@@ -167,27 +180,24 @@ bool control_conn_t::process_find_load(int pktType)
         record = services->find_service(serviceName.c_str());
     }
     
-    if (record != nullptr) {
-        // Allocate a service handle
-        handle_t handle = allocate_service_handle(record);
-        std::vector<char> rp_buf;
-        rp_buf.reserve(7);
-        rp_buf.push_back(DINIT_RP_SERVICERECORD);
-        rp_buf.push_back(static_cast<char>(record->get_state()));
-        for (int i = 0; i < (int) sizeof(handle); i++) {
-            rp_buf.push_back(*(((char *) &handle) + i));
-        }
-        rp_buf.push_back(static_cast<char>(record->get_target_state()));
+    if (record == nullptr) {
+        std::vector<char> rp_buf = { fail_code };
         if (! queue_packet(std::move(rp_buf))) return false;
+        return true;
     }
-    else {
-        std::vector<char> rp_buf = { DINIT_RP_NOSERVICE };
-        if (! queue_packet(std::move(rp_buf))) return false;
+
+    // Allocate a service handle
+    handle_t handle = allocate_service_handle(record);
+    std::vector<char> rp_buf;
+    rp_buf.reserve(7);
+    rp_buf.push_back(DINIT_RP_SERVICERECORD);
+    rp_buf.push_back(static_cast<char>(record->get_state()));
+    for (int i = 0; i < (int) sizeof(handle); i++) {
+        rp_buf.push_back(*(((char *) &handle) + i));
     }
+    rp_buf.push_back(static_cast<char>(record->get_target_state()));
+    if (! queue_packet(std::move(rp_buf))) return false;
     
-    // Clear the packet from the buffer
-    rbuf.consume(chklen);
-    chklen = 0;
     return true;
 }
 

src/dinitctl.cc

@@ -639,7 +639,7 @@ static int start_stop_service(int socknum, cpbuffer_t &rbuffer, const char *serv
         ignore_unstarted = false;
     }
 
-    if (! load_service(socknum, rbuffer, service_name, &handle, &state, !ignore_unstarted)) {
+    if (!load_service(socknum, rbuffer, service_name, &handle, &state, !ignore_unstarted)) {
         return ignore_unstarted ? 0 : 1;
     }
 
@@ -794,7 +794,22 @@ static int check_load_reply(int socknum, cpbuffer_t &rbuffer, handle_t *handle_p
     }
     else if (rbuffer[0] == DINIT_RP_NOSERVICE) {
         if (write_error) {
-            cerr << "dinitctl: failed to find/load service." << endl;
+            cerr << "dinitctl: failed to find service description.\n";
+            cerr << "dinitctl: check service description file exists / service name spelling.\n";
+        }
+        return 1;
+    }
+    else if (rbuffer[0] == DINIT_RP_SERVICE_DESC_ERR) {
+        if (write_error) {
+            cerr << "dinitctl: error in service description.\n";
+            cerr << "dinitctl: try 'dinitcheck <service-name>' or check log for more information.\n";
+        }
+        return 1;
+    }
+    else if (rbuffer[0] == DINIT_RP_SERVICE_LOAD_ERR) {
+        if (write_error) {
+            cerr << "dinitctl: error loading service.\n";
+            cerr << "dinitctl: try 'dinitcheck <service-name>' or check log for more information.\n";
         }
         return 1;
     }

src/includes/control-cmds.h

@@ -111,6 +111,11 @@ constexpr static int DINIT_RP_SHUTTINGDOWN = 69;
 // Service status:
 constexpr static int DINIT_RP_SERVICESTATUS = 70;
 
+// Service description error:
+constexpr static int DINIT_RP_SERVICE_DESC_ERR = 71;
+// Service load error (general):
+constexpr static int DINIT_RP_SERVICE_LOAD_ERR = 72;
+
 
 // Information (out-of-band):