[3770] Added -t to kea-dhcp6

src/bin/dhcp6/kea-dhcp6.xml

@@ -52,6 +52,7 @@
       <arg><option>-V</option></arg>
       <arg><option>-W</option></arg>
       <arg><option>-d</option></arg>
+      <arg><option>-t</option></arg>
       <arg><option>-c<replaceable class="parameter">config-file</replaceable></option></arg>
       <arg><option>-p<replaceable class="parameter">port-number</replaceable></option></arg>
     </cmdsynopsis>
@@ -103,6 +104,14 @@
       </varlistentry>
 
       <varlistentry>
+        <term><option>-t</option></term>
+        <listitem><para>
+          Check the syntax of the configuration file and report the first
+          error if any.
+        </para></listitem>
+      </varlistentry>
+
+      <varlistentry>
         <term><option>-c</option></term>
         <listitem><para>
           Configuration file including the configuration for DHCPv6 server.

src/bin/dhcp6/main.cc

@@ -8,6 +8,7 @@
 
 #include <dhcp6/ctrl_dhcp6_srv.h>
 #include <dhcp6/dhcp6_log.h>
+#include <dhcp6/parser_context.h>
 #include <dhcpsrv/cfgmgr.h>
 #include <log/logger_support.h>
 #include <log/logger_manager.h>
@@ -18,6 +19,7 @@
 
 #include <iostream>
 
+using namespace isc::data;
 using namespace isc::dhcp;
 using namespace std;
 
@@ -43,11 +45,12 @@ usage() {
     cerr << "Kea DHCPv6 server, version " << VERSION << endl;
     cerr << endl;
     cerr << "Usage: " << DHCP6_NAME
-         << " -[v|V|W] [-d] [-c cfgfile] [-p port_number]" << endl;
+         << " -[v|V|W] [-d] [-t] [-c cfgfile] [-p port_number]" << endl;
     cerr << "  -v: print version number and exit." << endl;
     cerr << "  -V: print extended version and exit" << endl;
     cerr << "  -W: display the configuration report and exit" << endl;
     cerr << "  -d: debug mode with extra verbosity (former -v)" << endl;
+    cerr << "  -t: check the configuration file syntax and exit" << endl;
     cerr << "  -c file: specify configuration file" << endl;
     cerr << "  -p number: specify non-standard port number 1-65535 "
          << "(useful for testing only)" << endl;
@@ -61,16 +64,21 @@ main(int argc, char* argv[]) {
     int port_number = DHCP6_SERVER_PORT; // The default. Any other values are
                                          // useful for testing only.
     bool verbose_mode = false; // Should server be verbose?
+    bool check_mode = false;   // Check syntax
 
     // The standard config file
     std::string config_file("");
 
-    while ((ch = getopt(argc, argv, "dvVWc:p:")) != -1) {
+    while ((ch = getopt(argc, argv, "dtvVWc:p:")) != -1) {
         switch (ch) {
         case 'd':
             verbose_mode = true;
             break;
 
+        case 't':
+            check_mode = true;
+            break;
+
         case 'v':
             cout << Dhcpv6Srv::getVersion(false) << endl;
             return (EXIT_SUCCESS);
@@ -118,6 +126,24 @@ main(int argc, char* argv[]) {
         usage();
     }
 
+    if (check_mode) {
+        try {
+            Parser6Context parser;
+            ConstElementPtr json;
+            json = parser.parseFile(config_file, Parser6Context::PARSER_DHCP6);
+            if (!json) {
+                cerr << "No configuration found" << endl;
+                return (EXIT_FAILURE);
+            }
+            if (verbose_mode) {
+                cerr << "Syntax check OK" << endl;
+            }
+            return (EXIT_SUCCESS);
+        } catch (const std::exception& ex) {
+            cerr << "Syntax check failed with " << ex.what() << endl;
+        }
+        return (EXIT_FAILURE);
+    }
 
     int ret = EXIT_SUCCESS;
     try {

src/bin/dhcp6/tests/dhcp6_process_tests.sh.in

@@ -59,12 +59,50 @@ CONFIG="{
         ]
     }
 }"
+# Invalid configuration (syntax error) to check that Kea can check syntax.
+CONFIG_BAD_SYNTAX="{
+    \"Dhcp6\":
+    {
+        \"interfaces\": [ ],
+        \"preferred-lifetime\": 3000,
+        \"valid-lifetime\": 4000,
+        \"renew-timer\": 1000,
+        \"rebind-timer\": 2000,
+        \"lease-database\":
+        {
+            \"type\": \"memfile\",
+            \"persist\": false
+        },
+        \"subnet6\": [
+        {
+            \"subnet\": \"2001:db8:1::/64\",
+            \"pool\": [ { \"pool\": \"2001:db8:1::10-2001:db8:1::100\" } ]
+        } ]
+    },
+
+    \"Logging\":
+    {
+        \"loggers\": [
+        {
+            \"name\": \"kea-dhcp6\",
+            \"output_options\": [
+                {
+                    \"output\": \"$LOG_FILE\"
+                }
+            ],
+            \"severity\": \"INFO\"
+        }
+        ]
+    }
+}"
 # Invalid configuration (negative preferred-lifetime) to check that Kea
 # gracefully handles reconfiguration errors.
 CONFIG_INVALID="{
     \"Dhcp6\":
     {
-        \"interfaces\": [ ],
+        \"interfaces-config\": {
+          \"interfaces\": [ ]
+        },
         \"preferred-lifetime\": -3,
         \"valid-lifetime\": 4000,
         \"renew-timer\": 1000,
@@ -104,6 +142,36 @@ bin_path=@abs_top_builddir@/src/bin/dhcp6
 # Import common test library.
 . @abs_top_builddir@/src/lib/testutils/dhcp_test_lib.sh
 
+# This test verifies that syntax check works properly.
+syntax_check_test() {
+    # Log the start of the test and print test name.
+    test_start "dhcpv6_srv.syntax_check"
+    # Remove dangling Kea instances and remove log files.
+    cleanup
+    # Create correct configuration file.
+    create_config "${CONFIG}"
+    # Check it
+    printf "Running command %s.\n" "\"${bin_path}/${bin} -t -c ${CFG_FILE}\""
+    ${bin_path}/${bin} -t -c ${CFG_FILE}
+    exit_code=$?
+    if [ ${exit_code} -ne 0 ]; then
+        printf "ERROR: expected exit code 0, got ${exit_code}\n"
+        clean_exit 1
+    fi
+    # Create incorrect configuration file.
+    create_config "${CONFIG_BAD_SYNTAX}"
+    # Check it
+    printf "Running command %s.\n" "\"${bin_path}/${bin} -t -c ${CFG_FILE}\""
+    printf "A syntax error should be detected\n"
+    ${bin_path}/${bin} -t -c ${CFG_FILE}
+    if [ $? -eq 0 ]; then
+        printf "ERROR: expected exit code not 0, got 0\n"
+        clean_exit 1
+    fi
+    # All ok
+    clean_exit 0
+}
+
 # This test verifies that DHCPv6 can be reconfigured with a SIGHUP signal.
 dynamic_reconfiguration_test() {
     # Log the start of the test and print test name.
@@ -381,6 +449,7 @@ dynamic_reconfiguration_test
 shutdown_test "dhcpv6.sigterm_test" 15
 shutdown_test "dhcpv6.sigint_test" 2
 version_test "dhcpv6.version"
+syntax_check_test
 logger_vars_test "dhcpv6.variables"
 lfc_timer_test