Support daemon and pidfile.

.gitignore

@@ -15,3 +15,6 @@ corvus_test
 .*.sw[pon]
 
 .cache
+tags
+src/tags
+*.patch

corvus.conf

@@ -2,6 +2,14 @@ bind 12345
 node localhost:8000,localhost:8001,localhost:8002
 thread 4
 
+# pidfile settings
+pidfile /tmp/corvus.pid
+
+# daemon setting
+# 0: not daemon
+# 1: run as a daemon
+daemon 0
+
 # debug, info, warn, error
 loglevel debug
 syslog 0

src/config.c

@@ -38,6 +38,8 @@ const char * CONFIG_OPTIONS[] = {
     "slowlog-log-slower-than",
     "slowlog-max-len",
     "slowlog-statsd-enabled",
+    "pidfile",
+    "daemon",
 };
 
 void config_init()
@@ -60,6 +62,8 @@ void config_init()
     config.slowlog_max_len = 1024;
     config.slowlog_log_slower_than = -1;
     config.slowlog_statsd_enabled = 0;
+    config.pidfile = 0;
+    config.daemon = 0;
 
     memset(config.statsd_addr, 0, sizeof(config.statsd_addr));
     config.metric_interval = 10;
@@ -282,6 +286,13 @@ int config_add(char *name, char *value)
         config.slowlog_max_len = val;
     } else if (strcmp(name, "slowlog-statsd-enabled") == 0) {
         config_boolean(&config.slowlog_statsd_enabled, value);
+    } else if (strcmp(name, "pidfile") == 0) {
+        if (strlen(value) > 0) {
+            config.pidfile = cv_calloc(strlen(value) + 1, sizeof(char));
+            memcpy(config.pidfile, value, strlen(value));
+        }
+    } else if (strcmp(name, "daemon") == 0) {
+        config_boolean(&config.daemon, value);
     }
     return CORVUS_OK;
 }
@@ -335,6 +346,14 @@ int config_get(const char *name, char *value, size_t max_len)
         snprintf(value, max_len, "%d", config.slowlog_max_len);
     } else if (strcmp(name, "slowlog-statsd-enabled") == 0) {
         strncpy(value, BOOL_STR(config.slowlog_statsd_enabled), max_len);
+    } else if (strcmp(name, "pidfile") == 0) {
+        if (config.pidfile) {
+            strncpy(value, config.pidfile, max_len);
+        } else {
+            strncpy(value, "", max_len);
+        }
+    } else if (strcmp(name, "daemon") == 0) {
+        strncpy(value, BOOL_STR(config.daemon), max_len);
     } else {
         return CORVUS_ERR;
     }

src/config.h

@@ -5,6 +5,7 @@
 
 #define CLUSTER_NAME_SIZE 127
 #define CONFIG_FILE_PATH_SIZE 256
+#define PIDFILE_MAX_LEN 24
 
 struct node_conf {
     struct address *addr;
@@ -32,6 +33,8 @@ struct corvus_config {
     int slowlog_log_slower_than;
     int slowlog_max_len;
     bool slowlog_statsd_enabled;
+    char *pidfile;
+    bool daemon;
 } config;
 
 void config_init();
@@ -47,4 +50,4 @@ void config_node_dec_ref(struct node_conf *node);
 int config_add(char *name, char *value);
 bool config_option_changable(const char *option);
 
-#endif /* end of include guard: CONFIG_H */
+#endif /* end of include guard: CONFIG_H */

src/corvus.c

@@ -7,6 +7,8 @@
 #include <execinfo.h>
 #include <getopt.h>
 #include <errno.h>
+#include <fcntl.h>
+#include <sys/stat.h>
 #include "corvus.h"
 #include "mbuf.h"
 #include "slot.h"
@@ -17,6 +19,7 @@
 #include "dict.h"
 #include "timer.h"
 #include "alloc.h"
+#include "daemon.h"
 
 static pthread_spinlock_t signal_lock;
 static struct context *contexts;
@@ -324,6 +327,8 @@ static const struct option opts[] = {
     {"slowlog-time", required_argument, NULL, 'g'},
     {"slowlog-max", required_argument, NULL, 'G'},
     {"slowlog-statsd", required_argument, NULL, 'E'},
+    {"pidfile", optional_argument, NULL, 'p'},
+    {"daemon", no_argument, NULL, 'd'},
     { 0, 0, 0, 0 },
 };
 
@@ -344,6 +349,8 @@ static const char *opts_desc[] = {
     "slowlog time in microseconds",
     "slowlog max len",
     "slowlog whether writing to statsd",
+    "set pid file",
+    "run as a daemon",
 };
 
 static void usage(const char *cmd)
@@ -363,7 +370,7 @@ static int parameter_init(int argc, const char *argv[]) {
     int ch;
     opterr = optind = 0;
     do {
-        ch = getopt_long(argc, (char * const *)argv, ":n:t:c:b:l:s:B:C:S:A:m:L:P:g:G:E:", opts, NULL);
+        ch = getopt_long(argc, (char * const *)argv, ":n:t:c:b:l:s:B:C:S:A:m:L:P:g:G:E:p:d:", opts, NULL);
         if (ch < 0) {
             break;
         }
@@ -416,6 +423,12 @@ static int parameter_init(int argc, const char *argv[]) {
             case 'E':
                 config_add("slowlog-statsd-enabled", optarg);
                 break;
+            case 'p':
+                config_add("pidfile", optarg);
+                break;
+            case 'd':
+                config_add("daemon", optarg);
+                break;
             default:
                 fprintf(stderr, "unknow option: %c\n", ch);
                 return CORVUS_ERR;
@@ -424,6 +437,38 @@ static int parameter_init(int argc, const char *argv[]) {
     return CORVUS_OK;
 }
 
+
+int create_pidfile() {
+    char pid[PIDFILE_MAX_LEN];
+    int fd, pid_len;
+    fd = open(config.pidfile, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+    if (fd < 0) {
+        LOG(ERROR, "open pidfile failed: %s", strerror(errno));
+        return CORVUS_ERR;
+    }
+
+    pid_len = snprintf(pid, PIDFILE_MAX_LEN, "%d", getpid());
+
+    ssize_t n;
+    n = write(fd, pid, pid_len);
+    if (n < 0) {
+        LOG(ERROR, "write to pidfile failed: %s", strerror(errno));
+        return CORVUS_ERR;
+    }
+
+    close(fd);
+
+    return CORVUS_OK;
+}
+void remove_pidfile() {
+    int status;
+    status= unlink(config.pidfile);
+    if (status < 0) {
+        LOG(ERROR, "unlink pid file '%s' failed: %s",
+                config.pidfile, strerror(errno));
+    }
+}
+
 int main(int argc, const char *argv[])
 {
     int i, err;
@@ -464,6 +509,12 @@ int main(int argc, const char *argv[])
         openlog(NULL, LOG_NDELAY | LOG_NOWAIT, LOG_USER);
     }
 
+    if (config.daemon)
+        daemonize();
+
+    if (config.pidfile)
+        create_pidfile();
+
     // allocate memory for `contexts`
     build_contexts();
 
@@ -529,6 +580,10 @@ int main(int argc, const char *argv[])
     destroy_contexts();
     cmd_map_destroy();
     cv_free(config.requirepass);
+    if (config.pidfile) {
+        remove_pidfile();
+        cv_free(config.pidfile);
+    }
     config_free();
     if (config.syslog) closelog();
     return EXIT_SUCCESS;

src/daemon.c

@@ -0,0 +1,83 @@
+#include <unistd.h>
+#include <fcntl.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/stat.h>
+#include "corvus.h"
+#include "logging.h"
+#include "daemon.h"
+
+int daemonize() {
+    int status;
+    pid_t pid, sid;
+    int fd;
+
+    pid = fork();
+    switch (pid) {
+        case -1:
+            LOG(ERROR, "fork() failed: %s", strerror(errno));
+            return CORVUS_ERR;
+        case 0:
+            break;
+        default:
+            /* parent */
+            exit(0);
+    }
+
+    /* The first child is the session leader */
+    sid = setsid();
+    if (sid < 0) {
+        LOG(ERROR, "setsid() failed: %s", strerror(errno));
+        return CORVUS_ERR;
+    }
+
+    pid = fork();
+    switch (pid) {
+        case -1:
+            LOG(ERROR, "fork() failed: %s", strerror(errno));
+            return CORVUS_ERR;
+        case 0:
+            break;
+        default:
+            /* the first child terminates */
+            exit(0);
+    }
+
+    /* the second child continues */
+    umask(0);
+
+    /* redirect stdin,stdout,stderr to /dev/null */
+    fd = open("/dev/null", O_RDWR);
+    if (fd < 0) {
+        LOG(ERROR, "open(\"/dev/null\") failed: %s", strerror(errno));
+        return CORVUS_ERR;
+    }
+
+    status = dup2(fd, STDIN_FILENO);
+    if (status < 0) {
+        LOG(ERROR, "dup2(%d, STDIN) failed: %s", fd, strerror(errno));
+        close(fd);
+        return CORVUS_ERR;
+    }
+    status = dup2(fd, STDOUT_FILENO);
+    if (status < 0) {
+        LOG(ERROR, "dup2(%d, STDOUT) failed: %s", fd, strerror(errno));
+        close(fd);
+        return CORVUS_ERR;
+    }
+    status = dup2(fd, STDERR_FILENO);
+    if (status < 0) {
+        LOG(ERROR, "dup2(%d, STDERR) failed: %s", fd, strerror(errno));
+        close(fd);
+        return CORVUS_ERR;
+    }
+    if (fd > STDERR_FILENO) {
+        status = close(fd);
+        if (status < 0) {
+            LOG(ERROR, "close(%d) failed: %s", fd, strerror(errno));
+            close(fd);
+            return CORVUS_ERR;
+        }
+    }
+    return CORVUS_OK;
+}

src/daemon.h

@@ -0,0 +1,6 @@
+#ifndef DAEMON_H
+#define DAEMON_H
+
+int daemonize();
+
+#endif /* end of include guard: DAEMON_H */