Re: log files and permissions

Tom Lane wrote:
> Itagaki Takahiro <itagaki.takahiro@gmail.com> writes:
>> ...
>> We should also check the value not to be something like 0699.
>> How about checking it with (file_mode & ~0666) != 0 ?
>> ...
>> I want show_log_file_mode to print the setting value in octal format.
>
> It seems like a whole lot of lily-gilding is going on here.  Just make
> it work like unix_socket_permissions already does.  That's been there
> for years and nobody has complained about it.
>

Thanks, somehow I missed that we can already specify octal integers
as GUC-s. I now converted the log_file_mode to integer and dropped
the assign_log_file_mode function.

regards,
Martin
*** a/doc/src/sgml/config.sgml
--- b/doc/src/sgml/config.sgml
***************
*** 2789,2794 **** local0.*    /var/log/postgresql
--- 2789,2817 ----
        </listitem>
       </varlistentry>

+      <varlistentry id="guc-log-file-mode" xreflabel="log_file_mode">
+       <term><varname>log_file_mode</varname> (<type>integer</type>)</term>
+       <indexterm>
+        <primary><varname>log_file_mode</> configuration parameter</primary>
+       </indexterm>
+       <listitem>
+        <para>
+         On Unix systems this parameter sets the permissions for log files
+         when <varname>logging_collector</varname> is enabled. On Microsoft
+         Windows the file mode will be ignored.
+         The parameter value is expected to be a numeric mode
+         specified in the format accepted by the
+         <function>chmod</function> and <function>umask</function>
+         system calls.  (To use the customary octal format the number
+         must start with a <literal>0</literal> (zero).)
+        </para>
+        <para>
+         This parameter can only be set in the <filename>postgresql.conf</>
+         file or on the server command line.
+        </para>
+       </listitem>
+      </varlistentry>
+
       <varlistentry id="guc-log-rotation-age" xreflabel="log_rotation_age">
        <term><varname>log_rotation_age</varname> (<type>integer</type>)</term>
        <indexterm>
*** a/src/backend/postmaster/syslogger.c
--- b/src/backend/postmaster/syslogger.c
***************
*** 73,78 **** int            Log_RotationSize = 10 * 1024;
--- 73,79 ----
  char       *Log_directory = NULL;
  char       *Log_filename = NULL;
  bool        Log_truncate_on_rotation = false;
+ int            Log_file_mode = 0600;

  /*
   * Globally visible state (used by elog.c)
***************
*** 135,140 **** static void syslogger_parseArgs(int argc, char *argv[]);
--- 136,142 ----
  static void process_pipe_input(char *logbuffer, int *bytes_in_logbuffer);
  static void flush_pipe_input(char *logbuffer, int *bytes_in_logbuffer);
  static void open_csvlogfile(void);
+ static FILE *logfile_open(const char *filename, const char *mode, bool am_rotating);

  #ifdef WIN32
  static unsigned int __stdcall pipeThread(void *arg);
***************
*** 516,530 **** SysLogger_Start(void)
       */
      filename = logfile_getname(time(NULL), NULL);

!     syslogFile = fopen(filename, "a");
!
!     if (!syslogFile)
!         ereport(FATAL,
!                 (errcode_for_file_access(),
!                  (errmsg("could not create log file \"%s\": %m",
!                          filename))));
!
!     setvbuf(syslogFile, NULL, LBF_MODE, 0);

      pfree(filename);

--- 518,524 ----
       */
      filename = logfile_getname(time(NULL), NULL);

!     syslogFile = logfile_open(filename, "a", false);

      pfree(filename);

***************
*** 1004,1027 **** open_csvlogfile(void)

      filename = logfile_getname(time(NULL), ".csv");

!     fh = fopen(filename, "a");

!     if (!fh)
!         ereport(FATAL,
!                 (errcode_for_file_access(),
!                  (errmsg("could not create log file \"%s\": %m",
!                          filename))));

!     setvbuf(fh, NULL, LBF_MODE, 0);

! #ifdef WIN32
!     _setmode(_fileno(fh), _O_TEXT);        /* use CRLF line endings on Windows */
! #endif

!     csvlogFile = fh;

!     pfree(filename);

  }

  /*
--- 998,1050 ----

      filename = logfile_getname(time(NULL), ".csv");

!     fh = logfile_open(filename, "a", false);

!     csvlogFile = fh;

!     pfree(filename);

! }

! /*
!  * Open the logfile with proper permissions and buffering options.
!  *
!  * We ignore any errors if the logfile is opened as part of log rotation. In
!  * other cases the errors are treated as fatal.
!  */
! static FILE *
! logfile_open(const char *filename, const char *mode, bool am_rotating)
! {
!     mode_t    oumask;
!     FILE   *fh;

!     oumask = umask((mode_t) (~Log_file_mode & 0777));
!     fh = fopen(filename, mode);
!     umask(oumask);
!
!     if (fh)
!     {
!         setvbuf(fh, NULL, LBF_MODE, 0);
!
! #ifdef WIN32
!         _setmode(_fileno(fh), _O_TEXT); /* use CRLF line endings on Windows */
! #endif
!     }
!     else
!     {
!         if (am_rotating)
!             ereport(LOG,
!                     (errcode_for_file_access(),
!                      errmsg("could not create new log file \"%s\": %m",
!                             filename)));
!         else
!             ereport(FATAL,
!                     (errcode_for_file_access(),
!                      errmsg("could not create log file \"%s\": %m",
!                             filename)));
!     }

+     return fh;
  }

  /*
***************
*** 1070,1088 **** logfile_rotate(bool time_based_rotation, int size_rotation_for)
          if (Log_truncate_on_rotation && time_based_rotation &&
              last_file_name != NULL &&
              strcmp(filename, last_file_name) != 0)
!             fh = fopen(filename, "w");
          else
!             fh = fopen(filename, "a");

          if (!fh)
          {
              int            saveerrno = errno;

-             ereport(LOG,
-                     (errcode_for_file_access(),
-                      errmsg("could not open new log file \"%s\": %m",
-                             filename)));
-
              /*
               * ENFILE/EMFILE are not too surprising on a busy system; just
               * keep using the old file till we manage to get a new one.
--- 1093,1106 ----
          if (Log_truncate_on_rotation && time_based_rotation &&
              last_file_name != NULL &&
              strcmp(filename, last_file_name) != 0)
!             fh = logfile_open(filename, "w", true);
          else
!             fh = logfile_open(filename, "a", true);

          if (!fh)
          {
              int            saveerrno = errno;

              /*
               * ENFILE/EMFILE are not too surprising on a busy system; just
               * keep using the old file till we manage to get a new one.
***************
*** 1104,1115 **** logfile_rotate(bool time_based_rotation, int size_rotation_for)
              return;
          }

-         setvbuf(fh, NULL, LBF_MODE, 0);
-
- #ifdef WIN32
-         _setmode(_fileno(fh), _O_TEXT); /* use CRLF line endings on Windows */
- #endif
-
          fclose(syslogFile);
          syslogFile = fh;

--- 1122,1127 ----
***************
*** 1128,1146 **** logfile_rotate(bool time_based_rotation, int size_rotation_for)
          if (Log_truncate_on_rotation && time_based_rotation &&
              last_csv_file_name != NULL &&
              strcmp(csvfilename, last_csv_file_name) != 0)
!             fh = fopen(csvfilename, "w");
          else
!             fh = fopen(csvfilename, "a");

          if (!fh)
          {
              int            saveerrno = errno;

-             ereport(LOG,
-                     (errcode_for_file_access(),
-                      errmsg("could not open new log file \"%s\": %m",
-                             csvfilename)));
-
              /*
               * ENFILE/EMFILE are not too surprising on a busy system; just
               * keep using the old file till we manage to get a new one.
--- 1140,1153 ----
          if (Log_truncate_on_rotation && time_based_rotation &&
              last_csv_file_name != NULL &&
              strcmp(csvfilename, last_csv_file_name) != 0)
!             fh = logfile_open(csvfilename, "w", true);
          else
!             fh = logfile_open(csvfilename, "a", true);

          if (!fh)
          {
              int            saveerrno = errno;

              /*
               * ENFILE/EMFILE are not too surprising on a busy system; just
               * keep using the old file till we manage to get a new one.
***************
*** 1162,1173 **** logfile_rotate(bool time_based_rotation, int size_rotation_for)
              return;
          }

-         setvbuf(fh, NULL, LBF_MODE, 0);
-
- #ifdef WIN32
-         _setmode(_fileno(fh), _O_TEXT); /* use CRLF line endings on Windows */
- #endif
-
          fclose(csvlogFile);
          csvlogFile = fh;

--- 1169,1174 ----
*** a/src/backend/utils/misc/guc.c
--- b/src/backend/utils/misc/guc.c
***************
*** 174,179 **** static bool assign_autovacuum_max_workers(int newval, bool doit, GucSource sourc
--- 174,180 ----
  static bool assign_effective_io_concurrency(int newval, bool doit, GucSource source);
  static const char *assign_pgstat_temp_directory(const char *newval, bool doit, GucSource source);
  static const char *assign_application_name(const char *newval, bool doit, GucSource source);
+ static const char *show_log_file_mode(void);

  static char *config_enum_get_options(struct config_enum * record,
                          const char *prefix, const char *suffix,
***************
*** 2068,2073 **** static struct config_int ConfigureNamesInt[] =
--- 2069,2083 ----
          1024, 100, 102400, NULL, NULL
      },

+     {
+         {"log_file_mode", PGC_SIGHUP, LOGGING_WHERE,
+             gettext_noop("Sets the file permissions for log files."),
+             NULL
+         },
+         &Log_file_mode,
+         0600, 0000, 0777, NULL, show_log_file_mode
+     },
+
      /* End-of-list marker */
      {
          {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL
***************
*** 8072,8075 **** assign_application_name(const char *newval, bool doit, GucSource source)
--- 8082,8094 ----
          return newval;
  }

+ static const char *
+ show_log_file_mode(void)
+ {
+     static char buf[5];
+
+     snprintf(buf, sizeof(buf), "%04o", Log_file_mode);
+     return buf;
+ }
+
  #include "guc-file.c"
*** a/src/backend/utils/misc/postgresql.conf.sample
--- b/src/backend/utils/misc/postgresql.conf.sample
***************
*** 265,270 ****
--- 265,272 ----
                      # can be absolute or relative to PGDATA
  #log_filename = 'postgresql-%Y-%m-%d_%H%M%S.log'    # log file name pattern,
                      # can include strftime() escapes
+ #log_file_mode = 0600            # creation mode for log files,
+                     # begin with 0 to use octal notation
  #log_truncate_on_rotation = off        # If on, an existing log file of the
                      # same name as the new log file will be
                      # truncated rather than appended to.
*** a/src/include/postmaster/syslogger.h
--- b/src/include/postmaster/syslogger.h
***************
*** 68,73 **** extern int    Log_RotationSize;
--- 68,74 ----
  extern PGDLLIMPORT char *Log_directory;
  extern PGDLLIMPORT char *Log_filename;
  extern bool Log_truncate_on_rotation;
+ extern int Log_file_mode;

  extern bool am_syslogger;