Arduino Syslog Client Library: Unterschied zwischen den Versionen

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= Project Definition =
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We intend to upgrade our ATV relay DB0MHB in a way that it logs every event right on the second over the network to a syslog server. Since we are going to do this with an Arduino system, I understood that there is no such thing as a Syslog client library for Arduino.  
 
We intend to upgrade our ATV relay DB0MHB in a way that it logs every event right on the second over the network to a syslog server. Since we are going to do this with an Arduino system, I understood that there is no such thing as a Syslog client library for Arduino.  
  
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* http://code.google.com/p/ardusyslog/
 
* http://code.google.com/p/ardusyslog/
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= Advance Tests =
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== Understand the format of a Syslog message ==
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The format of a syslog message is defined in RFC5424. It is depicted as a transformational grammar:
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      SYSLOG-MSG      = HEADER SP STRUCTURED-DATA [SP MSG]
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      HEADER          = PRI VERSION SP TIMESTAMP SP HOSTNAME
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                        SP APP-NAME SP PROCID SP MSGID
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      PRI            = "<" PRIVAL ">"
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      PRIVAL          = 1*3DIGIT ; range 0 .. 191
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      VERSION        = NONZERO-DIGIT 0*2DIGIT
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      HOSTNAME        = NILVALUE / 1*255PRINTUSASCII
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      APP-NAME        = NILVALUE / 1*48PRINTUSASCII
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      PROCID          = NILVALUE / 1*128PRINTUSASCII
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      MSGID          = NILVALUE / 1*32PRINTUSASCII
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      TIMESTAMP      = NILVALUE / FULL-DATE "T" FULL-TIME
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      FULL-DATE      = DATE-FULLYEAR "-" DATE-MONTH "-" DATE-MDAY
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      DATE-FULLYEAR  = 4DIGIT
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      DATE-MONTH      = 2DIGIT  ; 01-12
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      DATE-MDAY      = 2DIGIT  ; 01-28, 01-29, 01-30, 01-31 based on
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                                ; month/year
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      FULL-TIME      = PARTIAL-TIME TIME-OFFSET
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      PARTIAL-TIME    = TIME-HOUR ":" TIME-MINUTE ":" TIME-SECOND
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                        [TIME-SECFRAC]
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      TIME-HOUR      = 2DIGIT  ; 00-23
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      TIME-MINUTE    = 2DIGIT  ; 00-59
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      TIME-SECOND    = 2DIGIT  ; 00-59
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      TIME-SECFRAC    = "." 1*6DIGIT
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      TIME-OFFSET    = "Z" / TIME-NUMOFFSET
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      TIME-NUMOFFSET  = ("+" / "-") TIME-HOUR ":" TIME-MINUTE
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      STRUCTURED-DATA = NILVALUE / 1*SD-ELEMENT
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      SD-ELEMENT      = "[" SD-ID *(SP SD-PARAM) "]"
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      SD-PARAM        = PARAM-NAME "=" %d34 PARAM-VALUE %d34
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      SD-ID          = SD-NAME
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      PARAM-NAME      = SD-NAME
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      PARAM-VALUE    = UTF-8-STRING ; characters '"', '\' and
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                                    ; ']' MUST be escaped.
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      SD-NAME        = 1*32PRINTUSASCII
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                        ; except '=', SP, ']', %d34 (")
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      MSG            = MSG-ANY / MSG-UTF8
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      MSG-ANY        = *OCTET ; not starting with BOM
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      MSG-UTF8        = BOM UTF-8-STRING
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      BOM            = %xEF.BB.BF
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      UTF-8-STRING    = *OCTET ; UTF-8 string as specified
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                        ; in RFC 3629
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      OCTET          = %d00-255
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      SP              = %d32
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      PRINTUSASCII    = %d33-126
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      NONZERO-DIGIT  = %d49-57
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      DIGIT          = %d48 / NONZERO-DIGIT
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      NILVALUE        = "-"
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This grammar defines nonstructured as well as structured presentations. So very basically, the Syslog message consists of the following basic form:
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      <PRI> TIMESTAMP TAG MESSAGE
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The PRI value is an integer number which calculates by the following metric:
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      8 x (facility code) + (severity code)
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 +
where the individual codes are those:
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Facilities:
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              0            kernel messages
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              1            user-level messages
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              2            mail system
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              3            system daemons
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              4            security/authorization messages
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              5            messages generated internally by syslogd
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              6            line printer subsystem
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              7            network news subsystem
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              8            UUCP subsystem
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              9            clock daemon
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            10            security/authorization messages
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            11            FTP daemon
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            12            NTP subsystem
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            13            log audit
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            14            log alert
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            15            clock daemon (note 2)
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            16            local use 0  (local0)
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            17            local use 1  (local1)
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            18            local use 2  (local2)
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            19            local use 3  (local3)
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            20            local use 4  (local4)
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            21            local use 5  (local5)
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            22            local use 6  (local6)
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            23            local use 7  (local7)
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Severities:
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              0      Emergency: system is unusable
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              1      Alert: action must be taken immediately
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              2      Critical: critical conditions
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              3      Error: error conditions
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              4      Warning: warning conditions
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              5      Notice: normal but significant condition
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              6      Informational: informational messages
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              7      Debug: debug-level messages
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The TIMESTAMP may be the NILVALUE if there is no time available.
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== Enable my local Syslog daemon to receive log messages over the network ==
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 +
Running a NATTY Ubuntu, I noticed that modern Ubuntu distros use Rainer Gerhards' '''rsyslog''' implementation.
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It has a section in the config file /etc/rsyslog.conf which just needs to be uncommented:
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# provides UDP syslog reception
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$ModLoad imudp
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$UDPServerRun 514
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Upon restarting the rsyslog service with the command '''service rsyslog restart''' you can check with '''netstat -tulpen''' if the service is listening on UDP port 514.
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== Trace the logger command ==

Version vom 23. Juni 2011, 20:01 Uhr

1 Project Definition

We intend to upgrade our ATV relay DB0MHB in a way that it logs every event right on the second over the network to a syslog server. Since we are going to do this with an Arduino system, I understood that there is no such thing as a Syslog client library for Arduino.

If something does not exist, you need to change that.

Please visit my Google Code site:

2 Advance Tests

2.1 Understand the format of a Syslog message

The format of a syslog message is defined in RFC5424. It is depicted as a transformational grammar: 

     SYSLOG-MSG      = HEADER SP STRUCTURED-DATA [SP MSG]

     HEADER          = PRI VERSION SP TIMESTAMP SP HOSTNAME
                       SP APP-NAME SP PROCID SP MSGID
     PRI             = "<" PRIVAL ">"
     PRIVAL          = 1*3DIGIT ; range 0 .. 191
     VERSION         = NONZERO-DIGIT 0*2DIGIT
     HOSTNAME        = NILVALUE / 1*255PRINTUSASCII

     APP-NAME        = NILVALUE / 1*48PRINTUSASCII
     PROCID          = NILVALUE / 1*128PRINTUSASCII
     MSGID           = NILVALUE / 1*32PRINTUSASCII

     TIMESTAMP       = NILVALUE / FULL-DATE "T" FULL-TIME
     FULL-DATE       = DATE-FULLYEAR "-" DATE-MONTH "-" DATE-MDAY
     DATE-FULLYEAR   = 4DIGIT
     DATE-MONTH      = 2DIGIT  ; 01-12
     DATE-MDAY       = 2DIGIT  ; 01-28, 01-29, 01-30, 01-31 based on
                               ; month/year
     FULL-TIME       = PARTIAL-TIME TIME-OFFSET
     PARTIAL-TIME    = TIME-HOUR ":" TIME-MINUTE ":" TIME-SECOND
                       [TIME-SECFRAC]
     TIME-HOUR       = 2DIGIT  ; 00-23
     TIME-MINUTE     = 2DIGIT  ; 00-59
     TIME-SECOND     = 2DIGIT  ; 00-59
     TIME-SECFRAC    = "." 1*6DIGIT
     TIME-OFFSET     = "Z" / TIME-NUMOFFSET
     TIME-NUMOFFSET  = ("+" / "-") TIME-HOUR ":" TIME-MINUTE
     STRUCTURED-DATA = NILVALUE / 1*SD-ELEMENT
     SD-ELEMENT      = "[" SD-ID *(SP SD-PARAM) "]"
     SD-PARAM        = PARAM-NAME "=" %d34 PARAM-VALUE %d34
     SD-ID           = SD-NAME
     PARAM-NAME      = SD-NAME
     PARAM-VALUE     = UTF-8-STRING ; characters '"', '\' and
                                    ; ']' MUST be escaped.
     SD-NAME         = 1*32PRINTUSASCII
                       ; except '=', SP, ']', %d34 (")
     MSG             = MSG-ANY / MSG-UTF8
     MSG-ANY         = *OCTET ; not starting with BOM
     MSG-UTF8        = BOM UTF-8-STRING
     BOM             = %xEF.BB.BF
     UTF-8-STRING    = *OCTET ; UTF-8 string as specified
                       ; in RFC 3629
     OCTET           = %d00-255
     SP              = %d32
     PRINTUSASCII    = %d33-126
     NONZERO-DIGIT   = %d49-57
     DIGIT           = %d48 / NONZERO-DIGIT
     NILVALUE        = "-"

This grammar defines nonstructured as well as structured presentations. So very basically, the Syslog message consists of the following basic form: 

     <PRI> TIMESTAMP TAG MESSAGE

The PRI value is an integer number which calculates by the following metric: 

     8 x (facility code) + (severity code)

where the individual codes are those:

Facilities: 

             0             kernel messages
             1             user-level messages
             2             mail system
             3             system daemons
             4             security/authorization messages
             5             messages generated internally by syslogd
             6             line printer subsystem
             7             network news subsystem
             8             UUCP subsystem
             9             clock daemon
            10             security/authorization messages
            11             FTP daemon
            12             NTP subsystem
            13             log audit
            14             log alert
            15             clock daemon (note 2)
            16             local use 0  (local0)
            17             local use 1  (local1)
            18             local use 2  (local2)
            19             local use 3  (local3)
            20             local use 4  (local4)
            21             local use 5  (local5)
            22             local use 6  (local6)
            23             local use 7  (local7)

Severities: 

             0       Emergency: system is unusable
             1       Alert: action must be taken immediately
             2       Critical: critical conditions
             3       Error: error conditions
             4       Warning: warning conditions
             5       Notice: normal but significant condition
             6       Informational: informational messages
             7       Debug: debug-level messages

The TIMESTAMP may be the NILVALUE if there is no time available.

2.2 Enable my local Syslog daemon to receive log messages over the network

Running a NATTY Ubuntu, I noticed that modern Ubuntu distros use Rainer Gerhards' rsyslog implementation.

It has a section in the config file /etc/rsyslog.conf which just needs to be uncommented: 

# provides UDP syslog reception
$ModLoad imudp
$UDPServerRun 514

Upon restarting the rsyslog service with the command service rsyslog restart you can check with netstat -tulpen if the service is listening on UDP port 514.

2.3 Trace the logger command

Abgerufen von „http://www.dl8rds.de/index.php?title=Arduino_Syslog_Client_Library&oldid=1846“