Smokeping/probes/Curl

# NAME

Smokeping::probes::Curl - a `curl(1)` probe for SmokePing

# OVERVIEW

Fetches an HTTP or HTTPS URL using curl(1).

# SYNOPSIS

     *** Probes ***

     +Curl

     binary = /usr/bin/curl
     forks = 5
     offset = 50%
     step = 300

     # The following variables can be overridden in each target section
     agent = User-Agent: Lynx/2.8.4rel.1 libwww-FM/2.14 SSL-MM/1.4.1 OpenSSL/0.9.6c
     extraargs = -6 --head --user user:password
     extrare = / /
     follow_redirects = yes
     include_redirects = yes
     insecure_ssl = 1
     interface = eth0
     pings = 5
     ssl2 = 1
     timeout = 20
     urlformat = http://%host%/ # mandatory

     # [...]

     *** Targets ***

     probe = Curl # if this should be the default probe

     # [...]

     + mytarget
     # probe = Curl # if the default probe is something else
     host = my.host
     agent = User-Agent: Lynx/2.8.4rel.1 libwww-FM/2.14 SSL-MM/1.4.1 OpenSSL/0.9.6c
     extraargs = -6 --head --user user:password
     extrare = / /
     follow_redirects = yes
     include_redirects = yes
     insecure_ssl = 1
     interface = eth0
     pings = 5
     ssl2 = 1
     timeout = 20
     urlformat = http://%host%/ # mandatory

# DESCRIPTION

(see `curl(1)` for details of the options below)

# VARIABLES

Supported probe-specific variables:

binary

  The location of your curl binary.

  Default value: /usr/bin/curl

forks

  Run this many concurrent processes at maximum

  Example value: 5

  Default value: 5

offset

  If you run many probes concurrently you may want to prevent them from hitting your network all at the same time. Using the probe-specific offset parameter you can change the point in time when each probe will be run. Offset is specified in % of total interval, or alternatively as 'random', and the offset from the 'General' section is used if nothing is specified here. Note that this does NOT influence the rrds itself, it is just a matter of when data acqusition is initiated. (This variable is only applicable if the variable 'concurrentprobes' is set in the 'General' section.)

  Example value: 50%

step

  Duration of the base interval that this probe should use, if different from the one specified in the 'Database' section. Note that the step in the RRD files is fixed when they are originally generated, and if you change the step parameter afterwards, you'll have to delete the old RRD files or somehow convert them. (This variable is only applicable if the variable 'concurrentprobes' is set in the 'General' section.)

  Example value: 300

Supported target-specific variables:

agent

  The ``-A'' `curl(1)` option. This is a full HTTP User-Agent header including the words ``User-Agent:''. Note that it does not need any quotes around it.

  Example value: User-Agent: Lynx/2.8.4rel.1 libwww-FM/2.14 SSL-MM/1.4.1 OpenSSL/0.9.6c

extraargs

  Any extra arguments you might want to hand to curl(1). The arguments should be separated by the regexp specified in ``extrare'', which contains just the space character (`` '') by default.

  Note that curl will be called with the resulting list of arguments without any shell expansion. If you need to specify any arguments containing spaces, you should set ``extrare'' to something else.

  As a complicated example, to explicitly set the ``Host:'' header in Curl requests, you need to set ``extrare'' to something else, eg. ``/;/'', and then specify `extraargs = --header;Host: www.example.com`.

  Example value: -6 --head --user user:password

extrare

  The regexp used to split the extraargs string into an argument list, in the ``/regexp/'' notation. This contains just the space character (`` '') by default, but if you need to specify any arguments containing spaces, you can set this variable to a different value.

  Example value: / /

  Default value: / /

follow_redirects

  If this variable is set to 'yes', curl will follow any HTTP redirection steps (the '-L' option). If set to 'no', HTTP Location: headers will not be followed. See also 'include_redirects'.

  Example value: yes

  Default value: no

include_redirects

  If this variable is set to 'yes', the measurement result will include the time spent on following any HTTP redirection steps. If set to 'no', only the last step is measured. See also 'follow_redirects'.

  Example value: yes

  Default value: no

insecure_ssl

  The ``-k'' `curl(1)` option. Accept SSL connections that don't have a secure certificate chain to a trusted CA. Note that if you are going to monitor https targets, you'll probably have to either enable this option or specify the CA path to curl through extraargs below. For more info, see the `curl(1)` manual page.

  Example value: 1

interface

  The ``--interface'' `curl(1)` option. Bind to a specific interface, IP address or host name.

  Example value: eth0

pings

  How many pings should be sent to each target, if different from the global value specified in the Database section. Note that the number of pings in the RRD files is fixed when they are originally generated, and if you change this parameter afterwards, you'll have to delete the old RRD files or somehow convert them.

  Example value: 5

ssl2

  The ``-2'' `curl(1)` option. Force SSL2.

  Example value: 1

timeout

  The ``-m'' `curl(1)` option. Maximum timeout in seconds.

  Example value: 20

  Default value: 10

urlformat

  The template of the URL to fetch. Can be any one that curl supports. Any occurrence of the string '%host%' will be replaced with the host to be probed.

  Example value: http://%host%/

  This setting is mandatory.

# AUTHORS

     Gerald Combs <gerald [AT] ethereal.com>
     Niko Tyni <ntyni@iki.fi>

# NOTES

You should consider setting a lower value for the `pings` variable than the default 20, as repetitive URL fetching may be quite heavy on the server.

The URL to be tested used to be specified by the variable 'url' in earlier versions of Smokeping, and the 'host' setting did not influence it in any way. The variable name has now been changed to 'urlformat', and it can (and in most cases should) contain a placeholder for the 'host' variable.

# SEE ALSO

curl(1), http://curl.haxx.se/