[clue-tech] Script to check Apache

[Chris Hirsch]

David L. Anselmi wrote:
> Deepan wrote:
>> Hi All,
>> I am looking for a script to check if Apache is up
>> and running,
>
> This is what monitoring programs like big brother, nagios, etc do.  
> Just get one of them, it isn't worth it to write your own script.
>
> Now all the programmers out there will write and tell you how it only 
> takes 15 minutes to write a program to do this vs. days to learn how 
> to configure a monitoring system.
>
> IMHO it's better to learn how to use something that's out there if you 
> plan to live longer than the next week.  The world doesn't need 
> another half-axxxd monitor script.  (Ditto for backup scripts.)
>
> But even if you want to write your own, go see how the other guys do 
> it.  Didn't some smart programmer say that the way to be a good 
> programmer was to read other people's code?  So here's your chance.
I'll second the recommendation. The package nagios-plugins can be 
installed for just about every major distro. If you choose not to use 
Nagios proper you can at least use the plugins.

you can then use the check_http command to check any site you want. 
Below is all of the available options to you to check http, https, 
certificates, etc.

check_http (nagios-plugins 1.4.9) 1.104
Copyright (c) 1999 Ethan Galstad <nagios at nagios.org>
Copyright (c) 1999-2006 Nagios Plugin Development Team
        <nagiosplug-devel at lists.sourceforge.net>

This plugin tests the HTTP service on the specified host. It can test
normal (http) and secure (https) servers, follow redirects, search for
strings and regular expressions, check connection times, and report on
certificate expiration times.


Usage: check_http -H <vhost> | -I <IP-address> [-u <uri>] [-p <port>]
       [-w <warn time>] [-c <critical time>] [-t <timeout>] [-L]
       [-a auth] [-f <ok | warn | critcal | follow>] [-e <expect>]
       [-s string] [-l] [-r <regex> | -R <case-insensitive regex>] [-P 
string]
       [-m <min_pg_size>:<max_pg_size>] [-4|-6] [-N] [-M <age>] [-A string]
       [-k string] [-S] [-C <age>] [-T <content-type>]
NOTE: One or both of -H and -I must be specified

Options:
 -h, --help
    Print detailed help screen
 -V, --version
    Print version information
 -H, --hostname=ADDRESS
    Host name argument for servers using host headers (virtual host)
    Append a port to include it in the header (eg: example.com:5000)
 -I, --IP-address=ADDRESS
    IP address or name (use numeric address if possible to bypass DNS 
lookup).
 -p, --port=INTEGER
 Port number (default: 80)
 -4, --use-ipv4
    Use IPv4 connection
 -6, --use-ipv6
    Use IPv6 connection
 -S, --ssl
   Connect via SSL. Port defaults to 443
 -C, --certificate=INTEGER
   Minimum number of days a certificate has to be valid. Port defaults 
to 443
   (when this option is used the url is not checked.)

 -e, --expect=STRING
    String to expect in first (status) line of server response (default:
HTTP/1.)
    If specified skips all other status line logic (ex: 3xx, 4xx, 5xx 
processing
)
 -s, --string=STRING
    String to expect in the content
 -u, --url=PATH
    URL to GET or POST (default: /)
 -P, --post=STRING
    URL encoded http POST data
 -N, --no-body
    Don't wait for document body: stop reading after headers.
    (Note that this still does an HTTP GET or POST, not a HEAD.)
 -M, --max-age=SECONDS
    Warn if document is more than SECONDS old. the number can also be of
    the form "10m" for minutes, "10h" for hours, or "10d" for days.
 -T, --content-type=STRING
    specify Content-Type header media type when POSTing

 -l, --linespan
    Allow regex to span newlines (must precede -r or -R)
 -r, --regex, --ereg=STRING
    Search page for regex STRING
 -R, --eregi=STRING
    Search page for case-insensitive regex STRING
 --invert-regex
    Return CRITICAL if found, OK if not

 -a, --authorization=AUTH_PAIR
    Username:password on sites with basic authentication
 -A, --useragent=STRING
    String to be sent in http header as "User Agent"
 -k, --header=STRING
     Any other tags to be sent in http header. Use multiple times for 
additional
 headers
 -L, --link
    Wrap output in HTML link (obsoleted by urlize)
 -f, --onredirect=<ok|warning|critical|follow>
    How to handle redirected pages
 -m, --pagesize=INTEGER<:INTEGER>
    Minimum page size required (bytes) : Maximum page size required (bytes)
 -w, --warning=DOUBLE
    Response time to result in warning status (seconds)
 -c, --critical=DOUBLE
    Response time to result in critical status (seconds)
 -t, --timeout=INTEGER
    Seconds before connection times out (default: 10)
 -v, --verbose
    Show details for command-line debugging (Nagios may truncate output)
Notes: This plugin will attempt to open an HTTP connection with the host.
 Successful connects return STATE_OK, refusals and timeouts return 
STATE_CRITICA
L
 other errors return STATE_UNKNOWN.  Successful connects, but incorrect 
reponse
 messages from the host result in STATE_WARNING return values.  If you are
 checking a virtual server that uses 'host headers' you must supply the FQDN
 (fully qualified domain name) as the [host_name] argument.
 This plugin can also check whether an SSL enabled web server is able to
 serve content (optionally within a specified time) or whether the X509
 certificate is still valid for the specified number of days.
Examples: CHECK CONTENT: check_http -w 5 -c 10 --ssl -H www.verisign.com

 When the 'www.verisign.com' server returns its content within 5 seconds,
 a STATE_OK will be returned. When the server returns its content but 
exceeds
 the 5-second threshold, a STATE_WARNING will be returned. When an error 
occurs,
 a STATE_CRITICAL will be returned.

 CHECK CERTIFICATE: check_http -H www.verisign.com -C 14

 When the certificate of 'www.verisign.com' is valid for more than 14 days,
 a STATE_OK is returned. When the certificate is still valid, but for 
less than
 14 days, a STATE_WARNING is returned. A STATE_CRITICAL will be returned 
when
 the certificate is expired.


Send email to nagios-users at lists.sourceforge.net if you have questions
regarding use of this software. To submit patches or suggest improvements,
send email to nagiosplug-devel at lists.sourceforge.net