check_http

Basic Usage

check_http -V

check_http v2.0.3 (nagios-plugins 2.0.3)

check_http <-H hostname | -I <IP> [-p <port>] [-u <uri>]

-I, --IP-address=ADDRESS

use numeric address if possible to bypass DNS lookup

-H, --hostname=ADDRESS

Hostname argument for servers using host headers

Append a port to include it in the header (eg: example.com:5000)

-u, --url=PATH

URL to GET or POST (default: /)

i.e.

./check_http -H datahunter.org

HTTP OK: HTTP/1.1 301 Moved Permanently - 348 bytes in 0.256 second response time |
  time=0.256357s;;;0.000000 size=348B;;;0

./check_http -I 192.168.123.11 -p 80 -H datahunter.org -u /systemcheck.php

define command{
        command_name    check_http_by_url
        command_line    $USER1$/check_http -I $HOSTADDRESS$ -H $ARG1$ -u $ARG2$
        }
        
define service{
        use                             service-medium
        host_name                       mydomain
        service_description             HTTP
        check_command   check_http_by_url!mydomain!/systemcheck.php
}

Adv. Opts

# SSL

-S, --ssl=VERSION                 # TLS Version: 1.1 = TLSv1.1, 1.2 = TLSv1.2

                                            # With a '+' suffix, newer versions are also accepted.

                                   # Port: 443/tcp

 * 在遇到 "CRITICAL - Socket timeout" 情況, 可以加入 "-S 1.1" 及 "-S 1.2" 測試

--sni                                     # Enable SSL/TLS hostname extension support (SNI)

i.e.

./check_http -S -H datahunter.org

# Header

-N, --no-body                         # Don't wait for document body: stop reading after headers.

-k, --header=STRING              # Any other tags to be sent in http header. (sent to http server)

-d, --header-string=STRING    # String to expect in the response headers (在 V2.2 唔 work)

-e, --expect=STRING              # Comma-delimited list of strings, at least one of them is expected in the response first line

i.e.

curl -I https://datahunter.org
HTTP/1.1 200 OK
Server: nginx
Date: Thu, 15 Oct 2020 07:08:19 GMT
Content-Type: text/html; charset=utf-8
...

Status Code 與 String

i.e. http reponse header:

HTTP/1.1 200 OK

# 用 status code. 可以用 string 的, 比如

-e 200

# plugin output msg

HTTP OK: Status line output matched "200" - HTTP/1.1 200 OK - 7946 bytes in 0.210 second response time

-e 'OK'      # 大細階係有分別的, 不能寫做 'ok'

# plugin output msg

HTTP OK: Status line output matched "OK" - HTTP/1.1 200 OK - 7946 bytes in 5.360 second response time

# Content

-s, --string=STRING               # String to expect in the content

-r, --regex, --ereg=STRING    # Search page for regex STRING

--invert-regex                       # Return CRITICAL if found, OK if not

-P, --post=STRING                # URL encoded http POST data

# auth

-a, --authorization=AUTH_PAIR    # Username:password on sites with basic authentication

# time

-t, --timeout=INTEGER                # Default: 10

# other

-E, --extended-perfdata               # Print additional performance data

Default 有

HTTP WARNING: HTTP/1.1 426 Upgrade header MUST be provided -
 235 bytes in 0.078 second response time |time=0.077948s;;;0.000000 size=235B;;;0 time_connect=0.013786s;;;

多了

time_ssl=0.044961s;;; time_headers=0.000024s;;; time_firstbyte=0.018999s;;; time_transfer=0.019029s;;;

ie.

./check_http -S -p 8889 -N -e 400 -I n.n.n.n -H datahunter.org

Example

websocket

# 要加 hostname, 因為有機會有 SNI

# Usage: check_wss_by_hostname_port!hostname!port
define command{
  command_name    check_wss_by_hostname_port
  command_line    $USER1$/check_http -S 1.2 --sni -k "Connection: Upgrade" -k "Upgrade: websocket" -e 400 -N -I $HOSTADDRESS$ -H $ARG1$ -p $ARG2$ 
}

softether

# Usage: check_softether_by_port!port
define command{
  command_name    check_softether_by_port
  command_line    $USER1$/check_http -S 1.2 -e 403 -N -I $HOSTADDRESS$ -p $ARG1$
}