minimon

Bash script to monitor HTTP and generic TCP services.

Only requires curl and ping (Linux and Windows is supported)
Supports ICMP, HTTP(S) and generic TCP connections
Enforce IPv4 or IPv6 for single checks
Define a alias name behind the URL
Send a ASCII Bell on state changes
Works on Git Bash (MinGW) on Windows
Limit the number of checks to use the script as healthcheck in CI pipelines
Use simple shell scripts as check plugins
Executes checks in parallel (controlled by --parallel option)
Load settings from a json file (see --config, requires jq)

Download

curl -L https://github.com/perryflynn/minimon/raw/master/minimon.sh > minimon.sh && chmod a+x minimon.sh

Usage

minimon by Christian Blechert
https://github.com/perryflynn/minimon

Usage: ./minimon.sh [--interval 30] [--tcp "example.com:4242[;aliasname]"]

--interval n       Delay between two checks
--tcp host:port    Check a generic TCP port
--tcp4 host:port   Check a generic TCP port, force IPv4
--tcp6 host:port   Check a generic TCP port, force IPv6
--http url         Check a HTTP(S) URL
--http4 url        Check a HTTP(S) URL, force IPv4
--http6 url        Check a HTTP(S) URL, force IPv6
--icmp host        Ping a Hostname/IP
--icmp4 host       Ping a Hostname/IP, force IPv4
--icmp6 host       Ping a Hostname/IP, force IPv6
--script script    Path to a script to use as a check

Append a alias name to a check separated by a semicolon:
--icmp "8.8.8.8;google"

Load settings from json files:
--config some-config.json

Schema for editors like VSCode:
https://files.serverless.industries/schemas/minimon.json

A script must output one line of text
and must set a exit code like so:
0=OK; 1=WARN; 2=NOK; 3=UNKNOWN

--max-checks n     Only test n times
exit 0 = all ok; exit 1 = partially ok; exit 2 = all failed

--no-redirect       Do not follow HTTP redirects
--invalid-tls       Ignore invalid TLS certificates
--timeout           curl operation timeout
--connect-timeout   curl connect timeout
--parallel 10       number of checks execute in parallel
--no-timestamps     disable timestamps
--short-timestamps  only show time, not the date
--time-spacer 30    add a spacer line if n seconds was no state change

-v, --verbose      Enable verbose mode
-w, --warnings     Show warning output
-e, --errors       Show error output
-h, --help         Print this help
-V, --version      Print the version

./minimon.sh --interval 60 \
    --tcp "localhost:22" \
    --tcp "files:445;fileserver" \
    --http "https://google.com;google" \
    --http "https://example.com" \
    --script "./myscript arg1;scriptname" \
    --icmp "8.8.8.8;google"

Output:

[2020-11-04T23:44:12+01:00] http_google - https://google.com - OK (0) - HTTP 200
[2020-11-04T23:44:13+01:00] http - https://example.com - OK (0) - HTTP 200
[2020-11-04T23:44:14+01:00] tcp - localhost:22 - NOK (2) - Connect failed
[2020-11-04T23:44:14+01:00] icmp_google - 8.8.8.8 - OK (0) - Ping succeeded (0% loss)
[2020-11-04T23:44:15+01:00] tcp_fileserver - files:445 - OK (0) - Connect successful
[2020-11-04T23:45:17+01:00] tcp - localhost:22 - OK (0) - Connect successful - changed after 63s

Verbose output:

[DEBUG] check_http https://google.com
0,179706    200    2    0
[2020-11-07T12:13:06+01:00] http_google - https://google.com - OK (0) - HTTP 200
[DEBUG] check_http https://example.com
0,436060    200    1    0
[2020-11-07T12:13:07+01:00] http - https://example.com - OK (0) - HTTP 200
[DEBUG] check_tcp localhost:22
* Rebuilt URL to: telnet://localhost:22/
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0*   Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to localhost (127.0.0.1) port 22 (#0)
[2020-11-07T12:13:08+01:00] tcp - localhost:22 - OK (0) - Connect successful
[DEBUG] check_tcp files:445
* Rebuilt URL to: telnet://files:445/
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0*   Trying 192.168.99.104...
* TCP_NODELAY set
* Connected to files (192.168.99.104) port 445 (#0)
[2020-11-07T12:13:09+01:00] tcp_fileserver - files:445 - OK (0) - Connect successful
[DEBUG] check_icmp 8.8.8.8
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
64 bytes from 8.8.8.8: icmp_seq=1 ttl=118 time=11.5 ms
64 bytes from 8.8.8.8: icmp_seq=2 ttl=118 time=11.7 ms
64 bytes from 8.8.8.8: icmp_seq=3 ttl=118 time=12.9 ms

--- 8.8.8.8 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2003ms
rtt min/avg/max/mdev = 11.585/12.084/12.968/0.633 ms