http-checks

Table of Contents

• Overview
• Usage examples
  • http-check
  • http-perf
  • http-json
• Configuration
  • Asset registration
  • Check definitions
• Installation from source
• Additional notes
• Contributing

Overview

The http-checks is a colleciton of Sensu Checks that providing monitoring
and metrics for HTTP based services.

This collection contains the following checks:

• http-check - for checking HTTP status or searching for a string in the response body
• http-perf - for checking HTTP performance by measuring response times, provides metrics in nagios_perfdata format
• http-json - for querying JSON output from an HTTP request

Usage examples

http-check

Help output

HTTP Status/String Check

Usage:
  http-check [flags]
  http-check [command]

Available Commands:
  help        Help about any command
  version     Print the version number of this plugin

Flags:
  -u, --url string               URL to test (default "http://localhost:80/")
  -s, --search-string string     String to search for, if not provided do status check only
  -r, --redirect-ok              Allow redirects
  -T, --timeout int              Request timeout in seconds (default 15)
  -t, --trusted-ca-file string   TLS CA certificate bundle in PEM format
  -i, --insecure-skip-verify     Skip TLS certificate verification (not recommended!)
  -h, --help                     help for http-check

Use "http-check [command] --help" for more information about a command.

Example(s)

http-check --url https://sensu.io --search-string Monitoring
http-check OK: found "Monitoring" at https://sensu.io

http-check --url https://sensu.io --search-string droids
http-check CRITICAL: "droids" not found at https://sensu.io

http-check --url https://sensu.io
http-check OK: HTTP Status 200 for https://sensu.io

http-check --url https://sensu.io/notfound
http-check WARNING: HTTP Status 301 for https://sensu.io/notfound  (redirects to /oops)

http-check --url https://sensu.io/notfound --redirect-ok
http-check OK: HTTP Status 200 for https://sensu.io/oops (redirect from https://sensu.io/notfound)

http-check --url https://discourse.sensu.io/notfound
http-check CRITICAL: HTTP Status 404 for https://discourse.sensu.io/notfound

Note(s)

• When using --redirect-ok it affects both the string search and status checkfunctionality.
  • For a string search, if true, it searches for the string in the eventual destination.
  • For a status check, if false, receiving a redirect will return a warning status. If true, it will return an ok status.

http-perf

Help output

HTTP Performance Check

Usage:
  http-perf [flags]
  http-perf [command]

Available Commands:
  help        Help about any command
  version     Print the version number of this plugin

Flags:
  -u, --url string               URL to test (default "http://localhost:80/")
  -T, --timeout int              Request timeout in seconds (default 15)
  -w, --warning string           Warning threshold, can be expressed as seconds or milliseconds (1s = 1000ms) (default "1s")
  -c, --critical string          Critical threshold, can be expressed as seconds or milliseconds (1s = 1000ms) (default "2s")
  -m, --output-in-ms             Provide output in milliseconds (default false, display in seconds)
  -t, --trusted-ca-file string   TLS CA certificate bundle in PEM format
  -i, --insecure-skip-verify     Skip TLS certificate verification (not recommended!)
  -h, --help                     help for http-perf

Use "http-perf [command] --help" for more information about a command.

Example(s)

http-perf --url https://sensu.io --warning 1s --critical 2s
http-perf OK: 0.243321s | dns_duration=0.016596, tls_handshake_duration=0.172235, connect_duration=0.022199, first_byte_duration=0.243267, total_request_duration=0.243321

# Let's make the warning threshold pretty improbable
http-perf --url https://sensu.io --warning 10ms --critical 1s
http-perf WARNING: 0.304795s | dns_duration=0.033904, tls_handshake_duration=0.198843, connect_duration=0.021858, first_byte_duration=0.304747, total_request_duration=0.304795

# Again, but with output in milliseconds
http-perf --url https://sensu.io --warning 10ms --critical 1s --output-in-ms
http-perf WARNING: 262ms | dns_duration=35, tls_handshake_duration=170, connect_duration=22, first_byte_duration=262, total_request_duration=262

Note(s)

• http-perf does not follow redirects, the page you are testing will need to
  be referenced explicitly.

http-json

Help output

HTTP JSON Check

Usage:
  http-json [flags]
  http-json [command]

Available Commands:
  help        Help about any command
  version     Print the version number of this plugin

Flags:
  -u, --url string               URL to test (default "http://localhost:80/")
  -T, --timeout int              Request timeout in seconds (default 15)
  -p, --path string              Path to query in JSON
  -e, --expression string        Expression to query in JSON
  -t, --trusted-ca-file string   TLS CA certificate bundle in PEM format
  -i, --insecure-skip-verify     Skip TLS certificate verification (not recommended!)
  -h, --help                     help for http-json

Use "http-json [command] --help" for more information about a command.

Example(s)

# Boolean example - checking Sensu cluster health
http-json --url http://backend:8080/health --path ClusterHealth.[0].Healthy --expression "== true"
http-json OK:  The value true found at ClusterHealth.[0].Healthy matched with expression "== true" and returned true

# String comparison expressions
http-json --url https://icanhazdadjoke.com/j/HeaFdiyIJe --path id --expression "== \"HeaFdiyIJe\""
http-json OK:  The value HeaFdiyIJe found at id matched with expression "== \"HeaFdiyIJe\"" and returned true

http-json --url https://icanhazdadjoke.com/j/HeaFdiyIJe --path id --expression "== \"BadText\""
http-json CRITICAL: The value HeaFdiyIJe found at id did not match with expression "== \"BadText\"" and returned false

# Numeric comparison expressions
http-json --url https://icanhazdadjoke.com/j/HeaFdiyIJe --path status --expression "== 200"
http-json OK:  The value 200 found at status matched with expression "== 200" and returned true

http-json --url https://icanhazdadjoke.com/j/HeaFdiyIJe --path status --expression "< 300"
http-json OK:  The value 200 found at status matched with expression "< 300" and returned true

http-json --url https://icanhazdadjoke.com/j/HeaFdiyIJe --path status --expression "> 300"
http-json CRITICAL: The value 200 found at status did not match with expression "> 300" and returned false

Configuration

Asset registration

Sensu Assets are the best way to make use of this plugin. If you're not
using an asset, please consider doing so! If you're using sensuctl 5.13 with
Sensu Backend 5.13 or later, you can use the following command to add the asset:

sensuctl asset add nixwiz/http-checks

If you're using an earlier version of sensuctl, you can find the asset on the Bonsai Asset Index.

Check definitions

http-check

---
type: CheckConfig
api_version: core/v2
metadata:
  name: http-check
  namespace: default
spec:
  command: http-check --url http://example.com
  subscriptions:
  - system
  runtime_assets:
  - nixwiz/http-checks

http-perf

---
type: CheckConfig
api_version: core/v2
metadata:
  name: http-perf
  namespace: default
spec:
  command: http-perf --url http://example.com
  subscriptions:
  - system
  runtime_assets:
  - nixwiz/http-checks
  output_metric_format: nagios_perfdata
  output_metric-handlers:
  - influxdb

http-json

---
type: CheckConfig
api_version: core/v2
metadata:
  name: http-json
  namespace: default
spec:
  command: http-json --url https://icanhazdadjoke.com/j/HeaFdiyIJe --path id --expression "== \"HeaFdiyIJe\""
  subscriptions:
  - system
  runtime_assets:
  - nixwiz/http-checks

Installation from source

The preferred way of installing and deploying this plugin is to use it as an
Asset. If you would like to compile and install the plugin from source or
contribute to it, download the latest version or create an executable script
from this source.

From the local path of the http-checks repository:

go build -o bin/http-check ./cmd/http-check
go build -o bin/http-perf ./cmd/http-perf
go build -o bin/http-json ./cmd/http-json

Additional notes

Portions of http-check and http-json are based on and/or derived from the HTTP
check found in the NCR DevOps Platform nagiosfoundation collection of
checks.

Contributing

For more information about contributing to this plugin, see Contributing.