Universal healthcheck and WAIT for DevOps :D

The easiest healthcheck.

This healthcheck is a hub of different healthcheck produced by community.

For	Type	When	Source
http	http	done	https://github.com/hypolas/hypolashlckhttp
API	http	done	https://github.com/hypolas/hypolashlckhttp
ICMP	ping	done	https://github.com/hypolas/hypolashlckping
PostgreSQL	""	Soon
MySQL	""	Soon
Redis	""	Planed

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Or what you want, don't hesitate to ask ;)

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Type corresponde to HYPOLAS_HEALTHCHECK_TYPE=\<type\>

All configuration by environnement variables.

Objective

• Include the same syntax for all care for hobbyists or engineers
• Remove all script command complexity
• Provide the ability to do a healthcheck without any driver installed on your operating system.

Advanced functions

Dynamic variable

All environment variables in the environment variable will be resolved. Exemple with ping healthcheck.

For an host with:

• MYENV_HOSTNAME=myhost exported
• IP = 10.10.10.20

You have set bevore: MYENV_HOSTNAME=myhost

With this settings:

export XXX_PING_HOST=\$MYENV_HOSTNAME
export XXX_PING_HOST="#CMDSTART# hostname -i #CMDEND#"

Env var	Your value	Resolve value	Resolved by env	Resolved by CMD
XXX_PING_HOST	\$MYENV_HOSTNAME	myhost	-	X
XXX_PING_HOST	#CMDSTART# hostname -i #CMDEND#	10.10.10.20	X	-

Exemple for Docker (Traefik)

FROM traefik:v2.9.8

ADD https://github.com/hypolas/healthcheck/releases/download/v0.4.1/healthcheck_hpl-linux-amd64 /usr/bin/healthcheck
RUN chmod +x /usr/bin/healthcheck

ENV HYPOLAS_HEALTHCHECK_TYPE=http
ENV HYPOLAS_HEALTHCHECK_HTTP_EXPECTED=OK
ENV HYPOLAS_HEALTHCHECK_HTTP_URL="http://#CMDSTART# hostname -i #CMDEND#:8082/ping"

HEALTHCHECK --start-period=10s --interval=10s --timeout=5s --retries=3 CMD healthcheck

Not again ready but in developpement =>

Using this healthcheck as waiter

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Use healthcheck for wait

In a particulaire case you can need wait before start service. A databbase for exemple.

For exemple I have a service on hostA. This service need access to two database:

1. BDD-A and
2. BDD-B

For the first database BDD-A (not real env var for ping healthcheck):

export XXX_TYPE=mysql
export XXX_WAIT=enable
export XXX_MYSQL_HOST=BDD-A

For the second database, we specify an id in latest command line

export XXX_MYID_TYPE=mysql
export XXX_MYID_WAIT=enable
export XXX_MYID_MYSQL_HOST=BDD-B

This call healthcheck with this command:

xxx && healthcheck && healthcheck -id MYID && serviceStart.sh

Pay attention to -id and changes in environment variables MYID

In this case, until the twice databases not responding, the services will wait.

Exemple with docker-compose.yml (not real env var for MySQL healthcheck):

version: '3'

services:
  web:
    image: myimage:1.0.0
    entrypoint: healthcheck && healthcheck -id MYID && serviceStart.sh
    environment:
      XXX_TYPE: mysql
      XXX_WAIT: enable
      XXX_MYSQL_HOST: BDD-A
      XXX_MYID_TYPE: mysql
      XXX_MYID_WAIT: enable
      XXX_MYID_MYSQL_HOST: BDD-B