NAME
Plack::Middleware::HealthCheck - A health check endpoint for your Plack app
VERSION
version v0.0.3
SYNOPSIS
$psgi_app = Plack::Middleware::HealthCheck->wrap( $psgi_app,
health_check => HealthCheck->new(...),
)This automatically serves the results as JSON at /healthz.
You can serve the results from different "health_check_paths" than the default, and you can specify which query parameters, other than the always allowed tags, are passed to the check with "allowed_params".
$psgi_app = HealthCheck::Diagnostic::LoadAverage->wrap( $psgi_app,
health_check => HealthCheck->new(...),
health_check_paths => ['/_healthcheck'],
allowed_params => [ 'foo', 'bar' ],
);Since you don't want to serve this HealthCheck everywhere on the internet, you should limit its access, for example using Plack::Middleware::Conditional to limit by IP address.
# Using enable_if
use Plack::Builder;
builder {
enable_if { $_[0]->{REMOTE_ADDR} =~ /^10\./ } 'HealthCheck',
health_check => HealthCheck->new(...),
;
$psgi_app;
};
# OO interface
$app = Plack::Middleware::Conditional->wrap(
$psgi_app,
condition => sub { $_[0]->{REMOTE_ADDR} =~ /^10\./ },
builder => sub {
Plack::Middleware::HealthCheck->wrap( $psgi_app,
health_check => HealthCheck->new(...),
)
},
);DESCRIPTION
Does a basic health check for your app, by default responding on "health_check_paths" with "serve_health_check".
You must provide your own "health_check" object that the checks will be run against.
NAME
Plack::Middleware::HealthCheck - Health checks for your plack app
ATTRIBUTES
health_check
A HealthCheck object that should have checks with the ecv_test tag.
The default object registers LoadAverage and HideFile checks with the values from "load_limit" and "hide_files".
health_check_paths
A list of URLs to "serve_health_check" from.
Defaults to ['/healthz'].
If you don't want any health check paths, set this to an empty arrayref ([]).
allowed_params
A list of query_params to pass through to check. Parameters are passed with the values in arrayrefs.
Defaults to undef, although tags are always passed by "serve_health_check".
METHODS
serve_health_check
Called with the Plack $env hash as an argument if "should_serve_health_check" returns true.
Reads the query parameters for any tags or other "allowed_params" and then calls the "health_check" check method with those parameters as well as passing $env under the "env" key.
Returns the result of passing the health check $result to "health_check_response".
should_serve_health_check
Receives the Plack $env as an argument and returns a truthy value if $env->{PATH_INFO} matches any of the "health_check_paths".
health_check_response
Takes a health check $result and returns a Plack response arrayref.
Returns a 200 response if the $result->{status} is "OK", otherwise returns a 503.
The body of the response is the $result JSON encoded.
Also takes an optional Plack::Request object as a second argument which it will check for the existence of a pretty query parameter in which case it will make the JSON response both pretty and canonical.
DEPENDENCIES
Plack::Middleware, HealthCheck
SEE ALSO
The GSG Health Check Standard
CONFIGURATION AND ENVIRONMENT
None
AUTHOR
Grant Street Group <developers@grantstreet.com>
COPYRIGHT AND LICENSE
This software is Copyright (c) 2019 - 2020 by Grant Street Group.
This is free software, licensed under:
The Artistic License 2.0 (GPL Compatible)