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 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)