deadtrickster / prometheus-httpd Goto Github PK

The idea is to have this lib as a foundation for other exporters - plugs, elli, cowboy, etc.

prometheus_httpd_config stays the same.
prometheus_http will have shared /metrics behaviour with two exports:

render/1

 `render(Env)`

Env is a map:

%{
  path => Path. %% present if you want prometheus_http to handle routing and registry extraction
  accept => Accept, %% accepted content types
  accept_encoding => AcceptEncoding, %% accepted encodings
  registry => Registry, %% ignored if path present, can generate 409 if registry config isn't auto
}

index/0

Renders standard welcome page with useful links and current metrics path.

Both return {Code, Headers, Body}.

the accept dependancy is missing and raise an undef error when the source code fall there:

https://github.com/deadtrickster/prometheus-httpd/blob/master/src/prometheus_http.erl#L133

By default all resources are public.
To enable authorizaton set authorizaton config entry to authorizaton provider.
prometheus_httpd comes with basic auth provider with configuration shortcuts:

%% enable basic auth
{authorizaton, {basic, Login, Password}}

%% enable basic auth with external credentials
%% CredentialsProvider is Callable or {Callable, Args}
%% Callable is Fun/2, Module exporting authorize/2, or {Module, authorize/2}
{authorizaton, {basic, CredentialsProvider}}

%% custom authorization provider
%% Provider = is Callable or {Callable, Args}
%% Callable is Fun/1, Module exporting authorize/1, or {Module, authorize/1}
{authorizaton, Provider}

I got server internal error when I start prometheus_httpd and visit http://ip:8081/metrics

Both prometheus_httpd and accept use the rebar3_archive_plugin, which in turn depends on the rebar3_elvis_plugin, which conflicts with rebar3_lint. Using the latter in a project that depends on prometheus_httpd may fail in weird ways.

The dependency has actually been removed from the current rebar3_archive_plugin code, but prometheus_httpd and accept depend on older versions of the plugin. It would be nice to update them to use the current rebar3_archive_plugin code (or to remove that dependency).

FWIW, this works for me as a workaround:

{overrides,
 [% The rebar3_archive_plugin (used by prometheus_httpd and accept) depends on
  % the rebar3_elvis_plugin, which conflicts with rebar3_lint.
  {del,
   [{plugins, [{rebar3_archive_plugin, "0.0.1"}]},
    {plugins, [{rebar3_archive_plugin, "0.0.2"}]}]}]}.

Rendering metrics

Configuration entry: registry, default is auto.
Dynamic value - from path /metrics(/:registry) with default to default.

If configured to auto, get registry from path. Otherwise, from configuration.
If configured to other than auto and /metrics/:registry should return 409 (conflict).

Telemetry metrics

Configuration entry: telemetry_registry, default is default.

I have a Diameter application (no Cowboy or other http servers) and I'm starting to add Prometheus metrics support.

I've added to my rebar dependencies:

{deps, [
    {lager, "3.8.0"},
    {prometheus, "4.5.0"},
    prometheus_diameter_collector,
    prometheus_httpd,
    prometheus_process_collector
]}.

Then, in my app.app.src, I added them to the applications part:

{application, dccaserver,
 [
  {description, "Diameter DCCA Server"},
  {vsn, "1"},
  {registered, []},
  {applications, [
                  kernel,
                  stdlib,
                  lager,
                  sasl,
                  diameter,
                  prometheus,
                  prometheus_process_collector,
                  prometheus_diameter_collector,
                  prometheus_httpd,
                  ocsgateway
                 ]},
  {mod, { dccaserver_app, []}},
  {env, []}
 ]}.

But prometheus_httpd is not started automatically on my application start. If I run it on a shell (rebar shell), and run prometheus_httpd:start(), the metrics are exposed correctly.

Am I doing something wrong?

Please add the LICENSE file. Not having the file might be a problem for some companies that want to use your software.