OpenTelemetryDecorator v0.3.0 OpenTelemetryDecorator
A function decorator for OpenTelemetry traces.
Usage
The span name can be any string.
defmodule MyApp.Worker do
use OpenTelemetryDecorator
@decorate trace("my_app.worker.do_work")
def do_work(arg1, arg2) do
...doing work
do_more_work(arg1)
end
@decorate trace("MyApp::Worker::do_more_work")
def do_more_work(arg1) do
...doing more work
end
end
We use OpenTelemetry.Tracer.current_span_ctx()
to automatically link new spans to the current trace (if it exists and is in the same process). So the above example will link the do_work
and do_more_work
spans for you by default.
You can provide span attributes by specifying a list of variable names as atoms.
This list can include...
Any variables (in the top level closure) available when the function exits:
defmodule MyApp.Math do
use OpenTelemetryDecorator
@decorate trace("my_app.math.add", [:a, :b, :sum])
def add(a, b) do
sum = a + b
{:ok, thing1}
end
end
The result of the function by including the atom :result
:
defmodule MyApp.Math do
use OpenTelemetryDecorator
@decorate trace("my_app.math.add", [:result])
def add(a, b) do
sum = a + b
{:ok, thing1}
end
end
Map/struct properties using nested lists of atoms:
defmodule MyApp.Worker do
use OpenTelemetryDecorator
@decorate trace("my_app.worker.do_work", [[:arg1, :count], [:arg2, :count], :total])
def do_work(arg1, arg2) do
total = arg1.count + arg2.count
{:ok, total}
end
end
Installation
Add open_telemetry_decorator
to your list of dependencies in mix.exs
and do a mix deps.get
:
def deps do
[
{:open_telemetry_decorator, "~> 0.1.0"}
]
end
Link to this section Summary
Functions
This method has to be public because it's used within the macro, but it shouldn't be called directly.
Decorate a function to add an OpenTelemetry trace with a named span.
This method has to be public because it's used within the macro, but it shouldn't be called directly.
Link to this section Functions
get_reportable_attrs(bound_variables, reportable_attr_keys, result \\ nil)
This method has to be public because it's used within the macro, but it shouldn't be called directly.
trace(span_name, attr_keys \\ [], body, context)
Decorate a function to add an OpenTelemetry trace with a named span.
You can provide span attributes by specifying a list of variable names as atoms. This list can include:
- any variables (in the top level closure) available when the function exits,
-
the result of the function by including the atom
:result
, - map/struct properties using nested lists of atoms.
defmodule MyApp.Worker do
use OpenTelemetryDecorator
@decorate trace("my_app.worker.do_work", [:arg1, [:arg2, :count], :total, :result])
def do_work(arg1, arg2) do
total = arg1.count + arg2.count
{:ok, total}
end
end
validate_args(span_name, attr_keys)
This method has to be public because it's used within the macro, but it shouldn't be called directly.