Add Prometheus Query Operations

These are basic fetch functions to query data from a prometheus endpoint.

1 files changed, 31 insertions, 0 deletions

diff --git a/lib/ex_prometheus_io.ex b/lib/ex_prometheus_io.ex
index e1c9427..cac39a5 100644
--- a/lib/ex_prometheus_io.ex
+++ b/lib/ex_prometheus_io.ex
@@ -1,2 +1,33 @@
 defmodule ExPrometheusIo do
+  use Application
+
+  def start(_, _) do
+    ExPrometheusIo.Supervisor.start_link
+  end
+
+  def query(query, _opts \\ []) do
+    query_opts = [query]
+    spawn_query(:fetch_query, query_opts)
+  end
+
+  def range(query, start_ts, end_ts, step, _opts \\ []) do
+    query_opts = [query, start_ts, end_ts, step]
+    spawn_query(:fetch_range, query_opts)
+  end
+
+  def series(matches, _opts \\ []) do
+    spawn_query(:fetch_series, [matches])
+  end
+
+  defp spawn_query(fetch, query_opts, _opts \\ []) do
+    query_ref = make_ref()
+    query_opts = query_opts ++ [query_ref, self()]
+    {:ok, pid} = Task.Supervisor.start_child(
+      ExPrometheusIo.QuerySupervisor,
+      ExPrometheusIo.Query,
+      fetch,
+      query_opts)
+    {pid, query_ref}
+  end
+
 end