Merge branch 'shared-connection-pool' into 'master'

fix: Share connection pools amongst repos that have equivalent config

See merge request mythic-insight/legendary!36

apps/core/lib/core/shared_db_connection_pool.ex

@@ -0,0 +1,46 @@
+defmodule Core.SharedDBConnectionPool do
+  @moduledoc """
+  A shareable connection pool. We use this so that all the apps connecting to
+  one database can use on connection pool, even if they have different repos.
+
+  This allows a reasonable number of connections to be available per application
+  without requiring a huge number of connections to the database.
+  """
+  alias DBConnection.ConnectionPool
+
+  def start_link({mod, opts}) do
+    case GenServer.start_link(ConnectionPool, {mod, opts}, Keyword.take(opts, [:name, :spawn_opt])) do
+      {:ok, pid} -> {:ok, pid}
+      {:error, {:already_started, pid}} -> {:ok, pid}
+      error -> error
+    end
+  end
+
+  def child_spec({mod, opts}) do
+    opts = Keyword.put_new(opts, :name, key(opts))
+    Supervisor.Spec.worker(Core.SharedDBConnectionPool, [{mod, opts}])
+  end
+
+  defp key(opts) do
+    key_hash =
+      case opts do
+        %{url: url} ->
+          Ecto.Repo.Supervisor.parse_url(url)
+        _ ->
+          opts
+      end
+      |> hash_opts()
+
+    String.to_atom("Core.SharedDBConnectionPool.#{key_hash}")
+  end
+
+  defp hash_opts(opts) do
+    unhashed_key =
+      opts
+      |> Keyword.take([:hostname, :username, :password, :database])
+      |> Keyword.values()
+      |> Enum.join("/")
+
+    :crypto.hash(:sha3_256, unhashed_key) |> Base.encode16()
+  end
+end

config/config.exs

@@ -32,10 +32,8 @@ end)
       ecto_repos: [repo],
       generators: [context_app: otp_app]
 
-  {otp_app, repo, context_app} ->
+    config otp_app, repo,
-    config otp_app,
+      pool: Core.SharedDBConnectionPool
-      ecto_repos: [repo],
-      generators: [context_app: context_app]
 end)
 
 config :core, :pow,

mix.lock

@@ -45,7 +45,7 @@
   "neotomex": {:hex, :neotomex, "0.1.7", "64f76513653aa87ea7abdde0fd600e56955d838020a13d88f2bf334c88ac3e7a", [:mix], [], "hexpm", "4b87b8f614d1cd89dc8ba80ba0e559bedb3ebf6f6d74cd774fcfdd215e861445"},
   "oban": {:hex, :oban, "2.1.0", "034144686f7e76a102b5d67731f098d98a9e4a52b07c25ad580a01f83a7f1cf5", [:mix], [{:ecto_sql, ">= 3.4.3", [hex: :ecto_sql, repo: "hexpm", optional: false]}, {:jason, "~> 1.1", [hex: :jason, repo: "hexpm", optional: false]}, {:postgrex, "~> 0.14", [hex: :postgrex, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "c6f067fa3b308ed9e0e6beb2b34277c9c4e48bf95338edabd8f4a757a26e04c2"},
   "parse_trans": {:hex, :parse_trans, "3.3.0", "09765507a3c7590a784615cfd421d101aec25098d50b89d7aa1d66646bc571c1", [:rebar3], [], "hexpm", "17ef63abde837ad30680ea7f857dd9e7ced9476cdd7b0394432af4bfc241b960"},
-  "phoenix": {:hex, :phoenix, "1.5.7", "2923bb3af924f184459fe4fa4b100bd25fa6468e69b2803dfae82698269aa5e0", [:mix], [{:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:phoenix_html, "~> 2.13", [hex: :phoenix_html, repo: "hexpm", optional: true]}, {:phoenix_pubsub, "~> 2.0", [hex: :phoenix_pubsub, repo: "hexpm", optional: false]}, {:plug, "~> 1.10", [hex: :plug, repo: "hexpm", optional: false]}, {:plug_cowboy, "~> 1.0 or ~> 2.2", [hex: :plug_cowboy, repo: "hexpm", optional: true]}, {:plug_crypto, "~> 1.1.2 or ~> 1.2", [hex: :plug_crypto, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "774cd64417c5a3788414fdbb2be2eb9bcd0c048d9e6ad11a0c1fd67b7c0d0978"},
+  "phoenix": {:hex, :phoenix, "1.5.8", "71cfa7a9bb9a37af4df98939790642f210e35f696b935ca6d9d9c55a884621a4", [:mix], [{:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:phoenix_html, "~> 2.13", [hex: :phoenix_html, repo: "hexpm", optional: true]}, {:phoenix_pubsub, "~> 2.0", [hex: :phoenix_pubsub, repo: "hexpm", optional: false]}, {:plug, "~> 1.10", [hex: :plug, repo: "hexpm", optional: false]}, {:plug_cowboy, "~> 1.0 or ~> 2.2", [hex: :plug_cowboy, repo: "hexpm", optional: true]}, {:plug_crypto, "~> 1.1.2 or ~> 1.2", [hex: :plug_crypto, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "35ded0a32f4836168c7ab6c33b88822eccd201bcd9492125a9bea4c54332d955"},
   "phoenix_ecto": {:hex, :phoenix_ecto, "4.1.0", "a044d0756d0464c5a541b4a0bf4bcaf89bffcaf92468862408290682c73ae50d", [:mix], [{:ecto, "~> 3.0", [hex: :ecto, repo: "hexpm", optional: false]}, {:phoenix_html, "~> 2.9", [hex: :phoenix_html, repo: "hexpm", optional: true]}, {:plug, "~> 1.0", [hex: :plug, repo: "hexpm", optional: false]}], "hexpm", "c5e666a341ff104d0399d8f0e4ff094559b2fde13a5985d4cb5023b2c2ac558b"},
   "phoenix_html": {:hex, :phoenix_html, "2.14.3", "51f720d0d543e4e157ff06b65de38e13303d5778a7919bcc696599e5934271b8", [:mix], [{:plug, "~> 1.5", [hex: :plug, repo: "hexpm", optional: false]}], "hexpm", "efd697a7fff35a13eeeb6b43db884705cba353a1a41d127d118fda5f90c8e80f"},
   "phoenix_html_sanitizer": {:hex, :phoenix_html_sanitizer, "1.0.2", "e2c8cfbc83660e362753de127cc957bec3442a8aecdf271fb65a684a906fccf5", [:mix], [{:html_sanitize_ex, "~> 1.0.0", [hex: :html_sanitize_ex, repo: "hexpm", optional: false]}, {:phoenix_html, "~> 2.0", [hex: :phoenix_html, repo: "hexpm", optional: false]}], "hexpm", "47aebb08fa954b7ad95f295fb701df9800ee3a489212119c9c6074a65e1e5a10"},