chg: [deploying] some clustering experiments

config/config.exs

@@ -74,6 +74,26 @@ config :fun_with_flags, :cache_bust_notifications,
   adapter: FunWithFlags.Notifications.PhoenixPubSub,
   client: Cocktailparty.PubSub
 
+config :libcluster,
+  debug: true,
+  topologies: [
+    gossip: [
+      strategy: Elixir.Cluster.Strategy.Gossip,
+      config: [
+        port: 45892,
+        if_addr: "0.0.0.0",
+        multicast_addr: "255.255.255.255",
+        broadcast_only: true,
+        secret: "thisismypassword"
+      ]
+    ]
+  ]
+
+# Setting defaults
+config :cocktailparty,
+  standalone: true,
+  broker: true
+
 # Import environment specific config. This must remain at the bottom
 # of this file so it overrides the configuration defined above.
 import_config "#{config_env()}.exs"

config/runtime.exs

@@ -114,7 +114,24 @@ if config_env() == :prod do
   # See https://hexdocs.pm/swoosh/Swoosh.html#module-installation for details.
   # Configure your redis connection
 
-  redis_uri = System.get_env("REDIS_URI") || "redis://127.0.0.1:6379/0"
+  standalone =
+    case System.get_env("STANDALONE") || true do
+      "true" -> true
+      "false" -> false
+      nil -> true
+    end
+
+  broker =
+    case System.get_env("BROKER") || true do
+      "true" -> true
+      "false" -> false
+      nil -> true
+    end
+
   config :cocktailparty,
-    redix_uri: redis_uri
+    redix_uri: System.get_env("REDIS_URI") || "redis://127.0.0.1:6379/0",
+    # won't start libcluster unless this is true
+    standalone: standalone,
+    # won't start the broker and redis connection unless this is true
+    broker: broker
 end

lib/cocktailparty/application.ex

@@ -7,26 +7,39 @@ defmodule Cocktailparty.Application do
 
   @impl true
   def start(_type, _args) do
-    children = [
-      # Start the Telemetry supervisor
-      CocktailpartyWeb.Telemetry,
-      # Start the Ecto repository
-      Cocktailparty.Repo,
-      # Start the PubSub system
-      {Phoenix.PubSub, name: Cocktailparty.PubSub},
-      # Start Finch
-      {Finch, name: Cocktailparty.Finch},
-      # Start the Endpoint (http/https)
-      CocktailpartyWeb.Endpoint,
-      # Start a worker by calling: Cocktailparty.Worker.start_link(arg)
-      # {Cocktailparty.Worker, arg}
-      # Redis connection
-      {Redix, {Application.get_env(:cocktailparty, :redix_uri), [name: :redix]}},
-      # Fun with Flags
-      FunWithFlags.Supervisor,
-      # Start the Broker once the application is started
-      Cocktailparty.Broker
-    ]
+    # Common children
+    children =
+      [
+        # Start the Telemetry supervisor
+        CocktailpartyWeb.Telemetry,
+        # Start the Ecto repository
+        Cocktailparty.Repo,
+        # Start the PubSub system
+        {Phoenix.PubSub, name: Cocktailparty.PubSub},
+        # Start Finch
+        {Finch, name: Cocktailparty.Finch},
+        # Start the Endpoint (http/https)
+        CocktailpartyWeb.Endpoint,
+        # Start a worker by calling: Cocktailparty.Worker.start_link(arg)
+        # {Cocktailparty.Worker, arg}
+        # Fun with Flags
+        FunWithFlags.Supervisor
+      ]
+      |> append_if_true(
+        !Application.get_env(:cocktailparty, :standalone),
+        {Cluster.Supervisor,
+         [Application.get_env(:libcluster, :topologies), [name: Cocktailparty.ClusterSupervisor]]}
+      )
+      |> append_if_true(
+        Application.get_env(:cocktailparty, :standalone) ||
+          Application.get_env(:cocktailparty, :broker),
+        {Redix, {Application.get_env(:cocktailparty, :redix_uri), [name: :redix]}}
+      )
+      |> append_if_true(
+        Application.get_env(:cocktailparty, :standalone) ||
+          Application.get_env(:cocktailparty, :broker),
+        Cocktailparty.Broker
+      )
 
     # See https://hexdocs.pm/elixir/Supervisor.html
     # for other strategies and supported options
@@ -41,4 +54,8 @@ defmodule Cocktailparty.Application do
     CocktailpartyWeb.Endpoint.config_change(changed, removed)
     :ok
   end
+
+  defp append_if_true(list, cond, extra) do
+    if cond, do: list ++ [extra], else: list
+  end
 end

mix.exs

@@ -61,7 +61,9 @@ defmodule Cocktailparty.MixProject do
       {:redix, "~>1.2.2"},
       # runtime: false because we don't want to start the FunWithFlags.Supervisor automatically
       {:fun_with_flags, "~> 1.10.1", runtime: false},
-      {:fun_with_flags_ui, "~> 0.8.1", runtime: false}
+      {:fun_with_flags_ui, "~> 0.8.1", runtime: false},
+      # Libcluster
+      {:libcluster, "~> 3.3"}
     ]
   end
 

mix.lock

@@ -20,6 +20,7 @@
   "gettext": {:hex, :gettext, "0.22.1", "e7942988383c3d9eed4bdc22fc63e712b655ae94a672a27e4900e3d4a2c43581", [:mix], [{:expo, "~> 0.4.0", [hex: :expo, repo: "hexpm", optional: false]}], "hexpm", "ad105b8dab668ee3f90c0d3d94ba75e9aead27a62495c101d94f2657a190ac5d"},
   "hpax": {:hex, :hpax, "0.1.2", "09a75600d9d8bbd064cdd741f21fc06fc1f4cf3d0fcc335e5aa19be1a7235c84", [:mix], [], "hexpm", "2c87843d5a23f5f16748ebe77969880e29809580efdaccd615cd3bed628a8c13"},
   "jason": {:hex, :jason, "1.4.0", "e855647bc964a44e2f67df589ccf49105ae039d4179db7f6271dfd3843dc27e6", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "79a3791085b2a0f743ca04cec0f7be26443738779d09302e01318f97bdb82121"},
+  "libcluster": {:hex, :libcluster, "3.3.2", "84c6ebfdc72a03805955abfb5ff573f71921a3e299279cc3445445d5af619ad1", [:mix], [{:jason, "~> 1.1", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "8b691ce8185670fc8f3fc0b7ed59eff66c6889df890d13411f8f1a0e6871d8a5"},
   "mime": {:hex, :mime, "2.0.3", "3676436d3d1f7b81b5a2d2bd8405f412c677558c81b1c92be58c00562bb59095", [:mix], [], "hexpm", "27a30bf0db44d25eecba73755acf4068cbfe26a4372f9eb3e4ea3a45956bff6b"},
   "mint": {:hex, :mint, "1.5.1", "8db5239e56738552d85af398798c80648db0e90f343c8469f6c6d8898944fb6f", [:mix], [{:castore, "~> 0.1.0 or ~> 1.0", [hex: :castore, repo: "hexpm", optional: true]}, {:hpax, "~> 0.1.1", [hex: :hpax, repo: "hexpm", optional: false]}], "hexpm", "4a63e1e76a7c3956abd2c72f370a0d0aecddc3976dea5c27eccbecfa5e7d5b1e"},
   "nimble_options": {:hex, :nimble_options, "1.0.2", "92098a74df0072ff37d0c12ace58574d26880e522c22801437151a159392270e", [:mix], [], "hexpm", "fd12a8db2021036ce12a309f26f564ec367373265b53e25403f0ee697380f1b8"},