JSON Module Support for Elixir 1.18 and CI Environment Updates

.github/workflows/elixir.yml

@@ -8,20 +8,25 @@ on:
 
 jobs:
   test:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     env:
       MIX_ENV: test
     strategy:
       fail-fast: false
       matrix:
         include:
           - pair:
-              elixir: "1.13"
-              otp: "22"
+              elixir: "1.16"
+              otp: "26"
+            lint: lint
           - pair:
               elixir: "1.17"
               otp: "27"
             lint: lint
+          - pair:
+              elixir: "1.18"
+              otp: "27"
+            lint: lint
     steps:
       - uses: actions/checkout@v4
 

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## Unreleased
 
 - Add `kubernetes_use_cached_resources` option to Kubernetes strategy
+* Use Elixir 1.18's built-in JSON module when available
 
 ## 3.4.1
 

lib/json.ex

@@ -0,0 +1,18 @@
+defmodule Cluster.JSON do
+  @moduledoc false
+
+  # Delegates to JSON in Elixir v1.18+ or Jason for earlier versions
+
+  cond do
+    Code.ensure_loaded?(JSON) ->
+      defdelegate decode!(data), to: JSON
+
+    Code.ensure_loaded?(Jason) ->
+      defdelegate decode!(data), to: Jason
+
+    true ->
+      message = "Missing a compatible JSON library, add `:jason` to your deps."
+
+      IO.warn(message, Macro.Env.stacktrace(__ENV__))
+  end
+end

lib/strategy/kubernetes.ex

@@ -409,7 +409,7 @@ defmodule Cluster.Strategy.Kubernetes do
 
         case :httpc.request(:get, {~c"https://#{master}/#{path}", headers}, http_options, []) do
           {:ok, {{_version, 200, _status}, _headers, body}} ->
-            parse_response(ip_lookup_mode, Jason.decode!(body))
+            parse_response(ip_lookup_mode, Cluster.JSON.decode!(body))
             |> Enum.map(fn node_info ->
               format_node(
                 Keyword.get(config, :mode, :ip),
@@ -421,7 +421,7 @@ defmodule Cluster.Strategy.Kubernetes do
             end)
 
           {:ok, {{_version, 403, _status}, _headers, body}} ->
-            %{"message" => msg} = Jason.decode!(body)
+            %{"message" => msg} = Cluster.JSON.decode!(body)
             warn(topology, "cannot query kubernetes (unauthorized): #{msg}")
             []
 

lib/strategy/rancher.ex

@@ -139,7 +139,7 @@ defmodule Cluster.Strategy.Rancher do
                []
              ) do
           {:ok, {{_version, 200, _status}, _headers, body}} ->
-            parse_response(app_name, Jason.decode!(body))
+            parse_response(app_name, Cluster.JSON.decode!(body))
 
           {:ok, {{_version, code, status}, _headers, body}} ->
             warn(

mix.exs

@@ -40,7 +40,7 @@ defmodule Cluster.Mixfile do
       {:ex_doc, ">= 0.0.0", only: :dev, runtime: false},
       {:dialyxir, "~> 1.0", only: :dev, runtime: false},
       {:exvcr, "~> 0.11", only: :test, runtime: false},
-      {:jason, "~> 1.1"},
+      {:jason, "~> 1.1", optional: true},
       {:telemetry, "~> 1.3"}
     ]
   end