More compatibility

.credo.exs

@@ -121,7 +121,7 @@
           #
           {Credo.Check.Refactor.Apply, []},
           {Credo.Check.Refactor.CondStatements, []},
-          {Credo.Check.Refactor.CyclomaticComplexity, [max_complexity: 10]},
+          {Credo.Check.Refactor.CyclomaticComplexity, []},
           {Credo.Check.Refactor.FilterCount, []},
           {Credo.Check.Refactor.FilterFilter, []},
           {Credo.Check.Refactor.FunctionArity, []},

.formatter.exs

@@ -1,5 +1,22 @@
 # Used by "mix format"
-[
-  plugins: [Styler],
-  inputs: ["{mix,.formatter}.exs", "{config,lib,test}/**/*.{ex,exs}"]
-]
+
+defmodule LocalFormat do
+  @moduledoc false
+  def format(styler_compat) when styler_compat in [:gt, :eq] do
+    [
+      plugins: [Styler],
+      inputs: ["{mix,.formatter}.exs", "{config,lib,test}/**/*.{ex,exs}"]
+    ]
+  end
+
+  def format(_) do
+    [
+      inputs: ["{mix,.formatter}.exs", "{config,lib,test}/**/*.{ex,exs}"]
+    ]
+  end
+end
+
+elixir_version = System.version()
+styler_compat = Version.compare(elixir_version, "1.14.0")
+
+LocalFormat.format(styler_compat)

.github/workflows/ci.yml

@@ -11,14 +11,51 @@ permissions:
 
 jobs:
   test_linux_elixir_latest:
-    name: ${{ matrix.os }}, Erlang/OTP ${{ matrix.otp_version }} Elixir ${{ matrix.elixir_version }}
+    name: ${{ matrix.os }}, Erlang/OTP ${{ matrix.otp-version }} Elixir ${{ matrix.elixir-version }}
     runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest]
-        elixir_version: ['1']
-        otp_version: ['26']
+        include:
+          - os: ubuntu-20.04
+            elixir-version: 1.12
+            otp-version: 24
+          - os: ubuntu-20.04
+            elixir-version: 1.13
+            otp-version: 24
+          - os: ubuntu-20.04
+            elixir-version: 1.13
+            otp-version: 25
+          - os: ubuntu-20.04
+            elixir-version: 1.14
+            otp-version: 24
+          - os: ubuntu-20.04
+            elixir-version: 1.14
+            otp-version: 25
+          - os: ubuntu-22.04
+            elixir-version: 1.14
+            otp-version: 26
+          - os: ubuntu-20.04
+            elixir-version: 1.15
+            otp-version: 24
+          - os: ubuntu-20.04
+            elixir-version: 1.15
+            otp-version: 25
+          - os: ubuntu-22.04
+            elixir-version: 1.15
+            otp-version: 26
+          - os: ubuntu-20.04
+            elixir-version: 1.16
+            otp-version: 24
+          - os: ubuntu-20.04
+            elixir-version: 1.16
+            otp-version: 25
+          - os: ubuntu-20.04
+            elixir-version: 1.16
+            otp-version: 26
+          - os: ubuntu-22.04
+            elixir-version: 1.16
+            otp-version: 26
     env:
       MIX_ENV: test
       GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
@@ -27,19 +64,21 @@ jobs:
     - name: Set up Elixir
       uses: erlef/setup-beam@v1
       with:
-        elixir-version:  ${{ matrix.elixir_version }}
-        otp-version:  ${{ matrix.otp_version }}
+        elixir-version:  ${{ matrix.elixir-version }}
+        otp-version:  ${{ matrix.otp-version }}
     - name: Restore dependencies cache
       uses: actions/cache@v4
       with:
         path: deps
-        key: ${{ runner.os }}-mix-${{ hashFiles('**/mix.lock') }}
-        restore-keys: ${{ runner.os }}-mix-
+        key: ${{ runner.os }}-${{ matrix.elixir-version }}-${{ matrix.otp-version}}-mix-${{ hashFiles('**/mix.lock') }}
+        restore-keys: ${{ runner.os }}-${{ matrix.elixir-version}}-${{ matrix.otp-version }}-mix-
     - name: Install dependencies
       run: mix deps.get
     - name: Run mix format
       run: mix format --check-formatted
-    - name: Run coverage export
-      run: mix coveralls.github
+      if: startsWith(matrix.elixir-version, '1.14') || startsWith(matrix.elixir-version, '1.15') || startsWith(matrix.elixir-version, '1.16')
     - name: Run tests
       run: mix test
+    - name: Run coverage export
+      run: mix coveralls.github
+      if: startsWith(matrix.elixir-version, '1.16') && startsWith(matrix.otp-version, '26')

.gitignore

@@ -27,3 +27,6 @@ dns_srv_cluster-*.tar
 
 # VSCode
 /.vscode/
+
+# ASDF
+.tool-versions

README.md

@@ -4,6 +4,7 @@ Elixir clustering with DNS SRV records.
 
 ---
 
+[![CI](https://github.com/pertsevds/dns_srv_cluster/actions/workflows/ci.yml/badge.svg)](https://github.com/pertsevds/dns_srv_cluster/actions/workflows/ci.yml)
 [![Coverage Status](https://coveralls.io/repos/github/pertsevds/dns_srv_cluster/badge.svg?branch=main)](https://coveralls.io/github/pertsevds/dns_srv_cluster?branch=main)
 
 ## Installation
@@ -21,10 +22,10 @@ end
 Add to your DNS zone your SRV record (https://en.wikipedia.org/wiki/SRV_record):
 
 ```sh
-_app._tcp.yourdomain.com. 86400 IN SRV 0 10 1234 node1.yourdomain.com.
-_app._tcp.yourdomain.com. 86400 IN SRV 0 10 1234 node2.yourdomain.com.
-_app._tcp.yourdomain.com. 86400 IN SRV 0 10 1234 node3.yourdomain.com.
-_app._tcp.yourdomain.com. 86400 IN SRV 0 10 1234 node4.yourdomain.com.
+_app._tcp.yourdomain.com. 60 IN SRV 0 10 1234 node1.yourdomain.com.
+_app._tcp.yourdomain.com. 60 IN SRV 0 10 1234 node2.yourdomain.com.
+_app._tcp.yourdomain.com. 60 IN SRV 0 10 1234 node3.yourdomain.com.
+_app._tcp.yourdomain.com. 60 IN SRV 0 10 1234 node4.yourdomain.com.
 ```
 
 Add to your config files (`config/prod.exs`, `config/dev.exs`):
@@ -49,7 +50,7 @@ either in your deployment platform or inside `rel/env.sh.eex`:
 export RELEASE_COOKIE="my-app-cookie"
 ```
 
-## All configuration options
+## Configuration options
 
   * `query` - your DNS SRV record, for example: "_app._tcp.yourdomain.com".
   * `interval` - the millisec interval between DNS queries. Defaults to `5_000`.
@@ -80,4 +81,16 @@ children = [
 {:ok, pid} = Supervisor.start_link(children, strategy: :one_for_one)
 ```
 
+## Support Matrix
+
+Tests automatically run against a matrix of OTP and Elixir Versions, see the [ci.yml](https://github.com/pertsevds/dns_srv_cluster/tree/main/.github/workflows/ci.yml) for details.
+
+| OTP \ Elixir | 1.12 | 1.13 | 1.14 | 1.15 | 1.16 |
+|:------------:|:----:|:----:|:----:|:----:|:----:|
+| 24           | ✅   | ✅   | ✅   | ✅   | ✅  |
+| 25           | N/A  | ✅   | ✅   | ✅   | ✅   |
+| 26           | N/A  | N/A  | ✅   | ✅   | ✅   |
+
+## Documentation
+
 Documentation can be found at <https://hexdocs.pm/dns_srv_cluster>.

lib/dns_srv_cluster/app.ex

@@ -56,11 +56,10 @@ defmodule DNSSRVCluster.App do
 
     case query do
       {:ok, query} ->
-        child_spec =
-          [
-            {DNSSRVCluster.Worker,
-             query: query, interval: interval(), connect_timeout: connect_timeout(), resolver: resolver()}
-          ]
+        child_spec = [
+          {DNSSRVCluster.Worker,
+           query: query, interval: interval(), connect_timeout: connect_timeout(), resolver: resolver()}
+        ]
 
         opts = [strategy: :one_for_one, name: DNSSRVCluster.Supervisor]
         Supervisor.start_link(child_spec, opts)

lib/dns_srv_cluster/resolver.ex

@@ -1,5 +1,9 @@
 defmodule DNSSRVCluster.Resolver do
   @moduledoc false
+  require Logger
+  require Record
+
+  Record.defrecord(:hostent, Record.extract(:hostent, from_lib: "kernel/include/inet.hrl"))
 
   # Public
 
@@ -20,11 +24,16 @@ defmodule DNSSRVCluster.Resolver do
   def list_connected_nodes, do: Node.list(:visible)
 
   def lookup(query, type) when is_binary(query) and type in [:srv] do
-    :inet_res.lookup(~c"#{query}", :in, type)
+    case :inet_res.getbyname(~c"#{query}", type) do
+      {:ok, hostent(h_addr_list: addr_list)} ->
+        addr_list
+
+      {:error, _} ->
+        Logger.warning(~s(inet_res.getbyname for query "#{query}" with type "#{type}"failed.))
+        []
+    end
   end
 
   @spec my_node() :: atom()
-  def my_node do
-    node()
-  end
+  def my_node, do: node()
 end

lib/dns_srv_cluster/worker.ex

@@ -96,20 +96,24 @@
     schedule_next_poll(state)
   end
 
+  # credo:disable-for-next-line
   defp warn_on_invalid_dist do
     release? = is_binary(System.get_env("RELEASE_NAME"))
-    %{started: started} = net_state = :net_kernel.get_state()
+    net_state = if function_exported?(:net_kernel, :get_state, 0), do: :net_kernel.get_state()
 
     cond do
-      started == :no and release? ->
+      !net_state ->
+        :ok
+
+      net_state.started == :no and release? ->
         Logger.warning("""
         Node not running in distributed mode. Ensure the following exports are set in your rel/env.sh.eex file:
 
             export RELEASE_DISTRIBUTION="${RELEASE_DISTRIBUTION:-"name"}"
             export RELEASE_NODE="${RELEASE_NODE:-"<%= @release.name %>"}"
         """)
 
-      started == :no or (!release? and started != :no and net_state[:name_domain] != :longnames) ->
+      net_state.started == :no or (!release? and net_state.started != :no and net_state[:name_domain] != :longnames) ->
         Logger.warning("""
         Node not running in distributed mode. When running outside of a release, you must start net_kernel manually with
         longnames.

mix.exs

@@ -6,10 +6,13 @@ defmodule DNSSRVCluster.MixProject do
   @maintainer "Dmitriy Pertsev"
 
   def project do
+    elixir_version = System.version()
+    styler_compat = Version.compare(elixir_version, "1.14.0")
+
     [
       app: :dns_srv_cluster,
       version: @version,
-      elixir: "~> 1.15",
+      elixir: "~> 1.12",
       start_permanent: Mix.env() == :prod,
       package: package(),
       aliases: aliases(),
@@ -21,7 +24,7 @@ defmodule DNSSRVCluster.MixProject do
         "coveralls.html": :test
       ],
       docs: docs(),
-      deps: deps(),
+      deps: deps(styler_compat),
       source_url: @scm_url,
       homepage_url: @scm_url,
       description: "Elixir clustering with DNS SRV records"
@@ -46,12 +49,20 @@ defmodule DNSSRVCluster.MixProject do
   end
 
   # Run "mix help deps" to learn about dependencies.
-  defp deps do
+  defp deps(styler_compat) when styler_compat in [:gt, :eq] do
     [
+      {:credo, "~> 1.7", only: [:dev, :test], runtime: false},
       {:excoveralls, "~> 0.10", only: :test, runtime: false},
       {:ex_doc, "~> 0.30", only: :dev, runtime: false},
+      {:styler, "~> 0.11", only: [:dev, :test], runtime: false}
+    ]
+  end
+
+  defp deps(_) do
+    [
       {:credo, "~> 1.7", only: [:dev, :test], runtime: false},
-      {:styler, "~> 0.9", only: [:dev, :test], runtime: false}
+      {:excoveralls, "~> 0.10", only: :test, runtime: false},
+      {:ex_doc, "~> 0.30", only: :dev, runtime: false}
     ]
   end