Add initial Homebrew formula

Formula/gotk.rb

@@ -0,0 +1,49 @@
+class Gotk < Formula
+  desc "Experimental toolkit for assembling CD pipelines the GitOps way"
+  homepage "https://toolkit.fluxcd.io/"
+  url "https://github.com/fluxcd/toolkit.git",
+      tag: "0.0.24",
+      revision: "d6c6c88e6e08d0ab7fa89c69241f1b1ca5aa658b"
+  head "https://github.com/fluxcd/toolkit.git"
+  license "Apache-2.0"
+
+  depends_on "go" => :build
+  depends_on "kubernetes-cli"
+
+  bottle :unneeded
+
+  def install
+    if build.stable?
+      bin.install "gotk"
+    else
+      ENV["CGO_ENABLED"] = "0"
+      cd buildpath/"cmd/gotk" do
+        system "go", "build", "-ldflags", "-s -w -X main.VERSION=#{version}", "-trimpath", "-o", bin/"gotk"
+      end
+    end
+  end
+
+  on_linux do
+    stable do
+      url "https://github.com/fluxcd/toolkit/releases/download/v0.0.24/gotk_0.0.24_linux_amd64.tar.gz"
+      sha256 "05684cbb7fb51c4695e52006a06fd8abdece1c41baba27d0867a4d3416491bb2"
+    end
+  end
+
+  on_macos do
+    stable do
+      url "https://github.com/fluxcd/toolkit/releases/download/v0.0.24/gotk_0.0.24_darwin_amd64.tar.gz"
+      sha256 "fcd6e68062bf811da031020ea7bb8640986b6407b66aa755af45d913e18c075e"
+    end
+  end
+
+  test do
+    run_output = shell_output("#{bin}/gotk 2>&1")
+    assert_match "Command line utility for assembling Kubernetes CD pipelines the GitOps way.", run_output
+
+    version_output = shell_output("#{bin}/gotk --version 2>&1")
+    assert_match version.to_s, version_output
+
+    system "#{bin}/gotk", "install", "--export"
+  end
+end