kubernetes-helmPlugins.helm-git: init at 0.10.0

This is necessary for running `helm` with a helmfile.yaml containing
git+https URLs.

pkgs/applications/networking/cluster/helm/plugins/default.nix

@@ -2,10 +2,12 @@
 
 {
 
-  helm-diff = callPackage ./helm-diff.nix {};
+  helm-diff = callPackage ./helm-diff.nix { };
 
-  helm-s3 = callPackage ./helm-s3.nix {};
+  helm-git = callPackage ./helm-git.nix { };
 
-  helm-secrets = callPackage ./helm-secrets.nix {};
+  helm-s3 = callPackage ./helm-s3.nix { };
+
+  helm-secrets = callPackage ./helm-secrets.nix { };
 
 }

pkgs/applications/networking/cluster/helm/plugins/helm-git.nix

@@ -0,0 +1,46 @@
+{ lib
+, stdenv
+, fetchFromGitHub
+, coreutils
+, findutils
+, git
+, gnugrep
+, gnused
+, makeWrapper
+}:
+
+stdenv.mkDerivation rec {
+  pname = "helm-git";
+  version = "0.10.0";
+
+  src = fetchFromGitHub {
+    owner = "aslafy-z";
+    repo = pname;
+    rev = "v${version}";
+    sha256 = "0hvycqibmlw2zw3nm8rn73v5x1zcgm2jrfdlljbvc1n4n5vnzdrg";
+  };
+
+  nativeBuildInputs = [ makeWrapper ];
+
+  # NOTE: helm-git is comprised of shell scripts.
+  dontBuild = true;
+
+  installPhase = ''
+    install -dm755 $out/${pname}
+    install -m644 -Dt $out/${pname} plugin.yaml
+    cp helm-git helm-git-plugin.sh $out/${pname}/
+
+    patchShebangs $out/${pname}/helm-git{,-plugin.sh}
+    wrapProgram $out/${pname}/helm-git \
+        --prefix PATH : ${lib.makeBinPath [ coreutils findutils git gnugrep gnused ]}
+
+    runHook postInstall
+  '';
+
+  meta = with lib; {
+    description = "The Helm downloader plugin that provides GIT protocol support";
+    inherit (src.meta) homepage;
+    license = licenses.mit;
+    maintainers = with maintainers; [ flokli ];
+  };
+}