switch from shell.nix to flake.nix

.envrc

@@ -1 +1 @@
-use_nix
+use_flake

flake.nix

@@ -0,0 +1,68 @@
+/*
+SPDX-FileCopyrightText: 2024 vasu1124
+
+SPDX-License-Identifier: Apache-2.0
+*/
+{
+  description = "Nix flake for introspect";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+  };
+
+  outputs = { self, nixpkgs, ... }:
+    let
+      pname = "introspect";
+
+      # System types to support.
+      supportedSystems = [ "x86_64-linux" "x86_64-darwin" "aarch64-linux" "aarch64-darwin" ];
+
+      # Helper function to generate an attrset '{ x86_64-linux = f "x86_64-linux"; ... }'.
+      forAllSystems = nixpkgs.lib.genAttrs supportedSystems;
+
+      # Nixpkgs instantiated for supported system types.
+      nixpkgsFor = forAllSystems (system: import nixpkgs { inherit system; });
+
+    in
+    {
+      # Add dependencies that are only needed for development
+      devShells = forAllSystems (system:
+        let 
+          pkgs = nixpkgsFor.${system};
+        in
+        {
+          default = pkgs.mkShell {
+            buildInputs = with pkgs; [ 
+              go_1_21   # golang 1.21
+              gopls     # go language server
+              gotools   # go imports
+              go-tools  # static checks
+              gnumake   # standard make
+
+              etcd
+              # mongodb-5_0
+              cfssl
+              istioctl
+              gettext
+              jq
+              fluxcd
+              kubernetes-helm
+              kustomize
+              krew
+              sops
+              minikube
+              kind
+              kubelogin-oidc
+              kubectx
+              tilt
+              kubebuilder
+              skaffold
+              delve
+              ctlptl
+              cue
+            ];
+          };
+        });
+
+    };
+}