Add flake.nix

Signed-off-by: Oliver Davies <oliver@oliverdavies.uk>

go-api/.envrc

@@ -1 +1 @@
-use flake "git+https://code.oliverdavies.uk/opdavies/dev-shells#go"
+use flake

go-api/flake.lock

@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1758277210,
+        "narHash": "sha256-iCGWf/LTy+aY0zFu8q12lK8KuZp7yvdhStehhyX1v8w=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "8eaee110344796db060382e15d3af0a9fc396e0e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

go-api/flake.nix

@@ -0,0 +1,23 @@
+{
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+
+  outputs =
+    { nixpkgs, ... }:
+    let
+      system = "x86_64-linux";
+      pkgs = import nixpkgs { inherit system; };
+    in
+    {
+      devShells.${system}.default = pkgs.mkShell {
+        packages = with pkgs; [
+          curlMinimal
+          go
+          jq
+        ];
+
+        shellHook = ''
+          go version
+        '';
+      };
+    };
+}