build: add nix flake

Signed-off-by: Mark Sagi-Kazar <mark.sagikazar@gmail.com>

flake.lock

@@ -0,0 +1,42 @@
+{
+  "nodes": {
+    "flake-utils": {
+      "locked": {
+        "lastModified": 1634851050,
+        "narHash": "sha256-N83GlSGPJJdcqhUxSCS/WwW5pksYf3VP1M13cDRTSVA=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "c91f3de5adaf1de973b797ef7485e441a65b8935",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1636800699,
+        "narHash": "sha256-SwbyVxXffu3G2ulJIbTf0iQfqhbGbdml4Dyv5j9BiAI=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "2fa862644fc15ecb525eb8cd0a60276f1c340c7c",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "ref": "nixos-unstable",
+        "type": "indirect"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,24 @@
+{
+  description = "OpenID Connect (OIDC) identity and OAuth 2.0 provider with pluggable connectors";
+
+  inputs = {
+    nixpkgs.url = "nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, flake-utils, ... }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+        buildDeps = with pkgs; [ git go_1_17 gnumake ];
+        devDeps = with pkgs;
+          buildDeps ++ [
+            golangci-lint
+            gotestsum
+            protobuf
+            protoc-gen-go
+            protoc-gen-go-grpc
+          ];
+      in
+      { devShell = pkgs.mkShell { buildInputs = devDeps; }; });
+}