Use Nix flakes for local development and GitHub workflows

.envrc

@@ -0,0 +1 @@
+use flake

.github/actions/setup-nix/action.yml

@@ -0,0 +1,31 @@
+name: Setup Nix
+description: Install Nix, restore/save the Nix store cache, and run flake check.
+
+inputs:
+  github-token:
+    description: Token passed to install-nix-action for authenticated fetches.
+    required: true
+
+runs:
+  using: composite
+  steps:
+    - name: Install Nix
+      uses: cachix/install-nix-action@v31
+      with:
+        github_access_token: ${{ inputs.github-token }}
+
+    - name: Cache Nix store
+      uses: nix-community/cache-nix-action@v7
+      with:
+        primary-key: nix-${{ runner.os }}-${{ hashFiles('flake.nix', 'flake.lock') }}
+        restore-prefixes-first-match: nix-${{ runner.os }}-
+        # Cap store at ~5 GiB on save so cache fits under GHA's 10 GB repo budget
+        gc-max-store-size-linux: 5368709120
+        purge: true
+        purge-prefixes: nix-${{ runner.os }}-
+        purge-created: 0
+        purge-primary-key: never
+
+    - name: Nix flake check
+      shell: bash
+      run: nix flake check

.github/workflows/ci.yml

@@ -18,19 +18,16 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v7.0.0
 
-      - name: Install Go
-        uses: actions/setup-go@v6.5.0
-        with:
-          go-version-file: go.mod
-          cache: true
+      - name: Setup Nix
+        uses: ./.github/actions/setup-nix
 
       - name: Check for vulnerabilities
-        run: go run golang.org/x/vuln/cmd/govulncheck@latest ./...
+        run: nix develop --command govulncheck ./...
 
       - name: golangci-lint
         uses: golangci/golangci-lint-action@ba0d7d2ec06a0ea1cb5fa41b2e4a3ab91d21278a # v9.3.0
         with:
           version: v2.12.2
 
       - name: Build and Test
-        run: make
+        run: nix develop --command make

Makefile

@@ -21,17 +21,17 @@ bin/.generate: $(go_files) bin/.vendor
 
 fmt: bin/.generate $(go_files)
 	# Formatting files...
-	@go run golang.org/x/tools/cmd/goimports -w $(go_files)
+	@goimports -w $(go_files)
 
 bin/.vet: bin/.generate $(go_files)
 	go vet ./...
 	@touch bin/.vet
 
 bin/.fmtcheck: bin/.generate $(go_files)
 	# Checking format of Go files...
-	@GOIMPORTS=$$(go run golang.org/x/tools/cmd/goimports -l $(go_files)) && \
+	@GOIMPORTS=$$(goimports -l $(go_files)) && \
 	if [ "$$GOIMPORTS" != "" ]; then \
-		go run golang.org/x/tools/cmd/goimports -d $(go_files); \
+		goimports -d $(go_files); \
 		exit 1; \
 	fi
 	@touch bin/.fmtcheck

README.md

@@ -42,6 +42,22 @@ func main() {
 }
 ```
 
+## Development
+
+The repo ships a [Nix flake](flake.nix) that pins the toolchain (Go, `golangci-lint`, `gotools`, `govulncheck`, GNU `make`) so local development matches CI. Combined with [direnv](https://direnv.net/), your shell automatically enters that environment when you `cd` into the repo.
+
+### Setup
+
+1. Install Nix with flakes enabled — the [Determinate Nix Installer](https://determinate.systems/nix-installer/) is the easiest option; the [official Nix installer](https://nixos.org/download/) works too but requires [enabling flakes manually](https://nixos.wiki/wiki/Flakes#Enable_flakes_permanently_in_NixOS).
+2. Install [direnv](https://direnv.net/docs/installation.html) and hook it into your shell.
+3. Install [nix-direnv](https://github.com/nix-community/nix-direnv) so direnv can load the flake's dev shell.
+4. From the repo root, activate the environment:
+   ```shell
+   direnv allow
+   ```
+
+Every subsequent `cd` into the repo brings up a shell with the pinned toolchain on `PATH`. Run `make` to execute the same checks CI runs.
+
 ## Releasing
 
 Releases are published as Git tags of the form `vX.Y.Z`, so Go consumers pull a

flake.nix

@@ -0,0 +1,35 @@
+{
+  description = "Flake for Redis Cloud Go API";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs =
+    {
+      self,
+      nixpkgs,
+      flake-utils,
+    }:
+    flake-utils.lib.eachDefaultSystem (
+      system:
+      let
+        pkgs = import nixpkgs {
+          inherit system;
+        };
+      in
+      {
+        devShells.default = pkgs.mkShell {
+          buildInputs = [
+            pkgs.gnumake
+
+            pkgs.go_1_25
+            pkgs.golangci-lint
+            pkgs.gotools
+            pkgs.govulncheck
+          ];
+        };
+      }
+    );
+}