From 2c59de8dcba6ec7ca386391cb139b06e40450bdd Mon Sep 17 00:00:00 2001
From: Tom <3460999-ridemybicycle@users.noreply.gitlab.com>
Date: Mon, 28 Jan 2019 14:21:51 +0000
Subject: [PATCH] README: include sha256 of the expected release tarball

Advantages of including the SHA256:
(i) removes the impurity of the tarball contents being changed
(ii) if sha256 is not included, then each nixops deploy triggers a re-download of the tarball

Here's how to get the expected hash:

$ nix-prefetch-url --unpack 'https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/archive/v2.2.0/nixos-mailserver-v2.2.0.tar.gz'
unpacking...
[0.0 MiB DL]
path is '/nix/store/dwg8xlfnlw7mhr4cjk1viwmm0b249b74-nixos-mailserver-v2.2.0.tar.gz'
0gqzgy50hgb5zmdjiffaqp277a68564vflfpjvk1gv6079zahksc
---
 README.md | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 7b79a34..f83215a 100644
--- a/README.md
+++ b/README.md
@@ -67,7 +67,10 @@ See the [mailing list archive](https://www.freelists.org/archive/snm/)
 { config, pkgs, ... }:
 {
   imports = [
-    (builtins.fetchTarball "https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/archive/v2.2.0/nixos-mailserver-v2.2.0.tar.gz")
+    (builtins.fetchTarball {
+      url = "https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/archive/v2.2.0/nixos-mailserver-v2.2.0.tar.gz";
+      sha256 = "0gqzgy50hgb5zmdjiffaqp277a68564vflfpjvk1gv6079zahksc";
+    })
   ];
 
   mailserver = {