add sourcehut integration test

flake.nix

@@ -501,6 +501,12 @@
           inherit (self) overlay;
         });
 
+        tests.sourcehutFlakes = (import ./tests/sourcehut-flakes.nix rec {
+          system = "x86_64-linux";
+          inherit nixpkgs;
+          inherit (self) overlay;
+        });
+
         tests.setuid = nixpkgs.lib.genAttrs
           ["i686-linux" "x86_64-linux"]
           (system:

tests/sourcehut-flakes.nix

@@ -0,0 +1,156 @@
+{ nixpkgs, system, overlay }:
+
+with import (nixpkgs + "/nixos/lib/testing-python.nix")
+{
+  inherit system;
+  extraConfigurations = [{ nixpkgs.overlays = [ overlay ]; }];
+};
+
+let
+  # Generate a fake root CA and a fake git.sr.ht certificate.
+  cert = pkgs.runCommand "cert" { buildInputs = [ pkgs.openssl ]; }
+    ''
+      mkdir -p $out
+
+      openssl genrsa -out ca.key 2048
+      openssl req -new -x509 -days 36500 -key ca.key \
+        -subj "/C=NL/ST=Denial/L=Springfield/O=Dis/CN=Root CA" -out $out/ca.crt
+
+      openssl req -newkey rsa:2048 -nodes -keyout $out/server.key \
+        -subj "/C=CN/ST=Denial/L=Springfield/O=Dis/CN=git.sr.ht" -out server.csr
+      openssl x509 -req -extfile <(printf "subjectAltName=DNS:git.sr.ht") \
+        -days 36500 -in server.csr -CA $out/ca.crt -CAkey ca.key -CAcreateserial -out $out/server.crt
+    '';
+
+  registry = pkgs.writeTextFile {
+    name = "registry";
+    text = ''
+      {
+        "flakes": [
+          {
+            "from": {
+              "type": "indirect",
+              "id": "nixpkgs"
+            },
+            "to": {
+              "type": "sourcehut",
+              "owner": "~NixOS",
+              "repo": "nixpkgs"
+            }
+          }
+        ],
+        "version": 2
+      }
+    '';
+    destination = "/flake-registry.json";
+  };
+
+  nixpkgs-repo = pkgs.runCommand "nixpkgs-flake" { }
+    ''
+      dir=NixOS-nixpkgs-${nixpkgs.shortRev}
+      cp -prd ${nixpkgs} $dir
+
+      # Set the correct timestamp in the tarball.
+      find $dir -print0 | xargs -0 touch -t ${builtins.substring 0 12 nixpkgs.lastModifiedDate}.${builtins.substring 12 2 nixpkgs.lastModifiedDate} --
+
+      mkdir -p $out/archive
+      tar cfz $out/archive/${nixpkgs.rev}.tar.gz $dir --hard-dereference
+
+      echo 'ref: refs/heads/master' > $out/HEAD
+
+      mkdir -p $out/info
+      echo '${nixpkgs.rev} refs/heads/master' > $out/info/refs
+    '';
+
+in
+
+makeTest (
+
+  {
+    name = "sourcehut-flakes";
+
+    nodes =
+      {
+        # Impersonate git.sr.ht
+        sourcehut =
+          { config, pkgs, ... }:
+          {
+            networking.firewall.allowedTCPPorts = [ 80 443 ];
+
+            services.httpd.enable = true;
+            services.httpd.adminAddr = "foo@example.org";
+            services.httpd.extraConfig = ''
+              ErrorLog syslog:local6
+            '';
+            services.httpd.virtualHosts."git.sr.ht" =
+              {
+                forceSSL = true;
+                sslServerKey = "${cert}/server.key";
+                sslServerCert = "${cert}/server.crt";
+                servedDirs =
+                  [
+                    {
+                      urlPath = "/~NixOS/nixpkgs";
+                      dir = nixpkgs-repo;
+                    }
+                    {
+                      urlPath = "/~NixOS/flake-registry/blob/master";
+                      dir = registry;
+                    }
+                  ];
+              };
+          };
+
+        client =
+          { config, lib, pkgs, nodes, ... }:
+          {
+            virtualisation.writableStore = true;
+            virtualisation.diskSize = 2048;
+            virtualisation.pathsInNixDB = [ pkgs.hello pkgs.fuse ];
+            virtualisation.memorySize = 4096;
+            nix.binaryCaches = lib.mkForce [ ];
+            nix.extraOptions = ''
+              experimental-features = nix-command flakes
+              flake-registry = https://git.sr.ht/~NixOS/flake-registry/blob/master/flake-registry.json
+            '';
+            environment.systemPackages = [ pkgs.jq ];
+            networking.hosts.${(builtins.head nodes.sourcehut.config.networking.interfaces.eth1.ipv4.addresses).address} =
+              [ "git.sr.ht" ];
+            security.pki.certificateFiles = [ "${cert}/ca.crt" ];
+          };
+      };
+
+    testScript = { nodes }: ''
+      # fmt: off
+      import json
+      import time
+
+      start_all()
+
+      sourcehut.wait_for_unit("httpd.service")
+
+      client.succeed("curl -v https://git.sr.ht/ >&2")
+      client.succeed("nix registry list | grep nixpkgs")
+
+      rev = client.succeed("nix flake info nixpkgs --json | jq -r .revision")
+      assert rev.strip() == "${nixpkgs.rev}", "revision mismatch"
+
+      client.succeed("nix registry pin nixpkgs")
+
+      client.succeed("nix flake info nixpkgs --tarball-ttl 0 >&2")
+
+      # Shut down the web server. The flake should be cached on the client.
+      sourcehut.succeed("systemctl stop httpd.service")
+
+      info = json.loads(client.succeed("nix flake info nixpkgs --json"))
+      date = time.strftime("%Y%m%d%H%M%S", time.gmtime(info['lastModified']))
+      assert date == "${nixpkgs.lastModifiedDate}", "time mismatch"
+
+      client.succeed("nix build nixpkgs#hello")
+
+      # The build shouldn't fail even with --tarball-ttl 0 (the server
+      # being down should not be a fatal error).
+      client.succeed("nix build nixpkgs#fuse --tarball-ttl 0")
+    '';
+
+  })