Use Niv to pin nixpkgs releases

Before using Niv, we were following channels meaning we can not
reproduce CI jobs easily.

In this change, we use Niv to pin these dependencies. We are also
addding a tests/default.nix to be able to run these tests locally.

For instance, to run the test extern.nix on the nixpkgs-19.09 release:

    nix-build tests/default.nix -A extern.nixpkgs_19_09

Fixes #178

5 files changed, 68 insertions, 4 deletions

diff --git a/tests/clamav.nix b/tests/clamav.nix
index 955d1ac..62b8d7d 100644
--- a/tests/clamav.nix
+++ b/tests/clamav.nix
@@ -14,7 +14,9 @@
 #  You should have received a copy of the GNU General Public License
 #  along with this program. If not, see <http://www.gnu.org/licenses/>
 
-import <nixpkgs/nixos/tests/make-test.nix> {
+{ pkgs ? import <nixpkgs> {}}:
+
+import (pkgs.path + "/nixos/tests/make-test.nix") {
 
   nodes = {
     server = { config, pkgs, lib, ... }:
diff --git a/tests/default.nix b/tests/default.nix
new file mode 100644
index 0000000..7de029e
--- /dev/null
+++ b/tests/default.nix
@@ -0,0 +1,57 @@
+# Generate an attribute sets containing all tests for all releaeses
+# It looks like:
+# - extern.nixpkgs_19_09
+# - extern.nixpkgs_20.03
+# - extern.nixpkgs_unstable
+# - intern.nixpkgs_19_09
+# - intern.nixpkgs_20.03
+# - intern.nixpkgs_unstable
+
+# Modify pkgs to run the tests on non KVM machines
+{ noKVM ? false }: 
+
+with builtins;
+
+let
+  sources = import ../nix/sources.nix;
+
+  releases = listToAttrs (map genRelease releaseNames);
+
+  genRelease = name: {
+    name = name;
+    value = import sources."${name}" {};
+  };
+
+  genTest = testName: release:
+  let
+    pkgs = releases."${release}";
+    noKVMPkgs = p: if noKVM
+      then import ./lib/pkgs.nokvm.nix { pkgs = p; }
+      else p;
+    test = pkgs.callPackage (./. + "/${testName}.nix") { };
+  in {
+    "name"= builtins.replaceStrings ["." "-"] ["_" "_"] release;
+    "value"= test {
+      pkgs = (noKVMPkgs pkgs);
+    };
+  };
+
+  releaseNames = [
+    "nixpkgs-19.09"
+    "nixpkgs-20.03"
+    "nixpkgs-unstable"
+  ];
+
+  testNames = [
+    "intern"
+    "extern"
+    "clamav"
+  ];
+
+  # Generate an attribute set containing one test per releases
+  genTests = testName: {
+    name = testName;
+    value = listToAttrs (map (genTest testName) (builtins.attrNames releases));
+  };
+  
+in listToAttrs (map genTests testNames)
diff --git a/tests/extern.nix b/tests/extern.nix
index cde05d8..6a4f6e7 100644
--- a/tests/extern.nix
+++ b/tests/extern.nix
@@ -14,7 +14,9 @@
 #  You should have received a copy of the GNU General Public License
 #  along with this program. If not, see <http://www.gnu.org/licenses/>
 
-import <nixpkgs/nixos/tests/make-test.nix> {
+{ pkgs ? import <nixpkgs> {}}:
+
+import (pkgs.path + "/nixos/tests/make-test.nix") {
 
   nodes = {
     server = { config, pkgs, ... }:
diff --git a/tests/intern.nix b/tests/intern.nix
index 5abf379..62e03a8 100644
--- a/tests/intern.nix
+++ b/tests/intern.nix
@@ -14,7 +14,9 @@
 #  You should have received a copy of the GNU General Public License
 #  along with this program. If not, see <http://www.gnu.org/licenses/>
 
-import <nixpkgs/nixos/tests/make-test.nix> {
+{ pkgs ? import <nixpkgs> {}}:
+
+import (pkgs.path + "/nixos/tests/make-test.nix") {
 
   machine =
     { config, pkgs, ... }:
diff --git a/tests/lib/pkgs.nokvm.nix b/tests/lib/pkgs.nokvm.nix
index fa13fde..8832f08 100644
--- a/tests/lib/pkgs.nokvm.nix
+++ b/tests/lib/pkgs.nokvm.nix
@@ -1,5 +1,6 @@
+{ pkgs }:
+
 let
-    pkgs = (import <nixpkgs> { system = builtins.currentSystem; config = {}; });
     patchedMachinePM = pkgs.writeTextFile {
         name = "Machine.pm.patched-to-wait-longer-for-vm";
         text = builtins.replaceStrings ["alarm 600;"] ["alarm 1200;"] (builtins.readFile (<nixpkgs>+"/nixos/lib/test-driver/Machine.pm"));