nixos/griphite: Migrate to python3, drop graphite-pager

nixos/tests/graphite.nix

@@ -12,15 +12,19 @@ import ./make-test-python.nix ({ pkgs, ... } :
         virtualisation.memorySize = 1024;
         time.timeZone = "UTC";
         services.graphite = {
-          web.enable = true;
+          web = {
+            enable = true;
+            extraConfig = ''
+              SECRET_KEY = "abcd";
+            '';
+          };
           api = {
             enable = true;
             port = 8082;
-            finders = [ pkgs.python27Packages.influxgraph ];
+            finders = [ pkgs.python3Packages.influxgraph ];
           };
           carbon.enableCache = true;
-          seyren.enable = true;
-          pager.enable = true;
+          seyren.enable = false;  # Implicitely requires openssl-1.0.2u which is marked insecure
           beacon.enable = true;
         };
       };
@@ -31,16 +35,16 @@ import ./make-test-python.nix ({ pkgs, ... } :
     one.wait_for_unit("default.target")
     one.wait_for_unit("graphiteWeb.service")
     one.wait_for_unit("graphiteApi.service")
-    one.wait_for_unit("graphitePager.service")
     one.wait_for_unit("graphite-beacon.service")
     one.wait_for_unit("carbonCache.service")
-    one.wait_for_unit("seyren.service")
     # The services above are of type "simple". systemd considers them active immediately
     # even if they're still in preStart (which takes quite long for graphiteWeb).
     # Wait for ports to open so we're sure the services are up and listening.
     one.wait_for_open_port(8080)
     one.wait_for_open_port(2003)
     one.succeed('echo "foo 1 `date +%s`" | nc -N localhost 2003')
-    one.wait_until_succeeds("curl 'http://localhost:8080/metrics/find/?query=foo&format=treejson' --silent | grep foo >&2")
+    one.wait_until_succeeds(
+        "curl 'http://localhost:8080/metrics/find/?query=foo&format=treejson' --silent | grep foo >&2"
+    )
   '';
 })