From ecf531aeb4a6e98c07590bbb56290dc1361f5201 Mon Sep 17 00:00:00 2001
From: Jaka Hudoklin <jaka@gatehub.net>
Date: Mon, 25 Feb 2019 17:14:48 +0100
Subject: [PATCH] feat: implement k8s-submodules

---
 default.nix             |  1 +
 k8s/submodule.nix       | 52 ++++++++++++++++++++++++++++++++++
 tests/k8s/submodule.nix | 62 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 115 insertions(+)
 create mode 100644 k8s/submodule.nix
 create mode 100644 tests/k8s/submodule.nix

diff --git a/default.nix b/default.nix
index f635e4b..7ba1e46 100644
--- a/default.nix
+++ b/default.nix
@@ -26,6 +26,7 @@ let
     lib = lib';
     submodules = ./submodules.nix;
     k8s = ./k8s;
+    k8s-submodules = ./k8s/submodule.nix;
     istio = ./istio;
     testing = ./testing;
   };
diff --git a/k8s/submodule.nix b/k8s/submodule.nix
new file mode 100644
index 0000000..143682f
--- /dev/null
+++ b/k8s/submodule.nix
@@ -0,0 +1,52 @@
+{ config, lib, kubenix, ... }:
+
+with lib;
+
+let
+  globalConfig = config;
+in {
+  imports = [ kubenix.submodules ];
+
+  options = {
+    kubernetes.propagateDefaults = mkOption {
+      description = "Whehter to propagate child defaults to submodules";
+      type = types.bool;
+      default = true;
+    };
+
+    submodules.instances = mkOption {
+       type = types.attrsOf (types.submodule ({config, ...}: {
+        options = {
+          namespace = mkOption {
+            description = "Default kubernetes namespace";
+            type = types.str;
+            default = "default";
+          };
+        };
+
+        config.config = {
+          kubernetes.api.defaults.all.metadata.namespace =
+            mkDefault config.namespace;
+        };
+      }));
+    };
+  };
+
+  config = {
+    submodules.defaults = mkMerge [{
+      imports = [ kubenix.k8s ];
+      kubernetes.version = mkDefault config.kubernetes.version;
+      kubernetes.api.defaults =
+        mkIf config.kubernetes.propagateDefaults config.kubernetes.api.defaults;
+      } ({config, ...}: {
+        kubernetes.api.defaults.all.metadata.labels = {
+          "kubenix/module-name" = config.submodule.name;
+          "kubenix/module-version" = config.submodule.version;
+        };
+      })];
+
+    kubernetes.objects = mkMerge (mapAttrsToList (_: submodule:
+      submodule.config.kubernetes.objects
+    ) config.submodules.instances);
+  };
+}
diff --git a/tests/k8s/submodule.nix b/tests/k8s/submodule.nix
new file mode 100644
index 0000000..6fb68f4
--- /dev/null
+++ b/tests/k8s/submodule.nix
@@ -0,0 +1,62 @@
+{ name, config, lib, kubenix, images, ... }:
+
+with lib;
+
+let
+  cfg = config.submodules.instances.test.config;
+  deployment = cfg.kubernetes.api.deployments.nginx;
+  image = images.nginx;
+in {
+  imports = [
+    kubenix.k8s-submodules
+  ];
+
+  test = {
+    name = "k8s-submodules";
+    description = "Simple k8s submodule test";
+    assertions = [{
+      message = "Namespace not propagated";
+      assertion = deployment.metadata.namespace == "test";
+    } {
+      message = "Version not propagated";
+      assertion = cfg.kubernetes.version == config.kubernetes.version;
+    }];
+    testScript = ''
+      $kube->waitUntilSucceeds("docker load < ${image}");
+      $kube->waitUntilSucceeds("kubectl apply -f ${toYAML config.kubernetes.generated}");
+
+      $kube->succeed("kubectl get deployment -n test | grep -i test-nginx");
+      $kube->waitUntilSucceeds("kubectl get deployment -n test -o go-template test-nginx --template={{.status.readyReplicas}} | grep 1");
+    '';
+  };
+
+  submodules.imports = [{
+    module = {name, config, ...}: {
+      submodule.name = "nginx";
+      kubernetes.api.deployments.nginx = {
+        metadata = {
+          name = "${name}-nginx";
+          labels.app = name;
+        };
+        spec = {
+          replicas = 1;
+          selector.matchLabels.app = "nginx";
+          template.metadata.labels.app = "nginx";
+          template.spec = {
+            containers.nginx = {
+              image = "${image.imageName}:${image.imageTag}";
+              imagePullPolicy = "Never";
+            };
+          };
+        };
+      };
+    };
+  }];
+
+  kubernetes.api.namespaces.test = {};
+
+  submodules.instances.test = {
+    submodule = "nginx";
+    namespace = "test";
+  };
+}