prometheus-operator: Add conversion tests

- This commit adds new conversion test to verify if the external_url
  works fine.

- This commit adds test cases in TestRenderManifest to verify if the
  prometheus external_url and prometheus ingress host matches.

Signed-off-by: Suraj Deshmukh <suraj@kinvolk.io>

pkg/components/internal/testutil/common.go

@@ -0,0 +1,61 @@
+// Copyright 2020 The Lokomotive Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package testutil
+
+import (
+	"testing"
+
+	"github.com/hashicorp/hcl/v2"
+
+	"github.com/kinvolk/lokomotive/pkg/components"
+	"github.com/kinvolk/lokomotive/pkg/components/util"
+)
+
+// ConfigFromMap takes a map and a key and returns the value associated with the key. If the key
+// does not exists in that map it fails.
+func ConfigFromMap(t *testing.T, m map[string]string, k string) string {
+	ret, ok := m[k]
+	if !ok {
+		t.Fatalf("Config not found with filename: %q", k)
+	}
+
+	return ret
+}
+
+// RenderManifests converts a component into YAML manifests.
+func RenderManifests(
+	t *testing.T, component components.Component, componentName string, hclConfig string,
+) map[string]string {
+	body, diagnostics := util.GetComponentBody(hclConfig, componentName)
+	if diagnostics.HasErrors() {
+		t.Fatalf("Getting component body: %v", diagnostics.Errs())
+	}
+
+	diagnostics = component.LoadConfig(body, &hcl.EvalContext{})
+	if diagnostics.HasErrors() {
+		t.Fatalf("Loading configuration: %v", diagnostics)
+	}
+
+	ret, err := component.RenderManifests()
+	if err != nil {
+		t.Fatalf("Rendering manifests: %v", err)
+	}
+
+	if len(ret) == 0 {
+		t.Fatalf("Rendered manifests shouldn't be empty")
+	}
+
+	return ret
+}

pkg/components/internal/testutil/doc.go

@@ -0,0 +1,16 @@
+// Copyright 2020 The Lokomotive Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package testutil contains helper functions for component unit tests.
+package testutil

pkg/components/internal/testutil/jsonpath.go

@@ -0,0 +1,91 @@
+// Copyright 2020 The Lokomotive Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package testutil
+
+import (
+	"reflect"
+	"testing"
+
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	yamlserializer "k8s.io/apimachinery/pkg/runtime/serializer/yaml"
+	"k8s.io/client-go/util/jsonpath"
+)
+
+// unstructredObj accepts a Kubernetes manifest in YAML format and returns an object of type
+// `unstructured.Unstructured`. This object has many methods that can be used by the consumer to
+// extract metadata from the Kubernetes manifest.
+func unstructredObj(t *testing.T, yamlObj string) *unstructured.Unstructured {
+	u := &unstructured.Unstructured{}
+
+	// Decode YAML into `unstructured.Unstructured`.
+	dec := yamlserializer.NewDecodingSerializer(unstructured.UnstructuredJSONScheme)
+	if _, _, err := dec.Decode([]byte(yamlObj), nil, u); err != nil {
+		t.Fatalf("Converting config to unstructured.Unstructured: %v", err)
+	}
+
+	return u
+}
+
+// valFromObject takes a JSON path as a string and an object of type `unstructured.Unstructured`.
+// This function returns an object of type `reflect.Value` at that JSON path.
+func valFromObject(t *testing.T, jp string, obj *unstructured.Unstructured) reflect.Value {
+	jPath := jsonpath.New("parse")
+	if err := jPath.Parse(jp); err != nil {
+		t.Fatalf("Parsing JSONPath: %v", err)
+	}
+
+	v, err := jPath.FindResults(obj.Object)
+	if err != nil {
+		t.Fatalf("Finding results using JSONPath in the YAML file: %v", err)
+	}
+
+	if len(v) == 0 || len(v[0]) == 0 {
+		t.Fatalf("No result found")
+	}
+
+	return v[0][0]
+}
+
+// jsonPathValue extracts an object at a JSON path from a YAML config, and returns an interface
+// object.
+func jsonPathValue(t *testing.T, yamlConfig string, jsonPath string) interface{} {
+	u := unstructredObj(t, yamlConfig)
+	got := valFromObject(t, jsonPath, u)
+
+	switch got.Kind() { //nolint:exhaustive
+	case reflect.Interface:
+		// TODO: Add type switch here for concrete types.
+		return got.Interface()
+	default:
+		t.Fatalf("Extracted object has an unknown type: %v", got.Kind())
+	}
+
+	return nil
+}
+
+// MatchJSONPathStringValue is a helper function for component unit tests. It compares the string at
+// a JSON path in a YAML config to the expected string.
+func MatchJSONPathStringValue(t *testing.T, yamlConfig string, jsonPath string, expected string) {
+	obj := jsonPathValue(t, yamlConfig, jsonPath)
+
+	got, ok := obj.(string)
+	if !ok {
+		t.Fatalf("Value is not string: %#v", obj)
+	}
+
+	if got != expected {
+		t.Fatalf("Expected: %s, Got: %s", expected, got)
+	}
+}

pkg/components/prometheus-operator/component_test.go

@@ -17,6 +17,7 @@ package prometheus
 import (
 	"testing"
 
+	"github.com/kinvolk/lokomotive/pkg/components/internal/testutil"
 	"github.com/kinvolk/lokomotive/pkg/components/util"
 )
 
@@ -62,6 +63,34 @@ component "prometheus-operator" {
 }`,
 			wantErr: true,
 		},
+		{
+			desc: "prometheus ingress and external_url given and are different",
+			hcl: `
+component "prometheus-operator" {
+  prometheus {
+	external_url = "https://prometheus.notmydomain.net"
+    ingress {
+      host = "prometheus.mydomain.net"
+    }
+  }
+}
+`,
+			wantErr: true,
+		},
+		{
+			desc: "prometheus ingress and external_url given and are same",
+			hcl: `
+component "prometheus-operator" {
+  prometheus {
+	external_url = "https://prometheus.mydomain.net"
+    ingress {
+      host = "prometheus.mydomain.net"
+    }
+  }
+}
+`,
+			wantErr: false,
+		},
 	}
 
 	for _, tc := range tests {
@@ -98,3 +127,75 @@ component "prometheus-operator" {
 		})
 	}
 }
+
+//nolint:funlen
+func TestConversion(t *testing.T) {
+	testCases := []struct {
+		name                 string
+		inputConfig          string
+		expectedManifestName string
+		expected             string
+		jsonPath             string
+	}{
+		{
+			name: "use external_url param",
+			inputConfig: `
+component "prometheus-operator" {
+  prometheus {
+    external_url = "https://prometheus.externalurl.net"
+  }
+}
+`,
+			expectedManifestName: "prometheus-operator/templates/prometheus/prometheus.yaml",
+			expected:             "https://prometheus.externalurl.net",
+			jsonPath:             "{.spec.externalUrl}",
+		},
+		{
+			name: "no external_url param",
+			inputConfig: `
+		component "prometheus-operator" {
+		  prometheus {
+		    ingress {
+		      host                       = "prometheus.mydomain.net"
+		      class                      = "contour"
+		      certmanager_cluster_issuer = "letsencrypt-production"
+		    }
+		  }
+		}
+		`,
+			expectedManifestName: "prometheus-operator/templates/prometheus/prometheus.yaml",
+			expected:             "https://prometheus.mydomain.net",
+			jsonPath:             "{.spec.externalUrl}",
+		},
+		{
+			name: "ingress creation for prometheus",
+			inputConfig: `
+		component "prometheus-operator" {
+		  prometheus {
+		    ingress {
+		      host                       = "prometheus.mydomain.net"
+		      class                      = "contour"
+		      certmanager_cluster_issuer = "letsencrypt-production"
+		    }
+		  }
+		}
+		`,
+			expectedManifestName: "prometheus-operator/templates/prometheus/ingress.yaml",
+			expected:             "prometheus.mydomain.net",
+			jsonPath:             "{.spec.rules[0].host}",
+		},
+	}
+
+	for _, tc := range testCases {
+		tc := tc
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			component := newComponent()
+			m := testutil.RenderManifests(t, component, name, tc.inputConfig)
+			gotConfig := testutil.ConfigFromMap(t, m, tc.expectedManifestName)
+
+			testutil.MatchJSONPathStringValue(t, gotConfig, tc.jsonPath, tc.expected)
+		})
+	}
+}

vendor/modules.txt

@@ -575,6 +575,7 @@ k8s.io/apimachinery/pkg/runtime/serializer/protobuf
 k8s.io/apimachinery/pkg/runtime/serializer/recognizer
 k8s.io/apimachinery/pkg/runtime/serializer/streaming
 k8s.io/apimachinery/pkg/runtime/serializer/versioning
+k8s.io/apimachinery/pkg/runtime/serializer/yaml
 k8s.io/apimachinery/pkg/selection
 k8s.io/apimachinery/pkg/types
 k8s.io/apimachinery/pkg/util/cache