Add a list api for instances

curl -X GET /v1/instance
returns all the instances created.
It returns abbreviated instances for improved readability.
For details on what resources were created
for each instance, use the ID with GET.

Issue-ID: MULTICLOUD-715
Change-Id: I05afe0fd2c254acbca4329289c81545f95c9fac5
Signed-off-by: Kiran Kamineni <kiran.k.kamineni@intel.com>

4 files changed, 177 insertions, 2 deletions

diff --git a/src/k8splugin/api/api.go b/src/k8splugin/api/api.go
index 353972a1..1bbe14a3 100644
--- a/src/k8splugin/api/api.go
+++ b/src/k8splugin/api/api.go
@@ -38,6 +38,7 @@ func NewRouter(defClient rb.DefinitionManager,
 	instHandler := instanceHandler{client: instClient}
 	instRouter := router.PathPrefix("/v1").Subrouter()
 	instRouter.HandleFunc("/instance", instHandler.createHandler).Methods("POST")
+	instRouter.HandleFunc("/instance", instHandler.listHandler).Methods("GET")
 	instRouter.HandleFunc("/instance/{instID}", instHandler.getHandler).Methods("GET")
 	instRouter.HandleFunc("/instance/{instID}", instHandler.deleteHandler).Methods("DELETE")
 	// (TODO): Fix update method
diff --git a/src/k8splugin/api/instancehandler.go b/src/k8splugin/api/instancehandler.go
index 42f3b212..3ec055bc 100644
--- a/src/k8splugin/api/instancehandler.go
+++ b/src/k8splugin/api/instancehandler.go
@@ -106,6 +106,24 @@ func (i instanceHandler) getHandler(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
+// getHandler retrieves information about an instance via the ID
+func (i instanceHandler) listHandler(w http.ResponseWriter, r *http.Request) {
+
+	resp, err := i.client.List()
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	err = json.NewEncoder(w).Encode(resp)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+}
+
 // deleteHandler method terminates an instance via the ID
 func (i instanceHandler) deleteHandler(w http.ResponseWriter, r *http.Request) {
 	vars := mux.Vars(r)
diff --git a/src/k8splugin/api/instancehandler_test.go b/src/k8splugin/api/instancehandler_test.go
index 35cef531..83fa3d2b 100644
--- a/src/k8splugin/api/instancehandler_test.go
+++ b/src/k8splugin/api/instancehandler_test.go
@@ -21,6 +21,7 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"reflect"
+	"sort"
 	"testing"
 
 	"github.com/onap/multicloud-k8s/src/k8splugin/internal/app"
@@ -38,8 +39,9 @@ type mockInstanceClient struct {
 	app.InstanceManager
 	// Items and err will be used to customize each test
 	// via a localized instantiation of mockInstanceClient
-	items []app.InstanceResponse
-	err   error
+	items     []app.InstanceResponse
+	miniitems []app.InstanceMiniResponse
+	err       error
 }
 
 func (m *mockInstanceClient) Create(inp app.InstanceRequest) (app.InstanceResponse, error) {
@@ -58,6 +60,14 @@ func (m *mockInstanceClient) Get(id string) (app.InstanceResponse, error) {
 	return m.items[0], nil
 }
 
+func (m *mockInstanceClient) List() ([]app.InstanceMiniResponse, error) {
+	if m.err != nil {
+		return []app.InstanceMiniResponse{}, m.err
+	}
+
+	return m.miniitems, nil
+}
+
 func (m *mockInstanceClient) Find(rbName string, ver string, profile string, labelKeys map[string]string) ([]app.InstanceResponse, error) {
 	if m.err != nil {
 		return nil, m.err
@@ -297,6 +307,110 @@ func TestInstanceGetHandler(t *testing.T) {
 	}
 }
 
+func TestInstanceListHandler(t *testing.T) {
+	testCases := []struct {
+		label            string
+		input            string
+		expectedCode     int
+		expectedResponse []app.InstanceMiniResponse
+		instClient       *mockInstanceClient
+	}{
+		{
+			label:        "Fail to List Instance",
+			input:        "HaKpys8e",
+			expectedCode: http.StatusInternalServerError,
+			instClient: &mockInstanceClient{
+				err: pkgerrors.New("Internal error"),
+			},
+		},
+		{
+			label:        "Succesful List Instances",
+			expectedCode: http.StatusOK,
+			expectedResponse: []app.InstanceMiniResponse{
+				{
+					ID: "HaKpys8e",
+					Request: app.InstanceRequest{
+						RBName:      "test-rbdef",
+						RBVersion:   "v1",
+						ProfileName: "profile1",
+						CloudRegion: "region1",
+					},
+					Namespace: "testnamespace",
+				},
+				{
+					ID: "HaKpys8f",
+					Request: app.InstanceRequest{
+						RBName:      "test-rbdef-two",
+						RBVersion:   "versionsomething",
+						ProfileName: "profile3",
+						CloudRegion: "region1",
+					},
+					Namespace: "testnamespace-two",
+				},
+			},
+			instClient: &mockInstanceClient{
+				miniitems: []app.InstanceMiniResponse{
+					{
+						ID: "HaKpys8e",
+						Request: app.InstanceRequest{
+							RBName:      "test-rbdef",
+							RBVersion:   "v1",
+							ProfileName: "profile1",
+							CloudRegion: "region1",
+						},
+						Namespace: "testnamespace",
+					},
+					{
+						ID: "HaKpys8f",
+						Request: app.InstanceRequest{
+							RBName:      "test-rbdef-two",
+							RBVersion:   "versionsomething",
+							ProfileName: "profile3",
+							CloudRegion: "region1",
+						},
+						Namespace: "testnamespace-two",
+					},
+				},
+			},
+		},
+	}
+
+	for _, testCase := range testCases {
+		t.Run(testCase.label, func(t *testing.T) {
+			request := httptest.NewRequest("GET", "/v1/instance", nil)
+			resp := executeRequest(request, NewRouter(nil, nil, testCase.instClient, nil, nil, nil))
+
+			if testCase.expectedCode != resp.StatusCode {
+				t.Fatalf("Request method returned: %v and it was expected: %v",
+					resp.StatusCode, testCase.expectedCode)
+			}
+			if resp.StatusCode == http.StatusOK {
+				var response []app.InstanceMiniResponse
+				err := json.NewDecoder(resp.Body).Decode(&response)
+				if err != nil {
+					t.Fatalf("Parsing the returned response got an error (%s)", err)
+				}
+
+				// Since the order of returned slice is not guaranteed
+				// Sort them first and then do deepequal
+				// Check both and return error if both don't match
+				sort.Slice(response, func(i, j int) bool {
+					return response[i].ID < response[j].ID
+				})
+
+				sort.Slice(testCase.expectedResponse, func(i, j int) bool {
+					return testCase.expectedResponse[i].ID < testCase.expectedResponse[j].ID
+				})
+
+				if reflect.DeepEqual(testCase.expectedResponse, response) == false {
+					t.Fatalf("TestGetHandler returned:\n result=%v\n expected=%v",
+						&response, testCase.expectedResponse)
+				}
+			}
+		})
+	}
+}
+
 func TestDeleteHandler(t *testing.T) {
 	testCases := []struct {
 		label        string
diff --git a/src/k8splugin/internal/app/instance.go b/src/k8splugin/internal/app/instance.go
index 5272d60f..d28fe799 100644
--- a/src/k8splugin/internal/app/instance.go
+++ b/src/k8splugin/internal/app/instance.go
@@ -19,6 +19,7 @@ package app
 import (
 	"encoding/base64"
 	"encoding/json"
+	"log"
 	"math/rand"
 
 	"github.com/onap/multicloud-k8s/src/k8splugin/internal/db"
@@ -46,10 +47,20 @@ type InstanceResponse struct {
 	Resources []helm.KubernetesResource `json:"resources"`
 }
 
+// InstanceMiniResponse contains the response from instantiation
+// It does NOT include the created resources.
+// Use the regular GET to get the created resources for a particular instance
+type InstanceMiniResponse struct {
+	ID        string          `json:"id"`
+	Request   InstanceRequest `json:"request"`
+	Namespace string          `json:"namespace"`
+}
+
 // InstanceManager is an interface exposes the instantiation functionality
 type InstanceManager interface {
 	Create(i InstanceRequest) (InstanceResponse, error)
 	Get(id string) (InstanceResponse, error)
+	List() ([]InstanceMiniResponse, error)
 	Find(rbName string, ver string, profile string, labelKeys map[string]string) ([]InstanceResponse, error)
 	Delete(id string) error
 }
@@ -171,6 +182,37 @@ func (v *InstanceClient) Get(id string) (InstanceResponse, error) {
 	return InstanceResponse{}, pkgerrors.New("Error getting Instance")
 }
 
+// List returns the instance for corresponding ID
+// Empty string returns all
+func (v *InstanceClient) List() ([]InstanceMiniResponse, error) {
+
+	dbres, err := db.DBconn.ReadAll(v.storeName, v.tagInst)
+	if err != nil || len(dbres) == 0 {
+		return []InstanceMiniResponse{}, pkgerrors.Wrap(err, "Listing Instances")
+	}
+
+	var results []InstanceMiniResponse
+	for key, value := range dbres {
+		//value is a byte array
+		if value != nil {
+			resp := InstanceResponse{}
+			err = db.DBconn.Unmarshal(value, &resp)
+			if err != nil {
+				log.Printf("[Instance] Error: %s Unmarshaling Instance: %s", err.Error(), key)
+			}
+
+			miniresp := InstanceMiniResponse{
+				ID:        resp.ID,
+				Request:   resp.Request,
+				Namespace: resp.Namespace,
+			}
+			results = append(results, miniresp)
+		}
+	}
+
+	return results, nil
+}
+
 // Find returns the instances that match the given criteria
 // If version is empty, it will return all instances for a given rbName
 // If profile is empty, it will return all instances for a given rbName+version