feat(client): implemented ListInstances

internal/client/client.go

@@ -250,6 +250,64 @@ func (e *EdgeConnect) ShowAppInstance(ctx context.Context, appinstkey AppInstanc
 	return response.Data, nil
 }
 
+func (e *EdgeConnect) ShowAppInstances(ctx context.Context, appinstkey AppInstanceKey, region string) ([]AppInstance, error) {
+	token, err := e.RetrieveToken(ctx)
+	if err != nil {
+		return []AppInstance{}, err
+	}
+
+	input := struct {
+		App struct {
+			AppInstKey AppInstanceKey `json:"key"`
+		} `json:"appinst"`
+		Region string `json:"Region"`
+	}{
+		App: struct {
+			AppInstKey AppInstanceKey `json:"key"`
+		}{
+			AppInstKey: appinstkey,
+		},
+		Region: region,
+	}
+
+	json_data, err := json.Marshal(input)
+	if err != nil {
+		return []AppInstance{}, err
+	}
+
+	request, err := http.NewRequestWithContext(ctx, "POST", e.BaseURL+"/api/v1/auth/ctrl/ShowAppInst", bytes.NewBuffer(json_data))
+	if err != nil {
+		return []AppInstance{}, err
+	}
+	request.Header.Set("Content-Type", "application/json")
+	request.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token))
+
+	resp, err := e.HttpClient.Do(request)
+	if err != nil {
+		return []AppInstance{}, err
+	}
+
+	defer resp.Body.Close()
+	type response struct {
+		Data AppInstance `json:"data"`
+	}
+
+	appinstances := []AppInstance{}
+	decoder := json.NewDecoder(resp.Body)
+	for {
+		var d response
+		if err := decoder.Decode(&d); err != nil {
+			if err.Error() == "EOF" {
+				break
+			}
+			log.Fatal(err)
+		}
+		appinstances = append(appinstances, d.Data)
+	}
+
+	return appinstances, nil
+}
+
 func (e *EdgeConnect) RetrieveToken(ctx context.Context) (string, error) {
 	json_data, err := json.Marshal(map[string]string{
 		"username": e.Credentials.Username,