handlerNodes.go

/* ****************************************************************************
 * Copyright 2020 51 Degrees Mobile Experts Limited (51degrees.com)
 *
 * 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 swift

import (
	"encoding/json"
	"net/http"
	"time"
)

// NodeView is a struct containing the node fields to display in the nodes
// swiftNodesTemplate
type NodeView struct {
	Network  string    // The name of the network the node belongs to
	Domain   string    // The domain name associated with the node
	Created  time.Time // The time that the node first came online
	Starts   time.Time // The time that the node will begin operation
	Expires  time.Time // The time that the node will retire from the network
	Role     int       // The role the node has in the network
	Accessed time.Time // The time the node was last accessed
	Alive    bool      // True if the node is reachable via a HTTP request
}

// NodeViews is a struct which contains an array of NodeView which is used
// to display a list of nodes using the swiftNodesTemplate
type NodeViews struct {
	Nodes []NodeView
}

// Get the NodeView
func (nv *NodeViews) NodeViewItems() []NodeView {
	return nv.Nodes
}

// HandlerNodes is a handler that returns a list of all the known nodes, each
// node is converted into a NodeView item which is then used to populate an HTML
// template.
func HandlerNodes(s *Services) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		nvs, err := getNodesView(s)
		if err != nil {
			returnAPIError(s, w, err, http.StatusInternalServerError)
		}
		sendHTMLTemplate(s, w, swiftNodesTemplate, &nvs)
	}
}

// HandlerNodesJSON is a handler that returns a list of all the alive nodes
// which is then used to serialize to JSON.
func HandlerNodesJSON(s *Services) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		j, err := getJSON(s)
		if err != nil {
			returnAPIError(s, w, err, http.StatusInternalServerError)
			return
		}
		sendResponse(s, w, "application/json", j)
	}
}

func getJSON(s *Services) ([]byte, error) {

	// Get all the nodes.
	ns, err := s.store.getAllNodes()
	if err != nil {
		return nil, err
	}

	// Turn them into a map.
	nis := make(map[string]*node)
	for _, n := range ns {
		if n.alive {
			nis[n.domain] = n
		}
	}

	// Turn the map into a JSON string.
	j, err := json.Marshal(nis)
	if err != nil {
		return nil, err
	}

	return j, nil
}

func getNodesView(s *Services) (*NodeViews, error) {
	var nvs NodeViews
	ns, err := s.store.getAllNodes()
	if err != nil {
		return nil, err
	}
	for _, n := range ns {
		nv := NodeView{
			Network:  n.network,
			Domain:   n.domain,
			Created:  n.created,
			Starts:   n.starts,
			Expires:  n.expires,
			Role:     n.role,
			Accessed: n.accessed,
			Alive:    n.alive,
		}
		nvs.Nodes = append(nvs.Nodes, nv)
	}
	return &nvs, nil
}