Firabase Functions deploy had errors - firebase

Question

I'm trying to deploy my app to firebase but every time give me this issue but I don't know what is it need !?
this is my code in app.js
//construct
const functions = require("firebase-functions")
const express = require('express');
const app = express();
const path = require('path');
const bodyParser = require('body-parser');
const cors = require('cors');
const config = require('./config');
//const port = config.port;
//initialize
app.use(cors());
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true}));
app.use(express.static(path.join(__dirname,'../public')));
const books= require('./routes/books');
app.use('/books', books);
exports.app = functions.https.onRequest(app)
//start server code
// app.listen(port, ()=> {
// console.log('node serve has been started on port : '+port);
// })
functions: Finished running predeploy script. i functions: ensuring necessary APIs are enabled...
functions: all necessary APIs are enabled i functions: preparing functions directory for uploading... i functions: packaged functions
(57.1 KB) for uploading
functions: functions folder uploaded successfully i hosting[angular6test-1c758]: beginning deploy... i
hosting[angular6test-1c758]: found 68 files in public
hosting[angular6test-1c758]: file upload complete i functions: updating Node.js 6 function app(us-central1)... !
functions[app(us-central1)]: Deployment error. Build failed: exit
status 1
canvas#2.4.1 install /workspace/node_modules/canvas
node-pre-gyp install --fallback-to-build
node-pre-gyp WARN Using needle for node-pre-gyp https download
node-pre-gyp WARN Tried to download(404):
https://github.com/node-gfx/node-canvas-prebuilt/releases/download/v2.4.1/canvas-v2.4.1-node-v48-linux-glibc-x64.tar.gz
node-pre-gyp WARN Pre-built binaries not found for canvas#2.4.1 and
node#6.16.0 (node-v48 ABI, glibc) (falling back to source compile with
node-gyp) /bin/sh: 1: pkg-config: not found gyp: Call to 'pkg-config
pixman-1 --libs' returned exit status 127 while in binding.gyp. while
trying to load binding.gyp gyp ERR! configure error gyp ERR! stack
Error: gyp failed with exit code: 1 gyp ERR! stack at
ChildProcess.onCpExit
(/nodejs/lib/node_modules/npm/node_modules/node-gyp/lib/configure.js:305:16)
gyp ERR! stack at emitTwo (events.js:106:13) gyp ERR! stack at
ChildProcess.emit (events.js:191:7) gyp ERR! stack at
Process.ChildProcess._handle.onexit (internal/child_process.js:219:12)
gyp ERR! System Linux 4.15.0-1028-gcp gyp ERR! command
"/nodejs/bin/node"
"/nodejs/lib/node_modules/npm/node_modules/node-gyp/bin/node-gyp.js"
"configure" "--fallback-to-build"
"--module=/workspace/node_modules/canvas/build/Release/canvas.node"
"--module_name=canvas"
"--module_path=/workspace/node_modules/canvas/build/Release"
"--napi_version=3" "--node_abi_napi=napi" "--napi_build_version=0"
"--node_napi_label=node-v48" gyp ERR! cwd
/workspace/node_modules/canvas gyp ERR! node -v v6.16.0 gyp ERR!
node-gyp -v v3.4.0 gyp ERR! not ok node-pre-gyp ERR! build error
node-pre-gyp ERR! stack Error: Failed to execute '/nodejs/bin/node
/nodejs/lib/node_modules/npm/node_modules/node-gyp/bin/node-gyp.js
configure --fallback-to-build
--module=/workspace/node_modules/canvas/build/Release/canvas.node --module_name=canvas --module_path=/workspace/node_modules/canvas/build/Release --napi_version=3 --node_abi_napi=napi --napi_build_version=0 --node_napi_label=node-v48' (1) node-pre-gyp ERR! stack at ChildProcess.
(/workspace/node_modules/canvas/node_modules/node-pre-gyp/lib/util/compile.js:83:29)
node-pre-gyp ERR! stack at emitTwo (events.js:106:13) node-pre-gyp
ERR! stack at ChildProcess.emit (events.js:191:7) node-pre-gyp
ERR! stack at maybeClose (internal/child_process.js:920:16)
node-pre-gyp ERR! stack at Process.ChildProcess._handle.onexit
(internal/child_process.js:230:5) node-pre-gyp ERR! System Linux
4.15.0-1028-gcp node-pre-gyp ERR! command "/nodejs/bin/node" "/workspace/node_modules/canvas/node_modules/.bin/node-pre-gyp"
"install" "--fallback-to-build" node-pre-gyp ERR! cwd
/workspace/node_modules/canvas node-pre-gyp ERR! node -v v6.16.0
node-pre-gyp ERR! node-pre-gyp -v v0.11.0 node-pre-gyp ERR! not ok
Failed to execute '/nodejs/bin/node
/nodejs/lib/node_modules/npm/node_modules/node-gyp/bin/node-gyp.js
configure --fallback-to-build
--module=/workspace/node_modules/canvas/build/Release/canvas.node --module_name=canvas --module_path=/workspace/node_modules/canvas/build/Release --napi_version=3 --node_abi_napi=napi --napi_build_version=0 --node_napi_label=node-v48' (1) aa14#0.0.1 /workspace `-- merge-images#1.1.0
npm ERR! Linux 4.15.0-1028-gcp npm ERR! argv "/nodejs/bin/node"
"/nodejs/bin/npm" "--global-style" "--production" "--fetch-retries=5"
"--fetch-retry-factor=2" "--fetch-retry-mintimeout=1000" "install"
"/workspace" npm ERR! node v6.16.0 npm ERR! npm v3.10.10 npm ERR!
code ELIFECYCLE
npm ERR! canvas#2.4.1 install: node-pre-gyp install
--fallback-to-build npm ERR! Exit status 1 npm ERR! npm ERR! Failed at the canvas#2.4.1 install script 'node-pre-gyp install
--fallback-to-build'. npm ERR! Make sure you have the latest version of node.js and npm installed. npm ERR! If you do, this is most likely
a problem with the canvas package, npm ERR! not with npm itself. npm
ERR! Tell the author that this fails on your system: npm ERR!
node-pre-gyp install --fallback-to-build npm ERR! You can get
information on how to open an issue for this project with: npm ERR!
npm bugs canvas npm ERR! Or if that isn't available, you can get their
info via: npm ERR! npm owner ls canvas npm ERR! There is likely
additional logging output above.
npm ERR! Please include the following file with any support request:
npm ERR! /workspace/npm-debug.log
Functions deploy had errors with the following functions:
app
To try redeploying those functions, run:
firebase deploy --only functions:app
To continue deploying other features (such as database), run:
firebase deploy --except functions
Error: Functions did not deploy properly.
**
I Found the answer
**
firebase deploy using node 6 as default
add "engines": { "node": "8" } to upgrade the node