How to use Loopback ACL modify permissions on the user role - node.js

Question

I am trying to understand the loopback acl but failed, if I can use loopback acl control role authorization, what should I do?
When I get request
GET http://localhost:1337/api/Employees 401 (Unauthorized)
{
"error": {
"name": "Error",
"status": 401,
"message": "Authorization Required",
"statusCode": 401,
"stack": "Error: Authorization Required
}
}
Here is an employee. The JSON configuration
{
"name": "Employee",
"base": "User",
"properties": {
"nickname": {
"type": "string"
}
},
"validations": [],
"relations": {},
"acls": [
{
"principalType": "ROLE",
"principalId": "admin",
"permission": "ALLOW",
"accessType": "READ"
}
],
"methods": []
}
The following code is to add an employee
{
"nickname": "",
"realm": "",
"username": "",
"credentials": "object",
"challenges": "object",
"email": "",
"emailVerified": false,
"verificationToken": "",
"status": "",
"created": "",
"lastUpdated": "",
"id": 0
}
I don't know the inside of the loopback acls. How do I go to change To achieve access control effect?

Answer 1

To support a custom role like admin, you need to define the role and add your users to the role. Here is some code I use for an internal project:
// Admin users
var adminUsers = require('../config/users.json').admins;
app.models.role.findOrCreate({where: {name: 'admin'}}, {name: 'admin'},
function (err, role) {
if (err) {
return console.error(err);
}
// role.principals() doesn't work here as the role.id might have a different
// type than roleMapping.roleId
app.models.roleMapping.find({where: {roleId: role.id.toString()}},
function (err, principals) {
if (err) {
return console.error(err);
}
var mapping = {};
principals.forEach(function (p) {
if (p.principalType === 'USER') {
mapping[p.principalId] = p;
}
});
app.models.user.find({where: {email: {inq: adminUsers}}},
function (err, users) {
if (err) {
return console.error(err);
}
if (users && users.length) {
users.forEach(function (user) {
if (mapping[user.id.toString()]) {
console.log('User %s (%s) found in role %s', user.username,
user.email, role.name);
return;
}
role.principals.create({principalType: 'USER', principalId: user.id},
function (err, mapping) {
if (err) {
return console.error(err);
}
console.log('User %s (%s) added to role %s', user.username,
user.email, role.name);
});
});
}
});
};
});