mongodb-migrator
v0.9.0
Published
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mongodb-migrator
Table of Contents
Installation
$ npm install -g mongodb-migrator
CLI usage
The package installs a single CLI executable — mdbmigrator
.
When installing locally to your project this executable can be found at
./node_modules/.bin/mdbmigrator
.
When installing globally the executable should automatically become accessible on your PATH.
Configuration
The configuration can be passed as a file (js or json):
// myconfig.json
{
"mongourl": "mongodb://localhost:27017/migrations",
"host": "localhost",
"port": 27017,
"db": "migrations",
"user": "username",
"password": "secret_password",
"collection": "migrations_track",
"directory": "migrations"
}
mdbmigrator --config myconfig.json create mynewmigration
or cli arguments:
mdbmigrator --host 127.0.0.1 --port 27017 --db migrations create newmigrationname
Creating Migrations
The app simplifies creating migration stubs by providing a command
$ mdbmigrator create 'migration name'
This creates file migration-name.js
inside of the directory
defined in the configuration file.
Sample migration file
module.exports = {
name: 'migration name',
after: null
up: function (db, cb) {
cb();
},
down: function (db, cb) {
cb();
}
}
Where
migration name
— a unique name for migration.up
— a function used for forward migration.down
— a function used for backward migration.
Migration functions
The up
and down
functions take for two parameters db
- mongodb connection and callback cb
up: function(db, cb) {
db.collection('users').insertOne({name:"firstadmin",pass:"very_secure_password"}, function (err, result) {
if(err) return cb(err);
console.log("all done");
cb();
});
}
Running migrations
Applying all new migrations from the directory
(specified in
Configuration) by calling
$ mdbmigrator apply
Rollbacks are automatically called in the reverse order when an error occurs.
The library only runs migrations that:
- have
up
function defined, - were not ran before against this database.
- were rollback at any moment
Successfully applied migrations are recorded in the collection
specified in Configuration and successfully
canceled migrations remove the record from the collection
.
The migration process is stopped instantly if some migration fails (returns error in its callback), then beginning roll back process.
Check for new migrations
$ mdbmigrator check
Programmatic usage
The library also supports programmatic usage.
Start with require
'ing it:
var MongoMigrator = require('mongodb-migrator');
var migrator = new MongoMigrator(options);
Using migrator
Next, you can use migrator instance as was described before:
// Load all migrations
var migrationsArray = migrator.loadMigrations();
// Check for circularity's and count new migrations
migrator.check();
// Apply new migrations
migrator.apply();