use redfox;
db.users.createIndex({ "username": 1 }, { unique: true });
db.users.insertMany([ { username: "root" }, { username: "sample" }, ])
db.users.find({})
docker run -d --name jaeger -p 16686:16686 -p 14268:14268 jaegertracing/all-in-one:1.6 http://localhost:16686