gpad / ms-practical-ws

ms-template

Microservice template

Just before to start, tart the docker-compose docker-compose up -d

Create the 2 databases (the ms_template_dev should be already present):

$ docker exec -it ms-template-db /bin/bash -c "createdb -U postgres ms_template_dev"
$ docker exec -it ms-template-db /bin/bash -c "createdb -U postgres ms_template_test"

Run Test

Run tests:

$ npm run test

You should see something like this:

> ms-template@1.0.0 test
> mocha test



> Migrating files:
> - 1636137304939_add-user-table
### MIGRATION 1636137304939_add-user-table (UP) ###
  GET /
Running in  test
No migrations to run!
    ✔ should return 200 OK

  status controller
    ✔ return 200 for /healthz
    ✔ return 200 and db stats
    ✔ return 200 and db rabbit info


  4 passing (303ms)

By default the logs are suppressed in test, but you can activate in this way:

SILENT_LOG=FALSE npm run test

Running locally

If you want to simply start the server you can:

$ npm run build && npm start

If you want to start the server in debug and watching mode:

$ npm run debug

How to generate a new migration

Suppose you have to create a migration to add a new field in a table you can execute this file:

$ npm run create-migration add field to a table

and a file called 1637739601040_add-field-to-a-table.js (the number will be different) will be created in the folder migration.

When you run the test or the project the migrations are executed automatically but iy you want to run manually you have to execute this command:

$ DATABASE_URL=postgres://postgres:postgres@localhost:5432/ms_template_dev npm run migrate up

If you want to recreate your db you can execute these commands:

$ docker exec -it ms-template-db /bin/bash -c "dropdb -U postgres ms_template_dev"
$ docker exec -it ms-template-db /bin/bash -c "createdb -U postgres ms_template_dev"

How to dump a new sql-schema

DATABASE_URL=postgres://postgres:postgres@localhost:5432/ms_template_dev npm run dump-structure

this command will run the migration before to dump the structure.

Scheduled Job

In docker-compose there is a scheduled task that call /healtz every 30 seconds. See ofelia on github for more info.

Observability

Tracing

To see the application tracing we use Jaeger: https://www.jaegertracing.io/

Start the application with

npm run trace

Open http://localhost:16686/ to see the Jaeger console

Metrics

You can see the metrics you are exporting going here: http://localhost:3000/metrics. You can see the metrics on Prometheus here: http://localhost:9090/metrics. At the end you can see the metrics on Grafana going here: http://localhost:3333/. Credentials: admin admin.

Some queries could be:

increase(created_users[10m])
created_users