Healthchecks are a great way to achieve this.

As this repository mentions, this is the example using PostgreSQL.

depends_on: postgres-database: condition: service_healthy

healthcheck: test: ["CMD-SHELL", "pg_isready"] interval: 10s timeout: 5s retries: 5

However, PostgreSQL has already a command for this called pg_isready.

How is this going to work for other cases such as MySQL?

> How is this going to work for other cases such as MySQL?

You could do a query like SHOW DATABASES as a healthcheck for mysql.

To be honest, I wanted to make the title more specific regarding dependencies but the title was already too big.

That's true.

For example, in the case of PostgreSQL, there is already a tool called pg_isready [0] to do this inside a healthcheck as you described.

services: postgres-db: image: postgres healthcheck: test: ["CMD-SHELL", "pg_isready -U postgres"]

  application:
    image: image
    depends_on:
      postgres-db:
        condition: service_healthy

However, this is not the case for other databases/services.

[0] https://www.postgresql.org/docs/current/app-pg-isready.html

Can you suggest to me one way for an API service to wait for a database to accept connections to run the database migrations without the API depending on the liveness of the database to start up?

I think the pragmatic answer is you should wait for your database to be live before starting up. One just wants to lean on the side of depending on a few critical services rather than all potentially-utlizied application services.

Start the server and respond 503 every time when your database and other dependencies are not ready. Couldn’t be easier.

Many people have the following setup in docker-compose.yml file.

version: '3' services: mysql: image: mysql:8.0

  app:
    build: .
    command: is_ready --timeout 10 --addr mysql:3306 -- <run migrations command>

For cases like this, returning 503 every time the database is not ready, is not very convenient.

Interesting idea for a feature request. I would love to read a GitHub issue with your specific case so I can start investigating and think about how to solve a problem like this.

I considered starting to write myself a Rust "wait for it" app myself this past week with more features than the standard one. Not sure how I didn't come across yours during my initial search.

There could be some useful functionality that could be found in startup and health probe topics [1] in Kubernetes for example. But at least in that world, it may be easier, and more transparent, to plug in a startup bash script to run before the main app. For example the Postgres Docker image [2] will run any scripts that may be mounted in a docker-entrypoint-initdb.d directory before starting the server. So putting a bash script in a ConfigMap that gets used as a disk volume, could be easier that downloading/auditing a binary "wait for it" container image.

[1] https://kubernetes.io/docs/tasks/configure-pod-container/con...

[2] https://hub.docker.com/_/postgres

Interesting project, I was not familiar with that. Thanks for letting me know :)

Regarding zero dependencies, I meant that it is a static binary and does not need any external tools to be installed. For example, some alternatives require netcat to be installed.

This is fine, and what I understood from "zero dependencies", that I can drop it in a directory and it'll just work. As far as I'm concerned, this complaint is moot.

is_ready is an alternative to this.

I built it for many reasons: - Most docker images do not contain netcat so you would have to download one of them in any case. - In the case of is_ready, you won't have to write this script yourself. - Repositories like this had a lot of traffic so I supposed that engineers need a similar tool but this repository requires wget and netcat as dependencies. For this reason, I built my own without any dependencies. https://github.com/eficode/wait-for

I also believe that one week and 30mins are are not enough for 1-on-1s.

In my company, we do 1-on-1s once a month for 1 hour. The manager asks questions like:

- How are you? - What's the skill that you are trying to improve this month? - How I (the manager) or the company can help you to improve this skill? -Do you feel that your responsibilities in the company are common with your personal goals?

I think that these meetings are successful when there is a clear agenda and both sides are prepared.

Personally, I feel very happy with these meetings.

> Do you feel that your responsibilities in the company are common with your personal goals?

That’s funny. Why would they be?