How to configure ngnix with ssl certificates for two or more api rest with docker and spring boot

[cesarjv]

Good afternoon I am working with ngnix as a reverse proxy, and with spring boot to develop api rest, all raising with docker, the question is that I need to work with secure https, for which I create my self-signed certificates as detailed below:

Prepare my certificates with openssl:

#!/bin/bash
echo "Generating an SSL private key to sign your certificate..."
openssl genrsa -des3 -out myssl.key 1024
 
echo "Generating a Certificate Signing Request..."
openssl req -new -key myssl.key -out myssl.csr
 
echo "Removing passphrase from key (for nginx)..."
cp myssl.key myssl.key.org
openssl rsa -in myssl.key.org -out myssl.key
rm myssl.key.org
 
echo "Generating certificate..."
openssl x509 -req -days 365 -in myssl.csr -signkey myssl.key -out myssl.crt

My directory where is my applications and docker-compose yml file:

My Docker Compose:

version: '3'
services:
  nginx:
   container_name: ngnix
   image: nginx:1.13
   restart: always
   ports:
   - 37004:80
   - 37005:443
   volumes:
   - ./nginx-conf.d:/etc/nginx/conf.d
   - ./data-cert:/certs
   depends_on:
   - app
   - app2

  app:
    image: prueba-https
    container_name: prueba-https
    restart: unless-stopped
    build:
      context: ./app
      dockerfile: Dockerfile
    expose:
      - "8080"
    ports:
      - 37006:8080

  app2:
    image: prueba-https-2
    container_name: prueba-https-2
    restart: unless-stopped
    build:
      context: ./app2
      dockerfile: Dockerfile
    expose:
      - "8080"
    ports:
      - 37007:8080

Internally (not on the host) I am exposing the containers by port 8080, as seen in the yml file, I don't know if this can be done to configure ssl, or if app2 should expose it on port 8081, for example, they would like help me clarify that.

Inside the nginx-conf.d folder I have my app.conf file, which is in the volume defined in my docker-compose yml file:

app.conf

server { 
    listen *:80; 
    return 301 https://$host$request_uri; 
} 

server { 
      listen 443 ssl; 
      ssl on; ssl_certificate /certs/myssl.crt; 
       ssl_certificate_key /certs/myssl.key; 
}

My containers raised

All good so far, but when I am going to test the api rest in postman, with the container that rises on port 37006 everything is fine with https, but with the port that rises on port 37007 I cannot use https:

HTTPS Ok (37006)

Bad HTTPS (37007)

What am I doing wrong?

I am not using domain, in my company the api are handled as I show, using the POST method always

Should I generate a certificate for each application individually?

Should I expose my app2 application on port 8081, example?

I'm totally new to ngnix and I couldn't find a solution to this problem