I need to start backend-container after start database-container. How can I do it with docker-compose?

        

    
    
        
            asked May 2, 2019 at 20:51
        
        
    
    
        
    
    

    





                
                
                    


                                        

    
    
Use a depends_on clause on your backend-container. Something like that :

version: "3.7"
services:
  web:
    build: .
    depends_on:
      - db
  db:
    image: postgres


Here is the documentation about it. 
Have fun!
    
    
    
        
            answered May 2, 2019 at 20:57
        
        
    
    
        
    
    
        SchismeSchisme4632 silver badges6 bronze badges
        
    

    


                                        

    
    
You should look into the depends_on configuration for docker compose.

In short, you should be able to do something like:

services:
  database-container:
    # configuration
  backend-container:
    depends_on:
      - database-container
    # configuration

    
    
    
        
            answered May 2, 2019 at 20:57
        
        
    
    
        
    
    

    

                                        

    
    
The depends_on field will work with docker-compose, but you will find it is not supported if you upgrade to swarm mode. It also guarantees the database container is created, but not necessarily ready to receive connections.

For that, there are several options:


Let the backend container fail and configure a restart policy. This is ugly, leads to false errors being reported, but it's also the easiest to implement.
Perform a connection from your app with a retry loop, a sleep between retries, and a timeout in case the database doesn't start in a timely fashion. This is usually my preferred method, but it requires a change to your application.
Use an entrypoint script with a command like wait-for-it.sh that waits for a remote resource to become available, and once that command succeeds, launch your app. This doesn't cover all the scenarios as a complete client connection, but can be less intrusive to implement since it only requires changes to an entrypoint script rather than the app itself.

    
    
    
        
            answered May 3, 2019 at 3:04
        
        
    
    
        
    
    
        BMitchBMitch265k50 gold badges542 silver badges499 bronze badges
        
    

    


                        


                            
                                
                                        Start asking to get answers
                                        Find the answer to your question by asking.
                                        Ask question
                                    
                                
                                        Explore related questions
                                        
                                        See similar questions with these tags.