• 18 Posts
  • 310 Comments
Joined 2 years ago
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Cake day: July 5th, 2023

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  • Scary indeed.

    This one could be helped by always using this pattern whenever you write a function that returns a value, in any language, along with no early returns:

    int func(...) {
        int result = -1;
        ...
        return result;
    }
    

    I always start with writing my result default value, ideally indicating failure, and the return line. Then I implement the rest. We often don’t have the luxury of choosing the language we work with that has the features we like, but consistently enforced code style can help with a lot of problems. Anyone can make mistakes like the one in this bug regardless of experience so every little bit helps.


  • Well, you gotta start it somehow. You could rely on compose’es built-in service management which will restart containers upon system reboot if they were started with -d, and have the right restart policy. But you still have to start those at least once. How’d you do that? Unless you plan to start it manually, you have to use some service startup mechanism. That leads us to systemd unit. I have to write a systemd unit to do docker compose up -d. But then I’m splitting the service lifecycle management to two systems. If I want to stop it, I no longer can do that via systemd. I have to go find where the compose file is and issue docker compose down. Not great. Instead I’d write a stop line in my systemd unit so I can start/stop from a single place. But wait 🫷 that’s kinda what I’m doing isn’t it? Except if I start it with docker compose up without -d, I don’t need a separate stop line and systemd can directly monitor the process. As a result I get logs in journald too, and I can use systemd’s restart policies. Having the service managed by systemd also means I can use aystemd dependencies such as fs mounts, network availability, you name it. It’s way more powerful than compose’s restart policy. Finally, I like to clean up any data I haven’t explicitly intended to persist across service restarts so that I don’t end up in a situation where I’m debugging an issue that manifests itself because of some persisted piece of data I’m completely unaware of.







  • Because I clean everything up that’s not explicitly on disk on restart:

    [Unit]
    Description=Immich in Docker
    After=docker.service 
    Requires=docker.service
    
    [Service]
    TimeoutStartSec=0
    
    WorkingDirectory=/opt/immich-docker
    
    ExecStartPre=-/usr/bin/docker compose kill --remove-orphans
    ExecStartPre=-/usr/bin/docker compose down --remove-orphans
    ExecStartPre=-/usr/bin/docker compose rm -f -s -v
    ExecStartPre=-/usr/bin/docker compose pull
    ExecStart=/usr/bin/docker compose up
    
    Restart=always
    RestartSec=30
    
    [Install]
    WantedBy=multi-user.target