Which command only updates the Docker image?

תמיכה התקנה

סיכום מבוסס בינה מלאכותית

该讨论主题探讨了如何单独更新Discourse的Docker基础镜像，以优化在网络不佳环境下的重建流程。singi2016cn指出当前没有专门的命令仅拉取镜像，导致rebuild时会卡在镜像下载步骤，建议官方增加类似./launcher pull-docker的功能。

Lilly提供了替代方案：首先通过git pull更新启动脚本，然后使用grep查找当前使用的镜像标签（如discourse/base:2.0.20260915-0028），并手动执行docker pull进行下载。这样在后续执行./launcher rebuild app时，系统会检测到镜像已是最新，从而跳过下载过程。针对singi2016cn关于自动化脚本可能因官方更新而失效的担忧，Lilly认为短期内兼容性风险不大，建议可通过Bash脚本结合Cron任务实现自动化。

singi2016cn承认这是最坏情况的假设，并表示会采取“先执行再调整”的策略。随后singi2016cn更新了查找镜像标签的方法，建议使用grep base_image /var/discourse/templates/*.yml来更准确地获取模板中定义的镜像版本（如2.0.20261027-1647），再执行相应的docker pull命令。总结来说，虽然没有原生的一键更新镜像命令，但通过查找最新镜像标签并预先手动拉取，可以有效解决重建时的下载瓶颈。

1

Which command is used to update only the Docker image?

/var/discourse# ./launcher -h
Usage: launcher COMMAND CONFIG [--skip-prereqs] [--docker-args STRING]
Commands:
    start:       Start/initialize a container
    stop:        Stop a running container
    restart:     Restart a container
    destroy:     Stop and remove a container
    enter:       Open a shell to run commands inside the container
    logs:        View the Docker logs for a container
    bootstrap:   Bootstrap a container for the config based on a template
    run:         Run the given command with the config in the context of the last bootstrapped image
    rebuild:     Rebuild a container (destroy old, bootstrap, start new)
    cleanup:     Remove all containers that have stopped for > 24 hours
    start-cmd:   Generate docker command used to start container

Options:
    --skip-prereqs             Don't check launcher prerequisites
    --docker-args              Extra arguments to pass when running docker
    --skip-mac-address         Don't assign a mac address
    --run-image                Override the image used for running the container

My use case is:
Currently, during the build process, if a Docker image update is required but the server’s network connection is poor, the process gets stuck at the image update step for a very long time. I would like to have a dedicated command for updating the Docker image, so that I can update the image in advance separately and then build the code without any rush. For example:

./launcher pull-docker

I know I can manually create a working version, but I would still prefer if the official team could provide one.

2

hmmm, only way i know is to first update the launcher script:

cd /var/discourse
git pull

then find the default image tag the launcher is using:

grep -m1 '^image=' launcher

the output should look like:

image="discourse/base:2.0.20260915-0028"

then run:

docker pull discourse/base:2.0.20260915-0028

then when you run ./launcher rebuild app it should skip the download i think.

it should say Status: Image is up to date for discourse/base:2.0.20260915-0028 when you run the rebuild…

3

Thanks for the reply. I’m currently updating using a similar method, but it’s quite cumbersome. I’d like to write my own automation script, but I’m worried about potential incompatibility after official updates.

4

you can do it with an executable bash script and even use a cron job to automate it. not sure why it would become incompatible any time soon.

5

What I mean is that it might become incompatible in the future, and I may need to check this script every single time, which undoubtedly adds extra work. I’m just assuming the worst-case scenario :joy:. Of course, when it comes to solving the problem, let’s just get started first and adjust as we go.

6

The latest way to check images

grep base_image /var/discourse/templates/*.yml

Output:

/var/discourse/templates/postgres.template.yml:base_image: discourse/base:2.0.20261027-1647
/var/discourse/templates/redis.template.yml:base_image: discourse/base:2.0.20261027-1647
/var/discourse/templates/web.template.yml:base_image: discourse/base:2.0.20261027-1647
/var/discourse/templates/web.webonly.template.yml:base_image: discourse/base:2.0.20261027-1647-web-only

Then manually update by running

docker pull discourse/base:2.0.20261027-1647