如何使用 docker-compose 为 mongo 数据库做种? [英] How do I seed a mongo database using docker-compose?

问题描述

我正在尝试分发一组在多个链接容器中运行的连接应用程序，其中包含需要的 mongo 数据库:

I am trying to distribute a set of connected applications running in several linked containers that includes a mongo database that is required to:

• 分发包含一些种子数据；
• 允许用户添加其他数据.

理想情况下，数据也将保存在链接的数据卷容器中.

Ideally the data will also be persisted in a linked data volume container.

我可以使用不挂载任何卷的 mongo 基础实例将数据放入 mongo 容器(dockerhub 图像:psychemedia/mongo_nomount - 这本质上是基本的 mongo Dockerfile 没有 VOLUME/data/db 语句)和一个 Dockerfile 配置沿着:

I can get the data into the mongo container using a mongo base instance that doesn't mount any volumes (dockerhub image: psychemedia/mongo_nomount - this is essentially the base mongo Dockerfile without the VOLUME /data/db statement) and a Dockerfile config along the lines of:

ADD . /files
WORKDIR /files
RUN mkdir -p /data/db && mongod --fork --logpath=/tmp/mongodb.log && sleep 20 && 
mongoimport  --db testdb --collection testcoll  --type csv --headerline --file ./testdata.csv  #&& mongod --shutdown

其中 ./testdata.csv 与 Dockerfile 位于同一目录 (./mongo-with-data).

where ./testdata.csv is in the same directory (./mongo-with-data) as the Dockerfile.

我的 docker-compose 配置文件包括以下内容:

My docker-compose config file includes the following:

mongo:
  #image: mongo
  build: ./mongo-with-data
  ports:
    - "27017:27017"
  #Ideally we should be able to mount this against a host directory
  #volumes:
  #  - ./db/mongo/:/data/db
  #volumes_from:
  #  - devmongodata

#devmongodata:
#    command: echo created
#    image: busybox
#    volumes: 
#       - /data/db

每当我尝试挂载 VOLUME 时，似乎原始种子数据 - 存储在 /data/db 中 - 被删除.我猜当一个卷安装到 /data/db 时，它会替换当前存在的任何内容.

Whenever I try to mount a VOLUME it seems as if the original seeded data - which is stored in /data/db - is deleted. I guess that when a volume is mounted to /data/db it replaces whatever is there currently.

也就是说，docker userguide 建议:卷在容器已创建.如果容器的基础镜像包含指定挂载点的数据，那么在卷初始化时将现有数据复制到新卷中?因此，如果我在播种 RUN 命令之后放置 VOLUME 命令，我希望数据能够保留?

That said, the docker userguide suggests that: Volumes are initialized when a container is created. If the container’s base image contains data at the specified mount point, that existing data is copied into the new volume upon volume initialization? So I expected the data to persist if I placed the VOLUME command after the seeding RUN command?

那我做错了什么?

长远来看，我想自动构建多个链接的容器，然后分发一个 Vagrantfile/docker-compose YAML 文件，该文件将启动一组链接的应用程序，其中包括一个带有(部分预填充的)持久数据容器的预种子 mongo 数据库.

The long view is that I want to automate the build of several linked containers, and then distribute a Vagrantfile/docker-compose YAML file that will fire up a set of linked apps, that includes a pre-seeded mongo database with a (partially pre-populated) persistent data container.

推荐答案

我使用另一个 docker 容器来执行此操作，其唯一目的是播种 mongo，然后退出.我怀疑这与 ebaxt 的想法相同，但是当我寻找答案时，我只是想要看看一个快速而肮脏但简单的例子.所以这是我的:

I do this using another docker container whose only purpose is to seed mongo, then exit. I suspect this is the same idea as ebaxt's, but when I was looking for an answer to this, I just wanted to see a quick-and-dirty, yet straightforward, example. So here is mine:

docker-compose.yml

mongodb:
  image: mongo
  ports:
    - "27017:27017"

mongo-seed:
  build: ./mongo-seed
  links:
    - mongodb

# my webserver which uses mongo (not shown in example)
webserver:
  build: ./webserver
  ports:
    - "80:80"
  links:
    - mongodb

mongo-seed/Dockerfile

FROM mongo

COPY init.json /init.json
CMD mongoimport --host mongodb --db reach-engine --collection MyDummyCollection --type json --file /init.json --jsonArray

mongo-seed/init.json

[
  {
    "name": "Joe Smith",
    "email": "[e-mail]",
    "age": 40,
    "admin": false
  },
  {
    "name": "Jen Ford",
    "email": "[e-mail]",
    "age": 45,
    "admin": true
  }
]

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