为什么在Docker编译期间所做的所有更改在运行时不可用？
我正在尝试制作一个Docker镜像，它只是MongoDB原始镜像，另外还有一个在数据库上configuration的pipe理员用户帐户。 我的目标是简单地在auth模式下启动一个带有mongo实例的容器，然后使用mongo admin -u root -p rootlogin到它。
这是我的Dockerfile ：
FROM mongo:latest RUN mongod --fork --logpath /var/log/mongodb.log \ && mongo admin --eval " \ db.createUser({ user: 'root', pwd: 'root', roles: [ 'root' ]}); \ db.shutdownServer() \ " CMD ["mongod", "--auth"]
这是docker build --tag lvbarbosa/task-db .的输出docker build --tag lvbarbosa/task-db . 命令在与Dockerfile相同的目录中执行：
Sending build context to Docker daemon 2.048kB Step 1/3 : FROM mongo:latest latest: Pulling from library/mongo 5233d9aed181: Pull complete 5bbfc055e8fb: Pull complete aaf85a329dc4: Pull complete 1360aef7d266: Pull complete 9cb9d47c5d80: Pull complete 80e12bf92c3c: Pull complete fd3679b936e6: Pull complete 5cb080b90ae5: Pull complete 46cf38664c75: Pull complete 59693a4ecb90: Pull complete dff9fc3b430d: Pull complete Digest: sha256:90b78c44a58d6d927f96baabea3212d8c756017846715b630044aefcabcab2eb Status: Downloaded newer image for mongo:latest ---> 6833171fe0ad Step 2/3 : RUN mongod --fork --logpath /var/log/mongodb.log && mongo admin --eval " db.createUser({ user: 'root', pwd: 'root', roles: [ 'root' ]}); db.shutdownServer() " ---> Running in 6c1a5530b7b6 about to fork child process, waiting until server is ready for connections. forked process: 10 child process started successfully, parent exiting MongoDB shell version v3.4.6 connecting to: mongodb://127.0.0.1:27017/admin MongoDB server version: 3.4.6 Successfully added user: { "user" : "root", "roles" : [ "root" ] } server should be down... ---> 82fa5430003c Removing intermediate container 6c1a5530b7b6 Step 3/3 : CMD mongod ---> Running in 42f240f05661 ---> 90ec29686438 Removing intermediate container 42f240f05661 Successfully built 90ec29686438 Successfully tagged lvbarbosa/task-db:latest
接下来，我使用docker run --detach --publish 27017:27017 --name task-db lvbarbosa/task-db创build一个包含该映像的容器。 当我尝试使用我的主机terminal和命令mongo admin -u root -p root连接到实例时，login失败。 我得到一个user not found错误信息。
看起来在编译期间对UFS所做的更改不会持久。 但是，如何在编译期间将数据下载/复制到FS中，并且可以在上层使用，而对数据库文件的更改则不是这样？ 我很困惑。 这是从启动时间到尝试失败logging的完整容器日志。
2017-07-27T13:20:47.687+0000 I CONTROL [initandlisten] MongoDB starting : pid=1 port=27017 dbpath=/data/db 64-bit host=86b7b24efed4 2017-07-27T13:20:47.687+0000 I CONTROL [initandlisten] db version v3.4.6 2017-07-27T13:20:47.687+0000 I CONTROL [initandlisten] git version: c55eb86ef46ee7aede3b1e2a5d184a7df4bfb5b5 2017-07-27T13:20:47.687+0000 I CONTROL [initandlisten] OpenSSL version: OpenSSL 1.0.1t 3 May 2016 2017-07-27T13:20:47.687+0000 I CONTROL [initandlisten] allocator: tcmalloc 2017-07-27T13:20:47.687+0000 I CONTROL [initandlisten] modules: none 2017-07-27T13:20:47.687+0000 I CONTROL [initandlisten] build environment: 2017-07-27T13:20:47.687+0000 I CONTROL [initandlisten] distmod: debian81 2017-07-27T13:20:47.687+0000 I CONTROL [initandlisten] distarch: x86_64 2017-07-27T13:20:47.687+0000 I CONTROL [initandlisten] target_arch: x86_64 2017-07-27T13:20:47.688+0000 I CONTROL [initandlisten] options: { security: { authorization: "enabled" } } 2017-07-27T13:20:47.690+0000 I STORAGE [initandlisten] 2017-07-27T13:20:47.690+0000 I STORAGE [initandlisten] ** WARNING: Using the XFS filesystem is strongly recommended with the WiredTiger storage engine 2017-07-27T13:20:47.690+0000 I STORAGE [initandlisten] ** See http://dochub.mongodb.org/core/prodnotes-filesystem 2017-07-27T13:20:47.690+0000 I STORAGE [initandlisten] wiredtiger_open config: create,cache_size=3474M,session_max=20000,eviction=(threads_min=4,threads_max=4),config_base=false,statistics=(fast),log=(enabled=true,archive=true,path=journal,compressor=snappy),file_manager=(close_idle_time=100000),checkpoint=(wait=60,log_size=2GB),statistics_log=(wait=0), 2017-07-27T13:20:47.719+0000 I FTDC [initandlisten] Initializing full-time diagnostic data capture with directory '/data/db/diagnostic.data' 2017-07-27T13:20:47.727+0000 I INDEX [initandlisten] build index on: admin.system.version properties: { v: 2, key: { version: 1 }, name: "incompatible_with_version_32", ns: "admin.system.version" } 2017-07-27T13:20:47.727+0000 I INDEX [initandlisten] building index using bulk method; build may temporarily use up to 500 megabytes of RAM 2017-07-27T13:20:47.728+0000 I INDEX [initandlisten] build index done. scanned 0 total records. 0 secs 2017-07-27T13:20:47.728+0000 I COMMAND [initandlisten] setting featureCompatibilityVersion to 3.4 2017-07-27T13:20:47.728+0000 I NETWORK [thread1] waiting for connections on port 27017 2017-07-27T13:20:48.963+0000 I NETWORK [thread1] connection accepted from 172.17.0.1:45804 #1 (1 connection now open) 2017-07-27T13:20:48.963+0000 I NETWORK [conn1] received client metadata from 172.17.0.1:45804 conn1: { application: { name: "MongoDB Shell" }, driver: { name: "MongoDB Internal Client", version: "3.4.6" }, os: { type: "Darwin", name: "Mac OS X", architecture: "x86_64", version: "17.0.0" } } 2017-07-27T13:20:48.970+0000 I ACCESS [conn1] SCRAM-SHA-1 authentication failed for root on admin from client 172.17.0.1:45804 ; UserNotFound: Could not find user root@admin 2017-07-27T13:20:48.972+0000 I - [conn1] end connection 172.17.0.1:45804 (1 connection now open)
Mongo的原始Dockerfile存在于他们的github 。
我已经做了一些研究，有些人提到了在数据库阶段使用的“临时文件系统”，这就是为什么变化没有被持续的原因。 因此，我应该让用户在运行时添加function，而不是生成时间。 但是在编译期间应该有一种方法来configuration它，不应该在那里？
我猜想修改是在/data/db或/data/configdb 。 但是在基本的mongodb映像中，这些文件夹被声明为VOLUME ，相应的文档是 ：
更改Dockerfile中的音量 ：如果任何构build步骤在声明后更改了音量内的数据，则这些更改将被丢弃。