我想使用Docker在我的 CentOs 7 服务器上部署网站分析工具 Piwik 。
为实现这一点，我遵循了this page，其中规定，为了运行 piwik容器，必须运行 mysql容器。所以我先用这种方式运行 mysql-docker-container ：
docker run --name some-mysql -e MYSQL_ROOT_PASSWORD=my-secret-pw -d mysql:latest
之后我按照这样运行 piwik-docker-container ：
docker run --name some-piwik --link some-mysql:mysql -p 6969:9000 -d piwik
根据the site，现在应该可以浏览到http://localhost:6969以查看Piwik登录页面。
不幸的是使用我选择的浏览器（lynx），我收到以下错误消息：
[root@localhost /]# lynx localhost:6969
Looking up localhost first
Looking up localhost:6969
Making HTTP connection to localhost:6969
Sending HTTP request.
HTTP request sent; waiting for response.
Alert!: Unexpected network read error; connection aborted.
Can't Access `http://localhost:6969/'
Alert!: Unable to access document.
lynx: Can't access startfile
要调试此行为，我列出了所有正在运行的容器：
[root@localhost /]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
091d56f024f7 piwik "/entrypoint.sh php-f" About an hour ago Up About an hour 0.0.0.0:6969->9000/tcp some-piwik
0d869ba11123 mysql:latest "/entrypoint.sh mysql" About an hour ago Up About an hour 3306/tcp some-mysql
结论：似乎端口已映射，两个容器都在运行。
为了找到问题根源的另一个可能的提示，我检查了容器的日志：
[root@localhost gitlab]# docker logs some-piwik
[22-Mar-2016 14:53:08] NOTICE: fpm is running, pid 1
[22-Mar-2016 14:53:08] NOTICE: ready to handle connections
结论：似乎piwik容器已经准备就绪。
[root@localhost gitlab]# docker logs some-mysql
Initializing database
2016-03-22T14:31:30.234530Z 0 [Warning] InnoDB: New log files created, LSN=45790
2016-03-22T14:31:30.715480Z 0 [Warning] InnoDB: Creating foreign key constraint system tables.
2016-03-22T14:31:30.803664Z 0 [Warning] No existing UUID has been found, so we assume that this is the first time that this server has been started. Generating a new UUID: c4f82d8d-f03a-11e5-b9ab-0242ac110003.
2016-03-22T14:31:30.807955Z 0 [Warning] Gtid table is not ready to be used. Table 'mysql.gtid_executed' cannot be opened.
2016-03-22T14:31:30.808521Z 1 [Warning] root@localhost is created with an empty password ! Please consider switching off the --initialize-insecure option.
2016-03-22T14:31:32.217007Z 1 [Warning] 'user' entry 'root@localhost' ignored in --skip-name-resolve mode.
2016-03-22T14:31:32.217054Z 1 [Warning] 'user' entry 'mysql.sys@localhost' ignored in --skip-name-resolve mode.
2016-03-22T14:31:32.217074Z 1 [Warning] 'db' entry 'sys mysql.sys@localhost' ignored in --skip-name-resolve mode.
2016-03-22T14:31:32.217092Z 1 [Warning] 'proxies_priv' entry '@ root@localhost' ignored in --skip-name-resolve mode.
2016-03-22T14:31:32.217148Z 1 [Warning] 'tables_priv' entry 'sys_config mysql.sys@localhost' ignored in --skip-name-resolve mode.
Database initialized
MySQL init process in progress...
2016-03-22T14:31:34.152405Z 0 [Note] mysqld (mysqld 5.7.11) starting as process 45 ...
2016-03-22T14:31:34.157555Z 0 [Note] InnoDB: PUNCH HOLE support available
2016-03-22T14:31:34.157593Z 0 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2016-03-22T14:31:34.157601Z 0 [Note] InnoDB: Uses event mutexes
2016-03-22T14:31:34.157608Z 0 [Note] InnoDB: GCC builtin __atomic_thread_fence() is used for memory barrier
2016-03-22T14:31:34.157617Z 0 [Note] InnoDB: Compressed tables use zlib 1.2.8
2016-03-22T14:31:34.157623Z 0 [Note] InnoDB: Using Linux native AIO
2016-03-22T14:31:34.157969Z 0 [Note] InnoDB: Number of pools: 1
2016-03-22T14:31:34.158117Z 0 [Note] InnoDB: Using CPU crc32 instructions
2016-03-22T14:31:34.171400Z 0 [Note] InnoDB: Initializing buffer pool, total size = 128M, instances = 1, chunk size = 128M
2016-03-22T14:31:34.183239Z 0 [Note] InnoDB: Completed initialization of buffer pool
2016-03-22T14:31:34.186125Z 0 [Note] InnoDB: If the mysqld execution user is authorized, page cleaner thread priority can be changed. See the man page of setpriority().
2016-03-22T14:31:34.198794Z 0 [Note] InnoDB: Highest supported file format is Barracuda.
2016-03-22T14:31:34.212704Z 0 [Note] InnoDB: Creating shared tablespace for temporary tables
2016-03-22T14:31:34.212824Z 0 [Note] InnoDB: Setting file './ibtmp1' size to 12 MB. Physically writing the file full; Please wait ...
2016-03-22T14:31:34.543252Z 0 [Note] InnoDB: File './ibtmp1' size is now 12 MB.
2016-03-22T14:31:34.544661Z 0 [Note] InnoDB: 96 redo rollback segment(s) found. 96 redo rollback segment(s) are active.
2016-03-22T14:31:34.544685Z 0 [Note] InnoDB: 32 non-redo rollback segment(s) are active.
2016-03-22T14:31:34.545567Z 0 [Note] InnoDB: Waiting for purge to start
2016-03-22T14:31:34.595786Z 0 [Note] InnoDB: 5.7.11 started; log sequence number 2492554
2016-03-22T14:31:34.595979Z 0 [Note] InnoDB: Loading buffer pool(s) from /var/lib/mysql/ib_buffer_pool
2016-03-22T14:31:34.596205Z 0 [Note] Plugin 'FEDERATED' is disabled.
2016-03-22T14:31:34.597885Z 0 [Note] InnoDB: Buffer pool(s) load completed at 160322 14:31:34
2016-03-22T14:31:34.598226Z 0 [Warning] Failed to set up SSL because of the following SSL library error: SSL context is not usable without certificate and private key
2016-03-22T14:31:34.622636Z 0 [Warning] 'user' entry 'root@localhost' ignored in --skip-name-resolve mode.
2016-03-22T14:31:34.622697Z 0 [Warning] 'user' entry 'mysql.sys@localhost' ignored in --skip-name-resolve mode.
2016-03-22T14:31:34.622731Z 0 [Warning] 'db' entry 'sys mysql.sys@localhost' ignored in --skip-name-resolve mode.
2016-03-22T14:31:34.622762Z 0 [Warning] 'proxies_priv' entry '@ root@localhost' ignored in --skip-name-resolve mode.
2016-03-22T14:31:34.624174Z 0 [Warning] 'tables_priv' entry 'sys_config mysql.sys@localhost' ignored in --skip-name-resolve mode.
2016-03-22T14:31:34.631086Z 0 [Note] Event Scheduler: Loaded 0 events
2016-03-22T14:31:34.631311Z 0 [Note] mysqld: ready for connections.
Version: '5.7.11' socket: '/var/run/mysqld/mysqld.sock' port: 0 MySQL Community Server (GPL)
Warning: Unable to load '/usr/share/zoneinfo/Factory' as time zone. Skipping it.
Warning: Unable to load '/usr/share/zoneinfo/iso3166.tab' as time zone. Skipping it.
Warning: Unable to load '/usr/share/zoneinfo/leap-seconds.list' as time zone. Skipping it.
Warning: Unable to load '/usr/share/zoneinfo/posix/Factory' as time zone. Skipping it.
Warning: Unable to load '/usr/share/zoneinfo/right/Factory' as time zone. Skipping it.
Warning: Unable to load '/usr/share/zoneinfo/zone.tab' as time zone. Skipping it.
2016-03-22T14:31:40.318193Z 4 [Warning] 'db' entry 'sys mysql.sys@localhost' ignored in --skip-name-resolve mode.
2016-03-22T14:31:40.318230Z 4 [Warning] 'proxies_priv' entry '@ root@localhost' ignored in --skip-name-resolve mode.
2016-03-22T14:31:40.318272Z 4 [Warning] 'tables_priv' entry 'sys_config mysql.sys@localhost' ignored in --skip-name-resolve mode.
/entrypoint.sh: ignoring /docker-entrypoint-initdb.d/*
2016-03-22T14:31:40.319867Z 0 [Note] Giving 0 client threads a chance to die gracefully
2016-03-22T14:31:40.319901Z 0 [Note] Shutting down slave threads
2016-03-22T14:31:40.319912Z 0 [Note] Forcefully disconnecting 0 remaining clients
2016-03-22T14:31:40.319921Z 0 [Note] Event Scheduler: Purging the queue. 0 events
2016-03-22T14:31:40.320014Z 0 [Note] Binlog end
2016-03-22T14:31:40.322853Z 0 [Note] Shutting down plugin 'ngram'
2016-03-22T14:31:40.322884Z 0 [Note] Shutting down plugin 'BLACKHOLE'
2016-03-22T14:31:40.322895Z 0 [Note] Shutting down plugin 'partition'
2016-03-22T14:31:40.322903Z 0 [Note] Shutting down plugin 'ARCHIVE'
2016-03-22T14:31:40.322909Z 0 [Note] Shutting down plugin 'MEMORY'
2016-03-22T14:31:40.322923Z 0 [Note] Shutting down plugin 'INNODB_SYS_VIRTUAL'
2016-03-22T14:31:40.322931Z 0 [Note] Shutting down plugin 'INNODB_SYS_DATAFILES'
2016-03-22T14:31:40.322940Z 0 [Note] Shutting down plugin 'INNODB_SYS_TABLESPACES'
2016-03-22T14:31:40.322946Z 0 [Note] Shutting down plugin 'INNODB_SYS_FOREIGN_COLS'
2016-03-22T14:31:40.322953Z 0 [Note] Shutting down plugin 'INNODB_SYS_FOREIGN'
2016-03-22T14:31:40.322959Z 0 [Note] Shutting down plugin 'INNODB_SYS_FIELDS'
2016-03-22T14:31:40.322965Z 0 [Note] Shutting down plugin 'INNODB_SYS_COLUMNS'
2016-03-22T14:31:40.322970Z 0 [Note] Shutting down plugin 'INNODB_SYS_INDEXES'
2016-03-22T14:31:40.322976Z 0 [Note] Shutting down plugin 'INNODB_SYS_TABLESTATS'
2016-03-22T14:31:40.322982Z 0 [Note] Shutting down plugin 'INNODB_SYS_TABLES'
2016-03-22T14:31:40.322987Z 0 [Note] Shutting down plugin 'INNODB_FT_INDEX_TABLE'
2016-03-22T14:31:40.322995Z 0 [Note] Shutting down plugin 'INNODB_FT_INDEX_CACHE'
2016-03-22T14:31:40.323002Z 0 [Note] Shutting down plugin 'INNODB_FT_CONFIG'
2016-03-22T14:31:40.323008Z 0 [Note] Shutting down plugin 'INNODB_FT_BEING_DELETED'
2016-03-22T14:31:40.323014Z 0 [Note] Shutting down plugin 'INNODB_FT_DELETED'
2016-03-22T14:31:40.323022Z 0 [Note] Shutting down plugin 'INNODB_FT_DEFAULT_STOPWORD'
2016-03-22T14:31:40.323028Z 0 [Note] Shutting down plugin 'INNODB_METRICS'
2016-03-22T14:31:40.323035Z 0 [Note] Shutting down plugin 'INNODB_TEMP_TABLE_INFO'
2016-03-22T14:31:40.323041Z 0 [Note] Shutting down plugin 'INNODB_BUFFER_POOL_STATS'
2016-03-22T14:31:40.323046Z 0 [Note] Shutting down plugin 'INNODB_BUFFER_PAGE_LRU'
2016-03-22T14:31:40.323051Z 0 [Note] Shutting down plugin 'INNODB_BUFFER_PAGE'
2016-03-22T14:31:40.323056Z 0 [Note] Shutting down plugin 'INNODB_CMP_PER_INDEX_RESET'
2016-03-22T14:31:40.323062Z 0 [Note] Shutting down plugin 'INNODB_CMP_PER_INDEX'
2016-03-22T14:31:40.323070Z 0 [Note] Shutting down plugin 'INNODB_CMPMEM_RESET'
2016-03-22T14:31:40.323077Z 0 [Note] Shutting down plugin 'INNODB_CMPMEM'
2016-03-22T14:31:40.323083Z 0 [Note] Shutting down plugin 'INNODB_CMP_RESET'
2016-03-22T14:31:40.323089Z 0 [Note] Shutting down plugin 'INNODB_CMP'
2016-03-22T14:31:40.323097Z 0 [Note] Shutting down plugin 'INNODB_LOCK_WAITS'
2016-03-22T14:31:40.323104Z 0 [Note] Shutting down plugin 'INNODB_LOCKS'
2016-03-22T14:31:40.323111Z 0 [Note] Shutting down plugin 'INNODB_TRX'
2016-03-22T14:31:40.323117Z 0 [Note] Shutting down plugin 'InnoDB'
2016-03-22T14:31:40.323250Z 0 [Note] InnoDB: FTS optimize thread exiting.
2016-03-22T14:31:40.323446Z 0 [Note] InnoDB: Starting shutdown...
2016-03-22T14:31:40.423749Z 0 [Note] InnoDB: Dumping buffer pool(s) to /var/lib/mysql/ib_buffer_pool
2016-03-22T14:31:40.424428Z 0 [Note] InnoDB: Buffer pool(s) dump completed at 160322 14:31:40
2016-03-22T14:31:42.259424Z 0 [Note] InnoDB: Shutdown completed; log sequence number 11991678
2016-03-22T14:31:42.263166Z 0 [Note] InnoDB: Removed temporary tablespace data file: "ibtmp1"
2016-03-22T14:31:42.263192Z 0 [Note] Shutting down plugin 'MyISAM'
2016-03-22T14:31:42.263204Z 0 [Note] Shutting down plugin 'MRG_MYISAM'
2016-03-22T14:31:42.263211Z 0 [Note] Shutting down plugin 'CSV'
2016-03-22T14:31:42.263217Z 0 [Note] Shutting down plugin 'PERFORMANCE_SCHEMA'
2016-03-22T14:31:42.263290Z 0 [Note] Shutting down plugin 'sha256_password'
2016-03-22T14:31:42.263306Z 0 [Note] Shutting down plugin 'mysql_native_password'
2016-03-22T14:31:42.263311Z 0 [Note] Shutting down plugin 'keyring_file'
2016-03-22T14:31:42.263600Z 0 [Note] Shutting down plugin 'binlog'
2016-03-22T14:31:42.264545Z 0 [Note] mysqld: Shutdown complete
MySQL init process done. Ready for start up.
2016-03-22T14:31:42.543163Z 0 [Note] mysqld (mysqld 5.7.11) starting as process 1 ...
2016-03-22T14:31:42.548164Z 0 [Note] InnoDB: PUNCH HOLE support available
2016-03-22T14:31:42.548207Z 0 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2016-03-22T14:31:42.548216Z 0 [Note] InnoDB: Uses event mutexes
2016-03-22T14:31:42.548225Z 0 [Note] InnoDB: GCC builtin __atomic_thread_fence() is used for memory barrier
2016-03-22T14:31:42.548234Z 0 [Note] InnoDB: Compressed tables use zlib 1.2.8
2016-03-22T14:31:42.548250Z 0 [Note] InnoDB: Using Linux native AIO
2016-03-22T14:31:42.548634Z 0 [Note] InnoDB: Number of pools: 1
2016-03-22T14:31:42.548800Z 0 [Note] InnoDB: Using CPU crc32 instructions
2016-03-22T14:31:42.563003Z 0 [Note] InnoDB: Initializing buffer pool, total size = 128M, instances = 1, chunk size = 128M
2016-03-22T14:31:42.574946Z 0 [Note] InnoDB: Completed initialization of buffer pool
2016-03-22T14:31:42.578836Z 0 [Note] InnoDB: If the mysqld execution user is authorized, page cleaner thread priority can be changed. See the man page of setpriority().
2016-03-22T14:31:42.591488Z 0 [Note] InnoDB: Highest supported file format is Barracuda.
2016-03-22T14:31:42.605952Z 0 [Note] InnoDB: Creating shared tablespace for temporary tables
2016-03-22T14:31:42.606098Z 0 [Note] InnoDB: Setting file './ibtmp1' size to 12 MB. Physically writing the file full; Please wait ...
2016-03-22T14:31:42.935219Z 0 [Note] InnoDB: File './ibtmp1' size is now 12 MB.
2016-03-22T14:31:42.936243Z 0 [Note] InnoDB: 96 redo rollback segment(s) found. 96 redo rollback segment(s) are active.
2016-03-22T14:31:42.936261Z 0 [Note] InnoDB: 32 non-redo rollback segment(s) are active.
2016-03-22T14:31:42.937391Z 0 [Note] InnoDB: Waiting for purge to start
2016-03-22T14:31:42.987575Z 0 [Note] InnoDB: 5.7.11 started; log sequence number 11991678
2016-03-22T14:31:42.988186Z 0 [Note] InnoDB: Loading buffer pool(s) from /var/lib/mysql/ib_buffer_pool
2016-03-22T14:31:42.988381Z 0 [Note] Plugin 'FEDERATED' is disabled.
2016-03-22T14:31:42.990760Z 0 [Warning] Failed to set up SSL because of the following SSL library error: SSL context is not usable without certificate and private key
2016-03-22T14:31:42.990791Z 0 [Note] Server hostname (bind-address): '*'; port: 3306
2016-03-22T14:31:42.990873Z 0 [Note] IPv6 is available.
2016-03-22T14:31:42.990895Z 0 [Note] - '::' resolves to '::';
2016-03-22T14:31:42.990909Z 0 [Note] Server socket created on IP: '::'.
2016-03-22T14:31:42.993822Z 0 [Note] InnoDB: Buffer pool(s) load completed at 160322 14:31:42
2016-03-22T14:31:43.027560Z 0 [Warning] 'db' entry 'sys mysql.sys@localhost' ignored in --skip-name-resolve mode.
2016-03-22T14:31:43.027600Z 0 [Warning] 'proxies_priv' entry '@ root@localhost' ignored in --skip-name-resolve mode.
2016-03-22T14:31:43.030086Z 0 [Warning] 'tables_priv' entry 'sys_config mysql.sys@localhost' ignored in --skip-name-resolve mode.
2016-03-22T14:31:43.037089Z 0 [Note] Event Scheduler: Loaded 0 events
2016-03-22T14:31:43.037341Z 0 [Note] mysqld: ready for connections.
Version: '5.7.11' socket: '/var/run/mysqld/mysqld.sock' port: 3306 MySQL Community Server (GPL)
结论：奇怪的是， mysql-container 日志不包含piwik容器以某种方式连接到它的任何消息。所以这表明这些容器之间的链接没有发生，尽管事实上piwik容器是用--link some-mysql:mysql标志运行的。