我有一个简单的连接被拒绝错误，但我不知道它是从哪里来的。
只需克隆此仓库https://github.com/allogic/domain_driven_design，然后从docker-compose up进入文件夹“服务/注册”即可。
这是我的docker-compose.yml
version: '3'
services:
database:
container_name: 'database'
image: 'mysql:8.0.15'
restart: 'always'
environment:
MYSQL_DATABASE: 'registration'
MYSQL_USER: 'root'
MYSQL_PASSWORD: 'root'
MYSQL_ROOT_PASSWORD: 'root'
expose:
- '3306'
registration:
container_name: 'registration'
image: 'node:8.15.1'
restart: 'always'
working_dir: '/usr/src/app'
command: 'npm start'
volumes:
- './src:/usr/src/app'
ports:
- '3000:3000'
depends_on:
- 'database'
links:
- 'database'
当我执行到注册容器中时，我可以对数据库执行ping操作，它可以解析dns名称，但是节点应用程序不能。
const express = require('express');
const mysql = require('mysql');
const app = express();
const db = mysql.createConnection({
host: 'database',
port: 3306,
user: 'root',
password: 'root',
database: 'registration'
});
try {
db.connect();
} catch (err) {
console.log(err);
}
app.get('/', (req, res) => {
res.send('Hello World\n');
});
app.listen(3000);
这里是错误消息
> registration@1.0.0 start /usr/src/app
> node app.js
events.js:183
throw er; // Unhandled 'error' event
^
Error: connect ECONNREFUSED 172.19.0.2:3306
at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1191:14)
--------------------
at Protocol._enqueue (/usr/src/app/node_modules/mysql/lib/protocol/Protocol.js:144:48)
at Protocol.handshake (/usr/src/app/node_modules/mysql/lib/protocol/Protocol.js:51:23)
at Connection.connect (/usr/src/app/node_modules/mysql/lib/Connection.js:118:18)
at Object.<anonymous> (/usr/src/app/app.js:15:6)
at Module._compile (module.js:653:30)
at Object.Module._extensions..js (module.js:664:10)
at Module.load (module.js:566:32)
at tryModuleLoad (module.js:506:12)
at Function.Module._load (module.js:498:3)
at Function.Module.runMain (module.js:694:10)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! registration@1.0.0 start: `node app.js`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the registration@1.0.0 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm ERR! A complete log of this run can be found in:
npm ERR! /root/.npm/_logs/2019-03-05T15_17_18_189Z-debug.log
docker inspect mysql的日志
[
{
"Id": "sha256:81f094a7e4ccc963fde3762e86625af76b6339924bf13f1b7bd3c51dbcfda988",
"RepoTags": [
"mysql:8.0.15",
"mysql:latest"
],
"RepoDigests": [
"mysql@sha256:a571337738c9205427c80748e165eca88edc5a1157f8b8d545fa127fc3e29269"
],
"Parent": "",
"Comment": "",
"Created": "2019-02-06T07:06:04.898919867Z",
"Container": "93d3c07fe0cba1f21dcc2e8e644ac8a897305eefee402f270dd6b1b2652635fc",
"ContainerConfig": {
"Hostname": "93d3c07fe0cb",
"Domainname": "",
"User": "",
"AttachStdin": false,
"AttachStdout": false,
"AttachStderr": false,
"ExposedPorts": {
"3306/tcp": {},
"33060/tcp": {}
},
"Tty": false,
"OpenStdin": false,
"StdinOnce": false,
"Env": [
"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
"GOSU_VERSION=1.7",
"MYSQL_MAJOR=8.0",
"MYSQL_VERSION=8.0.15-1debian9"
],
"Cmd": [
"/bin/sh",
"-c",
"#(nop) ",
"CMD [\"mysqld\"]"
],
"ArgsEscaped": true,
"Image": "sha256:f6ef3ab29f84d76d5b484c15354757977544e81d5da417d95c4116d682c0c331",
"Volumes": {
"/var/lib/mysql": {}
},
"WorkingDir": "",
"Entrypoint": [
"docker-entrypoint.sh"
],
"OnBuild": null,
"Labels": {}
},
"DockerVersion": "18.06.1-ce",
"Author": "",
"Config": {
"Hostname": "",
"Domainname": "",
"User": "",
"AttachStdin": false,
"AttachStdout": false,
"AttachStderr": false,
"ExposedPorts": {
"3306/tcp": {},
"33060/tcp": {}
},
"Tty": false,
"OpenStdin": false,
"StdinOnce": false,
"Env": [
"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
"GOSU_VERSION=1.7",
"MYSQL_MAJOR=8.0",
"MYSQL_VERSION=8.0.15-1debian9"
],
"Cmd": [
"mysqld"
],
"ArgsEscaped": true,
"Image": "sha256:f6ef3ab29f84d76d5b484c15354757977544e81d5da417d95c4116d682c0c331",
"Volumes": {
"/var/lib/mysql": {}
},
"WorkingDir": "",
"Entrypoint": [
"docker-entrypoint.sh"
],
"OnBuild": null,
"Labels": null
},
"Architecture": "amd64",
"Os": "linux",
"Size": 476982381,
"VirtualSize": 476982381,
"GraphDriver": {
"Data": {
"LowerDir": "/var/lib/docker/overlay2/e844699b8b52fe17126eb3fffad064c33c3604ef1d15c8d1db07cd3a8d42a9f6/diff:/var/lib/docker/overlay2/b7feb6ff662169e92a080cdfd0016a6171f4509dc223a1143f859f0855383286/diff:/var/lib/docker/overlay2/d215a62d46a307c23192f3b35a23915bf2d1793785970fc6ee2b9fb54ba1f9cc/diff:/var/lib/docker/overlay2/4e0cf7d7d6d3b22f3962b6cea7372a4a6428e30266b893c5b43ab6eaa8545813/diff:/var/lib/docker/overlay2/c40f3b76ca01fa8ac1776a21c5018da263b9340fad18c9f76e0a5785896526a6/diff:/var/lib/docker/overlay2/c8dfb8cf9a1d808d3b50127387cc7cd14f6877dbbb8a1ef9f9c8794f389fde41/diff:/var/lib/docker/overlay2/2ebda49992fb5c703d4fd07658f88a6332df76e8df75a22741c477e23a0796ab/diff:/var/lib/docker/overlay2/212abc22f2c50d69194fae07d459db74cb4bd965157ae886095b13bb0e43c1f5/diff:/var/lib/docker/overlay2/c136d29eb2119905dc5890c0a7b7cb4010d2040838a05270f8277dfaadd23139/diff:/var/lib/docker/overlay2/64b1725f0456a234d4b17f2d7315cbba3dc23b84775b4120938e97b8075da3c3/diff:/var/lib/docker/overlay2/2250130aac197d5a0d9f9e443aff2620c3524ca5b7e97fd94f4653d782a165a0/diff",
"MergedDir": "/var/lib/docker/overlay2/731b309199a97bbec5618839895a33533715d9222640bc1631b10240df36f1a2/merged",
"UpperDir": "/var/lib/docker/overlay2/731b309199a97bbec5618839895a33533715d9222640bc1631b10240df36f1a2/diff",
"WorkDir": "/var/lib/docker/overlay2/731b309199a97bbec5618839895a33533715d9222640bc1631b10240df36f1a2/work"
},
"Name": "overlay2"
},
"RootFS": {
"Type": "layers",
"Layers": [
"sha256:0a07e81f5da36e4cd6c89d9bc3af643345e56bb2ed74cc8772e42ec0d393aee3",
"sha256:3d33930b279aa4a88fe6dc381a0d4a2aca3a5cd0915565e41e9cf87174ca114e",
"sha256:7412b239e6a1c4a423a484a368f31fba65df0cb2e35bcf89d0d0e17a5631ed56",
"sha256:7756685f09e90e82438dd155b145875a02513a785efab1095b05f070b1d5de88",
"sha256:7d390c8db6fd855d93a68a3beab4b55571b29f603e472fc122c7e5b4f90e36fd",
"sha256:73ea790d3afa18621591a36a24c1254d68cb7ac66a6decc0d61df87ec30d7450",
"sha256:5d6846033b0c8ad9f20a4d9330437440877f26d9f5ab8a1fb7cfe2209f14e92c",
"sha256:506f749581f6ccda79e3a772666a9192f760628ec1035aef4524d658bb2e1e33",
"sha256:a1cb89945ac3ad7c0a0e91a613fdec4dc3f648b388c8e91d091a1d6411d6636d",
"sha256:8103990ddb33fb3195aed9edaeb522cd1a40bbc7fd57d358b1b52bb5290a9251",
"sha256:3aa676232fffeb4b0baeb760f1071736df9290e934f58ffbb5c8d4227920aabf",
"sha256:6e4a6c599b1d886a3565fe023cacd2724a8526ac591541604623b9507fe00891"
]
},
"Metadata": {
"LastTagTime": "0001-01-01T00:00:00Z"
}
}
]
docker logs database的日志
Initializing database
2019-03-05T15:17:16.039600Z 0 [Warning] [MY-011070] [Server] 'Disabling symbolic links using --skip-symbolic-links (or equivalent) is the default. Consider not using this option as it' is deprecated and will be removed in a future release.
2019-03-05T15:17:16.039689Z 0 [System] [MY-013169] [Server] /usr/sbin/mysqld (mysqld 8.0.15) initializing of server in progress as process 28
2019-03-05T15:17:19.335390Z 5 [Warning] [MY-010453] [Server] root@localhost is created with an empty password ! Please consider switching off the --initialize-insecure option.
2019-03-05T15:17:20.707524Z 0 [System] [MY-013170] [Server] /usr/sbin/mysqld (mysqld 8.0.15) initializing of server has completed
Database initialized
MySQL init process in progress...
mbind: Operation not permitted
2019-03-05T15:17:23.248237Z 0 [Warning] [MY-011070] [Server] 'Disabling symbolic links using --skip-symbolic-links (or equivalent) is the default. Consider not using this option as it' is deprecated and will be removed in a future release.
2019-03-05T15:17:23.248303Z 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.15) starting as process 79
2019-03-05T15:17:23.723233Z 0 [Warning] [MY-010068] [Server] CA certificate ca.pem is self signed.
2019-03-05T15:17:23.730096Z 0 [Warning] [MY-011810] [Server] Insecure configuration for --pid-file: Location '/var/run/mysqld' in the path is accessible to all OS users. Consider choosing a different directory.
2019-03-05T15:17:23.763955Z 0 [System] [MY-010931] [Server] /usr/sbin/mysqld: ready for connections. Version: '8.0.15' socket: '/var/run/mysqld/mysqld.sock' port: 0 MySQL Community Server - GPL.
2019-03-05T15:17:23.828356Z 0 [System] [MY-011323] [Server] X Plugin ready for connections. Socket: '/var/run/mysqld/mysqlx.sock'
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/zone.tab' as time zone. Skipping it.
Warning: Unable to load '/usr/share/zoneinfo/zone1970.tab' as time zone. Skipping it.
mysql: [Warning] Using a password on the command line interface can be insecure.
mysql: [Warning] Using a password on the command line interface can be insecure.
ERROR 1396 (HY000) at line 1: Operation CREATE USER failed for 'root'@'%'
2019-03-05T15:17:31.369099Z 0 [Warning] [MY-011070] [Server] 'Disabling symbolic links using --skip-symbolic-links (or equivalent) is the default. Consider not using this option as it' is deprecated and will be removed in a future release.
2019-03-05T15:17:31.369163Z 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.15) starting as process 12019-03-05T15:17:33.271312Z 0 [System] [MY-010229] [Server] Starting crash recovery...
2019-03-05T15:17:33.279645Z 0 [System] [MY-010232] [Server] Crash recovery finished.
2019-03-05T15:17:33.401824Z 0 [Warning] [MY-010068] [Server] CA certificate ca.pem is self signed.
2019-03-05T15:17:33.405919Z 0 [Warning] [MY-011810] [Server] Insecure configuration for --pid-file: Location '/var/run/mysqld' in the path is accessible to all OS users. Consider choosing a different directory.
2019-03-05T15:17:33.418808Z 0 [System] [MY-010931] [Server] /usr/sbin/mysqld: ready for connections. Version: '8.0.15' socket: '/var/run/mysqld/mysqld.sock' port: 3306 MySQL Community Server - GPL.
2019-03-05T15:17:33.497722Z 0 [System] [MY-011323] [Server] X Plugin ready for connections. Socket: '/var/run/mysqld/mysqlx.sock' bind-address: '::' port: 33060
答案 0 :(得分：1)
depends_on不能验证MySQL是否已准备好接收连接。无论数据库容器是否准备好进行连接，无论数据库容器是否正在运行，它都会启动第二个容器，这可能会导致您的应用程序出现此问题，因为它期望数据库已准备就绪，而这可能不是真的。
depends_on在启动Web之前不会等待db和redis处于“就绪”状态-仅在它们启动之前。
如果您需要等待服务就绪，请参阅Controlling startup order，以获取有关此问题的更多信息以及解决该问题的策略。
由于将MYSQL_USER设置为root，因此无法创建MySQL超级用户，因为该用户已存在于数据库中，并试图创建另一个。如果需要使用root用户本身，则只能使用此变量MYSQL_ROOT_PASSWORD或更改MYSQL_USER的值，以便可以安全地在应用程序中使用它而不是root用户。