docker-compose RabbitMQ与Nodejs接收端同时运行时的错误

首先讲一下背景:

我现在在开发的一个项目,需要运行RabbitMQ和Nodejs接收端(amqplib库),但是在Nodejs接收端运行时,无法连接至RabbitMQ端,经常提示说 connect ECONNREFUSED ,无法连接至RabbitMQ服务器,我在docker-compose.yml文件中明明在Nodejs接收端将RabbitMQ服务器设置为depends_on,即RabbitMQ运行之后Nodejs接收端才会启动,那么为什么还是无法连接呢?

我查找了相关的资料,终于找到了原因

RabbitMQ容器启动后,离服务可用还有一小段时间

Nodejs接收端容器,则是启动后,就开始尝试连接至RabbitMQ服务器,那么中间就会有一个时间差,当Nodejs接收端去连接RabbitMQ服务器,服务无法响应,则会造成无法连接的错误

docker-compose RabbitMQ与Nodejs接收端同时运行时的错误_第1张图片

那么应该如何解决这个问题呢?

找到一个解决方案:wait-for-it,这个库中会增加对IP和端口的监测,只有当某个IP和端口可访问后,才会进行下一步动作,正好解决了以上的关于服务启动的时间差问题

关于写法,可以参考《https://stackoverflow.com/questions/48015477/docker-and-rabbitmq-econnrefused-between-containers》

需要在Nodejs接收端中增加wait-for-it.sh文件,还需要在Dockfile中将sh文件加入至镜像中,并且启动的命令是,当RabbitMQ服务已经启动后,再尝试启动Nodejs服务,这样就可以正常的启动了

请注意:其中等待的最长时间是我们在脚本中定义好的,我这国定义的是120秒,即两分钟,如果容器在两分钟还是无法启动成功,估计是会造成失败的

docker-compose RabbitMQ与Nodejs接收端同时运行时的错误_第2张图片

wait-for-it.sh文件内容,请最好参考官方的github地址(https://github.com/vishnubob/wait-for-it/edit/master/wait-for-it.sh),我这边的是现在能用,但不能保证未来一定可用

#!/usr/bin/env bash
#   Use this script to test if a given TCP host/port are available

WAITFORIT_cmdname=${0##*/}

echoerr() { if [[ $WAITFORIT_QUIET -ne 1 ]]; then echo "$@" 1>&2; fi }

usage()
{
    cat << USAGE >&2
Usage:
    $WAITFORIT_cmdname host:port [-s] [-t timeout] [-- command args]
    -h HOST | --host=HOST       Host or IP under test
    -p PORT | --port=PORT       TCP port under test
                                Alternatively, you specify the host and port as host:port
    -s | --strict               Only execute subcommand if the test succeeds
    -q | --quiet                Don't output any status messages
    -t TIMEOUT | --timeout=TIMEOUT
                                Timeout in seconds, zero for no timeout
    -- COMMAND ARGS             Execute command with args after the test finishes
USAGE
    exit 1
}

wait_for()
{
    if [[ $WAITFORIT_TIMEOUT -gt 0 ]]; then
        echoerr "$WAITFORIT_cmdname: waiting $WAITFORIT_TIMEOUT seconds for $WAITFORIT_HOST:$WAITFORIT_PORT"
    else
        echoerr "$WAITFORIT_cmdname: waiting for $WAITFORIT_HOST:$WAITFORIT_PORT without a timeout"
    fi
    WAITFORIT_start_ts=$(date +%s)
    while :
    do
        if [[ $WAITFORIT_ISBUSY -eq 1 ]]; then
            nc -z $WAITFORIT_HOST $WAITFORIT_PORT
            WAITFORIT_result=$?
        else
            (echo > /dev/tcp/$WAITFORIT_HOST/$WAITFORIT_PORT) >/dev/null 2>&1
            WAITFORIT_result=$?
        fi
        if [[ $WAITFORIT_result -eq 0 ]]; then
            WAITFORIT_end_ts=$(date +%s)
            echoerr "$WAITFORIT_cmdname: $WAITFORIT_HOST:$WAITFORIT_PORT is available after $((WAITFORIT_end_ts - WAITFORIT_start_ts)) seconds"
            break
        fi
        sleep 1
    done
    return $WAITFORIT_result
}

wait_for_wrapper()
{
    # In order to support SIGINT during timeout: http://unix.stackexchange.com/a/57692
    if [[ $WAITFORIT_QUIET -eq 1 ]]; then
        timeout $WAITFORIT_BUSYTIMEFLAG $WAITFORIT_TIMEOUT $0 --quiet --child --host=$WAITFORIT_HOST --port=$WAITFORIT_PORT --timeout=$WAITFORIT_TIMEOUT &
    else
        timeout $WAITFORIT_BUSYTIMEFLAG $WAITFORIT_TIMEOUT $0 --child --host=$WAITFORIT_HOST --port=$WAITFORIT_PORT --timeout=$WAITFORIT_TIMEOUT &
    fi
    WAITFORIT_PID=$!
    trap "kill -INT -$WAITFORIT_PID" INT
    wait $WAITFORIT_PID
    WAITFORIT_RESULT=$?
    if [[ $WAITFORIT_RESULT -ne 0 ]]; then
        echoerr "$WAITFORIT_cmdname: timeout occurred after waiting $WAITFORIT_TIMEOUT seconds for $WAITFORIT_HOST:$WAITFORIT_PORT"
    fi
    return $WAITFORIT_RESULT
}

# process arguments
while [[ $# -gt 0 ]]
do
    case "$1" in
        *:* )
        WAITFORIT_hostport=(${1//:/ })
        WAITFORIT_HOST=${WAITFORIT_hostport[0]}
        WAITFORIT_PORT=${WAITFORIT_hostport[1]}
        shift 1
        ;;
        --child)
        WAITFORIT_CHILD=1
        shift 1
        ;;
        -q | --quiet)
        WAITFORIT_QUIET=1
        shift 1
        ;;
        -s | --strict)
        WAITFORIT_STRICT=1
        shift 1
        ;;
        -h)
        WAITFORIT_HOST="$2"
        if [[ $WAITFORIT_HOST == "" ]]; then break; fi
        shift 2
        ;;
        --host=*)
        WAITFORIT_HOST="${1#*=}"
        shift 1
        ;;
        -p)
        WAITFORIT_PORT="$2"
        if [[ $WAITFORIT_PORT == "" ]]; then break; fi
        shift 2
        ;;
        --port=*)
        WAITFORIT_PORT="${1#*=}"
        shift 1
        ;;
        -t)
        WAITFORIT_TIMEOUT="$2"
        if [[ $WAITFORIT_TIMEOUT == "" ]]; then break; fi
        shift 2
        ;;
        --timeout=*)
        WAITFORIT_TIMEOUT="${1#*=}"
        shift 1
        ;;
        --)
        shift
        WAITFORIT_CLI=("$@")
        break
        ;;
        --help)
        usage
        ;;
        *)
        echoerr "Unknown argument: $1"
        usage
        ;;
    esac
done

if [[ "$WAITFORIT_HOST" == "" || "$WAITFORIT_PORT" == "" ]]; then
    echoerr "Error: you need to provide a host and port to test."
    usage
fi

WAITFORIT_TIMEOUT=${WAITFORIT_TIMEOUT:-15}
WAITFORIT_STRICT=${WAITFORIT_STRICT:-0}
WAITFORIT_CHILD=${WAITFORIT_CHILD:-0}
WAITFORIT_QUIET=${WAITFORIT_QUIET:-0}

# check to see if timeout is from busybox?
WAITFORIT_TIMEOUT_PATH=$(type -p timeout)
WAITFORIT_TIMEOUT_PATH=$(realpath $WAITFORIT_TIMEOUT_PATH 2>/dev/null || readlink -f $WAITFORIT_TIMEOUT_PATH)
if [[ $WAITFORIT_TIMEOUT_PATH =~ "busybox" ]]; then
        WAITFORIT_ISBUSY=1
        WAITFORIT_BUSYTIMEFLAG="-t"

else
        WAITFORIT_ISBUSY=0
        WAITFORIT_BUSYTIMEFLAG=""
fi

if [[ $WAITFORIT_CHILD -gt 0 ]]; then
    wait_for
    WAITFORIT_RESULT=$?
    exit $WAITFORIT_RESULT
else
    if [[ $WAITFORIT_TIMEOUT -gt 0 ]]; then
        wait_for_wrapper
        WAITFORIT_RESULT=$?
    else
        wait_for
        WAITFORIT_RESULT=$?
    fi
fi

if [[ $WAITFORIT_CLI != "" ]]; then
    if [[ $WAITFORIT_RESULT -ne 0 && $WAITFORIT_STRICT -eq 1 ]]; then
        echoerr "$WAITFORIT_cmdname: strict mode, refusing to execute subprocess"
        exit $WAITFORIT_RESULT
    fi
    exec "${WAITFORIT_CLI[@]}"
else
    exit $WAITFORIT_RESULT
fi
view-for-it.sh

 

 

原本以为这个方案是十拿九稳的,在运行的过程中又出现了问题,即在Nodejs接收端,又出现了No such file or directory/usr/bin/env: bash的错误,这是个什么问题???

查找了网上的一些相关问题后,锁定了问题的原因,是因为Windows和Linux文件的编码问题,其中找到一个ELK的docker-compose也是相同的问题《https://github.com/deviantony/docker-elk/issues/36》

其中提到了两点,

1、使用Nodepad++替换指定的换行符

2、在docker-compose up -d启动前,使用docker-compose build命令编译一次

docker-compose RabbitMQ与Nodejs接收端同时运行时的错误_第3张图片

 

那好,第一步:将wait-for-it.sh文件使用Nodepad++处理一下

docker-compose RabbitMQ与Nodejs接收端同时运行时的错误_第4张图片

第二步:在docker-compose up -d前面执行docker-compose build一次

docker-compose RabbitMQ与Nodejs接收端同时运行时的错误_第5张图片

最后,在启动容器后,可以看到,在Nodejs接收端,wait-for-it作用后,过了九秒才启动Nodejs接收端

docker-compose RabbitMQ与Nodejs接收端同时运行时的错误_第6张图片 


2019-03-29 更新:当第二次使用容器时,出现另一个错误

ERROR: for mes-run_mesrabbitmqmonitoringclient_1  Cannot start service mesrabbitmqmonitoringclient: OCI runtime create failed: container_linux.go:348: starting container process caused "exec: \"./wait-for-it.sh\": permission denied": unknown

ERROR: for mesrabbitmqmonitoringclient  Cannot start service mesrabbitmqmonitoringclient: OCI runtime create failed: container_linux.go:348: starting container process caused "exec: \"./wait-for-it.sh\": permission denied": unknown
ERROR: Encountered errors while bringing up the project.

个人猜测原因是,代码是在Windows电脑上进行代码开发的,默认情况下在Docker Windows中build image时,会为文件默认增加运行(X)权限,然后将镜像tag image后,直接push image到docker hub上,在服务器中,使用Docker-compose直接从docker hub 上pull image后运行container

但现在为何不行?因为现在修改为使用Azure DevOps平台build image,默认是没有设置运行(X)权限的,pull image后,在运行wait-for-it.sh时,会无法检测到权限

接下来应该要解决的是,如何在运行前增加sudo 用户,并且chrom +x  ./wait-for-it.sh

docker-compose RabbitMQ与Nodejs接收端同时运行时的错误_第7张图片

2019-03-29 最终解决问题了

现在也依然是使用Azure DevOps build image,增加一行代码chmod +x ./wait-for-it.sh即可

# FROM BASIC IMAGE
FROM node:7

# CREATE AND SET WORK-DIRECTORY
RUN mkdir -p /usr/src/app
WORKDIR /usr/src/app

# INSTALL APP DEPENDENCIES
COPY package.json /usr/src/app/
RUN npm install -g cross-env babel-cli
RUN npm install

# DB ENVIRONMENT SETTING
# ENV NODE_ENV="local"

# BUILD SOURCE CODE
COPY . /usr/src/app
COPY wait-for-it.sh /usr/src/app
#这一行非常重要 RUN
chmod +x ./wait-for-it.sh RUN npm run build # No Need PORT(Just Command) # EXPOSE 3000 # DEFAULT COMMAND # CMD [ "npm", "start" ] CMD ["./wait-for-it.sh", "rabbitmq:5672", "-t", "120", "--", "npm", "start"]

如果问题没有得到解决,可以参考:https://github.com/nodejs/docker-node/issues/6

 

 

 

方案参考地址:

《Docker and Rabbitmq: ECONNREFUSED between containers》

《docker-compose start kibana failed!--No such file or directory/usr/bin/env: bash》

 

转载于:https://www.cnblogs.com/weschen/p/10253664.html

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