docker-compose 读取本地文件配置 docker-compose depends_on

使用depends_on进行容器排序时并不能完美的解决容器之间的依赖问题，原因是因为 depends_on只能保证容器进入到 运行状态而不是完全状态（不知道怎么描述了）。

网上已经列出来了解决方法，使用 wait-for-it或者 wait-for，在启动时对需要优先启动的容器进行访问，当可以访问成功时在启动，但是都不够详细，甚至很多都是同样的内容，（这里吐槽一下环境真乱）。

可能我比较笨，花了一天才解决，在这里记录下来。

我使用的是 wait-for ，wait-for-it.sh我测试的时候了出现了保错所以没用。

正文：

需求是要将一个 打包好的 ar文件注册到nacos中，但是nacos启动较慢，就需要进行顺序的设置。

将需要的 jar文件删除到虚拟机或服务器。接下来编写 dockerfile和docker-compose

FROM openjdk:8-jre  // 基于 openjdk 
COPY wait-for .     // 将 wait-for 拷贝到虚拟机中
RUN apt-get update  // 更新源，
RUN apt-get install netcat -y // 安装 netcat， wait-for 需要使用到
WORKDIR /app                // 设置落脚点
ADD course.jar course.jar   // 将 jar 文件 添加到 虚拟机中
EXPOSE 8002                 // 需要暴露的端口

我的配置是以图片为准的，代码块中的是为了更好的理解 ，想来应该没有差别。

docker-compose

version: '3.0'
services:
nacos:
image: nacos/nacos-server:1.1.4
container_name: nacos
ports:
- "8848:8848"
environment:
MODE: standalone   # nacos 单节点运行
 
course:
build: /root/
container_name: course
ports:
- "18002:18002"
depends_on:
- nacos
command: ["sh","wait-for","nacos:8848","--","java","-jar","course.jar"]

这里就不做过多的解释了，与平常相差不大。

我之前查找到的帖子中，没有贴出dockerfile文件在这里最重要的就是，将 wait-for文件拷贝到虚拟机中，因为在 docker-compose中配置的command所使用的 文件是容器中的，如果你没有拷贝那么将找不到文件。然后是 apt-get update和 apt-get install netcat -y则是安装 wait-for运行的环境

我的wait-for代码，26行为超时时间，刚开始是15，但是时间太短了 容器超时我就设置为了 60，这是我唯一跟原来不一样的地方,之后就可以测试运行了

#!/bin/sh
 
# The MIT License (MIT)
#
# Copyright (c) 2017 Eficode Oy
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
 
set -- "$@" -- "$TIMEOUT" "$QUIET" "$PROTOCOL" "$HOST" "$PORT" "$result"
TIMEOUT=60
QUIET=0
# The protocol to make the request with, either "tcp" or "http"
PROTOCOL="tcp"
 
echoerr() {
if [ "$QUIET" -ne 1 ]; then printf "%s\n" "$*" 1>&2; fi
}
 
usage() {
exitcode="$1"
cat << USAGE >&2
Usage:
$0 host:port|url [-t timeout] [-- command args]
-q | --quiet                        Do not output any status messages
-t TIMEOUT | --timeout=timeout      Timeout in seconds, zero for no timeout
-- COMMAND ARGS                     Execute command with args after the test finishes
USAGE
exit "$exitcode"
}
 
wait_for() {
case "$PROTOCOL" in
tcp)
if ! command -v nc >/dev/null; then
echoerr 'nc command is missing!'
exit 1
fi
;;
wget)
if ! command -v wget >/dev/null; then
echoerr 'wget command is missing!'
exit 1
fi
;;
esac
 
while :; do
case "$PROTOCOL" in
tcp) 
nc -w 1 -z "$HOST" "$PORT" > /dev/null 2>&1
;;
http)
wget --timeout=1 -q "$HOST" -O /dev/null > /dev/null 2>&1 
;;
*)
echoerr "Unknown protocol '$PROTOCOL'"
exit 1
;;
esac
 
result=$?
 
if [ $result -eq 0 ] ; then
if [ $# -gt 7 ] ; then
for result in $(seq $(($# - 7))); do
result=$1
shift
set -- "$@" "$result"
done
 
TIMEOUT=$2 QUIET=$3 PROTOCOL=$4 HOST=$5 PORT=$6 result=$7
shift 7
exec "$@"
fi
exit 0
fi
 
if [ "$TIMEOUT" -le 0 ]; then
break
fi
TIMEOUT=$((TIMEOUT - 1))
 
sleep 1
done
echo "Operation timed out" >&2
exit 1
}
 
while :; do
case "$1" in
http://*|https://*)
HOST="$1"
PROTOCOL="http"
shift 1
;;
*:* )
HOST=$(printf "%s\n" "$1"| cut -d : -f 1)
PORT=$(printf "%s\n" "$1"| cut -d : -f 2)
shift 1
;;
-q | --quiet)
QUIET=1
shift 1
;;
-q-*)
QUIET=0
echoerr "Unknown option: $1"
usage 1
;;
-q*)
QUIET=1
result=$1
shift 1
set -- -"${result#-q}" "$@"
;;
-t | --timeout)
TIMEOUT="$2"
shift 2
;;
-t*)
TIMEOUT="${1#-t}"
shift 1
;;
--timeout=*)
TIMEOUT="${1#*=}"
shift 1
;;
--)
shift
break
;;
--help)
usage 0
;;
-*)
QUIET=0
echoerr "Unknown option: $1"
usage 1
;;
*)
QUIET=0
echoerr "Unknown argument: $1"
usage 1
;;
esac
done
 
if ! [ "$TIMEOUT" -ge 0 ] 2>/dev/null; then
echoerr "Error: invalid timeout '$TIMEOUT'"
usage 3
fi
 
case "$PROTOCOL" in
tcp)
if [ "$HOST" = "" ] || [ "$PORT" = "" ]; then
echoerr "Error: you need to provide a host and port to test."
usage 2
fi
;;
http)
if [ "$HOST" = "" ]; then
echoerr "Error: you need to provide a host to test."
usage 2
fi
;;
esac
 
wait_for "$@"

到此这篇关于浅谈Docker-compose中的depends_on顺序的问题解决的文章就介绍到这了