Docker HEALTHCHECK在nodejs express应用程序中失败

Question

我为节点/快速容器设置了新的docker HEALTHCHECK命令，如下所示

HEALTHCHECK --interval=5m --timeout=5s \
  CMD $ROOT_APPLICATION/healthcheck.sh localhost $PORT || exit 1

healthcheck.sh脚本执行以下操作

function healthcheck () {
    pt=$2
    port=${pt:-"3000"}
    RES=$(curl -s http://$1:$2/status | jq '.status.online')
    if [ "$RES" == "true" ]; then
        return 0
    else
        return 1
    fi
}
healthcheck $@

节点api /status返回如下json

{
  "status": 
  {
     "online": true
  }
}

我确定健康检查正确无误，因为我可以在容器内这样做

# $ROOT_APPLICATION/healthcheck.sh localhost $PORT
# status=$?
# [ $status -eq 0 ] && echo "success" || echo "failed"
success

也手动调用运行状况检查端点：

# curl -s http://localhost:3000/ws/1.0/status| jq '.status.online'
true

[如果我检查容器状态，则会得到unhealthy状态

CONTAINER ID        IMAGE                              COMMAND                  CREATED             STATUS                         PORTS                              NAMES
d8539fa50a40        my_container         "node --max_old_sp..."   35 minutes ago      Up 35 minutes (unhealthy)      0.0.0.0:3000-3001->3000-3001/tcp   my_image

[UPDATE]

这里是docker container inspect的输出

    "FinishedAt": "0001-01-01T00:00:00Z",
    "Health": {
        "Status": "unhealthy",
        "FailingStreak": 9,
        "Log": [
            {
                "Start": "2020-03-25T10:11:17.687207876Z",
                "End": "2020-03-25T10:11:17.829283718Z",
                "ExitCode": -1,
                "Output": "rpc error: code = 2 desc = oci runtime error: exec failed: container_linux.go:247: starting container process caused \"invalid environment 'NODE_ID'\"\n"

要重现此问题，您必须定义未分配docker-compose变量environment的NODE_ID Yaml文件：

（最小Yaml文件）

version: '2'
services:
 my_service:
     environment:
        NODE_ID
        NODE_ENV=production

Answer 1

检查服务将显示运行状况检查的结果（并且完整的检查还将显示NODE_ID变量的问题）。

starting container process caused \"invalid environment 'NODE_ID'\"\n

提供的撰写文件中未分配的NODE_ID假定您已在运行docker-compose up或docker stack deploy命令的环境中定义了此变量。您可以对此进行调整以为其提供默认值：

version: '2'
services:
 my_service:
     environment:
        NODE_ID=${NODE_ID:-undefined}
        NODE_ENV=production

有关该语法的更多详细信息，请参见https://docs.docker.com/compose/compose-file/#variable-substitution