In Docker Swarm mode, is there a way to restart a Docker service, just before it reaches a specific threshold of cpu or memory?

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• best way to add a spring boot web application with JSPs to a docker container?

  so i have a spring boot web application, it uses JSPs, and im supposed to put it in a container .
  my question is what is the best way ? ive tried to copy the project and then run it there using a wmvn like so : dockerfile:

  FROM openjdk:8-jdk-alpine
  ADD . /input-webapp
  WORKDIR /input-webapp
  EXPOSE 8080:8080
  ENTRYPOINT ./mvnw spring-boot:run
  

  which works, but it takes a long time getting the dependencies and feels messy .
  

  and ive tried to package it into a jar, and then copy the jar only, and run it : dockerfile:

  FROM openjdk:8-jdk-alpine
  ADD target/input-webapp-0.0.1-SNAPSHOT.jar input-webapp-0.0.1-SNAPSHOT.jar
  EXPOSE 8080:8080
  ENTRYPOINT ["java","-jar","input-webapp-0.0.1-SNAPSHOT.jar"]
  

  but this way it cant see the JSPs, or at least i think this is the problem, as i get a 404.
  

  so is there a better way ? can i copy the jsps plus the jar to make it work? thanks
• build spring boot (mvnw) with docker can not use cache

  Spring Boot Docker Experimental Features Docker 18.06 comes with some “experimental” features, including a way to cache build dependencies. To switch them on, you need a flag in the daemon (dockerd) and an environment variable when you run the client. With the experimental features, you get different output on the console, but you can see that a Maven build now only takes a few seconds instead of minutes, provided the cache is warm.

  my dockerfile can not use cache.

  dockerfile

  # syntax=docker/dockerfile:experimental
  FROM openjdk:8-jdk-alpine as build
  WORKDIR /workspace/app
  
  COPY mvnw .
  COPY .mvn .mvn
  COPY pom.xml .
  COPY src src
  
  RUN --mount=type=cache,target=/root/.m2 ./mvnw install -DskipTests -s .mvn/wrapper/settings.xml
  RUN mkdir -p target/extracted && java -Djarmode=layertools -jar target/*.jar extract --destination target/extracted
  
  FROM openjdk:8-jre-alpine
  ENV TZ Asia/Shanghai
  RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone
  RUN addgroup -S spring && adduser -S spring -G spring
  USER spring:spring
  
  ARG EXTRACTED=/workspace/app/target/extracted
  ARG JAVA_OPTS="-Xmx100m -Xms100m"
  
  COPY --from=build ${EXTRACTED}/dependencies/ ./
  COPY --from=build ${EXTRACTED}/spring-boot-loader/ ./
  COPY --from=build ${EXTRACTED}/snapshot-dependencies/ ./
  COPY --from=build ${EXTRACTED}/application/ ./
  
  ENTRYPOINT ["sh", "-c","java ${JAVA_OPTS} org.springframework.boot.loader.JarLauncher"]
  

  run shell

  DOCKER_BUILDKIT=1 docker build -t org/spring-boot .
  

  every time use many minutes
• PyQT5 doesn't work on docker ImportError: libsmime3.so: cannot open shared object file: No such file or directory

  I have a Dockerfile with PyQT installed like below

  FROM ubuntu:20.04
  ENV DEBIAN_FRONTEND=noninteractive
  RUN adduser --quiet --disabled-password qtuser && usermod -a -G audio qtuser
  RUN apt-get update -y \
      && apt-get install alsa -y \
      && apt-get install -y python3-pyqt5 \
      && apt-get install python3-pip -y && \
      pip3 install pyqtwebengine
  WORKDIR /htmltopdf
  

  I built my image like this docker build -t html-to-pdf .

  Then I ran my image like this docker run --rm -v "$(pwd)":/htmltopdf -u qtuser -it html-to-pdf python3 htmlToPdfnew.py --url https://www.w3schools.com/howto/howto_css_register_form.asp

  But I'm getting below error

  Traceback (most recent call last):
    File "htmlToPdfnew.py", line 2, in <module>
      from PyQt5 import QtWidgets, QtWebEngineWidgets
  ImportError: libsmime3.so: cannot open shared object file: No such file or directory
  

  I do NOT get that error in my PC.

  below is my python code

  import sys
  from PyQt5 import QtWidgets, QtWebEngineWidgets
  from PyQt5.QtCore import QUrl, QTimer
  from PyQt5.QtGui import QPageLayout, QPageSize
  from PyQt5.QtWidgets import QApplication
  import argparse
  
  
  def main():
      url = ''
      parser = argparse.ArgumentParser(description="Just an example", formatter_class=argparse.ArgumentDefaultsHelpFormatter)
      parser.add_argument("--url", help="Type url")
      args = parser.parse_args()
      config = vars(args)
      url = config['url']
  
  
      app = QtWidgets.QApplication(sys.argv)
      loader = QtWebEngineWidgets.QWebEngineView()
      loader.setZoomFactor(1)
      layout = QPageLayout()
      layout.setPageSize(QPageSize(QPageSize.A4Extra))
      layout.setOrientation(QPageLayout.Portrait)
      loader.load(QUrl(url))
      loader.page().pdfPrintingFinished.connect(lambda *args: QApplication.exit())
  
      def emit_pdf(finished):
          QTimer.singleShot(2000, lambda: loader.page().printToPdf("test.pdf", pageLayout=layout))
  
      loader.loadFinished.connect(emit_pdf)
      sys.exit(app.exec_())
  
  if __name__ == '__main__':
      main()
  

  so how do I resolve below error ?

  Traceback (most recent call last):
    File "htmlToPdfnew.py", line 2, in <module>
      from PyQt5 import QtWidgets, QtWebEngineWidgets
  ImportError: libsmime3.so: cannot open shared object file: No such file or directory
  
• shell script : container vs host

  For Loop to start from 2nd argument behaving differently on container and host

  #!/bin/bash 
  
  for i in "${@:2}"
  do  
          echo $i
  done
  

  Call:

  script.sh 129 5 6 7
  

  Output: Container: Alpine:Latest #skipping 2 characters

  9 5 6 7
  

  Host: Debian GNU/Linux #skipping 1st argument complete

  5 6 7
  
• React error: Container "tripMap" not found. Suddenly not working or being despite no changes being made

  I'm working on a React project with the Trimble Map api. I've run into an issue with the map container not being found. It was working previously but when I restarted the local host the error occurred. Not sure exactly what's causing the problem.

  First guess would be that its trying to render before the map container is created and causing the error but not sure where the issue would be located.

  Below is my method. Thanks for any help you can provide

  
  **StyleMenu.jsx**
  **//This is the file the map is being created in and also a menu that lets you change the style on click. This was working previously but now its broken without any changes.**
  
  import React, { Component, useState } from "react"
  import TrimbleMaps, { MapMouseEvent } from "@trimblemaps/trimblemaps-js";
  import { MenuIcon, PlusIcon, MinusIcon } from "./IconSVG";
  
  export const tripMap = new TrimbleMaps.Map({ **//creation of the map**
    container: "tripMap", **//container that can't be found despite it being found previously**
    center: new TrimbleMaps.LngLat(-74.87136635072328, 39.64996988267103),
    zoom: 7,
    style: 'transportation' **//value I need to update with the onChange function below**
  })
  
  class StyleMenu extends Component {
      constructor(props) {
        super(props);
        this.state = {
          value: 'transportation',
          showing: false
      }
      
  
    }
      
      onChange = e =>{
        this.setState({value : e.target.value});
        tripMap.setStyle(e.target.value); **//what should set the value of the style of the map was working previous but container cannot be found now.**
      }
  
      render(){
        const {value} = this.state;
        const { showing } = this.state;
        console.log(this.state.value);
        return(
          <div>
            <button className="menu-btn" onClick={() => this.setState({ showing : !showing})}><MenuIcon /></button>
          {showing 
            ? <div className="menu-container">
                <div className="menu-header">
                  <p>MAP STYLES</p>
                </div>
                <div className="menu-list">
                  <form>
                      <label className="btn-transportation">
                      <span className="icon-transportation"></span> 
                          <input 
                                type="radio"
                                value="transportation"
                                checked={value === "transportation"}
                                onChange={this.onChange}
                                /> 
                              <div className="transportation-text">
                                Day
                              </div>
                      
                      </label>
                      <br/>
                      <label className="btn-transportation-dark">
                      <span className="icon-transportation-dark"></span>
                          <input type="radio"
                                value="transportation_dark"
                                checked={value === "transportation_dark"}
                                onChange={this.onChange}
                                />
                              <div className="transportation-dark-text">
                                Night
                              </div>   
                      </label>
                      <br/>
                      <label className="btn-satellite">
                      <span className="icon-satellite"></span>
                          <input type="radio"
                                value="satellite"
                                checked={value === "satellite"}
                                onChange={this.onChange}
                                />
                              <div className="satellite-text">
                                Satellite
                              </div>   
                      </label>
                      <br/>
                      <label className="btn-terrain">
                      <span className="icon-terrain"></span>
                          <input type="radio"
                                value="terrain"
                                checked={value === "terrain"}
                                onChange={this.onChange}
                                />
                              <div className="terrain-text">
                                Terrain
                              </div>   
                      </label>
                      <br/>
                      <label className="btn-basic">
                      <span className="icon-basic"></span>
                          <input type="radio"
                                value="basic"
                                checked={value === "basic"}
                                onChange={this.onChange}
                                />
                              <div className="basic-text">
                                Basic
                              </div>   
                      </label>
                      <br/>
                  </form>
                </div>
          </div> :null }
            
          <button className="menu-btn-2"><PlusIcon /></button>
          <button className="menu-btn-3"><MinusIcon /></button>
          </div>
          
          
        )
      }
    }
  
  
    
    
  export default StyleMenu;
  
  

  
  **Map.jsx**
  
  
  import React, { useEffect } from "react"
  import TrimbleMaps from "@trimblemaps/trimblemaps-js";
  import { Box } from "@mui/material";
  import { TripManagementClient, ShipmentDataPayload } from "../services/TripManagementClient";
  import StyleMenu, { tripMap} from "./StyleMenu";
  import { valueToPercent } from "@mui/base";
  
  export function Map({ height, coords }) {
    useEffect(() => {
      setupMap()
    }, []);
    
    /**
     * Creates an array of TrimbleMaps.LngLat objects from the `coords` collections prop
     * 
     * @returns Array<TimbleMaps.LngLat> 
     */
    const parseStops = () => {
      const trimbleStops = []
      coords.forEach(coord => {
        trimbleStops.push(new TrimbleMaps.LngLat(coord.long, coord.lat));
      });
  
      return trimbleStops;
    }
    
  
    const setupMap = () => {
      TrimbleMaps.APIKey = ""; //hidden for security
      
      <tripMap/> **//reference created map from the StyleMenu.js file.**
      const driverIcon = new TrimbleMaps.Marker().setLngLat([-74.415108, 39.362129]).addTo(tripMap); 
      const endIcon = new TrimbleMaps.Marker().setLngLat([-75.165222, 39.952583]).addTo(tripMap); 
      
      //All map customization and updates
      tripMap.on('load', function() { //updates the map after its initialized and loaded in the application. Most customizations done post initialization are placed here.
        //customize your map once loaded
        console.log("map loaded") //prints map loaded to the console
      });
      
    return tripMap;
  }
  
    return (
      <><StyleMenu /><Box id="tripMap" sx={{ height: height }}></Box></>  
    )
    
  }  
  
  
  

  **App.js
  //map and style menu joined and rendered here. below is the relevant code to the map**
  
  
    return (
      <div>
        <ThemeProvider theme={theme}>
          {payload &&
            <div>
              <Header customer={payload.orderNumber} />
              <Map height={300} coords={ getStops(payload) } /> //map rendering.
              <TripDetails {...payload} />
            </div>
          }
        </ThemeProvider>
        
      </div>
    );
  }
  
  export default App;
  
  
• Quarkus docker container failed to run / connect to the DB

  In my project, using Quarkus, Angular and PostgreSQL DB, when I run the backend & and the frontend in dev Mode, I can connect to the DB (which is postgreSQL image running in a docker container) and create new lines in the tables and just works fine. Of course the Quarkus docker file is auto-generated. Here is the "application.properties" file I typed (inside the Quarkus project) :

  quarkus.datasource.db-kind=postgresql
  quarkus.datasource.username= username
  quarkus.datasource.password= pwd
  quarkus.datasource.jdbc.url=jdbc:postgresql://localhost:5432/db-mcs-thirdparty
  quarkus.flyway.migrate-at-start=true
  quarkus.flyway.baseline-on-migrate=true
  quarkus.flyway.out-of-order=false
  quarkus.flyway.baseline-version=1
  

  and this is the "docker-compose.yml" file which I placed inside the backend folder (Quarkus):

  version: '3.8'
  services:
    db:
      container_name: pg_container
      image: postgres:latest
      restart: always
      environment:
        POSTGRES_USER: username
        POSTGRES_PASSWORD: pwd
        POSTGRES_DB: db-mcs-thirdparty
      ports:
        - "5432:5432"
  
    pgadmin:
        container_name: pgadmin4_container
        image: dpage/pgadmin4
        restart: always
        environment:
          PGADMIN_DEFAULT_EMAIL: usernamepgadmin
          PGADMIN_DEFAULT_PASSWORD: pwdpgadmin
        ports:
          - "5050:80"
  

  But when I build a Quarkus docker image and try to run it in docker container, it fails !! knowing that the Angular docker container runs well, also the DB. Here the error logs which I get after running the container:

  Starting the Java application using /opt/jboss/container/java/run/run-java.sh ...

  __  ____  __  _____   ___  __ ____  ______
   --/ __ \/ / / / _ | / _ \/ //_/ / / / __/
   -/ /_/ / /_/ / __ |/ , _/ ,< / /_/ /\ \
  --\___\_\____/_/ |_/_/|_/_/|_|\____/___/
  
  2022-05-06 12:58:31,967 WARN  [io.agr.pool] (agroal-11) Datasource '<default>': The connection attempt failed.
  2022-05-06 12:58:32,015 ERROR [io.qua.run.Application] (main) Failed to start application (with profile prod): java.net.UnknownHostException: db
  
  at java.base/java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:229)
  at java.base/java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
  at java.base/java.net.Socket.connect(Socket.java:609)
  at org.postgresql.core.PGStream.createSocket(PGStream.java:241)
  at org.postgresql.core.PGStream.<init>(PGStream.java:98)
  at org.postgresql.core.v3.ConnectionFactoryImpl.tryConnect(ConnectionFactoryImpl.java:109)
  at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:235)
  at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:49)
  at org.postgresql.jdbc.PgConnection.<init>(PgConnection.java:223)
  at org.postgresql.Driver.makeConnection(Driver.java:400)
  at org.postgresql.Driver.connect(Driver.java:259)
  at io.agroal.pool.ConnectionFactory.createConnection(ConnectionFactory.java:210)
  at io.agroal.pool.ConnectionPool$CreateConnectionTask.call(ConnectionPool.java:513)
  at io.agroal.pool.ConnectionPool$CreateConnectionTask.call(ConnectionPool.java:494)
  at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
  at io.agroal.pool.util.PriorityScheduledExecutor.beforeExecute(PriorityScheduledExecutor.java:75)
  at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1126)
  at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
  at java.base/java.lang.Thread.run(Thread.java:829)
  

  So I replaced "localhost" in the:

  quarkus.datasource.jdbc.url=jdbc:postgresql://localhost:5432/db-mcs-thirdparty
  

  with the IP address, with the DB's name, even I tried to enter the user name and the psw in that same line, etc ...., but didn't work.

  I even stopped all the running containers (DB, frontend) and tried to run only the Quarkus container, the same case happens. For the ports that I used, you can check the attached image. the used ports

  How should resolve this issue? thank you in advance.
• (Terraform) Error 400: Invalid request: instance name (pg_instance)., invalid

  On GCP, I'm trying to create a Cloud SQL instance with this Terraform code below:

  resource "google_sql_database_instance" "postgres" {
      name                = "pg_instance"
      database_version    = "POSTGRES_13"
      region              = "asia-northeast1"
      deletion_protection = false
  
      settings {
          tier      = "db-f1-micro"
          disk_size = 10
      }
  }
  
  resource "google_sql_user" "users" {
      name     = "postgres"
      instance = google_sql_database_instance.postgres.name
      password = "admin"
  }
  

  But I got this error:

  Error: Error, failed to create instance pg_instance: googleapi: Error 400: Invalid request: instance name (pg_instance)., invalid

  Are there any mistakes for my Terraform code?
• How does Kubernetes and Terraform work seamlessly together and what role do they each undertake?

  I am a bit confused about the individual roles of Kubernetes and Terraform when using them both on a project.

  Until very recently, I had a very clear understanding of both their purposes and everything made sense to me. But, then I heard in one of Nana's videos on Terraform, that Terraform was also very advanced in orchestration and I got confused.

  Here's my current understanding of both these tools:

  • Kubernetes: Orchestration software that controls many docker containers working together seamlessly. Kubernetes makes sure that new containers are deployed based on the desired infrastructure defined in configuration files (written with the help of a tool like Terraform, as IaC).

  • Terraform: Tool for provisioning, configuring, and managing infrastructure as IaC.

  So, when we say that Terraform is a good tool for orchestration, do we mean that it's a good tool for orchestrating infrastructure states or docker containers as well?

  I hope someone can clear that out for me!
• Automate Azure Devops (FTP Upload) and Git to upload on Remote Server

  The current setup is as below

  • Version Control - Git
  • Repos and Branch hosted on - Azure DevOps
  • Codebase - External server

  The dev team clones Azure Repo into local git project and any staged changes are committed via Git and pushed to specific branch of Azure DevOps. In this setup we would want to upload the changes to external FTP servers and avoid manual upload. Currently trying to use Azure Devops FTP Upload Task (https://docs.microsoft.com/en-us/azure/devops/pipelines/tasks/utility/ftp-upload?view=azure-devops), however facing issues; yaml script as below

  trigger:
  - main
  
  pool:
    vmImage: 'ubuntu-latest'
  
  variables:
    phpVersion: 7.4
    webAppName: 'Test Project'
    buildConfiguration: 'Release'
    vmImageName: 'ubuntu-latest'
  
  steps:
  
  - publish: $(System.DefaultWorkingDirectory)/AzureRepoName
    artifact: Test Project Deploy
  
  - task: FtpUpload@2
    displayName: 'FTP Upload'
    inputs:
      credentialsOption: inputs
      serverUrl: 'ftps://00.00.00.00:22'
      username: ftp-username
      password: ftp-password
      rootDirectory: '$(System.DefaultWorkingDirectory)/AzureRepoName'
      remoteDirectory: '/home/public_html'
      clean: false
      cleanContents: false
      preservePaths: true
      trustSSL: true
  

  PROBLEM

  Following errors occur when I commit (for test purposes) something.

  Starting: PublishPipelineArtifact
  ==============================================================================
  Task         : Publish Pipeline Artifacts
  Description  : Publish (upload) a file or directory as a named artifact for the current run
  Version      : 1.199.0
  Author       : Microsoft Corporation
  Help         : https://docs.microsoft.com/azure/devops/pipelines/tasks/utility/publish-pipeline-artifact
  ==============================================================================
  Artifact name input: Test Project Deploy
  ##[error]Path does not exist: /home/vsts/work/1/s/AzureRepoName
  Finishing: PublishPipelineArtifact
  

  I want to upload any staged change that is committed to main branch on Azure Devops to be automatically deploy on the remote FTP server

  Thanks
• invalid mount config for type "bind": bind source path does not exist: /container/tdarr-server/server

  I am trying to use an nfs share to use docker swarm with a single endpoint server for a drive, the NFS share its self does work as i can create files on it, however when trying to use it on a stack i get a bind source path error. my nfs share is set to /container on both machines so each machine can find it at the same location. here is what i have as a volume in my docker compose file:

      volumes:
    - /container/tdarr-server/server:/app/server
    - /container/tdarr-server/configs:/app/configs
    - /container/tdarr-server/logs:/app/logs
    - /container/plex/media:/media
    - /container/tdarr-server/transcode:/transcode
  
• add nodes to dockers swarm from different servers

  I am new to docker swarm, I read documentation and googled to the topic, but results was vague, Is it possible to add worker or manager node from distinct and separate Virtual private servers?