Docker Commands-Updated

• docker -v  returns docker version 

• docker login login to docker hub using command line

• docker pull hello-world retrieve hello-world docker image from docker hub

• docker run hello-world execute hello-world docker image

• docker ps -a list all processes in docker

• docker rmi hello-world --force delete hello-world image from docker forcefully 

• docker rm container_id --force delete container from docker forcefully 

• docker run -d nginx run nginx server in background

• docker ps list running processes in docker

• docker container inspect container_id get the all information about docker container 

• docker run -d -p 3600:80 --name sujith-nginx nginx port forwarding with docker images execution 

• docker exec -it container_d redis redis-cli access redis-cli after docker image execution

• set myvalue 5 set value redis

• get myvalue retrieve value

• docker run -it ubuntu bash run ubuntu with bash access in docker

• apt-get install git tree -y install git inside ubuntu

• ctrl + p + q exit to run git in background 

• docker container commit --author "sujith" -m "my custom image" running_container_id my_ubuntu_git_image create image using running git installed ubuntu container

• docker docker tag my_ubuntu_git_image sujithdc/my_ubuntu_git_image tagging docker image to push to docker hub

• docker push sujithdc/my_ubuntu_image push image to docker hub

fatal: Authentication failed git resolution

 If you have changed your certificate of your git repository, you will receive the following error message.

fatal: Authentication failed for for 'https://bitbucket.*****/***/usermgt*.git/'

You can follow following steps to resolve the issue.

1. Retrieve the remote URL

git remote -v

2. Remove the remote URL

git remote rm origin

3. Add URL as new remote URL

git remote add origin  https://bitbucket.*****/***/usermgt*.git

4. Make changes and push

git push origin master

git commands

List of important commands for git CLI users

• git clone - clone project to local machine

• git status - check current status  

• git add ./filename - add new changes locally

• git commit -m message - commit new changes into bitbucket

• git push - will send changes into bitbucket

• git pull - get updates from bitbucket to local repository

• git branch - view current working branch

• git branch dev - create a new branch called dev

• git checkout dev - switch into dev from current branch

• git push --set-upstream origin dev - push changes to dev branch

• git remote -v  - find remote repository url

• git remote set-url origin https://github.com/suji/TestApp.git - change remote repository url to  a new one
• git merge --abort -abort current merge command
• git remote rm origin -remove origin url of repository

Create a new repository on the command line

• echo "# TestApp" >> README.md

• git init

• git add README.md

• git commit -m "first commit"

• git remote add origin https://github.com/sujith/TestApp.git

• git push -u origin master

Push an existing repository from the command line

• git remote add origin https://github.com/sujith/TestApp.git

• git push -u origin master

When you add new file(which has already in the git repository) to git ignore file, run below command to ignore it. 

• git rm -r --cached .  

• git add .

• git commit -m 'removing ignored files'

Configure git for the first time

• git config --global user.name "Sujith Delpachithra"

• git config --global user.email "sujith@g**.lk"

If your code is already tracked by git then set this repository as your "origin" to push.

• cd existing-project

• git remote add origin http://bitbucket.mobitel.lk/suji/testapp.git

• git push -u origin --all

• git push origin --tags

You can use the git cherry-pick command to merge one branch to another.

• git cherry-pick d4d8e7c

(Replace d4d8e7c with  relevant commit id you need to merge from another branch to this branch)

You can revert to previous commit.

• git reset --hard <commit_id>

• git push -f origin staging

Let's say you want to merge local development branch into local staging branch.

Then first you need to checkout stating branch with this command.

• git checkout staging

Then you can do merging with this command.

• git merge development

How to merge development branch changes to staging branch.

1. First checkout to staging branch

2. Then execute below command

• git merge development

Sending mails/ sms from Linux server

You have to configure mail server in Linux server. Then you can use following command to send mails.

For mail -

mail -s "subject" recipients_emails < mail body

For SMS -

mail -s "subject" number@your_email_domain < mail body

Schell script to restart JAVA apps

#!/bin/bash

ps -ef |grep "java -jar" > /apps/sujith/apps

x=$(cat /apps/sujith/apps |grep "SMS_App.jar" |wc -l)

echo $x

        if [ $x = 0 ]

        then

                date

                echo " Starting ......Please check logs !! "

                echo ""

                cd /apps/sujith/sms

                nohup java -jar -Xms32m -Xmx128m SMS_App.jar 2>> SMS_App.err &

        elif [ $x = 1 ]

        then

                date

                echo "STOPPING "

                cat /apps/sujith/apps |grep "SMS_App.jar" | awk -F " " '{print $2}' | xargs kill -9

                echo "STOPPED "

                date

                echo "STARTING"

                cd /apps/sujith/sms

                nohup java -jar -Xms32m -Xmx128m SMS_App.jar 2>>SMS_App.err &

        else

                echo "SMS App"

        fi

sample docker file for JAVA application

 You can add following Dockerfile to JAVA docker image.

#Use open JDK 8 image as the base image
FROM openjdk:8

#Create a new app directory for my application files (Inside image file system)
RUN mkdir /app

#Set the directory for excuting future commands
WORKDIR /app

#Copy my application files from host machine into image file system
COPY target/docker-helloworld-1.0-SNAPSHOT.jar  app.jar

#Run jar file
ENTRYPOINT ["java","-jar","app.jar"]

#CMD java -jar app.jar

docker commands

• docker -version

checking current installed docker version

• docker container run hello-world

run hello-world docker image. if image is not available in local repository, above command will download the image from docker-hub

• docker run -it ubuntu bash

run ubuntu container in docker.

• docker ps

list running docker container

• docker image  build -t hello-world:1.0 .

use above command for buid a docker image. (here . means Dockerfile contains in the current directory)

• docker container run hello-world:1.0

use below command for run above docker image.

• docker image ls

list images in local repository