10/26/2021 0 Comments Docker Exercise For Mac
Lab exercise 1 latitude longitude and time answers.The overall workflow is show as the diagram below: The toolchain can pull Dockerfile from a GitHub repository. It builds the Docker image on a GitLab runner. It pushes the image to Docker Hub when a build is done. This is useful when an image is too big for Docker Hub to build it.
![]() Docker Exercise Free Login UsedIn the background: For long-running services like websites and databases.In this section you’ll try each of those options and see how Docker manages the workload. Interactively: This connects you to the container similar to the way you SSH into a remote server. To run a single task: This could be a shell script or a custom app. Task 1: Run some simple Docker containersThere are different ways to use containers. You will need this for later steps. Git clone If you do not have a DockerID (a free login used to access Docker Hub), please visit Docker Hub and register for one. When this happens, Docker automatically pulls it from Docker Hub.After the image is pulled, the container’s hostname is displayed ( 888e89a3b36b in the example below).CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES888e89a3b36b alpine "hostname" 50 seconds ago Exited (0) 49 seconds ago awesome_elionNote: The container ID is the hostname that the container displayed. Docker container run alpine hostnameThe output below shows that the alpine:latest image could not be found locally. The container will start, execute the hostname command, then exit.Run the following command in your Linux console. -rm tells Docker to go ahead and remove the container when it’s done executing.The first two parameters allow you to interact with the Docker container.We’re also telling the container to run bash as its main process (PID 1).When the container starts you’ll drop into the bash shell with the default prompt Docker has attached to the shell in the container, relaying input and output between your local session and the shell session in the container.Run the following commands in the container.Ls / will list the contents of the root director in the container, ps aux will show running processes in the container, cat /etc/issue will show which Linux distro the container is running, in this case Ubuntu 18.04.3 LTS. -interactive says you want an interactive session. Docker container run -interactive -tty -rm ubuntu bashIn this example, we’re giving Docker three parameters: Run an interactive Ubuntu containerYou can run a container based on a different version of Linux than is running on your Docker host.In the next example, we are going to run an Ubuntu Linux container on top of an Alpine Linux Docker host (Play With Docker uses Alpine Linux for its nodes).Run a Docker container and access its shell. Anyone can execute that task just by running the container - they don’t need the actual scripts or configuration information. You could build a Docker image that executes a script to configure something. As previously mentioned, the distribution of Linux inside the container does not need to match the distribution of Linux running on the Docker host.However, Linux containers require the Docker host to be running a Linux kernel. Cat /etc/issueNotice that our host VM is running Alpine Linux, yet we were able to run an Ubuntu container. This means if you run another docker container ls -all you won’t see the Ubuntu container.For fun, let’s check the version of our host VM. ExitNote: As we used the -rm flag when we started the container, Docker removed the container when it stopped. This will terminate the bash process, causing the container to exit. Run a background MySQL containerBackground containers are how you’ll run most applications. It’s much better to use a repeatable Dockerfile to build your image. You can run a container and verify all the steps you need to deploy your app, and capture them in a Dockerfile.You can commit a container to make an image from it - but you should avoid that wherever possible. The same is true of Windows containers - they need to run on a Docker host with a Windows kernel.Interactive containers are useful when you are putting together your own image. Executing the command below will give you an interactive shell ( sh) inside your MySQL container. -e will use an environment variable to specify the root password (NOTE: This should never be done in production).As the MySQL image was not available locally, Docker automatically pulled it from Docker Hub.Mysql: Using a password on the command line interface can be insecure.Mysql Ver 14.14 Distrib 5.7.19, for Linux (x86_64) using EditLine wrapperYou can also use docker container exec to connect to a new shell process inside an already-running container. -detach will run the container in the background. ExitTask 2: Package and run a custom app using DockerIn this step you’ll learn how to package your own apps as Docker images using a Dockerfile.The Dockerfile syntax is straightforward. Mysql -user=root -password=$MYSQL_ROOT_PASSWORD -versionType exit to leave the interactive shell session. This is because your shell is now connected to the sh process running inside of your container.Let’s check the version number by running the same command again, only this time from within the new shell session in the container. Cat DockerfileLet’s see what each of these lines in the Dockerfile do. Cd ~/linux_tweet_appDisplay the contents of the Dockerfile. Build a simple website imageLet’s have a look at the Dockerfile we’ll be using, which builds a simple website that allows you to send a tweet.Make sure you’re in the linux_tweet_app directory. EXPOSE documents which ports the application uses. And a graphic that will be used on our webpage. In this example, COPY is used to copy two files into the image: index.html. COPY copies files from the Docker host into the image, at a known location. For this example we’re starting from nginx:latest. -tag allows us to give the image a custom name. Echo $DOCKERIDUse the docker image build command to create a new Docker image using the instructions in the Dockerfile. Notice that we can specify the command, as well as run-time arguments.In order to make the following commands more copy/paste friendly, export an environment variable containing your DockerID (if you don’t have a DockerID you can get one for free via Docker Hub).You will have to manually type this command as it requires your unique DockerID.Echo the value of the variable back to the terminal to ensure it was stored correctly. Driver for ricoh mp c4503 on a macThe output below shows the Docker daemon executing each line in the DockerfileSending build context to Docker daemon 32.77kBDigest: sha256:af32e714a9cc3157157374e68c818b05ebe9e0737aac06b55a09da374209a8f9Status: Downloaded newer image for nginx:latestStep 2/5 : COPY index.html /usr/share/nginx/htmlStep 3/5 : COPY linux.png /usr/share/nginx/htmlRemoving intermediate container 47232cb5699fRemoving intermediate container 4623761274acSuccessfully tagged /linux_tweet_app:latestUse the docker container run command to start a new container from the image you created. Docker image build -tag $DOCKERID/linux_tweet_app:1.0. ) at the end of the command. Tells Docker to use the current directory as the build contextBe sure to include period (. Having the Docker ID attached to the name will allow us to store it on Docker Hub in a later step•.
0 Comments
Leave a Reply. |
AuthorKevin ArchivesCategories |