Docker-compose Is Sooo Slowww Issue 1395 Docker/for-mac
Reading Time: 8 minutes Released earlier in 2017, Docker’s new native applications for Windows and Mac replaced the older methods for running Docker on Windows and Mac and created a better experience for developers using those platforms. The previous solution, Docker Toolbox, depended on VirtualBox to create a small Linux virtual machine that hosted your images and containers. It worked well but could be unreliable at times and required workarounds that sometimes resulted in unexpected outcomes or not working at all.
Docker for Mac instead uses virtualization technology that is already part of Mac OS X:. Docker for Windows uses Microsoft’s virtualization technology,.
These changes aim to make your Docker containers run faster than before, take up less disk space, and fit better into your operating system. This post is intended as a getting-started overview alongside tips and gotchas that I noticed whilst using Docker on different platforms. I am by no means an advanced Docker user, but I hope having everything you need in one place is helpful to you.
Cracking open the Docker Mac application First launch and configuration When you first run the Docker application, it will check your system for compatibility and requirements, show a welcome screen, and then start the Docker process. Your main interaction with the Docker application will be via a menu bar item, for example, to stop and start the Docker process, open Kitematic for GUI access to your containers, find documentation, and access preferences. General The General pane has settings for launch, updates, usage statistics, and excluding the virtual machine from backups (Mac only), which is a simple but useful feature to have, as it can end up being a large file. File sharing While sharing volumes between Docker containers and the host operating system was possible with Docker Toolbox, it could be slow and suffer permissions issues. Docker for Mac uses a new file system created by Docker called ‘osxfs’.
I can’t find much detail on the new file system, but there is some info. You can add or remove share local paths to share with containers using the + and – buttons, but these paths shouldn’t overlap, e.g., not Users and Users/homefolder. Docker for Windows uses SMB and you can only share an entire drive to Docker.
Docker-compose Is Sooo Slowww Issue 1395 Docker/for-machine
Make sure you use credentials that have necessary permissions to access the paths you will need in containers. Advanced This pane lets you change the specs of the virtual machine and change the location of the disk image. Proxies The application should automatically detect any HTTP(s) proxy settings you have at an operating system level, but you can check or override them here. While not a part of this preference pane, it will also automatically detect any VPN settings you have, allowing access to any containers running within it. Daemon Finally, in the Daemon pane, you can opt in to experimental features and configure registries you use for custom images. If you’re feeling bold, you can configure the same options via the embedded JSON field. Using Docker natively Little of the process for using Docker has changed, except that it requires fewer steps.
To start Docker, open the Docker application, and quit it to stop Docker. While Docker is running, you should be able to access it via Kitematic and any Mac or Windows shells (except Bash for Windows, as that is its own virtualized environment) and issue Docker commands as normal. For example, with the application running, you can use Kitematic or the command line to download and start images as containers.
Here’s the ‘hello world’ image running in Kitematic. Application running Other Docker commands such as docker-compose and docker-machine work, but for Machine (and thus Swarm) you will need to define a. This means you can manage Docker Machine from your Mac or Windows machine, but they will still be hosted elsewhere and still need to be managed by the traditional eval $(docker-machine env default) commands. Bonus: Want to access the VM on a Mac? Oh just: screen /Library/Containers/com.docker.docker/Data/com.docker.driver.amd64-linux/tty – and boom you’re in the vm — Tupperware Man ™ (@fntlnz) Here’s a random tip that doesn’t completely fit into this post, but I wanted to share with you.
I was fortunate enough to have dinner with Lorenzo Fontana, a Docker Networking contributor and also. During dinner, he mentioned a peculiar command that allowed you to jump straight into the VM on a Mac. Screen /Library/Containers/com.docker.docker/Data/com.docker.driver.amd64-linux/tty This may or may not be useful to you, but I thought it was cool. Windows containers An interesting feature of Docker for Windows is the ability to toggle running Windows containers as well as Linux containers by changing the daemon that Docker speaks to in the settings pane. This means you can also experiment with containers running Windows server services and.NET applications. Linux Docker is Linux-native, so theoretically Linux should be the easiest platform to install on. Well, yes and no.
As is traditional with Linux, you have more control over setup, but that control requires extra steps and configuration. Installing Docker on Linux has become more complicated. As there are differences between the community and enterprise editions, I will stick to explaining the community edition. I won’t repeat the steps for installing Docker on every flavor of Linux here, as does a fine job, but I will highlight necessary steps to ensure you can follow easily, as well as problems I’ve experienced. System requirements For Docker to function, you need the Linux kernel version 3.10 or above. If you have an up-to-date version of Linux, you probably already have this installed, but you might not. You can update the kernel, but this can potentially change the behavior of your operating system in other ways.
If you want to give that a try, then will hopefully help. Most distributions need you to have certain packages installed. These are for storage drivers and secure repository access; again, these are all easy to install. Installing Before installing Docker, make sure you remove any older versions, as some distributions maintain their own packages that are out of date. As noted above, Docker now comes in two versions, so make sure that after following the prerequisite steps, you install the correct version: sudo apt-get install docker-ce # Community edition sudo apt-get install docker-ee # Enterprise edition Running Docker All interaction with Docker on Linux is via the command line, so you will need to. Running Docker as a non-root user As Docker binds to a Unix socket owned by the root user and not a TCP port, the Docker daemon by default runs as the root user.
When running Docker on a local machine, I found this can become annoying and confusing and I found myself wanting to switch to a non-root user. To change this behavior, you need to create a new group and give it permissions to access that socket. Note that while this is more convenient, it does grant privileges equivalent to a root user,. Create the group: sudo groupadd docker Add yourself to that group (or another user): sudo usermod -aG docker $USER Log out and log in again, and the following command should work: docker run hello-world Docker for All Recent additions to Docker editions have complicated this slightly, but now more than ever, you should find installing and using Docker as seamless as possible for your operating system, with earlier versions containing more irritations and edge cases. It’s still not perfect, but the team works hard to solve any issues you may find or propose workarounds.
What have been some of your biggest confusions with Docker on your OS of choice?
Email Post In the previous blog of this series I took you through the necessity of Docker and made you acquainted with Docker. In case you have missed to go through my first blog on Docker please to go through it. In this blog, I will explain – What is Docker & Docker Container in detail. Before we go ahead, let me summarize the learning till now:.
Virtual Machines are slow and takes a lot of time to boot. Containers are fast and boots quickly as it uses host operating system and shares the relevant libraries. Containers does not waste or block host resources unlike virtual machines. Containers have isolated libraries and binaries specific t o the application they are running. Containers are handled by Containerization engine. Docker is one of the containerization platforms which can be used to create and run containers. Now, after this recap, let me take you ahead and explore more on – What is Docker?
What is Docker & Docker Container? What is Docker? – Docker is a containerization platform that packages your application and all its dependencies together in the form of a docker container to ensure that your application works seamlessly in any environment.
What is Container? – Docker Container is a standardized unit which can be created on the fly to deploy a particular application or environment. It could be an Ubuntu container, CentOs container, etc.
To full-fill the requirement from an operating system point of view. Also, it could be an application oriented container like CakePHP container or a Tomcat-Ubuntu container etc. Let’s understand it with an example: A company needs to develop a Java Application. In order to do so the developer will setup an environment with tomcat server installed in it. Once the application is developed, it needs to be tested by the tester. Now the tester will again set up tomcat environment from the scratch to test the application. Once the application testing is done, it will be deployed on the production server.
Again the production needs an environment with tomcat installed on it, so that it can host the Java application. If you see the same tomcat environment setup is done thrice. There are some issues that I have listed below with this approach: 1) There is a loss of time and effort.
2) There could be a version mismatch in different setups i.e. The developer & tester may have installed tomcat 7, however the system admin installed tomcat 9 on the production server. Now, I will show you how Docker container can be used to prevent this loss. In this case, the developer will create a tomcat docker image ( A Docker Image is nothing but a blueprint to deploy multiple containers of the same configurations ) using a base image like Ubuntu, which is already existing in Docker Hub (Docker Hub has some base docker images available for free). Now this image can be used by the developer, the tester and the system admin to deploy the tomcat environment.
This is how docker container solves the problem. I hope you are now clear on What is Docker & Docker Container. In case you have any further doubts, please feel to leave a comment, I will be glad to help you.
However, now you would think that this can be done using Virtual Machines as well. However, there is catch if you choose to use virtual machine.
Let’s see a comparison between a Virtual machine and Docker Container to understand this better. Let me take you through the above diagram. Virtual Machine and Docker Container are compared on the following three parameters:. Size – This parameter will compare Virtual Machine & Docker Container on their resource they utilize. Startup – This parameter will compare on the basis of their boot time.
Integration – This parameter will compare on their ability to integrate with other tools with ease. I will follow the above order in which parameters are listed. So first parameter would be “Size”. Check out this video to know more about Docker. Size The following image explains how Virtual Machine and Docker Container utilizes the resources allocated to them. Consider a situation depicted in the above image. I have a host system with 16 Gigabytes of RAM and I have to run 3 Virtual Machines on it.
To run the Virtual Machines in parallel, I need to divide my RAM among the Virtual Machines. Suppose I allocate it in the following way:. 6 GB of RAM to my first VM,. 4 GB of RAM to my second VM, and. 6 GB to my third VM. In this case, I will not be left with anymore RAM even though the usage is:.
My first VM uses only 4 GB of RAM – Allotted 6 GB – 2 GB Unused & Blocked. My second VM uses only 3 GB of RAM – Allotted 4 GB – 1 GB Unused & Blocked.
My third VM uses only 2 GB of RAM – Allotted 6 GB – 4 GB Unused & Blocked This is because once a chunk of memory is allocated to a Virtual Machine, then that memory is blocked and cannot be re-allocated. I will be wasting 7 GB ( 2 GB + 1 GB + 4 GB) of RAM in total and thus cannot setup a new Virtual Machine.
This is a major issue because RAM is a costly hardware. So, how can I avoid this problem? If I use Docker, my CPU will allocates exactly the amount of memory that is required by the Docker Container. My first container will use only 4 GB of RAM – Allotted 4 GB – 0 GB Unused & Blocked. My second container will use only 3 GB of of RAM – Allotted 3 GB – 0 GB Unused & Blocked. My third container will use only 2 GB of RAM – Allotted 2 GB – 0 GB Unused & Blocked Since there is no allocated memory (RAM) which is unused, I save 7 GB ( 16 – 4 – 3 – 2) of RAM by using Docker Container.
I can even create additional containers from the leftover RAM and increase my productivity. So here Docker Container clearly wins over Virtual machine as I can efficiently use my resources as per my need. Start-Up When it comes to start-up, Virtual Machine takes a lot of time to boot up because the guest operating system needs to start from scratch, which will then load all the binaries and libraries. This is time consuming and will prove very costly at times when quick startup of applications is needed. In case of Docker Container, since the container runs on your host OS, you can save precious boot-up time. This is a clear advantage over Virtual Machine.
Consider a situation where I want to install two different versions of Ruby on my system. If I use Virtual Machine, I will need to set up 2 different Virtual Machines to run the different versions. Each of these will have its own set of binaries and libraries while running on different guest operating systems. Whereas if I use Docker Container, even though I will be creating 2 different containers where each container will have its own set of binaries and libraries, I will be running them on my host operating system. Running them straight on my Host operating system makes my Docker Containers lightweight and faster. So Docker Container clearly wins again from Virtual Machine based on Startup parameter. Now, finally let us consider the final parameter, i.e.
What about Integration? Integration of different tools using Virtual Machine maybe possible, but even that possibility comes with a lot of complications. I can have only a limited number of DevOps tools running in a Virtual Machine. As you can see in the image above, If I want many instances of Jenkins and Puppet, then I would need to spin up many Virtual Machines because each can have only one running instance of these tools. Setting up each VM brings with it, infrastructure problems.
I will have the same problem if I decide to setup multiple instances of Ansible, Nagios, Selenium and Git. It will also be a hectic task to configure these tools in every VM. This is where Docker comes to the rescue. Using Docker Container, we can set up many instances of Jenkins, Puppet, and many more, all running in the same container or running in different containers which can interact with one another by just running a few commands. I can also easily scale up by creating multiple copies of these containers. So configuring them will not be a problem.
To sum up, it won’t be an understatement to say that Docker is a more sensible option when compared to Virtual Machines. Docker is designed to benefit both Developers and System Administrators, making it a part of many DevOps toolchains. Developers can write their code without worrying about the testing or the production environment and system administrators need not worry about infrastructure as Docker can easily scale up and scale down the number of systems for deploying on the servers. What is Docker Engine? Now I will take you through Docker Engine which is the heart of the Docker system. Docker Engine is simply the docker application that is installed on your host machine.
It works like a client-server application which uses:. A server which is a type of long-running program called a daemon process.
A command line interface (CLI) client. REST API is used for communication between the CLI client and Docker Daemon As per the above image, in a Linux Operating system, there is a Docker client which can be accessed from the terminal and a Docker Host which runs the Docker Daemon. We build our Docker images and run Docker containers by passing commands from the CLI client to the Docker Daemon. However, in case of Windows/Mac there is an additional Docker Toolbox component inside the Docker host. This Docker Toolbox is an installer to quickly and easily install and setup a Docker environment on your Windows/iOS.
Docker Toolbox installs Docker Client, Machine, Compose (Mac only), Kitematic and VirtualBox. Let’s now understand three important terms, i.e.
Docker Images, Docker Containers and Docker Registry. What is Docker Image? Docker Image can be compared to a template which is used to create Docker Containers. They are the building blocks of a Docker Container. These Docker Images are created using the build command. These Read only templates are used for creating containers by using the run command.
We will explore Docker commands in depth in the “Docker Commands blog”. Docker lets people (or companies) create and share software through Docker images. Also, you don’t have to worry about whether your computer can run the software in a Docker image — a Docker container can always run it. I can either use a ready-made docker image from docker-hub or create a new image as per my requirement. In the Docker Commands blog we will see how to create your own image.
What is Docker Container? Containers are the ready applications created from Docker Images or you can say a Docker Container is a running instance of a Docker Image and they hold the entire package needed to run the application. This happens to be the ultimate utility of Docker. What is Docker Registry? Finally, Docker Registry is where the Docker Images are stored. The Registry can be either a user’s local repository or a public repository like a Docker Hub allowing multiple users to collaborate in building an application. Even with multiple teams within the same organization can exchange or share containers by uploading them to the Docker Hub.
Docker Hub is Docker’s very own cloud repository similar to GitHub. What is Docker Architecture? Docker Architecture includes a Docker client – used to trigger Docker commands, a Docker Host – running the Docker Daemon and a Docker Registry – storing Docker Images.
The Docker Daemon running within Docker Host is responsible for the images and containers. To build a Docker Image, we can use the CLI (client) to issue a build command to the Docker Daemon (running on DockerHost). The Docker Daemon will then build an image based on our inputs and save it in the Registry, which can be either Docker hub or a local repository. If we do not want to create an image, then we can just pull an image from the Docker hub, which would have been built by a different user. Finally, if we have to create a running instance of my Docker image, we can issue a run command from the CLI, which will create a Docker Container. This is the simple functionality of Docker:). I hope you enjoyed, “What is Docker and Docker Container” blog.
Now you are ready to get hands on with Docker. For hands on soon I will come up with the third blog in Docker Tutorial on Docker Commands. Now that you have understood what is DevOps, check out the by Edureka, a trusted online learning company with a network of more than 250,000 satisfied learners spread across the globe. The Edureka DevOps Certification Training course helps learners gain expertise in various DevOps processes and tools such as Puppet, Jenkins, Nagios, Ansible, Chef, Saltstack and GIT for automating multiple steps in SDLC. Got a question for us? Please mention it in the comments section and we will get back to you.