Dockerfile vs Docker Compose – What’s the Difference? (Pros and Cons)
Dockerfile vs Docker Compose – What’s the Difference? (Pros and Cons). Dockerfile is a simple text file that gives commands to users to assemble and build an image, whereas Docker Compose is used to define and run Docker applications and documents. Both Dockerfile and Docker Compose are Docker platforms, yet they are quite different from each other. In this article we explain features of both the Dockerfile and Docker Compose and in the last section we will discuss how the two applications differ from each other.
Let’s proceed with article Dockerfile vs Docker Compose – What’s the Difference? (Pros and Cons).
What is a Dockerfile?
You need a Dockerfile for building the docker image for your website. For creating Docker image, the Dockerfile gives the instructions to use the Nginx image from the Docker Hub. Then you need to copy all the content and files of your websites into the Nginx image web hosting history.
After composing the image, the docker file informs the docker build command to start with the latest Nginx image. Then it instructs to copy the image into the hello-world.html file in the file serving folder of Nginx.
In short, Docker file is responsible for executing the files and creating the Docker image. With Docker image it usually starts by putting another image. And it might be based on the particular operating system or Java distribution. Moreover Docker files perform the following features that help to perform various functions to build an image.
- Copies the host system into the container.
- Then run the arbitrary commands related to the image, for instance, if someone wants to run the Unix command to alter the file permission.
- Or install the new package with the help of the package manager.
- It then defines the command that needs to be executed after the creation of the container.
A typical example of a docker file:
FROM openjdk:17-alpine
ARG JAR_FILE=target/my-app.jar
COPY ${JAR_FILE} my-app.jar
ENTRYPOINT ["java","-jar","https://net.cloudinfrastructureservices.co.uk/my-app.jar"]
The above mentioned example is the docker image on the OpenJDK 17 alpine image. It then copies the compiled JAR file into the image. Following that it composes the start up commands as the Java commands with the JAR file. It is worth mentioning here that the Dockerfile is the only way to create a docker image.
Features of Dockerfile
- With Docker file it will command the docker build to create an image.
- Keeps the product image as lean as possible.
- The context of the snap is processed recursively.
- To use a file in the context, the docker file dispatches a particular set of instructions.
- Allows the type to select a repository and specific tag while saving the image.
- In addition Docker file gives you an option of the multiple -t that allows you to tag the image in several repositories after the build.
- If the process slows down, docker immediately uses the docker bud to speed up the process.
- Each induction is run independently on the docker file. And it creates a unique image, so Run-cd \ cd has no effect on the succeeding instructions.
Pros of Dockerfile
- An automated script of docker image.
- Creates the image with a different flavour with great ease. It saves you from the complicated steps of manual creation.
- The simple syntax of the Docker file can make many changes to the image. These changes take considerable time when done manually.
- Also the Docker file has an easy configuration, so simple to understand and run.
- Easy to know which base configuration has made the alterations in the image.
- And the Docker hub, when combined with the Docker file, gives the private repository with the Docker file.
- Moreover Docker file is super easy to share with organizations and group.
- Automatic image creation is super easy with the Docker file.
- Super easy to put a Docker file on GitHub or Bitbucket.
Cons of Dockerfile
- The process of making the multi stage container could be exhausting. It demands separate tags at every level.
- Running apt-get is present in every docker file. And it has its glitches.
- Some people use ADD instead of copy while copying their context to the docker file. ADD also copies the content, but it has magical features like extracting TAR files or detecting them.
- Don’t add ENV and EXPOSE on the top of any image. If the image cache busts, rebuilding them is instantaneous.
What is Docker Compose?
Docker Compose is an application for running and creating a multi container Docker application. It allows the image configuration with a multi container thanks to YAML configuration in one place. And it enables you to start and stop the containers at once, using a single command. Unlike the Docker image, Docker Compose does not build an image. Instead, it describes how to run the Docker image as a container.
The Docker Compose tells us how to pre parametrize the Docker image when it runs a container. The Dockerfile has almost all the information on how to run the Docker containe, and it includes;
- Security configuration.
- How many virtual CPUs to assign.
- Where to save the temporary files.
- Would it be okay to put a limit on reading and write.
- Restart policies.
- Network settings.
- Information regarding the memory storage.
- Post mappings of the Docker container.
version: '3.9'
services:
my-Nginx-service:
container name: my-website
image: my-nginx-image: latest
CPUs: 1.5
mem_limit: 2048m
Ports:
- "8080:80"
On the other hand Dockerfile also defines the services that compose your app in docker-compose.yml. So, you can run them together in an isolated environment. Helps to get an app running in one command by just running Docker Compose up. And it also allows you to define the objects by the Docker containers.
Features of Docker Compose
- Provides multiple isolated environments on a single host.
- Preserves the volume data for you when the containers are created.
- Allows you to run variables among the environment. And it is super easy.
- You can define your services in the docker-compose in an isolated environment.
- In addition Docker Compose presents a set of commands for managing the life cycle of your application. The commands include; run, stop, and recreate services.
- Reports on running services.
- Streams the log result of services.
- Displays a one off command on a service.
Pros of Docker Compose
- Multi container descriptor that makes things easier for the users.
- Easy to understand YAML configuration.
- Super quick and it allows you to go from templates to apply in just seconds.
- Delivers a fast development and easy setup.
- The linking of the container is super easy with the Docker Compose.
- Also Docker Compose applies a single order of start and stop (orchestrate) multiple containers.
- Has the Kubernetes integration and it also helps to orchestrate the container and helps in running the cluster of hosts.
- What is more Docker Compose delivers several customized options. You can choose the discovery back end.
Cons of Docker Compose
- Manual installation and running of the Docker Compose takes time and is complex.
- There is no health check in the production with the Docker Compose.
- Impossible to change a container without downtime and there are no rolling updates.
Dockerfile vs Docker Compose - Differences
Basic Differences
The aim of Dockerfile is to help and build the image. You input the information into the Dockerfile and it composes the custom image for you. But Docker Compose doesn’t create the images. It tells how to run the Docker image as the container in the Docker.
Compatibility with Docker Containers
Here the Docker Compose runs multiple containers from a single file. The compatibility with different containers helps in isolating the task and it helps in task management. On the other way Dockerfile works with a single container at a time. So, running multiple containers is not possible with the Dockerfile.
Security
Because Docker Compose provides high security. As we have described above it can work with multiple containers. Each isolated container keeps the information isolated from the other on the same network. Contrarily the Dockerfile uses a single container, which results in data mixing.
Productivity
In terms of productivity Docker Compose is far better than the Dockerfile. Moreover Docker Compose is more efficient in maintaining the task managing them and solving them according to the preference. This strategy helps in reducing the work burden and increases productivity. As shown above Dockerfile is less productive than Docker Compose. Taking multiple tasks at a time is not possible with the Dockerfile.
Thank you for reading Dockerfile vs Docker Compose – What’s the Difference? (Pros and Cons).
Dockerfile vs Docker Compose - What's the Difference Conclusion
Whenever you run a container in the development and testing environment, it should use the latest image with the most updated software. In this procedure, Docker Compose uses the Dockerfile to create the unique image.
Summarizing Docker Compose references or commands the Dockerfile to build a new docker image. Both of the applications are used together for the Docker container. However, the main difference between them are that the Docker file builds the images. Whereas the Docker Compose runs the Docker images. In addition Docker Compose can reference the Dockerfile, while the Dockerfile cannot refer to the Docker Compose.
Please take a look at our Docker content here.
