Docker on Ubuntu 18.04 LTS

My main use case for Docker  is to package applications into consistent, portable containers and use those images across CI/CD and production environments. I containerize applications so they can run the same in dev, test, and prod. I build Docker images in CI after code changes and run automated tests inside containers. My workflow is very critical, which is the reason I use Docker in it. Docker eliminates "works on my machine" issues, makes deployment repeatable and predictable, enables fast rollbacks by switching image versions, and works seamlessly with CI/CD and Kubernetes . In short, I mainly use Docker to containerize applications and ensure consistent, repeatable deployments across environments through CI/CD pipelines.

Beyond the main use case, Docker supports my workflow in additional ways. It helps me standardize build environments by ensuring the same build tools and versions run in CI and locally, preventing inconsistencies between developer machines and CI runners. Faster rollback and debugging are also easy with Docker. I can roll back by redeploying a previous image tag and run the same image locally to reproduce production issues. Beyond containerization, Docker enables standardized builds, fast rollbacks, secure deployments, and scalable microservices, making it a core part of my CI/CD and reliability strategy.

Docker has had a major positive impact by standardizing how applications are built, shipped, and deployed, which improved speed, reliability, and collaboration across my teams. The key improvements and big wins include consistent environments across dev, QA, and prod with the same Docker image used everywhere. It eliminated "works on my machine" issues, which really helped me fix issues by checking on every computer and fixing bugs and understanding why errors occur. Because when it runs on one computer, it will run perfectly on every other computer. Faster deployment and rollback are also great, offering container startup in seconds and rollback by redeploying a previous image tag. This impacted my team with faster release and quicker recovery during incidents. Better scalability and cloud readiness are offered by enabling microservices architectures and easy scaling with Kubernetes  and cloud platforms. This has a good impact on better handling of traffic spikes and growth. Docker also improves dev plus ops collaboration because developers define runtime in Dockerfiles, and operations teams deploy standardized images, resulting in fewer handoffs and clear ownership.

Docker gives me very clear, measurable improvements. Environment-related incidents were happening too frequently before I used Docker, and I saw frequent "works on my machine" issues. After using Docker, the same image across every environment runs smoothly, resulting in a 60 to 70% reduction in environment-related production issues. The rollback time is also great. Before, I had to do rollbacks manually by rebuilding, which took a long time. After using Docker, I can redeploy the older or previous images, achieving better results with faster times. Additionally, Docker reduces deployment time by up to 80% and cuts environment-related incidents by around 60 to 65%. It speeds up rollbacks by nearly 80 to 90% and improves CI pipeline speed and onboarding efficiency. These are approximate metrics based on operational tracking and team experience, but the improvement trend is consistent and very visible.

There are many valuable features that Docker offers. Portability is the first, with the concept of "build once, run anywhere." Docker packages the app with all dependencies and runs the same on laptops, CI servers, VMs, cloud, and Kubernetes. Additionally, lightweight containers share the host operating system kernel, making them much faster and smaller than virtual machines. This results in faster startup times, better resource utilization, and easier scaling. Fast CI/CD integration is another great feature, making it easy to build, test, and push images in CI pipelines and working seamlessly with GitLab  CI, Jenkins , and GitHub Actions . Isolation is also a great feature, where each container runs independently with no dependency conflicts between apps. Good security capabilities are included as well, providing image scanning, non-root containers, and minimal base images that reduce the attack surface.

Security capabilities are definitely the most valuable to me because they reduce the attack surface, and every organization wants to keep data secure with fewer attacks, which Docker offers. Lightweight containers sharing the host operating system kernel make it much faster and smaller than virtual machines, helping with faster startup times, better resource utilization, and easier scaling. I benefit from cost optimization because resource utilization is very minimal, using resources only when required. Scaling is also great, helping me in my day-to-day work. Portability is one feature that allows me to build once and run anywhere, helping me in day-to-day activities. When I build once, I can try and test anywhere. Docker packages the app with all dependencies, so I can run anywhere, anytime, without having to recreate setups repeatedly.

Image versioning and rollback is also a great feature that I would add. Docker tags images with versions and allows rollback by redeploying a previous image, helping me quickly recover from bad releases.

As Docker is already a very mature tool, there are areas where it can be improved based on real-world usage. One area I consider is the Windows container experience. The pain point here is that Windows containers are heavier and slower than Linux containers because I have worked in both environments and felt that Windows containers are heavier and slower than Linux containers. This also limits the ecosystem and tooling maturity compared to Linux containers. Improvements could include performance optimization and better parity with Linux container features. Apart from that, observability and debugging is another area. The pain point is the limited native metrics available and limited logging and tracing features. Improvements could include adding a good amount of metrics, logging, and tracing, as well as better built-in observability features and easier container introspection.

Network complexity is also present. I face issues with Docker networking that can become confusing in complex setups, and debugging container-to-container issues is not always intuitive. Improvements can be made with simpler networking abstractions and better built-in troubleshooting tools. Docker is excellent for containerization and CI/CD, but it can be improved in areas of built-in security, network simplicity, and observability. These points should be kept in mind and worked on.

I have been working in my current field for five plus years. I have been using Docker  for almost five years.

Docker has been very stable in my environment, especially once best practices and proper organization were in place.

Docker scalability for my workloads has been very strong, especially when used with an orchestrator Kubernetes. Docker by itself handles packaging and runtime well, while orchestration enables real horizontal scaling. Docker scales very well for my workload when combined with Kubernetes, allowing for fast horizontal scaling, efficient resource use, and predictable behavior during traffic spikes. A realistic metric I observe is that I can scale services from two to over 20 containers without code changes. Additionally, containers start in seconds versus minutes for virtual machines, which is great.

I have never had the chance to reach out to customer support, but my team members have reached out based on their working experience because they are senior and have more experience than me. From what I gather, customer support is great; they are quick and always available to support or help.

Positive

I started using Docker only and have never considered or thought to switch because I love it.

The challenges I faced during the initial adoption of Docker included a mix of technical, process, and mindset challenges. Most of these are very common when teams move from a traditional setup to containers. The challenges I faced included a learning curve and mindset shift where teams were accustomed to virtual machines and server-based deployments, and understanding images, containers, layers, and immutability took time. Apart from that, I faced challenges in writing efficient Dockerfiles, where early images were large, slow to build, and had poor layer caching and unnecessary packages, which taught me the lesson to adopt multi-stage builds and minimal base images. Furthermore, handling configuration and secrets was a key challenge, deciding what goes inside the image versus runtime configs. Also, managing secrets securely without including them in images was challenging. I found solutions in environment variables, secret managers, and CI/CD integration. There was also a necessity for security awareness, where early containers ran as root and images were pulled without scanning. The main challenges included the learning curve, writing efficient Dockerfiles, and handling configs and data correctly while stabilizing container security best practices.

I started using Docker only and have never considered or thought to switch because I love it.

Docker has always saved time because its features have helped me reduce time in many aspects and also reduce the number of human resources needed. I can do containerization and share it with every computer, making it work for everyone. Before Docker, it was very tough to set up every package on each computer, so it has helped reduce the number of employees needed.

The setup cost has balanced out, and I find Docker's pricing reasonable. Docker Engine is free and open source for Linux, and Docker Desktop is free for individual developers and small teams, but a paid subscription is required for large enterprises, which I am aware of. The setup cost is low.

I have not evaluated other options.

Docker is excellent for containerization, portability, CI/CD integration, and developer productivity. The ecosystem and community support are very strong. However, I have deducted 1.5 points because there are still some gaps around security, observability, and networking simplicity that can be addressed. Apart from that, dependency on external orchestration tools for large-scale production is present. There are also enterprise licensing constraints that Docker Desktop has. The bottom line is that Docker is still an industry standard and a core DevOps tool, but there is room for improvement. I gave Docker a rating of 8.5 out of 10, which is a fair and balanced score.

We are using AWS . It is on a private cloud. I primarily run application and supporting service workloads in Docker containers, especially where consistency, scalability, and fast delivery matter. The primary workload includes microservices, backend applications, web applications, CI/CD, and build jobs.

Docker fits naturally into my DevOps toolchain and acts as the common packaging layer between deployment, CI, CD, and production. It integrates with my DevOps tools and processes very well. The first point I cover is source control and CI, where code changes trigger CI pipelines, and Docker images are built using Dockerfiles and tagged with commit SHA or a version. The second point is deployment, which involves continuous deployment in Harness  and Kubernetes. CD tools pull pre-built Docker images, and deployments use rolling, blue-green, or canary strategies. The third point is infrastructure and orchestration where Docker containers run on Kubernetes and cloud services such as ECS, AKS, and EKS. The infrastructure is managed via IaC , which is Terraform . Docker acts as a standard packaging layer in my DevOps pipeline, integrating with CI for image builds, registries for versioning, CD tools for deployment, and Kubernetes for scalable production runtimes.

I will share all the feature details that Docker provides based on my experience. I would advise everyone, especially those from a DevOps or SRE team, to consider Docker because it is really great. The features it offers significantly help my team and organization.

Positive