Lessons Learned: Overcoming My First Docker Hiccups

As I dive deeper into my DevOps journey, Docker has quickly become an essential tool in my toolbox. However, like many learning experiences, I've hit a few bumps along the way. Two recent issues stand out, both of which taught me valuable lessons.

Issue 1: Forgetting to Use the Image ID with docker run

When I first started experimenting with Docker, I eagerly tried to run containers using the docker run command. However, I quickly realized that my attempts were failing. The problem? I wasn't specifying the image ID or name after the docker run command. Without telling Docker which image to use, the command simply couldn't work.

Lesson Learned: Always remember to specify the image name or ID when using the docker run command. For example:

docker run -p 3000:3000 myapp

This little detail is crucial for Docker to know what to spin up.

Issue 2: Using the Image ID Instead of the Container ID with docker stop

Once I had containers up and running, my next challenge was stopping them. I confidently issued the docker stop command, but Docker responded with an error: No such container. After some investigation, I realized I had been using the image ID instead of the container ID.

Lesson Learned: When stopping a container, it's the container ID (not the image ID) that Docker needs. To see a list of running containers and their IDs, you can use:

docker ps

And then stop the container with:

docker stop <container_id>

This subtle difference between image IDs and container IDs is easy to mix up, but understanding it is key to effectively managing containers.

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These early lessons in Docker have been invaluable, and I'm excited to continue exploring and sharing more about my DevOps journey. If you're starting out with Docker, I hope these tips help you avoid similar pitfalls!