To understand images and their layers, you can always inspect the image history. Let’s inspect the history of the last Docker image by running the following command: As you can see, there are several layers, and every layer has associated commands. You can also see when the layers were created and the size of the […]
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Layers in Docker are intermediate Docker images. The idea is that every Dockerfile statement we execute on top of a layer changes something within the layer and builds a new one. The subsequent statement modifies the current one to generate the next one. The final layer executes the Docker CMD or ENTRYPOINT command, and the […]
Read More… from The layered filesystem – Creating and Managing Container Images
So, Docker is like your magical kitchen where you make dishes (containers) using plans (Dockerfiles) and ingredients (images) with the assistance of your kitchen helpers (Docker Engine). You can even serve entire meals (Docker Compose) and use special storage areas (volumes) and communication paths (networks) to make your dishes even more amazing. Just like a […]
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Imagine you’re a passionate chef dedicated to creating mouthwatering dishes that satisfy hungry customers. In your kitchen, which is a magical place called Docker, you have special powers to plan, make, and showcase your culinary creations. Let’s break down the key parts: Ingredients (Application Code and Dependencies): Imagine your kitchen has shelves filled with ingredients […]
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In the previous chapter, we covered containerization with Docker, where we installed Docker and ran our first container. We covered some core fundamentals, including Docker volumes, mounts, storage drivers, and logging drivers. We also covered Docker Compose as a declarative method of managing containers. Now, we will discuss the core building blocks of containers: container […]
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Use an .env file to store sensitive variables You might not want to store sensitive content such as passwords and secrets in version control. Instead, you can use an .env file that contains a list of variable names and values and keep it in a secret management system such as HashiCorp Vault. Be mindful of […]
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Docker Compose best practices Docker Compose provides a declarative way of managing Docker container configuration. This enables GitOps for your Docker workloads. While Docker Compose is primarily used in development environments, you can use it in production very effectively, especially when Docker runs in production and does not use another container orchestrator such as Kubernetes. […]
Read More… from Separate multiple environment YAMLs using overrides – Containerization with Docker
The next step in the process is to create a docker-compose file. A docker-compose file is a YAML file that contains a list of services, networks, volumes, and other associated configurations. Let’s look at the following example docker-compose.yaml file to understand it better: version: “2.4” services: flask: image: “bharamicrosystems/python-flask-redis:latest” ports: networks: redis: image: “redis:alpine” networks: […]
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Docker Compose helps you manage multiple containers in a declarative way. You can create a YAML file and specify what you want to build, what containers you want to run, and how the containers interact with each other. You can define mounts, networks, port mapping, and many different configurations in the YAML file. After that, […]
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Metrics to monitor Monitoring metrics is a complex subject, and it would depend mostly on your use case. However, the following are some guidelines on what metrics you want to monitor. Host metrics You need to monitor your host metrics as your containers run on them. Some of the metrics that you can watch are […]
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