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 […]
Read More… from Docker architecture – Creating and Managing Container Images-2
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 […]
Read More… from Docker architecture – Creating and Managing Container Images-1
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 […]
Read More… from Technical requirements – Creating and Managing Container Images
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 […]
Read More… from Be mindful of dependencies in production – Containerization with Docker
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
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 […]
Read More… from Docker container metrics – Containerization with Docker
We will now configure Prometheus on the Prometheus machine so that it can scrape the metrics from cAdvisor. To do so, modify the /etc/prometheus/prometheus.yml file so that it includes the following within the server running Prometheus: $ sudo vim /etc/prometheus/prometheus.yml … scrape_interval: 5s static_configs: After changing this configuration, we need to restart the Prometheus service. […]
Read More… from Configuring Prometheus to scrape metrics – Containerization with Docker
The best setting for a highly available NGINX container should be something like the following: $ docker run -d –name nginx –restart unless-stopped \ -p 80:80 –memory 1000M –memory-reservation 250M nginx:1.18.0 Let’s take a look at this in more detail: We will look into other flags in the subsequent sections as we get more hands-on. […]
Read More… from Putting it all together – Containerization with Docker
To see what’s going on within the container, you can use the docker logs command. But before using that, we need to know the container’s ID or name to see the container’s logs. To get a list of containers running within the host, run the following command $ docker ps […]
Read More… from Troubleshooting containers – Containerization with Docker