Tutorials covering the tools that developers use every day — version control, editors, build systems, package managers, containers, and the command-line utilities that make work faster. Each chapter is standalone, built around real examples and verified commands.
A container’s writable layer is ephemeral. When the container is removed, everything written inside it is gone. This is by design—it makes containers disposable and reproducible. But real applications need persistence: a database must survive a restart, a log file must be available after the container stops, a configuration file must be shared with the…
Two fields in package.json control dependency resolution when the default behavior does not produce the tree the project needs. peerDependencies declares what a package expects its consumer to provide, and peerDependenciesMeta marks specific peers as optional. overrides forces a specific version of a package anywhere in the dependency tree, including transitive dependencies that the project…
A volume is a Docker-managed storage location that exists outside the container’s lifecycle. It is created, listed, inspected, and removed through the docker volume command family. Unlike a bind mount, which is a host path that Docker maps into a container, a volume is a first-class object with its own name, metadata, and driver. Docker…
A quick-reference for npm commands, configuration, and dependency resolution. Organized for lookup, not for reading. Core Commands Command Purpose npm init Create package.json interactively npm init -y Create with defaults npm install Install all dependencies npm install <pkg> Install and save to dependencies npm install <pkg>@<ver> Install specific version npm install -D <pkg> Install as…
A volume driver is the mechanism that determines where a volume’s data actually lives. The default driver stores it on the local host filesystem. Other drivers store it on an NFS server, a cloud block device, or a distributed storage cluster. The driver is specified when the volume is created, and it determines the volume’s…
A container’s root filesystem is writable by default. The application can write to any directory that its user has permission to write to, including the directories where the application’s own binaries and configuration files live. This is convenient for development and for applications that assume they can write anywhere. It is also a security liability….
The storage driver is the layer between a container’s filesystem and the host’s disk. It determines how image layers are stacked, how writes are handled, and how much space and inode overhead the container incurs. Docker supports several drivers, but overlay2 is the default on most Linux distributions and the one most LFCS and Docker…
A container’s network is not one thing. It is a namespace, a set of interfaces, a routing table, and a driver that constructs all three. The driver determines whether the container is isolated, shares the host’s network, or appears as a physical device on the LAN. The choice of driver is the choice of how…
Two containers on the same host cannot talk to each other by name unless they are on a user-defined network. The default bridge network, the one Docker creates automatically at installation, does not provide DNS resolution between containers. This is not a bug; it is a deliberate limitation, kept for backward compatibility with the legacy…
The host network driver removes the network namespace from the container. The container shares the host’s network stack directly, with the host’s IP address, the host’s interfaces, and the host’s ports. There is no NAT, no virtual bridge, and no port mapping. The container’s application binds to the host’s port directly, and the performance is…