I had a small task - run container with parameters:

1. Name is web
2. Image is nginx:latest
3. The container must be available on port 9099
4. The /var/log/nginx directory inside the container must be mounted to the /data/nginx/logs directory on the host system
5. When starting the container, the environment variable logging = true should be added

A finite-state machine (FSM) is a mathematical model of computation. It is an abstract machine that can be in exactly one of a finite number of states at any given time. The FSM can change from one state to another in response to some inputs; the change from one state to another is called a transition. An FSM is defined by a list of its states, its initial state, and the inputs that trigger each transition.

Computer programs are traditionally organized as one-directional computations, which perform operations on prespecified arguments to produce desired outputs. On the other hand, we often model systems in terms of relations among quantities. For example, a mathematical model of a mechanical structure might include the information that the deflection d of a metal rod is related to the force F on the rod, the length L of the rod, the cross-sectional area A, and the elastic modulus E via the equation dAE = FL. Such an equation is not one-directional. Given any four of the quantities, we can use it to compute the fifth. Yet translating the equation into a traditional computer language would force us to choose one of the quantities to be computed in terms of the other four. Thus, a procedure for computing the area A could not be used to compute the deflection d, even though the computations of A and d arise from the same equation.

Now I’m learning chapter 3. So far, I’ve read about imperative programming and mutable state. Not so interesting, if you use it several years. I’ve realised queue and deque, but author get more complicated example: “A Simulator for Digital Circuits”. All code in Clojure is here.

Data abstraction is a methodology that enables us to isolate how a compound data object is used from the details of how it is constructed from more primitive data objects. The consequence of this methodology is abstraction barriers. It’s a splitting a program into layers, where each layer uses the layer on the level below.

This cycle of articles is my small (or huge) experiment. I’ll try to get back to the basics and learn a something new.