Chapter 3: Common ecosystem

These tasks describe common crates and tools in Rust ecosystem required for application and library development.

❗️Before completing this task you should complete all its sub-tasks.

After doing them you should be able to answer the following questions:

What testing capabilities does Rust offer and when should I use them? Why should I follow BDD style?
What are macros? How do they differ? What benefits does their usage give? When should I write one?
How to work with date and time in Rust? How should I store time? How should I return it to other applications?
How are regular expressions used in Rust? When are they not enough? How can I write a custom parser in Rust?
How do iterator and collection compare and differ in Rust? What is the purpose of immutable collections? Why should I care about using concurrent collections?
What should I use for serialization in Rust? Why this is good or bad?
How can I generate randomness in Rust? Which guarantees of random generator should I choose and when?
What should I use for password hashing in Rust? How can I encrypt a message with Rust? How should I compare secret values and why?
How logging is organized in Rust ecosystem? Why should I care about structured logging?
What should I use for building CLI interface in Rust? How can I organize a configuration for my application and why?
Why multithreading is required for Rust programs and what problems does it solve? How threads concurrency differs with parallelism? How can I parallelize code in Rust?
What is asynchronicity and what problems does it solve? How is it compared to threads concurrency? What is Rust solution for asynchronicity and why it has such design?
What are actors? When are they useful?

Some usefull tools

Estimated time: 2 days

Write a CLI tool for stripping JPEG images metadata and minimizing their size (a simplified analogue of tinyjpg.com).

Requirements:

Accept input list of files and remote URLs via: either CLI arguments, STDIN, or read it from a specified file (EOL-separated).
Allow configuring how much images are processed at the same time.
Allow configuring the output directory to store processed images in.
Allow configuring the output JPEG quality of processed images.
Read configuration with ascending priority from: a file (format is on your choice), environment variables, CLI arguments. All are optional for specifying.
Support RUST_LOG environment variable, allowing granular tuning of log levels per module.
Print execution time in logs, so it's easy to see how much which operation takes during the execution.

If you have enough time after implementing base requirements, consider to add the following to your solution: