Many of the chapters have had updates to language libraries via their packaging systems (for example npm) to avoid security problems.
The Dockerfile has been modified to use ubuntu:10 as a base container, as it is the one that has a compatible PHP 7.3 runtime that the Dockerfile relies on.
The Dockerfile now uses ubuntu:focal as a base container. It originally used ubuntu:bionic as a base container and the now-obsolete Node 8 runtime and npm 3.5.2 within proved to be problematic in 2021. If you enabled verbose output on NPM install, it yielded an npm ERR! code EMISSINGARG error similar to the problem described in the lodash issue #4358. This is the sort of problem hinted at in Chapter 6 regarding using general-purpose OS images in the "Re-examining the initial Dockerfile" section, see pp. 122-134.
In switching from Ubuntu bionic (18.04) to focal (20.04) we also have to add an environment variable to the installation to force a non-interactive package installation, per this Ask Ubuntu article.
The Dockerfile has been modified to use node:14-alpine image which keeps Alpine Linux, but pins the version of node to Node 14, which is more stable than using the stock Alpine Docker container and installing Node using apk.
The Dockerfile has been modified to use node:14-alpine image which keeps Alpine Linux, but pins the version of node to Node 14, which is more stable than using the stock Alpine Docker container and installing Node using apk.
The Dockerfile has been modified to use node:14-alpine image which keeps Alpine Linux, but pins the version of node to Node 14, which is more stable than using the stock Alpine Docker container and installing Node using apk.
The Dockerfile has been modified to use node:14-alpine image which keeps Alpine Linux, but pins the version of node to Node 14, which is more stable than using the stock Alpine Docker container and installing Node using apk.
The Dockerfile has been modified to use node:14-alpine image which keeps Alpine Linux, but pins the version of node to Node 14, which is more stable than using the stock Alpine Docker container and installing Node using apk.
The Dockerfile has been modified to use node:14-alpine image which keeps Alpine Linux, but pins the version of node to Node 14, which is more stable than using the stock Alpine Docker container and installing Node using apk.
The Dockerfile has been modified to use the same Docker image printed in the book. You will still need to modify it before building, replacing user@host with a valid user and hostname for a server you control.
The Dockerfile has been modified to use an Alpine base container and fixes some erroneous smart quotes that were printed correctly in the book, but not in the repository originally.