docs: rework factory readme examples

MikeMcC399 · MikeMcC399 · commit 585b5e31e95c · 2024-06-10T14:11:25.000+02:00
diff --git a/factory/README.md b/factory/README.md
@@ -28,139 +28,175 @@ If no args are defined, only the default version of node will be installed. This
 
 The version of Node to install in the docker container. If the env is unset or an empty string, the default version of Node (defined [here](./.env)) is installed. Node is required. The exact version must be used, no wildcards or shorthands are supported.
 
-Example: `NODE_VERSION='16.18.1'`
+Example: `NODE_VERSION='20.14.0'`
 
 [Node Versions](https://nodejs.org/en/download/releases)
 
 ### YARN_VERSION
 
 The version of yarn to install (via npm). If the env is unset or an empty string, Yarn is not installed.
 
-Example: `YARN_VERSION='1.22.19'`
+Example: `YARN_VERSION='1.22.22'`
 
 [Yarn versions](https://www.npmjs.com/package/yarn)
 
 ### CYPRESS_VERSION
 
 The version of Cypress to install (via npm). If the env is unset or an empty string, Cypress is not installed.
 
-Example: `CYPRESS_VERSION='12.1.0'`
+Example: `CYPRESS_VERSION='13.11.0'`
 
 [Cypress versions](https://www.npmjs.com/package/cypress)
 
 ### CHROME_VERSION
 
 The version of Chrome to install. If the env is unset or an empty string, Chrome is not installed. The exact version must be used, no wildcards or shorthands are supported.
 
-Example: `CHROME_VERSION='107.0.5304.121-1'`
+Example: `CHROME_VERSION='125.0.6422.141-1'`
 
 [Chrome versions](https://www.ubuntuupdates.org/package/google_chrome/stable/main/base/google-chrome-stable)
 
 ### FIREFOX_VERSION
 
 The version of Firefox to install. If the env is unset or an empty string, Firefox is not installed. The exact version must be used, no wildcards or shorthands are supported.
 
-Example: `FIREFOX_VERSION='107.0'`
+Example: `FIREFOX_VERSION='126.0.1'`
 
 [Firefox versions](https://download-installer.cdn.mozilla.net/pub/firefox/releases/)
 
 ### EDGE_VERSION
 
 The version of Edge to install. If the env is unset or an empty string, Edge is not installed. The exact version must be used, no wildcards or shorthands are supported.
 
-Example: `EDGE_VERSION='100.0.1185.29-1'`
+Example: `EDGE_VERSION='125.0.2535.85-1'`
 
 [Edge versions](https://packages.microsoft.com/repos/edge/pool/main/m/microsoft-edge-stable/)
 
 ## Usage
 
-The cypress docker factory works by relying on the [`ONBUILD`](https://docs.docker.com/engine/reference/builder/#onbuild) docker instruction to run commands at the container's build time. To make use of the docker factory users will have to create a dockerfile to declare what dependency versions are desired. Docker `args` can be specified in a number of ways, some of which are demonstrated below. For each of these examples we are building the equivalent of the `cypress/browsers` docker image. In each instance since the example is only testing the chrome version, the examples could just install chrome by itself if the other browsers were not used.
+The cypress docker factory works by relying on the [`ONBUILD`](https://docs.docker.com/engine/reference/builder/#onbuild) docker instruction to run commands at the container's build time. To make use of the docker factory users will have to create a dockerfile to declare what dependency versions are desired. Docker `args` can be specified in a number of ways, some of which are demonstrated below. For each of these examples we are building the equivalent of the `cypress/browsers` docker image with Cypress additionally installed. In each instance, since the example is only testing the chrome version, the examples could just install chrome by itself if the other browsers were not used.
+
+In the examples below, we install Cypress into the Docker image using:
+
+```dockerfile
+RUN npm install cypress --save-dev
+RUN npx cypress install
+```
+
+The additional `npx cypress install` command ensures that the Cypress binary component is installed, even if the Docker build step is re-run. The [Docker build cache](https://docs.docker.com/build/cache/) process may otherwise incorrectly optimize the build and fail to include the Cypress binary in the image, leading to run failures.
+
+### Example project
+
+To test the following Docker build examples you need to have a Cypress project available. You can create a simple Cypress E2E project by following these steps:
+
+```shell
+mkdir cy-example-test # or another directory of your choice
+cd cy-example-test
+npm init -y
+npm install cypress --save-dev
+npx cypress open
+```
+
+In the Cypress GUI then:
+
+- Select "E2E Testing"
+- Select "Continue"
+- Select "Electron" browser
+- Select "Create new spec"
+- Select "Create spec"
+- Close all Cypress windows
+
+Finally, test that the spec `cypress/e2e/spec.cy.js` runs:
+
+```shell
+npx cypress run
+```
 
 ### In the Dockerfile
 
 Args can be defined directly in the Dockerfile to specify variables that are available when the container is built.
 
-Dockerfile
+Create a `Dockerfile` with the following content:
 
 ```dockerfile
 # Args are defined in the Dockerfile before the FROM command.
-# Using these args will cause an image to be created with node (default version is 16.18.1), chrome, firefox and edge.
-ARG CHROME_VERSION='107.0.5304.121-1'
-ARG EDGE_VERSION='100.0.1185.29-1'
-ARG FIREFOX_VERSION='107.0'
+# Using these args will cause an image to be created with
+# Node.js (default version from .env file), Chrome, Firefox and Edge.
+ARG CHROME_VERSION='125.0.6422.141-1'
+ARG EDGE_VERSION='125.0.2535.85-1'
+ARG FIREFOX_VERSION='126.0.1'
 
 FROM cypress/factory
 
 COPY . /opt/app
 WORKDIR /opt/app
-RUN npm install --save-dev cypress
+RUN npm install cypress --save-dev
+RUN npx cypress install
 ```
 
 Then, in the same directory as the Dockerfile, run the following commands to build the docker container and run Cypress against the chrome browser.
 
 ```bash
 docker build . -t test
-docker run -it test npm run test -b chrome
+docker run -it --rm test npx cypress run -b chrome
 ```
 
 ### At build time
 
 Args can be passed to the docker build command with the `--build-arg` flag. Note: any value set via the command line will override the ARG value provided in the Dockerfile.
 
-Dockerfile
+Create a `Dockerfile` with the following content:
 
 ```dockerfile
 FROM cypress/factory
 
 COPY . /opt/app
 WORKDIR /opt/app
-RUN npm install --save-dev cypress
+RUN npm install cypress --save-dev
+RUN npx cypress install
 ```
 
-build commands
+Run the Docker commands:
 
 ```bash
-docker build . --build-arg CHROME_VERSION='107.0.5304.121-1' --build-arg EDGE_VERSION='100.0.1185.29-1' --build-arg FIREFOX_VERSION='107.0' -t test
-
-docker run test npm run test -b chrome
+docker build . --build-arg CHROME_VERSION='125.0.6422.141-1' --build-arg EDGE_VERSION='125.0.2535.85-1' --build-arg FIREFOX_VERSION='126.0.1' -t test
+docker run -it --rm test npx cypress run -b chrome
 ```
 
 ### In docker-compose.yml
 
-Finally, args can be specified in the docker-compose.yml file.
+Finally, args can be specified in the `docker-compose.yml` file.
 
-docker-compose.yml
+Create a `docker-compose.yml` file with the following content:
 
 ```yml
-version: '3'
-
 services:
   test:
     build:
       context: .
       args:
-        CHROME_VERSION: '107.0.5304.121-1'
-        EDGE_VERSION: '100.0.1185.29-1'
-        FIREFOX_VERSION: '107.0'
-    command: npm run test
+        CHROME_VERSION: '125.0.6422.141-1'
+        EDGE_VERSION: '125.0.2535.85-1'
+        FIREFOX_VERSION: '126.0.1'
+    command: npx cypress run
 ```
 
-Dockerfile
+and a `Dockerfile` with this content:
 
 ```dockerfile
 FROM cypress/factory
 
 COPY . /opt/app
 WORKDIR /opt/app
-RUN npm install --save-dev cypress
+RUN npm install cypress --save-dev
+RUN npx cypress install
 ```
 
-docker commands
+Run the Docker commands:
 
 ```bash
 docker compose build test
-
-docker compose run test
+docker compose run --rm test
 ```
 
 ### Reducing the size of the docker container
@@ -169,28 +205,27 @@ As mentioned above we can reduce the size of the docker image by removing browse
 
 Since this example only uses chrome, removing edge and firefox is as simple as not including a version.
 
-Dockerfile
+Create a `Dockerfile` with the following content:
 
 ```dockerfile
-# Args are defined in the Dockerfile before the FROM command.
-# Using these args will cause an image to be created with node (default version is 16.18.1), chrome, firefox and edge.
-ARG CHROME_VERSION='107.0.5304.121-1'
+ARG CHROME_VERSION='125.0.6422.141-1'
 
 FROM cypress/factory
 
 COPY . /opt/app
 WORKDIR /opt/app
-RUN npm install --save-dev cypress
+RUN npm install cypress --save-dev
+RUN npx cypress install
 ```
 
 Then, in the same directory as the Dockerfile, run the following commands to build the docker container and run Cypress against the chrome browser.
 
 ```bash
 docker build . -t test
-docker run -it test npm run test -b chrome
+docker run -it --rm test npx cypress run -b chrome
 ```
 
-The docker image including chrome, edge and firefox weighs in a ~1.93 GB, by removing edge and firefox the image can be reduced to ~1.06 GB.
+The released [cypress/base](https://hub.docker.com/r/cypress/base) image (no browsers) has a compressed size on [Docker Hub](https://hub.docker.com/u/cypress) of ~ 230 MB. The [cypress/browsers](https://hub.docker.com/r/cypress/browsers) image for `linux/amd64` has a compressed image size of ~ 840 MB. By generating a custom image with unneeded browsers removed, the image size can be correspondingly reduced.
 
 ## Version Testing
 
