docs(docs-infra): update preview server setup instructions (#36837)

I recently went through the process of setting up a preview server VM
again and updated the instructions and references based on the latest
docs for Debian, Docker, Google Compute Engine, etc.

PR Close #36837

aio/aio-builds-setup/docs/vm-setup--attach-persistent-disk.md

@@ -3,7 +3,7 @@
 
 ## Create `aio-builds` persistent disk (if not already exists)
 - Follow instructions [here](https://cloud.google.com/compute/docs/disks/add-persistent-disk#create_disk).
-- `sudo mkfs.ext4 -F -E lazy_itable_init=0,lazy_journal_init=0,discard /dev/disk/by-id/google-aio-builds`
+- `sudo mkfs.ext4 -m 0 -E lazy_itable_init=0,lazy_journal_init=0,discard /dev/disk/by-id/google-aio-builds`
 
 
 ## Mount disk
@@ -14,7 +14,7 @@
 
 ## Mount disk on boot
 - Run:
-  ```
+  ```sh
   echo UUID=`sudo blkid -s UUID -o value /dev/disk/by-id/google-aio-builds` \
-    /mnt/disks/aio-builds ext4 discard,defaults,nofail 0 2 | sudo tee -a /etc/fstab
+    /mnt/disks/aio-builds ext4 defaults,discard,nofail 0 2 | sudo tee -a /etc/fstab
   ```

aio/aio-builds-setup/docs/vm-setup--create-docker-image.md

@@ -1,10 +1,12 @@
 # VM setup - Create docker image
 
 
-## Install node and yarn
-- Install [nvm](https://github.com/creationix/nvm#installation).
-- Install node.js: `nvm install 8`
-- Install yarn: `npm -g install yarn`
+## Install git, Node.js and yarn
+- `sudo apt-get update`
+- `sudo apt-get install -y git`
+- Install [nvm](https://github.com/nvm-sh/nvm#installing-and-updating).
+- Install Node.js: `nvm install 12`
+- Install yarn: `npm install --global yarn`
 
 
 ## Checkout repository
@@ -26,7 +28,7 @@ The following commands would create a docker image from GitHub repo `foo/bar` to
 
 - `git clone https://github.com/foo/bar.git foobar`
 - Run:
-  ```
+  ```sh
   ./foobar/aio-builds-setup/scripts/create-image.sh foobar-builds \
     --build-arg AIO_REPO_SLUG=foo/bar \
     --build-arg AIO_DOMAIN_NAME=foobar-builds.io \

aio/aio-builds-setup/docs/vm-setup--set-up-docker.md

@@ -3,24 +3,17 @@
 
 ## Install docker
 
-_Debian (jessie):_
-- `sudo apt-get update`
-- `sudo apt-get install -y apt-transport-https ca-certificates curl git software-properties-common`
-- `curl -fsSL https://apt.dockerproject.org/gpg | sudo apt-key add -`
-- `apt-key fingerprint 58118E89F3A912897C070ADBF76221572C52609D`
-- `sudo add-apt-repository "deb https://apt.dockerproject.org/repo/ debian-$(lsb_release -cs) main"`
-- `sudo apt-get update`
-- `sudo apt-get -y install docker-engine`
+Official installation instructions: https://docs.docker.com/engine/install
+Example:
 
-_Ubuntu (16.04):_
+_Debian (buster):_
 - `sudo apt-get update`
-- `sudo apt-get install -y curl git linux-image-extra-$(uname -r) linux-image-extra-virtual`
-- `sudo apt-get install -y apt-transport-https ca-certificates`
-- `curl -fsSL https://yum.dockerproject.org/gpg | sudo apt-key add -`
-- `apt-key fingerprint 58118E89F3A912897C070ADBF76221572C52609D`
-- `sudo add-apt-repository "deb https://apt.dockerproject.org/repo/ ubuntu-$(lsb_release -cs) main"`
+- `sudo apt-get install -y apt-transport-https ca-certificates curl gnupg-agent software-properties-common`
+- `curl -fsSL https://download.docker.com/linux/debian/gpg | sudo apt-key add -`
+- `sudo apt-key fingerprint 0EBFCD88`
+- `sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/debian $(lsb_release -cs) stable"`
 - `sudo apt-get update`
-- `sudo apt-get -y install docker-engine`
+- `sudo apt-get -y install docker-ce docker-ce-cli containerd.io`
 
 
 ## Start the docker

aio/aio-builds-setup/docs/vm-setup--update-docker-container.md

@@ -31,7 +31,7 @@ used for.
 ## Run the script manually
 You may choose to manually run the script, when necessary. Example:
 
-```
+```sh
 update-preview-server.sh \
     /path/to/repo \
     /path/to/localcerts \
@@ -43,10 +43,10 @@ update-preview-server.sh \
 
 ## Run the script automatically
 You may choose to automatically trigger the script, e.g. using a cronjob. For example, the following
-cronjob entry would run the script every hour and update the preview server (assuming the user has
-the necessary permissions):
+cronjob entry would run the script every 30 minutes, update the preview server (if necessary) and
+log its output to `update-preview-server.log` (assuming the user has the necessary permissions):
 
 ```
 # Periodically check for changes and update the preview server (if necessary)
-*/30 *  * * *   /path/to/update-preview-server.sh /path/to/repo /path/to/localcerts /path/to/secrets /path/to/builds /path/to/logs
+*/30 *  * * *   /path/to/update-preview-server.sh /path/to/repo /path/to/localcerts /path/to/secrets /path/to/builds /path/to/logs >> /path/to/update-preview-server.log 2>&1
 ```