Updating the AddressBook

As we are going to work with the application we wrote in Chapter 7, let’s copy it over to the chapter9 directory:

$ cp -R ../chapter7/cmd/addressbook cmd
$ cp -R ../chapter7/pkg/addressbook pkg
$ cp ../chapter7/main.go .
$ cp ../chapter7/proto/addressbook.proto proto

Now, because we were using a Go module name including chapter7, we will need to replace all the occurrences by chapter9. On Linux/Mac, we can run the following command:

$ find . -type f -exec sh -c "sed -i '' -e 's/chapter7/chapter9/g' {}" ";"

And on Windows (Powershell), we can run the following:

$ Get-ChildItem -Recurse -File -Include *.proto,*.go,go.mod | ForEach { (Get-Content $_ | ForEach  { $_ -replace ‘chapter7’, ‘chapter9’ }) | Set-Content $_ }

We are now all set up to start.

The first step is to update our proto file to use our custom option. To do that, we will import our validate.proto...