It would be beneficial to be familiar with the code for our service that we introduced in Chapter 4, Introduction to ACME registration service. You might also find it useful to read and run the full versions of the code for this chapter, which are available at https://github.com/PacktPublishing/Hands-On-Dependency-Injection-in-Go/tree/master/ch05.
Instructions to obtain the code and configure the sample service are available in the README here https://github.com/PacktPublishing/Hands-On-Dependency-Injection-in-Go/.
You can find the code for our service, with the changes from this chapter already applied, in ch05/acme.