refactor(database): move service logic into separate package

[jbrockopp]

Based off of #574, #663, #687, #692, #721, #722, #782 and #810

This change continues the refactor efforts initially introduced in the above PRs.

This adds a new service package to the github.com/go-vela/server/database package.

This contains a ServiceInterface interface declaring all functions necessary for service based interactions with the database:

server/database/service/interface.go

Lines 11 to 49 in d930b22

	// ServiceInterface represents the Vela interface for service
	// functions with the supported Database backends.
	//
	//nolint:revive // ignore name stutter
	type ServiceInterface interface {
	// Service Data Definition Language Functions
	//
	// https://en.wikipedia.org/wiki/Data_definition_language
	// CreateServiceTable defines a function that creates the services table.
	CreateServiceTable(string) error
	// Service Data Manipulation Language Functions
	//
	// https://en.wikipedia.org/wiki/Data_manipulation_language
	// CountServices defines a function that gets the count of all services.
	CountServices() (int64, error)
	// CountServicesForBuild defines a function that gets the count of services by build ID.
	CountServicesForBuild(*library.Build, map[string]interface{}) (int64, error)
	// CreateService defines a function that creates a new service.
	CreateService(*library.Service) error
	// DeleteService defines a function that deletes an existing service.
	DeleteService(*library.Service) error
	// GetService defines a function that gets a service by ID.
	GetService(int64) (*library.Service, error)
	// GetServiceForBuild defines a function that gets a service by number and build ID.
	GetServiceForBuild(*library.Build, int) (*library.Service, error)
	// ListServices defines a function that gets a list of all services.
	ListServices() ([]*library.Service, error)
	// ListServicesForBuild defines a function that gets a list of services by build ID.
	ListServicesForBuild(*library.Build, map[string]interface{}, int, int) ([]*library.Service, int64, error)
	// ListServiceImageCount defines a function that gets a list of all service images and the count of their occurrence.
	ListServiceImageCount() (map[string]float64, error)
	// ListServiceStatusCount defines a function that gets a list of all service statuses and the count of their occurrence.
	ListServiceStatusCount() (map[string]float64, error)
	// UpdateService defines a function that updates an existing service.
	UpdateService(*library.Service) error
	}

NOTE: The other refactor PRs above leveraged using the keyword "service" when referring to interfaces.

However, when I started that for this package, it left me with an interface{} type named ServiceService.

I thought this name wasn't great so I elected to refactor all of them from *Service -> *Interface.

This package also contains the engine which implements the above service interface:

server/database/service/service.go

Lines 23 to 38 in d930b22

	// engine represents the service functionality that implements the ServiceInterface interface.
	engine struct {
	// engine configuration settings used in service functions
	config *config
	// gorm.io/gorm database client used in service functions
	//
	// https://pkg.go.dev/gorm.io/gorm#DB
	client *gorm.DB
	// sirupsen/logrus logger used in service functions
	//
	// https://pkg.go.dev/github.com/sirupsen/logrus#Entry
	logger *logrus.Entry
	}
	)

This engine contains no raw SQL queries for integrating with the services table.

Instead, we leverage our DB library's (https://gorm.io/) agnostic abstraction for integrating with that table.

[codecov]

Codecov Report

Merging #816 (2cd9863) into main (cba432f) will decrease coverage by 0.22%.
The diff coverage is 82.40%.

@@            Coverage Diff             @@
##             main     #816      +/-   ##
==========================================
- Coverage   57.70%   57.49%   -0.22%     
==========================================
  Files         263      271       +8     
  Lines       15922    15892      -30     
==========================================
- Hits         9188     9137      -51     
- Misses       6319     6331      +12     
- Partials      415      424       +9     

Impacted Files	Coverage Δ
api/build.go	1.48% <0.00%> (ø)
api/metrics.go	0.00% <0.00%> (ø)
api/service.go	0.00% <0.00%> (ø)
api/step.go	0.00% <0.00%> (ø)
api/webhook.go	0.00% <0.00%> (ø)
database/hook/hook.go	51.72% <ø> (ø)
database/log/log.go	51.72% <ø> (ø)
database/pipeline/pipeline.go	51.72% <ø> (ø)
database/repo/repo.go	51.72% <ø> (ø)
database/secret/secret.go	51.72% <ø> (ø)
... and 27 more

[cognifloyd]

🎇

[KellyMerrick]

@jbrockopp We plan to review this within the next couple weeks.

[wass3rw3rk]

per githubstatus.com, github is having some issues currently. try rerunning workflows later.