Make DerivedState from Configs

[mlajkim]

Current SIA v3.2 turns on/off based on given configurations, but it has the following probles:

• Easy to make mistakes for developers
  • Let's say the following is the correct setting that makes SIA to read local instance cert
  • this.config.ProviderService === "" && this.config.CertFile === "" && this.config.KeyFile === ""
  • Developers might forget to include this.config.CertFile === "" && this.config.KeyFile === "" and only include this.config.ProviderService === ""
    • Actually happened and fixed in 27d3522
• Hard to read
  • The following code is so vague and has no meaning.
  • this.config.ProviderService === "" && this.config.CertFile === "" && this.config.KeyFile === ""
  • if we can have a DerivedState that holds such combination, it would be much easier to read

DerivedState := func() {
  if this.config.ProviderService != "" {
    return "identityd"
  }
  if config.CertFile === "" &&config.KeyFile === ""  {
    return "readLocalFile"
  }
  return "inactive"
}()

[mlajkim]

finish the review 2 hours before the Merge Done
(Merge Done) TODOs:

• (9/14 12:00) Refactor RoleCert with DerivedState: Role cert with derived state and its new config #145
• Bug fix: Fix Derived RoleCert Dir #146
• (9/14 20:00) Refactor: TargetDomainRoles parsed as idCfg: Refactor parseTargetDomainRoles with derived state DerivedRoleCert #147
• (9/15 12:00) Refactor: Use Formatter with DerivedState: Refactor derived-role-cert with Format & KeyFormat #148
• +added on Sep 16 10:58: We must refactor the k8s secret backup state: Refactor Backup Related State #152
• +added on Sep 14 19:58: For consistent log output, we need to refactor the ServiceCert Too: Refactor: Service Cert in Derived State #153
• +added on Sep 15 12:53: K8s (pod, ns, secret) related derived state is required too
  • removed on Sep 16 10:58: K8s does not have derived state, but it is more of the grouped ones: [DNM] Refactor: k8s derived state Prototype #151
• (9/15 20:00) (9/17 15:00)Feat: Introduce new RoleCertRelatedStuff: Feat/role cert naming format #149
• +added on Sep 18 09:28: Refactor tokenService with idCfg?: Remove unnecessary configurations for the TokenServer from service.go #159
• (9/16 12:00) (9/17 18:00)Refactor: TokenFile with DerivedState: Refactor: TokenFile with DerivedState #160
• +added on Sep 17 15:27: Refactor: TokenServer with DerviedState: Refactor: TokenServer with DerivedState #161
• +added on Sep 18 09:28: (optional) idCfg => only TokenFileState & TokenServerState=> decided not to as RoleCert does the same; simply sending the address of idCfg
• (9/16 20:00) (9/17 20:00)Refactor: Use Formatter for tokens: Refactor derived-token-file with Format #162
• (9/17 12:00) (9/18 15:00)Feat: Introduce new TokenRelatedStuff: Feat/token naming format #163
• (9/18 20:00) Feat: Introduce error handling: Terminate if file output fails in init mode #156
• Next actions:
  • Refactor: derivedTokenCacheConfig()
  • idCfg.Reloader, err = util.NewCertReloader(util.ReloadConfig{}?

[mlajkim]

Prototype as whole: #150, and learned to separate:
- kuberenetes
- X509
- service-cert
- log fix

Grouped States (No Derived State):

• Kubernetes
• X509

Derived State:

• SerivceCert

Log:
? Dont know yet

[mlajkim]

Optional TODOs:
Reorder the following based on the config/model.go:

• athenz-sia.env
• config/default.go
• config.config.go