Myujth

I'm building currently a service that uses acme/autocert. To use that service with more than 1 replicas, I had to write a persistent cache interface like DirCache. Then I noticed, that after restarting the service all valid certs in the Cache got ignored on the startup. The following sequence happens all the time:

• Cache put acme_account+key (even if it exists in the cache)


• Cache get acme_account+key


• Cache get my.domain.net (it returns the cached cert)


• Cache get acme_account+key


• Cache put my.domain.net+token


• Cache put HASH+http-01


• Cache delete HASH+http-01


• Cache delete my.domain.net+token


• Cache put my.domain.net (put the new cert)

Is this the correct behavior? Because every replica would create its own cert and a persistent Cache is not possible with this circumstances

Here is my manager factory

func NewManager(d *db.DynamoDB, staging bool) *Manager 
 manager := &Manager
 CertCache: NewPersistentCertCache(d),
 

 directoryURL := acme.LetsEncryptURL
 if staging 
 directoryURL = LetsEncryptStagingURL
 log.Infof("Using CA staging environment")
 
 log.Infof("CA URI %s", directoryURL)

 client := &acme.Client
 DirectoryURL: directoryURL,
 

 manager.AcmeManager = &autocert.Manager
 Prompt: autocert.AcceptTOS,
 HostPolicy: manager.AllowHostPolicy,
 Cache: manager.CertCache,
 Client: client,
 

 return manager

The solution for this question is that the cache interface and behavior works correctly. My cache implementation was faulty. I had a goroutine within the Cache.Get(...) that read from a DB to a channel, but unfortunately the outer func body did not wait for that channel and returns always a CacheMissed error. After the fix everything works fine. My fault sry