clear acme client cache whenever an acme issuer is changed

This is a very in-elegant solution to the problem, but it avoids
having to look at other extant issuers and having background processes.

Signed-off-by: Daniel Morsing <dmo@jetstack.io>

pkg/acme/acme.go

@@ -193,6 +193,12 @@ func lookupClient(spec *cmapi.ACMEIssuer, status *cmapi.ACMEIssuerStatus, pk *rs
 	return acmeCl
 }
 
+func ClearClientCache() {
+	clientRepoMu.Lock()
+	defer clientRepoMu.Unlock()
+	clientRepo = nil
+}
+
 // buildHTTPClient returns an HTTP client to be used by the ACME client.
 // For the time being, we construct a new HTTP client on each invocation.
 // This is because we need to set the 'skipTLSVerify' flag on the HTTP client

pkg/issuer/acme/setup.go

@@ -96,6 +96,8 @@ func (a *Acme) Setup(ctx context.Context) error {
 
 	}
 
+	acme.ClearClientCache()
+
 	cl, err := acme.ClientWithKey(a.issuer, pk)
 	if err != nil {
 		s := messageAccountVerificationFailed + err.Error()