Overhaul the auto-config translation

This fixes some issues around spurious warnings about using enterprise configuration in OSS.

agent/auto-config/config_translate.go

@@ -2,7 +2,6 @@ package autoconf
 
 import (
 	pbconfig "github.com/hashicorp/consul/agent/agentpb/config"
-	"github.com/hashicorp/consul/agent/config"
 )
 
 // translateAgentConfig is meant to take in a agent/agentpb/config.Config type
@@ -13,81 +12,149 @@ import (
 //
 // Why is this function not in the agent/agentpb/config package? The answer, that
 // package cannot import the agent/config package without running into import cycles.
-func translateConfig(c *pbconfig.Config) *config.Config {
-	out := config.Config{
-		Datacenter:        &c.Datacenter,
-		PrimaryDatacenter: &c.PrimaryDatacenter,
-		NodeName:          &c.NodeName,
-		SegmentName:       &c.SegmentName,
+//
+// If this function is meant to output an agent/config.Config then why does it output
+// a map[string]interface{}? The answer is that our config and command line option
+// parsing is messed up and it would require major changes to fix (we probably should
+// do them but not for the auto-config feature). To understand this we need to work
+// backwards. What we want to be able to do is persist the config settings from an
+// auto-config response configuration to disk. We then want that configuration
+// to be able to be parsed with the normal configuration parser/builder. It sort of was
+// working with returning a filled out agent/config.Config but the problem was that
+// the struct has a lot of non-pointer struct members. Thus, JSON serializtion caused
+// these to always be emitted even if they contained no non-empty fields. The
+// configuration would then seem to parse okay, but in OSS we would get warnings for
+// setting a bunch of enterprise fields like "audit" at the top level. In an attempt
+// to quiet those warnings, I had converted all the existing non-pointer struct fields
+// to pointers. Then there were issues with the builder code expecting concrete values.
+// I could add nil checks **EVERYWHERE** in builder.go or take a different approach.
+// I then made a function utilizing github.com/mitchellh/reflectwalk to un-nil all the
+// struct pointers after parsing to prevent any nil pointer dereferences. At first
+// glance this seemed like it was going to work but then I saw that nearly all of the
+// tests in runtime_test.go were failing. The first issues was that we were not merging
+// pointers to struct fields properly. It was simply taking the new pointer if non-nil
+// and defaulting to the original. So I updated that code, to properly merge pointers
+// to structs. That fixed a bunch of tests but then there was another issue with
+// the runtime tests where it was emitting warnings for using consul enterprise only
+// configuration. After spending some time tracking this down it turns out that it
+// was coming from our CLI option parsing. Our CLI option parsing works by filling
+// in a agent/config.Config struct. Along the way when converting to pointers to
+// structs I had to add a call to that function to un-nil various pointers to prevent
+// the CLI from segfaulting. However this un-nil operation was causing the various
+// enterprise only keys to be materialized. Thus we were back to where we were before
+// the conversion to pointers to structs and mostly stuck.
+//
+// Therefore, this function will create a map[string]interface{} that should be
+// compatible with the agent/config.Config struct but where we can more tightly
+// control which fields are output. Its not a nice solution. It has a non-trivial
+// maintenance burden. In the long run we should unify the protobuf Config and
+// the normal agent/config.Config so that we can just serialize the protobuf version
+// without any translation. For now, this hack is necessary :(
+func translateConfig(c *pbconfig.Config) map[string]interface{} {
+	out := map[string]interface{}{
+		"datacenter":         c.Datacenter,
+		"primary_datacenter": c.PrimaryDatacenter,
+		"node_name":          c.NodeName,
+	}
+
+	// only output the SegmentName in the configuration if its non-empty
+	// this will avoid a warning later when parsing the persisted configuration
+	if c.SegmentName != "" {
+		out["segment"] = c.SegmentName
 	}
 
 	// Translate Auto Encrypt settings
 	if a := c.AutoEncrypt; a != nil {
-		out.AutoEncrypt = config.AutoEncrypt{
-			TLS:      &a.TLS,
-			DNSSAN:   a.DNSSAN,
-			IPSAN:    a.IPSAN,
-			AllowTLS: &a.AllowTLS,
+		autoEncryptConfig := map[string]interface{}{
+			"tls":       a.TLS,
+			"allow_tls": a.AllowTLS,
 		}
+
+		if len(a.DNSSAN) > 0 {
+			autoEncryptConfig["dns_san"] = a.DNSSAN
+		}
+		if len(a.IPSAN) > 0 {
+			autoEncryptConfig["ip_san"] = a.IPSAN
+		}
+
+		out["auto_encrypt"] = autoEncryptConfig
 	}
 
 	// Translate all the ACL settings
 	if a := c.ACL; a != nil {
-		out.ACL = config.ACL{
-			Enabled:                &a.Enabled,
-			PolicyTTL:              &a.PolicyTTL,
-			RoleTTL:                &a.RoleTTL,
-			TokenTTL:               &a.TokenTTL,
-			DownPolicy:             &a.DownPolicy,
-			DefaultPolicy:          &a.DefaultPolicy,
-			EnableKeyListPolicy:    &a.EnableKeyListPolicy,
-			DisabledTTL:            &a.DisabledTTL,
-			EnableTokenPersistence: &a.EnableTokenPersistence,
-			MSPDisableBootstrap:    &a.MSPDisableBootstrap,
+		aclConfig := map[string]interface{}{
+			"enabled":                  a.Enabled,
+			"policy_ttl":               a.PolicyTTL,
+			"role_ttl":                 a.RoleTTL,
+			"token_ttl":                a.TokenTTL,
+			"down_policy":              a.DownPolicy,
+			"default_policy":           a.DefaultPolicy,
+			"enable_key_list_policy":   a.EnableKeyListPolicy,
+			"disabled_ttl":             a.DisabledTTL,
+			"enable_token_persistence": a.EnableTokenPersistence,
 		}
 
 		if t := c.ACL.Tokens; t != nil {
-			var tokens []config.ServiceProviderToken
+			var mspTokens []map[string]string
 
 			// create the slice of msp tokens if any
 			for _, mspToken := range t.ManagedServiceProvider {
-				tokens = append(tokens, config.ServiceProviderToken{
-					AccessorID: &mspToken.AccessorID,
-					SecretID:   &mspToken.SecretID,
+				mspTokens = append(mspTokens, map[string]string{
+					"accessor_id": mspToken.AccessorID,
+					"secret_id":   mspToken.SecretID,
 				})
 			}
 
-			out.ACL.Tokens = config.Tokens{
-				Master:                 &t.Master,
-				Replication:            &t.Replication,
-				AgentMaster:            &t.AgentMaster,
-				Default:                &t.Default,
-				Agent:                  &t.Agent,
-				ManagedServiceProvider: tokens,
+			tokenConfig := make(map[string]interface{})
+
+			if t.Master != "" {
+				tokenConfig["master"] = t.Master
 			}
+			if t.Replication != "" {
+				tokenConfig["replication"] = t.Replication
 			}
+			if t.AgentMaster != "" {
+				tokenConfig["agent_master"] = t.AgentMaster
+			}
+			if t.Default != "" {
+				tokenConfig["default"] = t.Default
+			}
+			if t.Agent != "" {
+				tokenConfig["agent"] = t.Agent
+			}
+			if len(mspTokens) > 0 {
+				tokenConfig["managed_service_provider"] = mspTokens
+			}
+
+			aclConfig["tokens"] = tokenConfig
+		}
+		out["acl"] = aclConfig
 	}
 
 	// Translate the Gossip settings
 	if g := c.Gossip; g != nil {
-		out.RetryJoinLAN = g.RetryJoinLAN
+		out["retry_join"] = g.RetryJoinLAN
 
 		// Translate the Gossip Encryption settings
 		if e := c.Gossip.Encryption; e != nil {
-			out.EncryptKey = &e.Key
-			out.EncryptVerifyIncoming = &e.VerifyIncoming
-			out.EncryptVerifyOutgoing = &e.VerifyOutgoing
+			out["encrypt"] = e.Key
+			out["encrypt_verify_incoming"] = e.VerifyIncoming
+			out["encrypt_verify_outgoing"] = e.VerifyOutgoing
 		}
 	}
 
 	// Translate the Generic TLS settings
 	if t := c.TLS; t != nil {
-		out.VerifyOutgoing = &t.VerifyOutgoing
-		out.VerifyServerHostname = &t.VerifyServerHostname
-		out.TLSMinVersion = &t.MinVersion
-		out.TLSCipherSuites = &t.CipherSuites
-		out.TLSPreferServerCipherSuites = &t.PreferServerCipherSuites
+		out["verify_outgoing"] = t.VerifyOutgoing
+		out["verify_server_hostname"] = t.VerifyServerHostname
+		if t.MinVersion != "" {
+			out["tls_min_version"] = t.MinVersion
+		}
+		if t.CipherSuites != "" {
+			out["tls_cipher_suites"] = t.CipherSuites
+		}
+		out["tls_prefer_server_cipher_suites"] = t.PreferServerCipherSuites
 	}
 
-	return &out
+	return out
 }

agent/auto-config/config_translate_test.go

@@ -1,6 +1,7 @@
 package autoconf
 
 import (
+	"encoding/json"
 	"testing"
 
 	pbconfig "github.com/hashicorp/consul/agent/agentpb/config"
@@ -94,7 +95,6 @@ func TestConfig_translateConfig(t *testing.T) {
 			EnableKeyListPolicy:    boolPointer(true),
 			DisabledTTL:            stringPointer("4s"),
 			EnableTokenPersistence: boolPointer(true),
-			MSPDisableBootstrap:    boolPointer(false),
 			Tokens: config.Tokens{
 				Master:      stringPointer("99e7e490-6baf-43fc-9010-78b6aa9a6813"),
 				Replication: stringPointer("51308d40-465c-4ac6-a636-7c0747edec89"),
@@ -117,6 +117,11 @@ func TestConfig_translateConfig(t *testing.T) {
 		},
 	}
 
-	actual := translateConfig(&original)
-	require.Equal(t, expected, actual)
+	translated := translateConfig(&original)
+	data, err := json.Marshal(translated)
+	require.NoError(t, err)
+
+	actual, _, err := config.Parse(string(data), "json")
+	require.NoError(t, err)
+	require.Equal(t, expected, &actual)
 }