feat: add PostgreSQL as storage backend

[radiohertz]

closes #88

Most of it is ported from #5.

• Used lib/pq as pgx requires go 1.21.
• How should I handle migrations? Any pointers? I didn't see any existing code from the mysql impl.

cc @jessepeterson

[jessepeterson]

@radiohertz hello. Re: migrations.

We've not used any schema migration tooling at all. In the other Nano* project MySQL backends we provide manually generated numbered SQL schema files. For example see NanoMDM's MySQL backend storage folder with the set of schema.0000X.sql files.

[jessepeterson]

@radiohertz Quick review thoughts. Wanna get these done and we can review again?

1. Include a generate.go for sqlc.
2. NanoMDM uses a backend name of pgsql which fits nicely with mysql. You've used psql here. I think I'd prefer that (not to mention is not to be confused with the psql CLI tool).
3. I think the pq driver natively supports parsing the time.Time types. So we can convert to using sqlc's native time handling (mysql driver is an optional argument I didn't want to require). I.e.:

diff --git a/storage/psql/psql.go b/storage/psql/psql.go
index 62ac2bd..7e07175 100644
--- a/storage/psql/psql.go
+++ b/storage/psql/psql.go
@@ -72,8 +72,6 @@ func New(opts ...Option) (*PSQLStorage, error) {
 
 }
 
-const timestampFormat = "2006-01-02T15:04:05Z"
-
 // RetrieveAuthTokens reads the DEP OAuth tokens for name (DEP name).
 func (s *PSQLStorage) RetrieveAuthTokens(ctx context.Context, name string) (*client.OAuth1Tokens, error) {
 	tokenRow, err := s.q.GetAuthTokens(ctx, name)
@@ -86,17 +84,12 @@ func (s *PSQLStorage) RetrieveAuthTokens(ctx context.Context, name string) (*cli
 	if !tokenRow.ConsumerKey.Valid { // all auth token fields are set together
 		return nil, fmt.Errorf("consumer key not valid: %w", storage.ErrNotFound)
 	}
-	fmt.Println(tokenRow.AccessTokenExpiry.String)
-	accessTokenExpiryTime, err := time.Parse(timestampFormat, tokenRow.AccessTokenExpiry.String)
-	if err != nil {
-		return nil, err
-	}
 	return &client.OAuth1Tokens{
 		ConsumerKey:       tokenRow.ConsumerKey.String,
 		ConsumerSecret:    tokenRow.ConsumerSecret.String,
 		AccessToken:       tokenRow.AccessToken.String,
 		AccessSecret:      tokenRow.AccessSecret.String,
-		AccessTokenExpiry: accessTokenExpiryTime,
+		AccessTokenExpiry: tokenRow.AccessTokenExpiry.Time,
 	}, nil
 }
 
@@ -108,7 +101,7 @@ func (s *PSQLStorage) StoreAuthTokens(ctx context.Context, name string, tokens *
 		ConsumerSecret:    sql.NullString{String: tokens.ConsumerSecret, Valid: true},
 		AccessToken:       sql.NullString{String: tokens.AccessToken, Valid: true},
 		AccessSecret:      sql.NullString{String: tokens.AccessSecret, Valid: true},
-		AccessTokenExpiry: sql.NullString{String: tokens.AccessTokenExpiry.Format(timestampFormat), Valid: true},
+		AccessTokenExpiry: sql.NullTime{Time: tokens.AccessTokenExpiry, Valid: true},
 	})
 }
 
@@ -158,7 +151,7 @@ func (s *PSQLStorage) RetrieveAssignerProfile(ctx context.Context, name string)
 		profileUUID = assignerRow.AssignerProfileUuid.String
 	}
 	if assignerRow.AssignerProfileUuidAt.Valid {
-		modTime, err = time.Parse(timestampFormat, assignerRow.AssignerProfileUuidAt.String)
+		modTime = assignerRow.AssignerProfileUuidAt.Time
 	}
 	return
 }
diff --git a/storage/psql/sqlc.yaml b/storage/psql/sqlc.yaml
index 4dbc2de..334bf67 100644
--- a/storage/psql/sqlc.yaml
+++ b/storage/psql/sqlc.yaml
@@ -24,9 +24,3 @@ sql:
             go_type:
               type: "byte"
               slice: true
-          - column: "dep_names.access_token_expiry"
-            go_type:
-              type: "sql.NullString"
-          - column: "dep_names.assigner_profile_uuid_at"
-            go_type:
-              type: "sql.NullString"
diff --git a/storage/psql/sqlc/db.go b/storage/psql/sqlc/db.go
index 2248616..c5852e0 100644
--- a/storage/psql/sqlc/db.go
+++ b/storage/psql/sqlc/db.go
@@ -1,6 +1,6 @@
 // Code generated by sqlc. DO NOT EDIT.
 // versions:
-//   sqlc v1.27.0
+//   sqlc v1.26.0
 
 package sqlc
 
diff --git a/storage/psql/sqlc/models.go b/storage/psql/sqlc/models.go
index a5669e4..b634a2d 100644
--- a/storage/psql/sqlc/models.go
+++ b/storage/psql/sqlc/models.go
@@ -1,6 +1,6 @@
 // Code generated by sqlc. DO NOT EDIT.
 // versions:
-//   sqlc v1.27.0
+//   sqlc v1.26.0
 
 package sqlc
 
@@ -14,7 +14,7 @@ type DepName struct {
 	ConsumerSecret         sql.NullString
 	AccessToken            sql.NullString
 	AccessSecret           sql.NullString
-	AccessTokenExpiry      sql.NullString
+	AccessTokenExpiry      sql.NullTime
 	ConfigBaseUrl          sql.NullString
 	TokenpkiCertPem        []byte
 	TokenpkiKeyPem         []byte
@@ -22,7 +22,7 @@ type DepName struct {
 	TokenpkiStagingKeyPem  []byte
 	SyncerCursor           sql.NullString
 	AssignerProfileUuid    sql.NullString
-	AssignerProfileUuidAt  sql.NullString
+	AssignerProfileUuidAt  sql.NullTime
 	CreatedAt              sql.NullTime
 	UpdatedAt              sql.NullTime
 }
diff --git a/storage/psql/sqlc/query.sql.go b/storage/psql/sqlc/query.sql.go
index 20d369a..0632f5d 100644
--- a/storage/psql/sqlc/query.sql.go
+++ b/storage/psql/sqlc/query.sql.go
@@ -1,6 +1,6 @@
 // Code generated by sqlc. DO NOT EDIT.
 // versions:
-//   sqlc v1.27.0
+//   sqlc v1.26.0
 // source: query.sql
 
 package sqlc
@@ -22,7 +22,7 @@ WHERE
 
 type GetAssignerProfileRow struct {
 	AssignerProfileUuid   sql.NullString
-	AssignerProfileUuidAt sql.NullString
+	AssignerProfileUuidAt sql.NullTime
 }
 
 func (q *Queries) GetAssignerProfile(ctx context.Context, name string) (GetAssignerProfileRow, error) {
@@ -50,7 +50,7 @@ type GetAuthTokensRow struct {
 	ConsumerSecret    sql.NullString
 	AccessToken       sql.NullString
 	AccessSecret      sql.NullString
-	AccessTokenExpiry sql.NullString
+	AccessTokenExpiry sql.NullTime
 }
 
 func (q *Queries) GetAuthTokens(ctx context.Context, name string) (GetAuthTokensRow, error) {
@@ -174,7 +174,7 @@ type StoreAuthTokensParams struct {
 	ConsumerSecret    sql.NullString
 	AccessToken       sql.NullString
 	AccessSecret      sql.NullString
-	AccessTokenExpiry sql.NullString
+	AccessTokenExpiry sql.NullTime
 }
 
 func (q *Queries) StoreAuthTokens(ctx context.Context, arg StoreAuthTokensParams) error {

[jessepeterson]

See last PR comment. :)