storage/sql: add a SQL storage implementation

This change adds support for SQLite3, and Postgres.

storage/sql/config.go

@@ -0,0 +1,113 @@
+package sql
+
+import (
+	"database/sql"
+	"fmt"
+	"net/url"
+	"strconv"
+
+	"github.com/coreos/dex/storage"
+)
+
+// SQLite3 options for creating an SQL db.
+type SQLite3 struct {
+	// File to
+	File string `yaml:"file"`
+}
+
+// Open creates a new storage implementation backed by SQLite3
+func (s *SQLite3) Open() (storage.Storage, error) {
+	return s.open()
+}
+
+func (s *SQLite3) open() (*conn, error) {
+	db, err := sql.Open("sqlite3", s.File)
+	if err != nil {
+		return nil, err
+	}
+	if s.File == ":memory:" {
+		// sqlite3 uses file locks to coordinate concurrent access. In memory
+		// doesn't support this, so limit the number of connections to 1.
+		db.SetMaxOpenConns(1)
+	}
+	c := &conn{db, flavorSQLite3}
+	if _, err := c.migrate(); err != nil {
+		return nil, fmt.Errorf("failed to perform migrations: %v", err)
+	}
+	return c, nil
+}
+
+const (
+	sslDisable    = "disable"
+	sslRequire    = "require"
+	sslVerifyCA   = "verify-ca"
+	sslVerifyFull = "verify-full"
+)
+
+// PostgresSSL represents SSL options for Postgres databases.
+type PostgresSSL struct {
+	Mode   string
+	CAFile string
+	// Files for client auth.
+	KeyFile  string
+	CertFile string
+}
+
+// Postgres options for creating an SQL db.
+type Postgres struct {
+	Database string
+	User     string
+	Password string
+	Host     string
+
+	SSL PostgresSSL `json:"ssl" yaml:"ssl"`
+
+	ConnectionTimeout int // Seconds
+}
+
+// Open creates a new storage implementation backed by Postgres.
+func (p *Postgres) Open() (storage.Storage, error) {
+	return p.open()
+}
+
+func (p *Postgres) open() (*conn, error) {
+	v := url.Values{}
+	set := func(key, val string) {
+		if val != "" {
+			v.Set(key, val)
+		}
+	}
+	set("connect_timeout", strconv.Itoa(p.ConnectionTimeout))
+	set("sslkey", p.SSL.KeyFile)
+	set("sslcert", p.SSL.CertFile)
+	set("sslrootcert", p.SSL.CAFile)
+	if p.SSL.Mode == "" {
+		// Assume the strictest mode if unspecified.
+		p.SSL.Mode = sslVerifyFull
+	}
+	set("sslmode", p.SSL.Mode)
+
+	u := url.URL{
+		Scheme:   "postgres",
+		Host:     p.Host,
+		Path:     "/" + p.Database,
+		RawQuery: v.Encode(),
+	}
+
+	if p.User != "" {
+		if p.Password != "" {
+			u.User = url.UserPassword(p.User, p.Password)
+		} else {
+			u.User = url.User(p.User)
+		}
+	}
+	db, err := sql.Open("postgres", u.String())
+	if err != nil {
+		return nil, err
+	}
+	c := &conn{db, flavorPostgres}
+	if _, err := c.migrate(); err != nil {
+		return nil, fmt.Errorf("failed to perform migrations: %v", err)
+	}
+	return c, nil
+}