refactor(internal): export internal packages (#887)

* refactor: export internal packages

* refactor(server): define Server

* refactor: fix lint issues

* test(integration): fix imports

pkg/commands/server/config.go

@@ -0,0 +1,45 @@
+package server
+
+import (
+	"github.com/urfave/cli/v2"
+
+	"github.com/aquasecurity/trivy/pkg/commands/config"
+)
+
+// Config holds the Trivy config
+type Config struct {
+	config.GlobalConfig
+	config.DBConfig
+	config.CacheConfig
+
+	Listen      string
+	Token       string
+	TokenHeader string
+}
+
+// NewConfig is the factory method to return config
+func NewConfig(c *cli.Context) Config {
+	// the error is ignored because logger is unnecessary
+	gc, _ := config.NewGlobalConfig(c) // nolint: errcheck
+	return Config{
+		GlobalConfig: gc,
+		DBConfig:     config.NewDBConfig(c),
+		CacheConfig:  config.NewCacheConfig(c),
+
+		Listen:      c.String("listen"),
+		Token:       c.String("token"),
+		TokenHeader: c.String("token-header"),
+	}
+}
+
+// Init initializes the config
+func (c *Config) Init() (err error) {
+	if err := c.DBConfig.Init(); err != nil {
+		return err
+	}
+	if err := c.CacheConfig.Init(); err != nil {
+		return err
+	}
+
+	return nil
+}