Rework templating for bootstrap

internal/config/template.go

@@ -0,0 +1,91 @@
+package config
+
+import (
+	"bytes"
+	"io"
+	"path/filepath"
+	"reflect"
+
+	"github.com/FAU-CDI/wisski-distillery/internal/core"
+	"github.com/FAU-CDI/wisski-distillery/pkg/hostname"
+	"github.com/FAU-CDI/wisski-distillery/pkg/password"
+	"github.com/FAU-CDI/wisski-distillery/pkg/unpack"
+
+	_ "embed"
+)
+
+// Template is a template for the cofiguration file
+type Template struct {
+	DeployRoot               string `env:"DEPLOY_ROOT"`
+	DefaultDomain            string `env:"DEFAULT_DOMAIN"`
+	SelfOverridesFile        string `env:"SELF_OVERRIDES_FILE"`
+	AuthorizedKeys           string `env:"AUTHORIZED_KEYS_FILE"`
+	TriplestoreAdminUser     string `env:"GRAPHDB_ADMIN_USER"`
+	TriplestoreAdminPassword string `env:"GRAPHDB_ADMIN_PASSWORD"`
+	MysqlAdminUsername       string `env:"MYSQL_ADMIN_USER"`
+	MysqlAdminPassword       string `env:"MYSQL_ADMIN_PASSWORD"`
+}
+
+// SetDefaults sets defaults on the template
+func (tpl *Template) SetDefaults() (err error) {
+	if tpl.DeployRoot == "" {
+		tpl.DeployRoot = core.BaseDirectoryDefault
+	}
+
+	if tpl.DefaultDomain == "" {
+		tpl.DefaultDomain = hostname.FQDN()
+	}
+
+	if tpl.SelfOverridesFile == "" {
+		tpl.SelfOverridesFile = filepath.Join(tpl.DeployRoot, core.OverridesJSON)
+	}
+
+	if tpl.AuthorizedKeys == "" {
+		tpl.AuthorizedKeys = filepath.Join(tpl.DeployRoot, core.AuthorizedKeys)
+	}
+
+	if tpl.TriplestoreAdminUser == "" {
+		tpl.TriplestoreAdminUser = "admin"
+	}
+
+	if tpl.TriplestoreAdminPassword == "" {
+		tpl.TriplestoreAdminPassword, err = password.Password(64)
+		if err != nil {
+			return err
+		}
+	}
+
+	if tpl.MysqlAdminUsername == "" {
+		tpl.MysqlAdminUsername = "admin"
+	}
+
+	if tpl.MysqlAdminPassword == "" {
+		tpl.MysqlAdminPassword, err = password.Password(64)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+//go:embed config_template
+var templateBytes []byte
+
+// MarshalTo marshals this template into dst
+func (tpl Template) MarshalTo(dst io.Writer) error {
+	tplVal := reflect.ValueOf(tpl)
+	tplType := reflect.TypeOf(tpl)
+
+	context := make(map[string]string, tplType.NumField())
+	for i := 0; i < tplType.NumField(); i++ {
+		field := tplType.Field(i)
+
+		key := field.Tag.Get("env")
+		value := tplVal.FieldByName(field.Name).String()
+
+		context[key] = value
+	}
+
+	return unpack.WriteTemplate(dst, context, bytes.NewReader(templateBytes))
+}