New resource: mysql_global_variable

To have state for MySQL global configuration with IaC I'd like to introduce new resource: mysql_global_variable

.gitignore

@@ -21,10 +21,14 @@ website/node_modules
 *~
 .*.swp
 .idea
+/.vscode
 *.iml
 *.test
 *.iml
 
+# goreleaser
+/dist
+
 website/vendor
 
 # Test exclusions

mysql/provider.go

@@ -131,12 +131,13 @@ func Provider() *schema.Provider {
 		},
 
 		ResourcesMap: map[string]*schema.Resource{
-			"mysql_database":      resourceDatabase(),
-			"mysql_grant":         resourceGrant(),
-			"mysql_role":          resourceRole(),
-			"mysql_user":          resourceUser(),
-			"mysql_user_password": resourceUserPassword(),
-			"mysql_sql":           resourceSql(),
+			"mysql_database":        resourceDatabase(),
+			"mysql_global_variable": resourceGlobalVariable(),
+			"mysql_grant":           resourceGrant(),
+			"mysql_role":            resourceRole(),
+			"mysql_sql":             resourceSql(),
+			"mysql_user_password":   resourceUserPassword(),
+			"mysql_user":            resourceUser(),
 		},
 
 		ConfigureFunc: providerConfigure,

mysql/resource_global_variable.go

@@ -0,0 +1,116 @@
+package mysql
+
+import (
+	"database/sql"
+	"fmt"
+	"log"
+
+	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema"
+)
+
+func resourceGlobalVariable() *schema.Resource {
+	return &schema.Resource{
+		Create: CreateGlobalVariable,
+		Read:   ReadGlobalVariable,
+		Update: UpdateGlobalVariable,
+		Delete: DeleteGlobalVariable,
+		Importer: &schema.ResourceImporter{
+			State: ImportGlobalVariable,
+		},
+		Schema: map[string]*schema.Schema{
+			"name": {
+				Type:     schema.TypeString,
+				Required: true,
+				ForceNew: true,
+			},
+			"value": {
+				Type:     schema.TypeString,
+				Required: true,
+			},
+		},
+	}
+}
+
+func CreateGlobalVariable(d *schema.ResourceData, meta interface{}) error {
+	db := meta.(*MySQLConfiguration).Db
+
+	name := d.Get("name").(string)
+	value := d.Get("value").(string)
+
+	sql := fmt.Sprintf("SET GLOBAL %s = %s", quoteIdentifier(name), quoteIdentifier(value))
+	log.Printf("[DEBUG] SQL: %s", sql)
+
+	_, err := db.Exec(sql)
+	if err != nil {
+		return fmt.Errorf("error setting value: %s", err)
+	}
+
+	d.SetId(name)
+
+	return nil
+}
+
+func ReadGlobalVariable(d *schema.ResourceData, meta interface{}) error {
+	db := meta.(*MySQLConfiguration).Db
+
+	stmt, err := db.Prepare("SHOW GLOBAL VARIABLES WHERE VARIABLE_NAME = ?")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	var name, value string
+	err = stmt.QueryRow(d.Id()).Scan(&name, &value)
+
+	if err != nil && err != sql.ErrNoRows {
+		d.SetId("")
+		return fmt.Errorf("Error during show global variables: %s", err)
+	}
+
+	d.Set("name", name)
+	d.Set("value", value)
+
+	return nil
+}
+
+func UpdateGlobalVariable(d *schema.ResourceData, meta interface{}) error {
+	db := meta.(*MySQLConfiguration).Db
+
+	name := d.Get("name").(string)
+	value := d.Get("value").(string)
+
+	sql := fmt.Sprintf("SET GLOBAL %s = %s", quoteIdentifier(name), quoteIdentifier(value))
+	log.Printf("[DEBUG] SQL: %s", sql)
+
+	_, err := db.Exec(sql)
+	if err != nil {
+		return fmt.Errorf("error update value: %s", err)
+	}
+	return ReadGlobalVariable(d, meta)
+}
+
+func DeleteGlobalVariable(d *schema.ResourceData, meta interface{}) error {
+	db := meta.(*MySQLConfiguration).Db
+	name := d.Get("name").(string)
+
+	sql := fmt.Sprintf("SET GLOBAL %s = DEFAULT", quoteIdentifier(name))
+	log.Printf("[DEBUG] SQL: %s", sql)
+
+	_, err := db.Exec(sql)
+	if err != nil {
+		log.Printf("[WARN] Variable_name (%s) not found; removing from state", d.Id())
+		d.SetId("")
+		return nil
+	}
+
+	return nil
+}
+
+func ImportGlobalVariable(d *schema.ResourceData, meta interface{}) ([]*schema.ResourceData, error) {
+	err := ReadGlobalVariable(d, meta)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return []*schema.ResourceData{d}, nil
+}