Erro de acesso ao banco

coloca tua configuração do datasource lá do wildfly, o login e senha do teu banco de dados local está correto? o driver foi criado corretamente? Um exemplo de um datasource meu configurado e funcionando corretamente para o postgres(wildfly/standalone/configuration/standalone.xml):

<datasources>
<datasource jndi-name="java:jboss/datasources/ExampleDS" pool-name="ExampleDS" enabled="true" use-java-context="true">
                    <connection-url>jdbc:h2:mem:test;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=FALSE</connection-url>
                    <driver>h2</driver>
                    <security>
                        <user-name>sa</user-name>
                        <password>sa</password>
                    </security>
                </datasource>
<datasource jndi-name="java:/FgDS" pool-name="FgDS" enabled="true" use-java-context="true">
                    <connection-url>jdbc:postgresql://localhost:5432/tce</connection-url>
                    <driver>postgresql</driver>
                    <security>
                        <user-name>postgres</user-name>
                        <password>postgres</password>
                    </security>
                </datasource>
                <drivers>
                    <driver name="h2" module="com.h2database.h2">
                        <xa-datasource-class>org.h2.jdbcx.JdbcDataSource</xa-datasource-class>
                    </driver>
                    <driver name="postgresql" module="org.postgresql">
                        <xa-datasource-class>org.postgresql.xa.PGXADataSource</xa-datasource-class>
                    </driver>
                </drivers>
            </datasources>

<subsystem xmlns="urn:jboss:domain:datasources:4.0">
            <datasources>
                <datasource jndi-name="java:jboss/datasources/ExampleDS" pool-name="ExampleDS" enabled="true" use-java-context="true">
                    <connection-url>jdbc:h2:mem:test;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=FALSE</connection-url>
                    <driver>h2</driver>
                    <security>
                        <user-name>sa</user-name>
                        <password>sa</password>
                    </security>
                </datasource>
                <datasource jndi-name="java:jboss/datasources/casadocodigoDS" pool-name="casadocodigoDS">
                    <connection-url>jdbc:mysql://localhost:3306/casadocodigo_javaee</connection-url>
                    <connection-property name="DatabaseName">
                        casadocodigo_javaee
                    </connection-property>
                    <driver>mysql</driver>
                    <pool>
                        <min-pool-size>10</min-pool-size>
                        <max-pool-size>20</max-pool-size>
                    </pool>
                    <security>
                        <user-name>root</user-name>
                        <password>123</password>
                    </security>
                </datasource>
                <drivers>
                    <driver name="h2" module="com.h2database.h2">
                        <xa-datasource-class>org.h2.jdbcx.JdbcDataSource</xa-datasource-class>
                    </driver>
                    <driver name="mysql" module="com.mysql">
                        <datasource-class>com.mysql.jdbc.jdbc2.optional.MysqlDataSource</datasource-class>
                    </driver>
                </drivers>
            </datasources>
        </subsystem>

module.xml

<?xml version="1.0" encoding="UTF-8"?>
<module xmlns="urn:jboss:module:1.3" name="com.mysql">
    <resources>
        <resource-root path="mysql-connector-java-5.1.35.jar"/>
    </resources>
    <dependencies>
        <module name="javax.api"/>
    </dependencies>
</module>

persistence.xml

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<persistence xmlns="http://xmlns.jcp.org/xml/ns/persistence"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    version="2.1" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence
    http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
    <persistence-unit name="casadocodigo-dev" transaction-type="JTA">
        <description>Dev persistence unit</description>
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <!-- java transaction api || JNDI (diretórios de nomes do java) -->
        <jta-data-source>java:jboss/datasources/casadocodigoDS</jta-data-source>
        <properties>
            <property name="hibernate.hbm2ddl.auto" value="update"/>
            <property name="hibernate.show_sql" value="true" />
            <property name="hibernate.format_sql" value="true" />
            <property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5InnoDBDialect"/>
        </properties>
    </persistence-unit>
</persistence>

Resolvido!

Alterei a senha do root através deste tutorial:

http://www.leandrosales.com.br/2016/09/17/reset-root-password-no-mysql-5-7/