[mavassil@fedora bin]$ ./elytron-tool.sh credential-store --create --location "/home/mavassil/Downloads/tests/jboss-eap-7.4.12/jboss-eap-7.4/domain/configuration/cred_stores/my_store.jceks" --password supersecretstorepassword
Credential Store has been successfully created

[mavassil@fedora bin]$ ./elytron-tool.sh credential-store --location "/home/mavassil/Downloads/tests/jboss-eap-7.4.12/jboss-eap-7.4/domain/configuration/cred_stores/my_store.jceks" --password supersecretstorepassword --add db-password --secret sa
Alias "db-password" has been successfully stored

[mavassil@fedora bin]$ ./jboss-cli.sh 
grep: warning: stray \ before -
grep: warning: stray \ before -
You are disconnected at the moment. Type 'connect' to connect to the server or 'help' for the list of supported commands.
[disconnected /] connect
[domain@localhost:9990 /] /host=master/subsystem=elytron/credential-store=CS:add(location="cred_stores/my_store.jceks",relative-to="jboss.domain.config.dir",credential-reference={clear-text=supersecretstorepassword},create=false)
{"outcome" => "success"}

[domain@localhost:9990 /] /profile=full/subsystem=elytron/credential-store=CS:add(location=/home/mavassil/Downloads/tests/jboss-eap-7.4.12/jboss-eap-7.4/domain/configuration/cred_stores/my_store.jceks,credential-reference={clear-text=supersecretstorepassword},create=false)
{
    "outcome" => "success",
    "result" => undefined,
    "server-groups" => {"main-server-group" => {"host" => {"master" => {
        "server-one" => {"response" => {"outcome" => "success"}},
        "server-two" => {"response" => {"outcome" => "success"}}
    }}}}
}

[domain@localhost:9990 /] batch
[domain@localhost:9990 / #] /profile=full/subsystem=datasources/data-source=ExampleDS:write-attribute(name=credential-reference,value={store=CS, alias=db-password})
[domain@localhost:9990 / #] /profile=full/subsystem=datasources/data-source=ExampleDS:undefine-attribute(name=password)
[domain@localhost:9990 / #] run-batch
The batch executed successfully

[domain@localhost:9990 /] reload --host=master