# OPA Quickstart Guide [![Slack](https://slack.minio.io/slack?type=svg)](https://slack.minio.io)

OPA is a lightweight general-purpose policy engine that can be co-located with MinIO server, in this document we talk about how to use OPA HTTP API to authorize requests. It can be used with any type of credentials (STS based like OpenID or LDAP, regular IAM users or service accounts).

OPA is enabled through MinIO's Access Management Plugin feature.

## Get started

     *
     * @param project The project being summarized, must not be {@code null}.
     * @param execTime The exec time of the project in milliseconds.
     * @param wallTime The wall time of the project in milliseconds.
     * @param cause The cause of the build failure, may be {@code null}.
     */
    public BuildFailure(MavenProject project, Duration execTime, Duration wallTime, Throwable cause) {

    }

    /**
     * Creates a new build summary for the specified project.
     *
     * @param project The project being summarized, must not be {@code null}.
     * @param wallTime The wall time of the project in milliseconds.
     * @param execTime The exec time of the project in milliseconds.
     */
    public BuildSuccess(MavenProject project, Duration wallTime, Duration execTime) {

 * fixed but arbitrary point in time. Note that most users should use {@link Stopwatch} instead of
 * interacting with this class directly.
 *
 * <p><b>Warning:</b> this interface can only be used to measure elapsed time, not wall time.
 *
 * @author Kevin Bourrillion
 * @since 10.0 (<a href="https://github.com/google/guava/wiki/Compatibility">mostly
 *     source-compatible</a> since 9.0)
 */
@GwtCompatible
public abstract class Ticker {

<img src="/img/tutorial/sub-applications/image02.png">

If you try interacting with any of the two user interfaces, they will work correctly, because the browser will be able to talk to each specific app or sub-app.

### Technical Details: `root_path` { #technical-details-root-path }

 *
 * <p>In contrast, <i>wall time</i> is a reading of "now" as given by a method like
 * {@link System#currentTimeMillis()}, best represented as an {@link java.time.Instant}. Such values
 * <i>can</i> be subtracted to obtain a {@link Duration} (such as by {@link Duration#between}), but
 * doing so does <i>not</i> give a reliable measurement of elapsed time, because wall time readings

        allowEmpty = false,
        description =
            "Command line option for the performance test task to enable profiling. " +
                "For example `async-profiler`, `async-profiler-heap`, `async-profiler-wall`, `async-profiler-all` or `jfr`. Use `none` for benchmarking only.",
    )
}

object AdHocPerformanceScenarioLinux : AdHocPerformanceScenario(Os.LINUX)

    assertFailsToDecode(base64(), "Wf2!", "Unrecognized character: !");
    // This sentence just isn't base64() encoded.
    assertFailsToDecode(base64(), "let's not talk of love or chains!");
    // A 4n+1 length string is never legal base64().
    assertFailsToDecode(base64(), "12345", "Invalid input length 5");

## Prerequisites

Install Dex by following [Dex Getting Started Guide](https://dexidp.io/docs/getting-started/)

### Start Dex

```

        packet.opCode = NameServicePacket.WACK;
        packet.resultCode = NameServicePacket.SRV_ERR;
        packet.questionType = NameServicePacket.NBSTAT;
        packet.recordType = NameServicePacket.NBSTAT;
        expectedString =