## Container Images

Docker has been one of the main tools to create and manage **container images** and **containers**.

And there's a public <a href="https://hub.docker.com/" class="external-link" target="_blank">Docker Hub</a> with pre-made **official container images** for many tools, environments, databases, and applications.

There's also the chance that for some reason you have a **spike** of usage of your API. Maybe it went viral, or maybe some other services or bots start using it. And you might want to have extra resources to be safe in those cases.

    return freshness.get();
  }

  @SuppressWarnings("removal") // b/321209431 -- maybe just use valueOf here?
  @Generates
  Integer generateInteger() {
    return new Integer(generateInt());
  }

  @Generates
  long generateLong() {
    return generateInt();
  }

  @SuppressWarnings("removal") // b/321209431 -- maybe just use valueOf here?
  @Generates
  Long generateLongObject() {

  define for each {{{../maven-model/maven.html#class_dependency}dependency type}} information on the artifact
  (classifier, extension, language) and how to manage it as dependency (add to classpath, include dependencies).

  They are replaced in Maven 4 with Maven 4 API Core's {{{../api/maven-api-core/apidocs/org/apache/maven/api/Type.html}Dependency Types}},

	optionalDeleteCmds := [][]string{
		// flush-then-delete our created chains
		{"-t", iptablesconstants.MANGLE, "-F", ChainInpodPrerouting},
		{"-t", iptablesconstants.MANGLE, "-F", ChainInpodOutput},
		{"-t", iptablesconstants.NAT, "-F", ChainInpodOutput},
		{"-t", iptablesconstants.MANGLE, "-X", ChainInpodPrerouting},
		{"-t", iptablesconstants.MANGLE, "-X", ChainInpodOutput},
		{"-t", iptablesconstants.NAT, "-X", ChainInpodOutput},
	}

!!! tip
    The `shutdown` would happen when you are **stopping** the application.

    Maybe you need to start a new version, or you just got tired of running it. 🤷

### Lifespan function

The first thing to notice, is that we are defining an async function with `yield`. This is very similar to Dependencies with `yield`.

    <version>4.0.0-beta-1-SNAPSHOT</version>
  </parent>

  <artifactId>maven-api</artifactId>
  <packaging>pom</packaging>
  <name>Maven 4 API</name>
  <description>A new immutable API for Maven 4 to better manage what plugins and extensions can influence.</description>

  <modules>
    <module>maven-api-meta</module>
    <module>maven-api-di</module>
    <module>maven-api-xml</module>
    <module>maven-api-model</module>

    as a dependency. All other OAuth2 classes inherit from it and customize it for
    each OAuth2 flow.

    You normally would not create a new class inheriting from it but use one of the
    existing subclasses, and maybe compose them if you want to support multiple flows.

    Read more about it in the
    [FastAPI docs for Security](https://fastapi.tiangolo.com/tutorial/security/).
    """

    def __init__(
        self,

Then we can test that it is used.

## Reading a `.env` file

If you have many settings that possibly change a lot, maybe in different environments, it might be useful to put them on a file and then read them from it as if they were environment variables.

			Key:         config.APISubSys,
			Description: "manage global HTTP API call specific features, such as throttling, authentication types, etc.",
		},
		config.HelpKV{
			Key:         config.ScannerSubSys,
			Description: "manage namespace scanning for usage calculation, lifecycle, healing and more",
		},
		config.HelpKV{
			Key:         config.BatchSubSys,
			Description: "manage batch job workers and wait times",
		},