* ensure that completed write operations performed by other threads are noticed. For most
     * purposes, the "count" field, tracking the number of elements, serves as that volatile
     * variable ensuring visibility. This is convenient because this field needs to be read in many
     * read operations anyway:
     *
     * - All (unsynchronized) read operations must first read the "count" field, and should not

   ([#123341](https://github.com/kubernetes/kubernetes/pull/123341), [@neolit123](https://github.com/neolit123))
- kubectl `port-forward` over websockets (tunneling SPDY) can now be enabled using an `Alpha` feature flag environment variable: KUBECTL_PORT_FORWARD_WEBSOCKETS=true. The API Server being communicated to must *also* have an `Alpha` feature flag enabled: PortForwardWebsockets.

#{divide($fs-min, $rfs-rem-value)}rem, #{$fs-min}px);\n\n      // Use `vmin` if two-dimensional is enabled\n      $variable-unit: if($rfs-two-dimensional, vmin, vw);\n\n      // Calculate the variable width between 0 and $rfs-breakpoint\n      $variable-width: #{divide($fs-diff * 100, $rfs-breakpoint)}#{$variable-unit};\n\n      // Set the calculated font-size\n      $rfs-fluid: calc(#{$min-width} + #{$variable-width}) #{$rfs-suffix};\n\n      // Breakpoint formatting\n      $mq-value: if($rfs-breakpoint-unit ==...

- Alpha implementation of Kubectl Command Headers: SIG CLI KEP 859 enabled when KUBECTL_COMMAND_HEADERS environment variable set on the client command line. ([#98952](https://github.com/kubernetes/kubernetes/pull/98952), [@seans3](https://github.com/seans3))
- Base-images: Update to debian-iptables:buster-v1.4.0
  - Uses iptables 1.8.5

- Users should not rely on unsupported CRON_TZ variable when specifying schedule, both the API server and cronjob controller will emit warnings pointing to https://kubernetes.io/docs/concepts/workloads/controllers/cron-jobs/ containing explanation ([#106455](https://github.com/kubernetes/kubernetes/pull/106455),...

- The certificate signer no longer accepts ca.key passwords via the `CFSSL_CA_PK_PASSWORD` environment variable. This capability was not prompted by user request, never advertised, and recommended against in the security audit. ([#84677](https://github.com/kubernetes/kubernetes/pull/84677), [@mikedanese](https://github.com/mikedanese))

* Remove environment variables and internal Kubernetes Docker labels from cAdvisor Prometheus metric labels. ([#31064](https://github.com/kubernetes/kubernetes/pull/31064), [@grobie](https://github.com/grobie))
    * Old behavior:

* Remove environment variables and internal Kubernetes Docker labels from cAdvisor Prometheus metric labels. ([#31064](https://github.com/kubernetes/kubernetes/pull/31064), [@grobie](https://github.com/grobie))
    * Old behavior:

        activated. On the other hand, {@code exists} will test for the existence of the file and if it is
        there, the profile will be activated.
        <p>Variable interpolation for these file specifications is limited to {@code ${project.basedir}},
        system properties and user properties.&lt;/p></description>
      <fields>
        <field>
          <name>missing</name>

# Configurações e Variáveis de Ambiente { #settings-and-environment-variables }

Em muitos casos, sua aplicação pode precisar de configurações externas, por exemplo chaves secretas, credenciais de banco de dados, credenciais para serviços de e-mail, etc.

A maioria dessas configurações é variável (pode mudar), como URLs de banco de dados. E muitas podem ser sensíveis, como segredos.

Por esse motivo, é comum fornecê-las em variáveis de ambiente lidas pela aplicação.