====== Tests de Docker ======

Contenido perteneciente al curso [[informatica:sistemas_operativos:cursos:docker_avanzado|Docker avanzado]].

===== Preguntas de certificación =====

**Which of the following commands will automatically create a volume when a container is started?**

  * A. ''docker container run --name nginxtest --volumes=/app nginx''
  * B. ''docker container run --name nginxtest -v /app:mount nginx''
  * C. ''docker container run --name nginxtest --volumes myvol:/app:new nginx''
  * D. ''docker container run --name nginxtest -v myvol:/app nginx'' (**Correcta**)

**Which one of the following commands will show a list of volumes for a specific container?**

  * A. ''docker container logs nginx --volumes''
  * B. ''docker container inspect nginx'' (**Correcta**)
  * C. ''docker volume inspect nginx'' 
  * D. ''docker volume logs nginx --containers''

**Which one of the following commands will result in the volume being removed automatically once the container has exited?**

  * A. ''docker run --del -v /foo busybox''
  * B. ''docker run --read-only -v /foo busybox''
  * C. ''docker run --rm -v /foo busybox'' 
  * D. ''docker run --remove -v /foo busybox''

No hay ninguna opción correcta ya que en todos los casos es incorrecta la sintaxis de los volúmenes.

**A container named "analytics" that stores results in a volume called "data" was created** (''docker run -d %%--%%name=analytics -v data:/data app1''). **How are the results accessed in "data" with another container called "app2"?**

  * A. ''docker run -d --name=reports --volume=data app2''
  * B. ''docker run -d --name=reports --volumes-from=analytics app2'' (**Correcta**)
  * C. ''docker run -d --name=reports --volume=app1 app2''
  * D. ''docker run -d --name=reports --mount=app1 app2''

**A server is running low on disk space. What command can be used to check the disk usage of images, containers, and volumes for Docker engine?**

  * A. ''docker system df'' (**Correcta**)
  * B. ''docker system prune''
  * C. ''docker system free''
  * D. ''docker system ps''

**Which of the following are types of namespaces used by Docker to provide isolation? (Choose 2.)**

  * A. Host
  * B. Network (**Correcta**)
  * C. Process ID (**Correcta**)
  * D. Authentication
  * E. Storage

**What is the difference between a resource limit and a resource reservation when scheduling services?**

  * A. A resource limit and a resource reservation can be used interchangeably.
  * B. A resource limit is a soft limit for your service, while a reservation is hard limit and the docker engine will do its best to keep your service at the limit. 
  * C. A resource limit is used to find a host with adequate resources for scheduling a hard limit for your service, while a reservation is hard limit for your service.
  * D. A resource limit is hard limit for your service, while a reservation is used to find a host with
adequate resources for scheduling. (**Correcta**)

**Which of the following namespaces is disabled by default and must be enabled at Docker engine runtime in order to be used?**

  * A. user (**Correcta**)
  * B. pid
  * C. net
  * D. mnt

<WRAP center round info 60%>
Útil para acceder por ejemplo a LDAP
</WRAP>

**Which of the following statements is true about secrets?**

  * A. Secrets can be created from any node in the cluster. 
  * B. Secrets can be modified after they are created.
  * C. Secrets are stored unencrypted on manager nodes.
  * D. Secrets can be created using standard input (STDIN) and a file. (**Correcta**)

<WRAP center round info 60%>
Existe el comando ''docker secret create''
</WRAP>

**Following the principle of least privilege, which of the following methods can be used to securely grant access to the specific user to communicate to a Docker engine? (Choose two.)**

  * A. Utilize the ''%%--%%host 0.0.0.0:2375'' option to the Docker daemon to listen on port 2375 over TCP on all interfaces
  * B. Utilize openssl to create TLS client and server certificates, configuring the Docker engine to use with mutual TLS over TCP. (**Correcta**)
  * C. Utilize the ''%%--%%host 127.0.0.1:2375'' option to the Docker daemon to listen on port 2375 over TCP on localhost
  * D. Give the user root access to the server to allow them to run Docker commands as root.
  * E. Add the user to the 'docker' group on the server or specify the grouè with the '--group' Docker daemon option. (**Correcta**)