Docker - Containers

Please answer the quiz and click the "Test" button at the bottom right.

Based on the below output of docker inspect 303ce6e8af55 on some running container:

[
    {
        "Id": "303ce6e8af55f0bd6a431a01dcc3dbca140bdcc5b55d4f1e21c6a3fcba3e5810",
        "Created": "2023-05-08T08:11:49.412947069Z",
        "Path": "docker-entrypoint.sh",
        "Args": [
            "mysqld"
        ],
        "State": {
            "Status": "running",
            "Running": true,
            "Paused": false,
            "Restarting": false,
            "OOMKilled": false,
            "Dead": false,
            "Pid": 294355,
            "ExitCode": 0,
            "Error": "",
            "StartedAt": "2023-05-08T08:11:51.873706592Z",
            "FinishedAt": "0001-01-01T00:00:00Z"
        },
        "Image": "sha256:8189e588b0e8fcc95b0d764d6f7bdb55b5b41e9249157177d73781058f603ca9",
        "ResolvConfPath": "/var/lib/docker/containers/303ce6e8af55f0bd6a431a01dcc3dbca140bdcc5b55d4f1e21c6a3fcba3e5810/resolv.conf",
        "HostnamePath": "/var/lib/docker/containers/303ce6e8af55f0bd6a431a01dcc3dbca140bdcc5b55d4f1e21c6a3fcba3e5810/hostname",
        "HostsPath": "/var/lib/docker/containers/303ce6e8af55f0bd6a431a01dcc3dbca140bdcc5b55d4f1e21c6a3fcba3e5810/hosts",
        "LogPath": "/var/lib/docker/containers/303ce6e8af55f0bd6a431a01dcc3dbca140bdcc5b55d4f1e21c6a3fcba3e5810/303ce6e8af55f0bd6a431a01dcc3dbca140bdcc5b55d4f1e21c6a3fcba3e5810-json.log",
        "Name": "/tender_keldysh",
        "RestartCount": 0,
        "Driver": "overlay2",
        "Platform": "linux",
        "MountLabel": "",
        "ProcessLabel": "",
        "AppArmorProfile": "docker-default",
        "ExecIDs": null,
        "HostConfig": {
            "Binds": null,
            "ContainerIDFile": "",
            "LogConfig": {
                "Type": "json-file",
                "Config": {}
            },
            "NetworkMode": "default",
            "PortBindings": {},
            "RestartPolicy": {
                "Name": "no",
                "MaximumRetryCount": 0
            },
            "AutoRemove": false,
            "VolumeDriver": "",
            "VolumesFrom": null,
            "CapAdd": null,
            "CapDrop": null,
            "CgroupnsMode": "host",
            "Dns": [],
            "DnsOptions": [],
            "DnsSearch": [],
            "ExtraHosts": null,
            "GroupAdd": null,
            "IpcMode": "private",
            "Cgroup": "",
            "Links": null,
            "OomScoreAdj": 0,
            "PidMode": "",
            "Privileged": false,
            "PublishAllPorts": false,
            "ReadonlyRootfs": false,
            "SecurityOpt": null,
            "UTSMode": "",
            "UsernsMode": "",
            "ShmSize": 67108864,
            "Runtime": "runc",
            "ConsoleSize": [
                0,
                0
            ],
            "Isolation": "",
            "CpuShares": 0,
            "Memory": 0,
            "NanoCpus": 0,
            "CgroupParent": "",
            "BlkioWeight": 0,
            "BlkioWeightDevice": [],
            "BlkioDeviceReadBps": null,
            "BlkioDeviceWriteBps": null,
            "BlkioDeviceReadIOps": null,
            "BlkioDeviceWriteIOps": null,
            "CpuPeriod": 0,
            "CpuQuota": 0,
            "CpuRealtimePeriod": 0,
            "CpuRealtimeRuntime": 0,
            "CpusetCpus": "",
            "CpusetMems": "",
            "Devices": [],
            "DeviceCgroupRules": null,
            "DeviceRequests": null,
            "KernelMemory": 0,
            "KernelMemoryTCP": 0,
            "MemoryReservation": 0,
            "MemorySwap": 0,
            "MemorySwappiness": null,
            "OomKillDisable": false,
            "PidsLimit": null,
            "Ulimits": null,
            "CpuCount": 0,
            "CpuPercent": 0,
            "IOMaximumIOps": 0,
            "IOMaximumBandwidth": 0,
            "MaskedPaths": [
                "/proc/asound",
                "/proc/acpi",
                "/proc/kcore",
                "/proc/keys",
                "/proc/latency_stats",
                "/proc/timer_list",
                "/proc/timer_stats",
                "/proc/sched_debug",
                "/proc/scsi",
                "/sys/firmware"
            ],
            "ReadonlyPaths": [
                "/proc/bus",
                "/proc/fs",
                "/proc/irq",
                "/proc/sys",
                "/proc/sysrq-trigger"
            ]
        },
        "GraphDriver": {
            "Data": {
                "LowerDir": "/var/lib/docker/overlay2/0527b66c2da10505245168d1f084e150f9e56e4d42624569e1215536ec68231e-init/diff:/var/lib/docker/overlay2/d583e5274db743d86305fcfd36400a8a7a284f85709be7867bc0aa0b4cfaf32c/diff:/var/lib/docker/overlay2/0894921d7fe333aecd2516569141b5b70bfc2176128bf702eb7a974b8b7d183f/diff:/var/lib/docker/overlay2/c85383b79b37477fcbc236d42a5c5d228aea3f6933545e766a18029bc15b325d/diff:/var/lib/docker/overlay2/e7b712edcfed325a29bd24988e0d333fe8319398d3b38f71693af0a42e0a44a1/diff:/var/lib/docker/overlay2/ec9e92d41afa2d9fce8319582088669a16a48410d4e6ada53808d3089edc1765/diff:/var/lib/docker/overlay2/dc8021555938324415ceb966ce65bf42d6073797506032e69ed20448a7782e12/diff:/var/lib/docker/overlay2/040dae4ad608f96f9d68bee713db988728c6eadb6b516fabbf7d6b894be3b38d/diff:/var/lib/docker/overlay2/977da7c8267e343cad6a45505a2b590751988723e82b010a3e244f7132c0eeac/diff:/var/lib/docker/overlay2/da5008015b904ebf4b70df8d72c7a52567153d1586a0f7725d30036cd872f5ac/diff:/var/lib/docker/overlay2/253485cdcce0d7e45d6da86be4bee0dace9eef58fbf02bc1f009b3c7a95ab54d/diff:/var/lib/docker/overlay2/b89da9e305923e3c37291ad5f0cd90696d6f2e5e76f0fca87d1e1bcf9178714d/diff",
                "MergedDir": "/var/lib/docker/overlay2/0527b66c2da10505245168d1f084e150f9e56e4d42624569e1215536ec68231e/merged",
                "UpperDir": "/var/lib/docker/overlay2/0527b66c2da10505245168d1f084e150f9e56e4d42624569e1215536ec68231e/diff",
                "WorkDir": "/var/lib/docker/overlay2/0527b66c2da10505245168d1f084e150f9e56e4d42624569e1215536ec68231e/work"
            },
            "Name": "overlay2"
        },
        "Mounts": [
            {
                "Type": "volume",
                "Name": "d6865699c2f97b1abd429d41e9902e29f1a909355242ef1f6f4bb7abf0dd296e",
                "Source": "/var/lib/docker/volumes/d6865699c2f97b1abd429d41e9902e29f1a909355242ef1f6f4bb7abf0dd296e/_data",
                "Destination": "/var/lib/mysql",
                "Driver": "local",
                "Mode": "",
                "RW": true,
                "Propagation": ""
            }
        ],
        "Config": {
            "Hostname": "303ce6e8af55",
            "Domainname": "",
            "User": "",
            "AttachStdin": false,
            "AttachStdout": true,
            "AttachStderr": true,
            "ExposedPorts": {
                "3306/tcp": {},
                "33060/tcp": {}
            },
            "Tty": false,
            "OpenStdin": false,
            "StdinOnce": false,
            "Env": [
                "MYSQL_ROOT_PASSWORD=1234",
                "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
                "GOSU_VERSION=1.16",
                "MYSQL_MAJOR=8.0",
                "MYSQL_VERSION=8.0.33-1.el8",
                "MYSQL_SHELL_VERSION=8.0.33-1.el8"
            ],
            "Cmd": [
                "mysqld"
            ],
            "Image": "mysql",
            "Volumes": {
                "/var/lib/mysql": {}
            },
            "WorkingDir": "",
            "Entrypoint": [
                "docker-entrypoint.sh"
            ],
            "OnBuild": null,
            "Labels": {}
        },
        "NetworkSettings": {
            "Bridge": "",
            "SandboxID": "ee1dd90916d4b1078246e248676863a4d3c0ab454bef7a1bc5476da95aa0f176",
            "HairpinMode": false,
            "LinkLocalIPv6Address": "",
            "LinkLocalIPv6PrefixLen": 0,
            "Ports": {
                "3306/tcp": null,
                "33060/tcp": null
            },
            "SandboxKey": "/var/run/docker/netns/ee1dd90916d4",
            "SecondaryIPAddresses": null,
            "SecondaryIPv6Addresses": null,
            "EndpointID": "6cf6a9c5505da1d30922219bccbd91c6fea71aaa3c67ab53163b99144e40bd11",
            "Gateway": "172.17.0.1",
            "GlobalIPv6Address": "",
            "GlobalIPv6PrefixLen": 0,
            "IPAddress": "172.17.0.3",
            "IPPrefixLen": 16,
            "IPv6Gateway": "",
            "MacAddress": "02:42:ac:11:00:03",
            "Networks": {
                "bridge": {
                    "IPAMConfig": null,
                    "Links": null,
                    "Aliases": null,
                    "NetworkID": "c870c05c5ce1e9d7a8711ada1826eead7e54ecf4847f61e43be30e672008bdbd",
                    "EndpointID": "6cf6a9c5505da1d30922219bccbd91c6fea71aaa3c67ab53163b99144e40bd11",
                    "Gateway": "172.17.0.1",
                    "IPAddress": "172.17.0.3",
                    "IPPrefixLen": 16,
                    "IPv6Gateway": "",
                    "GlobalIPv6Address": "",
                    "GlobalIPv6PrefixLen": 0,
                    "MacAddress": "02:42:ac:11:00:03",
                    "DriverOpts": null
                }
            }
        }
    }
]

Answer the bellow 5 questions.

Question 1

What is the IP address of the container?

172.17.0.1.
172.17.0.3.
127.0.0.1.
IP v6: 02:42:ac:11:00:03.

Question 2

How many ports are exposed by the container?

0
1
2
3
None of the above

Question 3

How many environment variables are given to the container process?

Question 4

The container status is:

Exited
Created
Running
Restarting
We couldn't know from the output.

Question 5

Which command can help you to resolve the following error:

Error response from daemon: You cannot remove a running container 76004df79402d330992abe9f423715904fb590663f797fee3bca4e9e877f0ac0. Stop the container before attempting removal or force remove

docker run 76004df794
docker top 76004df794
docker stop 76004df794
docker pause 76004df794

Question 6

Consider the bellow two docker run commands:

docker run -p 8080:80 nginx
docker run -p 8080:80 nginx

Assume there are no other containers running on the host machine. Choose the correct sentence:

The commands create and run two different containers successfully.
The second command does nothing since the first command runs the nginx container image successfully.
The seconds command will fail since you are not able to run two different containers from the nginx image.
The seconds command will fail since port 8080 is bound to the first container.

Question 7

The following command has run successfully:

docker run -it ubuntu /bin/bash

What can be id for sure regarding the container:

The ubuntu image existed on the machine before the command was executed.
The binary /bin/bash exists in the container's file system.
The -it flags allow you to run within the container every command that is available on the host machine.
None of the above.

Question 8

You are trying to run an mysql container using the following command:

docker run --name some-mysql -e DEBUG=true mysql

But encounter the following error:

docker: Error response from daemon: Conflict. The container name "/some-mysql" is already in use by container "761aacef37cfe438f77fe92d6e4a2eeecc6d72c9cea9eb5f73d5af5a1ae377d2". You have to remove (or rename) that container to be able to reuse that name.
See 'docker run --help'

Which command can help you resolve the problem?

docker run --force --name some-mysql -e DEBUG=true mysql
docker rm some-mysql
docker kill some-mysql
None of the above