Virtualization
The Docker feature is not supported in director systems.
MLNX-OS
allows the user to run their own applications on a Linux docker image embedded in the switch software. The container is a pure application sandbox with resource isolation of both memory and compute from the system code/NOS.
Docker container implementation in the OS enhances its VM support to provide a new set of capabilities:
Network traffic access
Docker containers are implemented in the OS in the same name-space as the network devices allowing the software to send and receive packets from the switch ports by opening a standard Linux socket over the network devices and using an IP address assigned to the device via the legacy management interface (e.g., JSON over HTTP).WarningIt is recommended to assign a unique port number to the Linux socket to prevent ambiguity of applications between the container and the OS.
Calling the SDK interfaces
Applications running in the docker container are able to implement a set of tools pertaining only to the container such as telemetry features within the network devices. By calling the switch SDK APIs, it can also read data that is not exposed in the OS user interface, or register to receive events that occur in the system (e.g., port up/down).WarningThe container implementation does not limit the container developer from calling the SDK to set parameters. However this is strongly discouraged as it may cause unexpected system behavior where the OS and the container application manage the same resources.
Query the Linux tables provisioned by OS such as neighbor cache, routing tables, L3 interfaces attributes etc.
It is possible to configure multiple containers in dockers, however, they would compete for the same memory and compute resources allocated by the switch software (varies for different systems). To ensure system stability and that no random process is killed to free up memory, it is strongly recommended that all resource configurations done in the container utilize OS user interfaces such as JSON/SNMP and take advantage of the internal loopback interface.
Memory Resources Allocation Protocol
The Linux docker supports a hard limit to control memory resource allocation which limits the container to a given amount of user/system memory.
To set the amount of memory allocated to the container, run the following command:
switch
(config) # docker start imagename latestver containername init memory 25
label newlabel privileged sdk network docker usb-mount
CPU Resource Allocation Protocol
Containers have unrestricted access to the host machine’s CPU cycles but it is possible to set a number of constraints to limit the containers’ access.
To set up limitations or regulate the containers access to CPU resources, run the following command:
docker start imagename latestver containername init cpus 0.2
label new_label privileged sdk network
Changing Docker Storage Driver
As a result of the upgrade, the docker’s storage driver changes, which may cause a few additional changes:
The containers and docker images become inaccessible to the user (the docker process will not run)
The user can reach their old containers after a rollback procedure
The “no docker” command erases all containers and images, including those that were reachable after rollback. Rollbacking after running the “no docker” command may result in failure to create configured containers from unknown images.
The user is advised to execute the “no docker” command at some point in order to clear unused disk space
It is possible to reload the Docker images after upgrade with the command: docker load <image_name>_<image_version>.img.gz
The images are presented with tab-tab after “docker load “ (in cli)
It is also possible to load the images after rollback after "no docker” was execute. That means that containers can be restarted after upgrade/rollback if their images are loaded (with “docker load”).
It is possible to move containers from the current version to the updated one by executing the following steps:
Before upgrade:
Save the container as an image—run the command: “docker commit
”. For example: docker commit my_name my_image my_version. You can see the new image by running: “show docker images”. Save the image—run the command: “docker save
”. For example: docker save my_image my_version. Upload the image—save the image to a local repository by running: “image upload
”. For example: image upload my_image_my_version.img.gz scp://username:password@fit150/auto/my_dir. The is presented after clicking tab-tab.
After upgrade:
Start docker—run the “no docker shutdown” command.
Fetch the restored image—run the “image fetch
” command. For example: image fetch scp://username:password@fit150/auto/my_dir/my_image_my_version.img.gz Load the image—run the “docker load
” command. For example: docker load my_image_my_version.img.gz Start a container with the defined image—now that the image with all the content from the container is available in the new environment, start a container with this image. Run the command: “docker start
| privileged | label | memory | cpus | usb-mount”. For example: docker start my_image my_version new_container now
After an upgrade operation there is a need to rerun copy-sdk command (in case in use).
docker
docker [logging-level <log-level>] no docker Enables dockers then enters docker configuration context. The no form of the command disables dockers, removes configuration, and deletes all containers and docker images. |
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Syntax Description |
N/A
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Default |
N/A |
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Configuration Mode |
config |
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History |
3.6.2940 3.9.2300—Added log-level option |
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Example |
switch (config) # docker |
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Related Commands |
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Notes |
docker login
docker login <username> <cleartext password> [server <server address>] Logs in to remote docker repositories. |
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Syntax Description |
username |
Username |
cleartext password |
There are 2 options to enter password using the above command:
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server |
The "server" field is not mandatory. In case it is not present, the docker will try to login into docker hub repository. |
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Default |
N/A |
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Configuration Mode |
config |
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History |
3.9.1600 |
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Example |
switch (config) # docker login abcd 1234 |
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Related Commands |
show docker login |
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Notes |
docker logout
docker logout [server <server address>] Logs out from remote server. |
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Syntax Description |
N/A |
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Default |
N/A |
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Configuration Mode |
config |
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History |
3.9.1600 |
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Example |
switch (config) # docker logout |
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Related Commands |
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Notes |
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commit
commit <container-name> <image-name> <image-version> Creates a new image from a running container. |
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Syntax Description |
container-name |
Name of the running container to commit (limited to 180 characters) |
image-name |
Name of the new image to be created |
|
image-version |
Version of the new image to be created |
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Default |
N/A |
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Configuration Mode |
config docker |
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History |
3.6.2940 3.6.8008: Added new character limitation for container-name |
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Example |
switch (config docker) # commit mycontainer test latest |
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Related Commands |
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Notes |
copy-sdk
copy-sdk The command provides access to the switch SDK APIs giving applications running on docker access to the switch hardware. |
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Syntax Description |
N/A |
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Default |
N/A |
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Configuration Mode |
config docker |
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History |
3.6.4110 3.8.1000: Updated notes 3.8.2100: Updated notes |
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Example |
switch (config docker) # copy-sdk |
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Related Commands |
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Notes |
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remove image
remove image <image-name> <image-version> Removes an image from the Linux docker service. |
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Syntax Description |
image-name |
Name of the new image to be deleted |
image-version |
Version of the new image to be deleted |
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Default |
N/A |
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Configuration Mode |
config docker |
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History |
3.6.3520 3.6.2940 |
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Example |
switch (config docker) # remove image test latest |
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Related Commands |
docker |
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Notes |
exec
exec <container-name> <program-executable> Executes a program within a running container. |
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Syntax Description |
container-name |
Name of the running container to commit (limited to 180 characters) |
program-executable |
Linux command |
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Default |
N/A |
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Configuration Mode |
config docker |
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History |
3.6.3520 3.6.2940 |
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Example |
switch (config docker) # exec mycontainer "ls -la" |
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Related Commands |
docker |
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Notes |
label
label <label name> no label <label name> Creates a label which can be used as a shared storage between containers. The no form of the command removes the label. |
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Syntax Description |
N/A |
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Default |
N/A |
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Configuration Mode |
config docker |
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History |
3.6.4110 |
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Example |
switch (config docker) # label new_label |
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Related Commands |
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Notes |
load
load <image-name> Loads an image from a TAR archive. |
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Syntax Description |
image-name |
Name of the TAR image to be loaded |
Default |
N/A |
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Configuration Mode |
config docker |
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History |
3.6.2940 |
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Example |
switch (config docker) # load test |
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Related Commands |
docker |
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Notes |
pull
pull <image-name>[:<version>] Pulls a docker image from a docker repository. |
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Syntax Description |
image-name |
Image name Format: Name:Version If only “Name” is provided, “version” defaults to latest |
Default |
N/A |
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Configuration Mode |
config docker |
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History |
3.6.2940 |
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Example |
switch (config docker) # pull test |
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Related Commands |
docker |
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Notes |
save
save <image-name> <image-version> <filename> Saves an image to a TAR archive. |
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Syntax Description |
image-name |
Image name |
image-version |
Image version |
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filename |
Name of the file in which to save the image |
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Default |
N/A |
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Configuration Mode |
config docker |
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History |
3.6.2940 3.6.8008: Updated command syntax |
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Example |
switch (config docker) # save busybox latest my_image |
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Related Commands |
docker docker load |
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Notes |
After the file is created, the filename gets appended a *.gz suffix. |
shutdown
shutdown no shutdown Stops all docker containers, and deletes all non-auto containers. The no form of the command enables the docker Linux service and runs all configured auto-start containers |
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Syntax Description |
N/A |
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Default |
N/A |
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Configuration Mode |
config docker |
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History |
3.6.2940 |
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Example |
switch (config docker) # no shutdown |
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Related Commands |
docker |
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Notes |
start
start <image-name> <image-version> <container-name> <starting-point> [privileged {network | sdk}] [cpus <max-cpu-resources>] [memory <max-memory>] [usb-mount] [host-trust [user <username>]] [logging-facility <logging-facility-level>] [user-env <env-string>] no start <container-name> Starts a new container from an image. The no form of the command stops a running docker container. |
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Syntax Description |
image-name |
Name of the new image to start. |
image-version |
Version of the image to start. |
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container-name |
Name of the running container to commit (limited to 180 characters). |
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privileged |
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starting-point |
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cpus |
Sets how much of the available CPU resources a container can use (e.g., “cpus 1.5” guarantees at most one and a half of the available CPUs for the container). |
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memory |
Sets the maximum amount of memory the container can use in MB. The minimum amount of memory to configure is 4MB. |
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usb-mount |
Enables USB mount to the docker container. |
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host-trust |
Allows SSH operation from within the container to localhost without the need to supply password. |
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logging-facility-level |
Available Parameters: auth, authpriv daemon, ftp, kern, local0, local1, local2, local3, local4, local5, local6, local7, lpr, mail, news, syslog, user, uucp |
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env-string |
Up to 16 user-defined environment variables. User-defined environment variable are separated by a comma (e.g., key1=value1,key2=value2) |
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Default |
N/A |
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Configuration Mode |
config docker |
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History |
3.6.2940 3.6.3520: Added “privileged” parameter 3.6.8008: Added the options “now-and-data-path-ready” and “now-and-init”, new character limitation for container-name, and updated the description of the parameter “memory” 3.8.1000; Updated syntax description 3.9.2000: Added host-trust option which adds support for SSH operation from within the container to localhost without the need to supply password (when activating host-trust without supplying user, user admin will be used). 3.9.2300: Added logging-facility and user-env options |
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Example |
switch (config docker) # start centos latest test now |
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Related Commands |
docker |
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Notes |
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image upload
image upload <filename> <upload_url> Uploads an image file to a remote host. |
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Syntax Description |
filename |
Name of file |
upload_url |
FTP, TFTP, SCP and SFTP are supported (e.g., scp://username[:password]@hostname-or-ip/path/filename) |
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Default |
N/A |
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Configuration Mode |
config |
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History |
3.6.2940 |
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Example |
switch (config) # image upload centos.img.gz scp://username:password@192.168.10.125/var/www/html/<image_name> |
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Related Commands |
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Notes |
file image upload
file image upload <filename> <upload_url> Uploads a file to a remote host. |
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Syntax Description |
filename |
Name of file |
upload_url |
FTP, TFTP, SCP and SFTP are supported (e.g., scp://username[:password]@hostname/path/filename) |
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Default |
N/A |
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Configuration Mode |
config |
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History |
3.6.2940 |
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Example |
switch (config) # file image upload centos.img.gz scp://username:password@192.168.10.125/var/www/html/<image_name> |
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Related Commands |
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Notes |
show docker
show docker Displays docker running state. |
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Syntax Description |
N/A |
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Default |
N/A |
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Configuration Mode |
Any command mode |
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History |
3.9.2000 |
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Example |
switch (config) # show docker Docker log-level: warn |
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Related Commands |
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Notes |
show docker containers
show docker containers <container_name> Displays set parameters on containers already running, and containers planned to run in the future. |
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Syntax Description |
N/A |
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Default |
N/A |
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Configuration Mode |
Any command mode |
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History |
3.6.8008 3.8.1000: Updated example 3.9.2000: Updated example, adding host-trust option 3.9.2300: Updated example, adding "user-defined variables" and "log-facility" fields |
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Example |
switch (config) # show docker containers OS_SYSTEM_TYPE : MSB7700 3 OS_DOCKERD_VRF_CONTEXT : vrf-default OS_SYSTEM_TYPE : MSB7700
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Related Commands |
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Notes |
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show docker images
show docker images Display docker images. |
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Syntax Description |
N/A |
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Default |
N/A |
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Configuration Mode |
Any command mode |
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History |
3.6.3520 3.6.2940: Updated example |
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Example |
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switch (config) # show docker images ------------------------------------------------------------- |
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Related Commands |
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Notes |
show docker ps
show docker ps Display docker containers. |
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Syntax Description |
N/A |
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Default |
N/A |
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Configuration Mode |
Any command mode |
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History |
3.6.3520 3.6.2940: Updated example |
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Example |
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switch (config) # show docker ps --------------------------------------------------------------------------------- |
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Related Commands |
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Notes |
This command is available only after Linux dockers are enabled (“no dockers shutdown”) |
show docker labels
show docker labels Displays docker labels. |
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Syntax Description |
N/A |
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Default |
N/A |
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Configuration Mode |
Any command mode |
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History |
3.6.4110 |
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Example |
switch (config) # show docker labels |
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Related Commands |
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Notes |
show docker login
show docker login Displays docker login. |
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Syntax Description |
N/A |
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Default |
N/A |
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Configuration Mode |
Any command mode |
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History |
3.9.1600 |
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Example |
switch (config) # show docker login |
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Related Commands |
docker login |
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Notes |
show docker stats
show docker stats [<name>] Displays Linux docker statistics. |
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Syntax Description |
name |
Docker whose stats to display |
Default |
N/A |
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Configuration Mode |
Any command mode |
|
History |
3.6.8008 2.9.2300: Added example |
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Example |
switch (config) # show docker stats |
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Related Commands |
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Notes |
This command is available only after Linux dockers are enabled (“no dockers shutdown”) |