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exec command#

Description#

The exec command allows to run a command inside the nodes that part of a certain lab.

This command does exactly the same thing as docker exec does, but it allows to run the same command across all the nodes of a lab.

Usage#

containerlab [global-flags] exec [local-flags]

Flags#

topology#

With the global --topo | -t flag a user specifies from which lab to take the containers and perform the exec command.

cmd#

The command to be executed on the nodes is provided with --cmd flag. The command is provided as a string, thus it needs to be quoted to accommodate for spaces or special characters.

format#

The --format | -f flag allows to select between plain text format output or a json variant. Consult with the examples below to see the differences between these two formatting options.

Defaults to plain output format.

label#

By default exec command will attempt to execute the command across all the nodes of a lab. To limit the scope of the execution, the users can leverage the --label flag to filter out the nodes of interest.

Examples#

# show ipv4 information from all the nodes of the lab
# with a plain text output
❯ containerlab exec -t srl02.yml --cmd 'ip -4 a show dummy-mgmt0'
INFO[0000] clab-srl02-srl1: stdout:
6: dummy-mgmt0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN group default qlen 1000
    inet 172.20.20.3/24 brd 172.20.20.255 scope global dummy-mgmt0
       valid_lft forever preferred_lft forever
INFO[0000] clab-srl02-srl2: stdout:
6: dummy-mgmt0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN group default qlen 1000
    inet 172.20.20.2/24 brd 172.20.20.255 scope global dummy-mgmt0
       valid_lft forever preferred_lft forever


# execute a CLI command with a plain text output
❯ containerlab exec -t srl02.yml --cmd 'sr_cli  "show version"'
INFO[0001] clab-srl02-srl1: stdout:
----------------------------------------------------
Hostname          : srl1
Chassis Type      : 7250 IXR-6
Part Number       : Sim Part No.
Serial Number     : Sim Serial No.
System MAC Address: 02:00:6B:FF:00:00
Software Version  : v20.6.3
Build Number      : 145-g93496a3f8c
Architecture      : x86_64
Last Booted       : 2021-06-24T10:25:26.722Z
Total Memory      : 24052875 kB
Free Memory       : 21911906 kB
----------------------------------------------------
INFO[0003] clab-srl02-srl2: stdout:
----------------------------------------------------
Hostname          : srl2
Chassis Type      : 7250 IXR-6
Part Number       : Sim Part No.
Serial Number     : Sim Serial No.
System MAC Address: 02:D8:A9:FF:00:00
Software Version  : v20.6.3
Build Number      : 145-g93496a3f8c
Architecture      : x86_64
Last Booted       : 2021-06-24T10:25:26.904Z
Total Memory      : 24052875 kB
Free Memory       : 21911914 kB
----------------------------------------------------


# execute a CLI command with a json output
❯ containerlab exec -t srl02.yml --cmd 'sr_cli  "show version | as json"' -f json | jq
{
  "clab-srl02-srl1": {
    "stderr": "",
    "stdout": {
      "basic system info": {
        "Architecture": "x86_64",
        "Build Number": "145-g93496a3f8c",
        "Chassis Type": "7250 IXR-6",
        "Free Memory": "21911367 kB",
        "Hostname": "srl1",
        "Last Booted": "2021-06-24T10:25:26.722Z",
        "Part Number": "Sim Part No.",
        "Serial Number": "Sim Serial No.",
        "Software Version": "v20.6.3",
        "System MAC Address": "02:00:6B:FF:00:00",
        "Total Memory": "24052875 kB"
      }
    }
  },
  "clab-srl02-srl2": {
    "stderr": "",
    "stdout": {
      "basic system info": {
        "Architecture": "x86_64",
        "Build Number": "145-g93496a3f8c",
        "Chassis Type": "7250 IXR-6",
        "Free Memory": "21911367 kB",
        "Hostname": "srl2",
        "Last Booted": "2021-06-24T10:25:26.904Z",
        "Part Number": "Sim Part No.",
        "Serial Number": "Sim Serial No.",
        "Software Version": "v20.6.3",
        "System MAC Address": "02:D8:A9:FF:00:00",
        "Total Memory": "24052875 kB"
      }
    }
  }
}