validate command#

Description#

The validate command parses a topology definition file and runs the same schema, node, and link checks that the deploy or destroy commands perform but without deploying or destroying the lab.

It is useful for catching errors in a topology file before deploying it, for example as a linting step in a CI pipeline.

If the topology is valid, containerlab reports the lab name along with the number of nodes and links and exits with a zero exit code. If the topology is invalid, the offending error is printed and containerlab exits with a non-zero exit code.

Usage#

containerlab [global-flags] validate [local-flags]

aliases: val

Flags#

All command line arguments can be also provided via environment variables (CLI flags take precedence). The environment variable names are constructed by prepending CLAB_ to the flag name, then adding the command path and ending with the flag name in its full form, all in uppercase and with hyphens replaced by underscores.

For example, the --max-workers flag for the deploy command can be set via CLAB_DEPLOY_MAX_WORKERS environment variable. Or CLAB_INSPECT_ALL=1 to set --all flag for the inspect command. Or CLAB_TOPO=srlinux.dev/clab-srl clab dep -c to deploy a lab with the topology passed via environment variable.

Topology#

With the global --topo | -t flag a user sets the path to the topology definition file that will be validated.

When the topology path refers to a directory, containerlab will look for a file with .clab.yml or .clab.yaml extension in that directory and use it as a topology definition file.

When the topology file flag is omitted, containerlab will try to find the matching file name by looking at the current working directory.

If more than one file is found for directory-based path or when the flag is omitted entirely, containerlab will open an interactive selector to let you pick the topology file from the discovered clab.yml or clab.yaml files.

Examples#

Validate a lab using the given topology file#

containerlab validate -t mylab.clab.yml

Validate a lab without specifying topology file#

Given that a single topology file is present in the current directory.

containerlab validate

Validate a lab using short flag names#

clab val -t mylab.clab.yml