tpaexec eval

tpaexec eval#

You can use the eval command to evaluate an arbitrary Jinja/Ansible expression in the context of the cluster’s inventory. The information can be related to variables, inventory, gathered OS facts, computed paths, package names, etc.

Usage#

  • Run tpaexec eval ~/clusters/speedy '<expression>'

Options#

  • tpaexec eval ~/clusters/speedy '<expression>' --hosts <pattern>

Restrict evaluation to a host pattern. The pattern can be a single instance name (unreal ), a colon-separated list (unreal:ultra ), localhost , or a group name (role_primary , role_etcd ).

  • tpaexec eval ~/clusters/speedy '<expression>' --no-init

Skip the cluster initialisation playbook. Only variables derived from config.yml and the generated inventory are available; ansible_* host facts will be undefined. Recommended for quick inventory inspection.

Example Output#

Look up a value from config.yml for a single host:

tpaexec eval ~/clusters/speedy {{ postgres_version }} --no-init --hosts unreal

  unreal => {
    "msg": "17"
}

Print a value for every host in the cluster:

tpaexec eval ~/clusters/speedy {{ ip_address }} --no-init

  unreal => {
    "msg": "10.33.155.2"
}
  ultra => {
    "msg": "10.33.155.3"
}
  quondam => {
    "msg": "10.33.155.4"
}

Inspect inventory-wide data by targeting localhost :

tpaexec eval ~/clusters/speedy {{ groups.keys() | list }} --no-init --hosts localhost

  localhost => {
    "msg": [
        "all",
        "ungrouped",
        "tag_Cluster_speedy"
    ]
}

List every variable defined for a host (useful when you don’t yet know the name of the variable you want):

tpaexec eval ~/clusters/speedy {{ hostvars[inventory_hostname].keys() | list | sort }} --no-init --hosts unreal

  unreal => {
    "msg": [
        "ansible_user",
        "backup",
        "cluster_name",
        "failover_manager",
        "ip_address",
        "postgres_version",
        "role",
        "..."
    ]
}

Read a fact gathered from the host itself (omit --no-init so the initialisation playbook runs and populates ansible_* facts):

tpaexec eval ~/clusters/speedy {{ ansible_distribution }} --hosts unreal

  unreal => {
    "msg": "Debian"
}
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