Module: LanguageOperator::CLI::Helpers::LabelUtils

Defined in:
lib/language_operator/cli/helpers/label_utils.rb

Overview

Utilities for working with Kubernetes labels

Class Method Summary collapse

Class Method Details

.agent_pod_selector(agent_name) ⇒ String

Build a label selector for finding agent pods

Parameters:

  • agent_name (String) —

    The agent name

Returns:

  • (String) —

    A label selector string



29
30
31
32
 
# File 'lib/language_operator/cli/helpers/label_utils.rb', line 29

def self.agent_pod_selector(agent_name)
  normalized_name = normalize_agent_name(agent_name)
  Constants::KubernetesLabels.agent_selector(normalized_name)
end

.debug_pod_search(ctx, agent_name) ⇒ Hash

Get debugging information about label selector matching

Parameters:

  • ctx (ClusterContext) —

    Kubernetes context

  • agent_name (String) —

    Agent name being searched

Returns:

  • (Hash) —

    Debug information about the search



59
60
61
62
63
64
65
66
67
68
69
 
# File 'lib/language_operator/cli/helpers/label_utils.rb', line 59

def self.debug_pod_search(ctx, agent_name)
  selector = agent_pod_selector(agent_name)

  {
    agent_name: agent_name,
    normalized_name: normalize_agent_name(agent_name),
    label_selector: selector,
    namespace: ctx.namespace,
    valid_label_value: valid_label_value?(agent_name)
  }
end

.find_pods_by_deployment_labels(ctx, deployment_name, labels) ⇒ Array

Convert deployment labels to pod selector and find matching pods

This method handles the common pattern of extracting selector labels from a deployment, converting them to a label selector string, and finding matching pods.

Parameters:

  • ctx (ClusterContext) —

    Kubernetes context with client and namespace

  • deployment_name (String) —

    Name of the deployment (for error messages)

  • labels (Hash, Object) —

    Deployment selector labels (may be K8s::Resource or Hash)

Returns:

  • (Array) —

    Array of pod resources matching the labels

Raises:

  • (RuntimeError) —

    If labels are nil, empty, or no pods found



81
82
83
84
85
86
87
88
89
90
91
92
93
 
# File 'lib/language_operator/cli/helpers/label_utils.rb', line 81

def self.find_pods_by_deployment_labels(ctx, deployment_name, labels)
  raise "Deployment '#{deployment_name}' has no selector labels" if labels.nil?

  # Convert to hash if needed (K8s API may return K8s::Resource objects)
  labels_hash = labels.respond_to?(:to_h) ? labels.to_h : labels
  raise "Deployment '#{deployment_name}' has empty selector labels" if labels_hash.empty?

  # Convert labels to Kubernetes label selector format
  label_selector = labels_hash.map { |k, v| "#{k}=#{v}" }.join(',')

  # Find matching pods
  ctx.client.list_resources('Pod', namespace: ctx.namespace, label_selector: label_selector)
end

.normalize_agent_name(agent_name) ⇒ String

Normalize an agent name for use as a Kubernetes label value

Kubernetes label values must follow DNS-1123 subdomain format:

  • contain only lowercase alphanumeric characters, '-' or '.'
  • start and end with an alphanumeric character
  • be at most 63 characters

Parameters:

  • agent_name (String) —

    The agent name to normalize

Returns:

  • (String) —

    A valid label value



19
20
21
22
23
 
# File 'lib/language_operator/cli/helpers/label_utils.rb', line 19

def self.normalize_agent_name(agent_name)
  # Agent names should already be valid Kubernetes resource names,
  # which are compatible with label values. Just ensure lowercase.
  agent_name.to_s.downcase
end

.valid_label_value?(agent_name) ⇒ Boolean

Validate that an agent name will work as a label value

Parameters:

  • agent_name (String) —

    The agent name to validate

Returns:

  • (Boolean) —

    true if valid, false otherwise



38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
 
# File 'lib/language_operator/cli/helpers/label_utils.rb', line 38

def self.valid_label_value?(agent_name)
  return false if agent_name.nil? || agent_name.empty?

  # Check original string first (before normalization)
  agent_str = agent_name.to_s

  # Check DNS-1123 subdomain requirements:
  # - 63 characters or less
  # - lowercase letters, numbers, hyphens, and dots only
  # - start and end with alphanumeric character
  return false if agent_str.length > 63
  return false unless agent_str.match?(/\A[a-z0-9]([a-z0-9\-.]*[a-z0-9])?\z/)

  true
end