a script that outputs start time of a scheduled pod and the time taken to become ready

measure_pod_start.sh

#!/usr/bin/env bash

if [ $# -ne 1 ]; then
  echo "Usage: $0 <namespace>"
  exit 1
fi

namespace="$1"

# Get the list of pod names in the specified namespace
pod_names=($(kubectl get pods -n "$namespace" -o=jsonpath='{.items[*].metadata.name}'))
echo "Pods in $1 namespace"
# Initialize arrays to store data
pod_data=()
scheduled_data=()
launch_data=()

# Add column headings
pod_data+=("Pod Name")
scheduled_data+=("Scheduled Time")
launch_data+=("Launch Time (Seconds)")

for pod in "${pod_names[@]}"; do
  scheduled=$(kubectl get pod "$pod" -n "$namespace" -o json | jq -r '.status.conditions[] | select(.type=="PodScheduled") | .lastTransitionTime')
  ready=$(kubectl get pod "$pod" -n "$namespace" -o json | jq -r '.status.conditions[] | select(.type=="Ready") | .lastTransitionTime')

  scheduled_epoch=$(date -j -u -f "%Y-%m-%dT%H:%M:%SZ" "$scheduled" "+%s" 2>/dev/null)
  ready_epoch=$(date -j -u -f "%Y-%m-%dT%H:%M:%SZ" "$ready" "+%s" 2>/dev/null)

  if [ -z "$scheduled_epoch" ] || [ -z "$ready_epoch" ]; then
    echo "Error: Failed to parse timestamps for $pod."
    continue
  fi

  scheduled_time=$(date -j -r "$scheduled_epoch" "+%H:%M:%S")
  load_seconds=$((ready_epoch - scheduled_epoch))

  # Print data
  echo "${pod} scheduled at ${scheduled_time}"
  echo "${pod} launch time: ${load_seconds} seconds"
  echo
done

To run this do the following

./measure_pod_start.sh <namespace>

e.g
./measure_pod_start.sh grafana

To make executable run
chmod +x measure_pod_start.sh