A terrible terrible hack to automatically trace shell function exeuction

otel-auto-trace.sh

#!/bin/bash
export OTEL_EXPORTER_OTLP_ENDPOINT=localhost:4317

function gen-uid() {
  tr -dc 'a-f0-9' < /dev/urandom | head -c$1
}

trace=`gen-uid 32`
spans=()
starts=()
function my_debug_stuff() {
    [[ ${FUNCNAME[1]} != $BASH_COMMAND ]] && return
    local tp=`gen-uid 16`
    spans+=("$tp")
    starts+=("$(date -u +%s.%N)")
    echo "DEBUG: Starting [$BASH_COMMAND] Spans=${spans[@]}"
}
function my_return() {
    local tp=""
    if [[ ${#spans[@]} -gt 1 ]]; then
      echo "override tp"
      tp="00-${trace}-${spans[-2]}-01"
    fi
    local span="${spans[-1]}"
    local start="${starts[-1]}"
    echo "RETURN ${FUNCNAME[1]}, span=${spans[-1]}, start=$start, parent=$tp"
    unset spans[-1]
    unset starts[-1]
    TRACEPARENT=$tp otel-cli span \
      --service "test4" \
      --name "${FUNCNAME[1]}" \
      --start "$start" \
      --end "$(date -u +%s.%N)" \
      --force-trace-id "$trace" \
      --force-span-id "$span"
}

traceparent=""
function do-work() {
  sleep 1
}

function inner() {
  sleep .1
  inner-deep
  inner-deep
}

function inner-deep() {
  sleep .01
}

function outer() {
    inner
    inner
    sleep .2
    inner
}

set -o functrace
trap my_return RETURN
trap my_debug_stuff DEBUG


outer
do-work