#!/usr/bin/env bash
# external-dns/external-dns 1.21.1 - base variant: dry-run-txt-registry
# Path: fetch this entry's retained objects, check their SHA-256, then apply
# them with kubectl. It uses curl, shasum, awk and kubectl. It needs no cub
# CLI and no ConfigHub account.
# Generated by scripts/generate-public-site.mjs from this entry's listing:
# https://confighub.github.io/helm-expt/site/listings/external-dns-external-dns-1-21-1-dry-run-txt-registry.json
# Entry page: https://confighub.github.io/helm-expt/site/charts/external-dns-external-dns-1-21-1.html
set -euo pipefail

say() { printf '\n>> %s\n' "$*"; }

for tool in curl awk kubectl; do
  if ! command -v "$tool" >/dev/null 2>&1; then
    printf '%s is required and was not found.\n' "$tool" >&2
    exit 1
  fi
done
if command -v shasum >/dev/null 2>&1; then
  sha256_of() { shasum -a 256 "$1" | awk '{print $1}'; }
elif command -v sha256sum >/dev/null 2>&1; then
  sha256_of() { sha256sum "$1" | awk '{print $1}'; }
else
  printf 'shasum is required and was not found.\n' >&2
  exit 1
fi

work=./external-dns-external-dns-1-21-1-dry-run-txt-registry-objects
objects_url=https://raw.githubusercontent.com/confighub/helm-expt/main/recipes/external-dns/external-dns/1.21.1/revisions/dry-run-txt-registry/r001/rendered/release-objects.yaml
objects_sha256=8e3b831abefa8ca2b8754e4beb16fbc1e369965dc95b8f83e1de76cd8f2a3e62

say "Fetch the retained objects into $work/objects.yaml"
mkdir -p "$work"
curl -fsSL -o "$work/objects.yaml" "$objects_url"

say "Check the file against the SHA-256 in the listing"
fetched_sha256="$(sha256_of "$work/objects.yaml")"
if [ "$fetched_sha256" != "$objects_sha256" ]; then
  printf 'The file differs from the listing, so the script stops. Nothing was applied.\n  listing: %s\n  fetched: %s\n' "$objects_sha256" "$fetched_sha256" >&2
  exit 1
fi
printf 'The file matches: sha256 %s\n' "$fetched_sha256"

say "Split the file into its 4 objects. The cluster is untouched so far"
rm -rf "$work/docs" "$work/crds" "$work/rest"
mkdir -p "$work/docs" "$work/crds" "$work/rest"
awk -v dir="$work/docs" 'BEGIN { n = 0; f = sprintf("%s/doc-%04d.yaml", dir, n) } /^---[ \t]*$/ { close(f); n++; f = sprintf("%s/doc-%04d.yaml", dir, n); next } { print > f }' "$work/objects.yaml"
for n in 0001; do mv "$work/docs/doc-$n.yaml" "$work/crds/"; done
for n in 0002 0003 0004; do mv "$work/docs/doc-$n.yaml" "$work/rest/"; done
ls "$work/crds" "$work/rest"

say "Check that kubectl reaches a cluster"
if ! kubectl get --raw /version >/dev/null 2>&1; then
  printf 'kubectl cannot reach a cluster. Point it at a throwaway cluster and re-run this script.\n' >&2
  exit 1
fi
kubectl config current-context 2>/dev/null || true

say "Create the default namespace if it does not exist"
if ! kubectl get namespace default >/dev/null 2>&1; then
  kubectl create namespace default
fi

wait_for_crd() {
  crd_name="$1"
  deadline=$(( $(date +%s) + 180 ))
  until kubectl get "crd/${crd_name}" >/dev/null 2>&1; do
    if [ "$(date +%s)" -ge "$deadline" ]; then
      printf "CRD %s did not appear within 180 seconds.\n" "$crd_name" >&2
      return 1
    fi
    sleep 2
  done
  kubectl wait --for=condition=Established --timeout=120s "crd/${crd_name}"
}

say "Check the 1 CRD this file holds"
missing_crds=0
if ! kubectl get crd/dnsendpoints.externaldns.k8s.io >/dev/null 2>&1; then
  missing_crds=1
fi
if [ "$missing_crds" -eq 1 ]; then
  say "The CRD is missing, so apply the file's CRD first"
  kubectl apply --server-side -f "$work/crds"
  crd_outcome="was applied first"
elif kubectl diff --server-side -f "$work/crds" >/dev/null 2>&1; then
  say "The CRD already exists and matches this file. The script leaves it under its current owner"
  crd_outcome="already existed and matched, so the script left it alone"
elif [ "${APPLY_CRDS:-0}" = "1" ]; then
  say "The existing CRD differs from this file. APPLY_CRDS=1 is set, so the script applies the file's CRD"
  kubectl apply --server-side -f "$work/crds"
  crd_outcome="differed and was applied, because APPLY_CRDS=1 was set"
else
  say "The CRD already exists and differs from this file, or another tool owns it"
  cat <<'EOF_CRDS'
This script does not change CRDs it did not just create.
If this is an upgrade, the objects that follow may need the newer CRDs.
To let this script apply the file's CRD, re-run with:
  APPLY_CRDS=1 bash try-objects.sh
EOF_CRDS
  exit 1
fi
wait_for_crd dnsendpoints.externaldns.k8s.io

say "Apply the other 3 objects"
kubectl apply -f "$work/rest"

say "Done. The 1 CRD $crd_outcome. kubectl applied the other 3 objects of this entry's retained file."
say "The script stops here. It did not wait for any workload to start"