# Shared hive-CA trust plumbing for containers that must trust the
# self-signed gateway/forge leaf for *outbound* TLS (webhook delivery,
# CI artifact upload, …). The hive CA is generated at runtime by the host
# `hive-tls-ca.service` (see `hive-tls.nix`) — it can't be baked into a
# derivation — so each such container binds the public `ca.pem` read-only
# and orders its `container@<name>` unit after `hive-tls-ca.service` so the
# bind source exists before nspawn sets the mount up.
#
# This is the language-agnostic half (bind-mount + systemd ordering). The
# *consumption* differs per runtime and stays at each call site: Node's
# `NODE_EXTRA_CA_CERTS` is additive (hive-ci), Go's `SSL_CERT_FILE` replaces
# the bundle so it needs a system-CAs+hive-CA concat step (hive-forge).
#
# Pure function — NOT a NixOS module (don't add it to the host-modules
# aggregator). Call it from a module's `let`:
#
#   caTrust = import ./lib/hive-ca-trust.nix { inherit lib tlsCfg gatewayCfg; };
#   # then, in the container:
#   #   bindMounts = { … } // caTrust.bindMount;
#   #   systemd.services."container@hive-ci" = lib.mkMerge [ caTrust.containerOrdering … ];
#   #   environment.NODE_EXTRA_CA_CERTS = caTrust.caContainerPath;  # consumption, per-caller
#
# `tlsCfg`     = config.services.hyperhive.tls
# `gatewayCfg` = config.services.hyperhive.gateway
{
  lib,
  tlsCfg,
  gatewayCfg,
}:
let
  # `gateway.useSelfSigned` is the single source of truth for the
  # self-signed condition — no duplicated derivation.
  useSelfSigned = gatewayCfg.useSelfSigned;
  # The bundle, not `ca.pem`: the hive CA is an intermediate under the
  # swarm root, and openssl (which is what both consumers below sit on —
  # Node's `NODE_EXTRA_CA_CERTS`, Go's `SSL_CERT_FILE`) will not end a
  # chain at a trusted cert that isn't self-signed. `hive-tls.nix` writes
  # the bundle next to the CA and explains the split.
  caHostPath = "${tlsCfg.stateDir}/trust-bundle.pem";
  caContainerPath = "/run/hive-ca/trust-bundle.pem";
in
{
  inherit useSelfSigned caContainerPath;

  # Fold into the container's `bindMounts` via `//`. Binds ONLY the public
  # CA cert (never the `hive-tls` state dir — it holds the CA + leaf private
  # keys), read-only. Empty when not self-signed, so the whole trust path
  # drops out cleanly.
  bindMount = lib.optionalAttrs useSelfSigned {
    ${caContainerPath} = {
      hostPath = caHostPath;
      isReadOnly = true;
    };
  };

  # Fold into the caller's `container@<name>` unit (via `lib.mkMerge` if the
  # caller adds its own keys, e.g. hive-ci's `TimeoutStartSec`). Orders the
  # container after the host `hive-tls-ca.service` so the bind source exists
  # before nspawn sets the mount up — a condition-skipped/late CA would
  # otherwise fail the container start.
  containerOrdering = lib.mkIf useSelfSigned {
    after = [ "hive-tls-ca.service" ];
    requires = [ "hive-tls-ca.service" ];
  };
}