feat: add PR number to pretty version name; move commit hash last

Refine the pretty version name for PR preview builds:

- Add `coderBox.prNumber` (the GitHub PR ID), read from CODER_BOX_PR_NUMBER and
  set in CI from github.event.pull_request.number. Woven into the menu label as
  "#46" and the file name as "-46" when present.
- The installer boot-menu label now puts the PR reference first and moves the
  commit hash to the very end when a PR title is present:
    " - Coder Box Installer - PR #46: <title> (<rev>)"
  Non-PR builds are unchanged: " - Coder Box Installer (<rev>)".

Example file name: coder-box-installer-x86_64-linux-pr-46-fix-the-thing.iso

Author: phorcys420

.github/workflows/test.yml

@@ -138,11 +138,13 @@ jobs:
       # Resolved per-kind plan from the `plan` job. Steps below branch on these.
       INSTALLER_FULL: ${{ needs.plan.outputs.installer_full }}
       APPLIANCE_FULL: ${{ needs.plan.outputs.appliance_full }}
-      # PR title woven into the image's pretty version name (boot-menu label +
-      # ISO file name) via coderBox.prTitle. Set through `env:` (not inlined into
-      # a run script) so an arbitrary title can't break the shell, and empty for
-      # non-PR events so tag/main builds keep their plain names.
+      # PR title + number woven into the image's pretty version name (boot-menu
+      # label + ISO file name) via coderBox.prTitle / coderBox.prNumber. Set
+      # through `env:` (not inlined into a run script) so an arbitrary title
+      # can't break the shell, and empty for non-PR events so tag/main builds
+      # keep their plain names.
       CODER_BOX_PR_TITLE: ${{ github.event.pull_request.title }}
+      CODER_BOX_PR_NUMBER: ${{ github.event.pull_request.number }}
     strategy:
       fail-fast: false
       matrix:
@@ -181,7 +183,7 @@ jobs:
           docker run --rm \
             -v "$PWD":/work -w /work \
             -v "$dist":/dist \
-            -e INSTALLER_FULL -e APPLIANCE_FULL -e CODER_BOX_PR_TITLE \
+            -e INSTALLER_FULL -e APPLIANCE_FULL -e CODER_BOX_PR_TITLE -e CODER_BOX_PR_NUMBER \
             nixos/nix:latest \
             sh -euc '
               # The Makefile builds via "nix build --impure" and needs flakes +

Makefile

@@ -48,13 +48,14 @@ FLAKE ?= .
 # checkout (the module then falls back to self.rev / "unknown").
 GIT_REV := $(shell git rev-parse HEAD 2>/dev/null)$(shell git diff-index --quiet HEAD -- 2>/dev/null || echo -dirty)
 
-# Optional PR title woven into the image's pretty version name (boot-menu label
-# + ISO file name) via coderBox.prTitle. Not injected through the Nix expression
-# (an arbitrary title would need shell-escaping); instead the option reads the
-# CODER_BOX_PR_TITLE environment variable under `--impure` (which box_cfg already
-# uses). CI sets it for PR builds; locally you can preview with e.g.
-#   CODER_BOX_PR_TITLE="fix the thing" make installer/iso
-# Unset → plain names (the option defaults to "").
+# Optional PR title + number woven into the image's pretty version name
+# (boot-menu label + ISO file name) via coderBox.prTitle / coderBox.prNumber.
+# Not injected through the Nix expression (an arbitrary title would need
+# shell-escaping); instead the options read the CODER_BOX_PR_TITLE /
+# CODER_BOX_PR_NUMBER environment variables under `--impure` (which box_cfg
+# already uses). CI sets them for PR builds; locally you can preview with e.g.
+#   CODER_BOX_PR_TITLE="fix the thing" CODER_BOX_PR_NUMBER=46 make installer/iso
+# Unset → plain names (the options default to "").
 
 # Normalize an arch token to a *-linux triple: $(call norm_arch,aarch64) -> aarch64-linux
 norm_arch = $(if $(filter %-linux,$(1)),$(1),$(1)-linux)

nixos/_images/box-turnkey.nix

@@ -43,6 +43,13 @@ let
     in lib.removeSuffix "-" (lib.removePrefix "-" capped);
 
   prSlug = slugify prTitle;
+
+  # PR number (the GitHub PR "ID"). CI injects it alongside the title; included
+  # in both the menu label ("#46") and the file name ("-46") when present so an
+  # image can be traced straight back to its PR. Empty for non-PR builds.
+  prNumber  = config.coderBox.prNumber;
+  prNumMenu = lib.optionalString (prNumber != "") " #${prNumber}";
+  prNumFile = lib.optionalString (prNumber != "") "-${prNumber}";
 in
 {
   imports = [
@@ -82,22 +89,31 @@ in
     description = "Pull-request title this image was built for, woven into the pretty version name (boot-menu label + ISO file name) when non-empty.";
   };
 
+  # PR number (GitHub PR "ID") for a pull-request preview build. CI sets it via
+  # CODER_BOX_PR_NUMBER (read under `--impure` like prTitle); empty otherwise.
+  options.coderBox.prNumber = lib.mkOption {
+    type        = lib.types.str;
+    default     = builtins.getEnv "CODER_BOX_PR_NUMBER";
+    description = "Pull-request number (ID) this image was built for, woven into the pretty version name when non-empty.";
+  };
+
   # Derived, read-only fragments so every image flavour appends the PR identity
   # the same way. coderBox.prMenuSuffix goes on the boot-menu label;
-  # coderBox.prFileSuffix goes on the ISO file name. Both are empty when there's
-  # no PR title, so they're safe to interpolate unconditionally.
+  # coderBox.prFileSuffix goes on the ISO file name. Both carry the PR number
+  # ("#46" / "-46") when known, and are empty when there's no PR title, so
+  # they're safe to interpolate unconditionally.
   options.coderBox.prMenuSuffix = lib.mkOption {
     type        = lib.types.str;
     internal    = true;
     readOnly    = true;
-    default     = lib.optionalString (prTitle != "") " - PR: ${menuTitle}";
+    default     = lib.optionalString (prTitle != "") " - PR${prNumMenu}: ${menuTitle}";
     description = "Boot-menu label fragment naming the PR this image was built for (empty for non-PR builds).";
   };
   options.coderBox.prFileSuffix = lib.mkOption {
     type        = lib.types.str;
     internal    = true;
     readOnly    = true;
-    default     = lib.optionalString (prSlug != "") "-pr-${prSlug}";
+    default     = lib.optionalString (prSlug != "") "-pr${prNumFile}-${prSlug}";
     description = "ISO file-name fragment naming the PR this image was built for (empty for non-PR builds).";
   };
 

nixos/_images/installer/iso.nix

@@ -68,10 +68,15 @@ in
     isoImage.volumeID          = "CODER_BOX_INSTALLER";
     # Boot-menu label (BIOS/isolinux + EFI/grub). See ../appliance/iso.nix for
     # the format; leading space is required. Include the short build revision so
-    # the boot menu shows exactly which image you're booting. The PR-title
-    # suffix (coderBox.prMenuSuffix, set in box-turnkey.nix) is empty unless this
-    # is a PR preview build.
-    isoImage.appendToMenuLabel = " - Coder Box Installer (${boxRevShort})${config.coderBox.prMenuSuffix}";
+    # the boot menu shows exactly which image you're booting. For a PR preview
+    # build (coderBox.prMenuSuffix non-empty) the PR reference comes first and
+    # the commit hash moves to the very end, so the label reads
+    # " - Coder Box Installer - PR #46: <title> (<rev>)"; otherwise it's just
+    # " - Coder Box Installer (<rev>)".
+    isoImage.appendToMenuLabel =
+      if config.coderBox.prMenuSuffix != ""
+      then " - Coder Box Installer${config.coderBox.prMenuSuffix} (${boxRevShort})"
+      else " - Coder Box Installer (${boxRevShort})";
 
     # Record the full build revision for install.sh to print (the baked repo
     # under /etc/nixos-repo has no .git, so the script can't get it from git).