add branch-specific nightly build

Author: sjpb

.github/workflows/nightlybuild.yml

@@ -33,13 +33,16 @@ jobs:
       OS_CLOUD: openstack
       CI_CLOUD: ${{ github.event.inputs.ci_cloud || vars.CI_CLOUD }}
       ARK_PASSWORD: ${{ secrets.ARK_PASSWORD }}
+      # set the image version to empty string for cron else branch name suffix
+      IMAGE_VER: ${{ (github.event_name == 'schedule' && '') || format('-{0}', github.ref_name) }}
 
     steps:
       - uses: actions/checkout@v2
 
       - name: Record settings for CI cloud
         run: |
           echo CI_CLOUD: ${{ env.CI_CLOUD }}
+          echo IMAGE_VER: ${{ env.IMAGE_VER }}
 
       - name: Setup ssh
         run: |
@@ -81,6 +84,7 @@ jobs:
           -var-file=$PKR_VAR_environment_root/${{ env.CI_CLOUD }}.pkrvars.hcl \
           -var "source_image_name=${{ matrix.build.source_image_name }}" \
           -var "image_name=rocky-latest-${{ matrix.build.label }}" \
+          -var "image_name_version=${{ env.IMAGE_VER }}" \
           -var "inventory_groups=update" \
           openstack.pkr.hcl
 
@@ -120,6 +124,8 @@ jobs:
       group: ${{ github.workflow }}-${{ github.ref }}-${{ matrix.build.label }}-${{ matrix.target_cloud }}
       cancel-in-progress: true
     runs-on: ubuntu-22.04
+    # Don't sync manually-triggered image builds
+    if: ${{ github.event_name == 'schedule' }}
     strategy:
       fail-fast: false
       matrix:

packer/openstack.pkr.hcl

@@ -23,7 +23,7 @@ data "git-commit" "cwd-head" { }
 locals {
     git_commit = data.git-commit.cwd-head.hash
     timestamp = formatdate("YYMMDD-hhmm", timestamp())
-    image_name_version = var.image_name_version == "auto" ? "-${local.timestamp}-${substr(local.git_commit, 0, 8)}" : var.image_name_version
+    image_name_version = var.image_name_version == "auto" ? "-${local.timestamp}-${substr(local.git_commit, 0, 8)}" : replace(var.image_name_version, "/", "")
 }
 
 # Path pointing to root of repository - automatically set by environment variable PKR_VAR_repo_root
@@ -146,7 +146,7 @@ variable "image_name" {
 
 variable "image_name_version" {
   type = string
-  description = "Suffix for image name giving version. Default of 'auto' appends timestamp + short commit"
+  description = "Suffix for image name giving version. Default of 'auto' appends timestamp + short commit. Note / characters are stripped to allow using branch names"
   default = "auto"
 }