refactor: modernise RPM builder with Python tooling v2

- Migrate from legacy shell-based build system to modern Python tooling
- Update all metadata.yaml files to new schema with per-distro builds
- Standardise build scripts with curl -L, envsubst, and error handling
- Convert nfpm.yaml templates to use environment variable substitution
- Update Dockerfile to accept all package metadata as build arguments
- Modernise Makefile to use new Python build tool commands
- Update CI workflow to use tools/build instead of make

rpms/boilerplate/metadata.yaml

@@ -1,9 +1,18 @@
-name: boilerplate
-release: 1
-version: 0.6.1
-build:
-- distro: el/8
-  image: git.unkin.net/unkin/almalinux8-rpmbuilder:latest
-- distro: el/9
-  image: git.unkin.net/unkin/almalinux9-rpmbuilder:latest
+---
+arch: amd64
+builds:
+  - image: git.unkin.net/unkin/almalinux8-rpmbuilder:latest
+    release: '1'
+    repository: [almalinux/el8]
+    version: 0.6.1
+  - image: git.unkin.net/unkin/almalinux9-rpmbuilder:latest
+    release: '1'
+    repository: [almalinux/el9]
+    version: 0.6.1
+description: Boilerplate is a tool for generating files and folders (boilerplate) from a set of templates.
 github: gruntwork-io/boilerplate
+homepage: https://github.com/gruntwork-io/boilerplate
+license: MIT
+maintainer: Gruntwork
+name: boilerplate
+platform: linux

rpms/boilerplate/resources/build.sh

@@ -1,7 +1,11 @@
 #!/usr/bin/bash
+set -e
 
 # Download the required files
 wget -O /app/boilerplate https://github.com/gruntwork-io/boilerplate/releases/download/v${PACKAGE_VERSION}/boilerplate_linux_amd64
 
+# Process nfpm.yaml with envsubst
+envsubst < /app/resources/nfpm.yaml > /app/nfpm.yaml
+
 # Build the RPM
-nfpm pkg --config /app/resources/nfpm.yaml --target /app/dist --packager rpm
+nfpm pkg --config /app/nfpm.yaml --target /app/dist --packager rpm

rpms/boilerplate/resources/nfpm.yaml

@@ -1,17 +1,17 @@
 # nfpm.yaml
 
-name: boilerplate
+name: ${PACKAGE_NAME}
 version: ${PACKAGE_VERSION}
 release: ${PACKAGE_RELEASE}
-arch: amd64
-platform: linux
+arch: ${PACKAGE_ARCH}
+platform: ${PACKAGE_PLATFORM}
 section: default
 priority: extra
-description: "Boilerplate is a tool for generating files and folders (boilerplate) from a set of templates."
+description: "${PACKAGE_DESCRIPTION}"
 
-maintainer: Gruntwork
-homepage: https://github.com/gruntwork-io/boilerplate
-license: MIT
+maintainer: ${PACKAGE_MAINTAINER}
+homepage: ${PACKAGE_HOMEPAGE}
+license: ${PACKAGE_LICENSE}
 
 disable_globbing: false