Improve release changelogs (#117)

This improves the release by only adding the relevant parts of the
CHANGELOG.md file. Besides that it also adds information on how to
reproduce the build with srtool.

Closes: #66

<!-- Remember that you can run `/merge` to enable auto-merge in the PR
-->

---------

Co-authored-by: Oliver Tale-Yazdi <[email protected]>

.github/changelog-processor.py

@@ -26,21 +26,38 @@
     help="Should a release be made? Prints `1` or `0`.",
     action="store_true"
 )
+group.add_argument(
+    "--print-changelog-from-last-release",
+    dest="changelog_last_release",
+    help="Print the changelog from the last release.",
+    action="store_true"
+)
 
 args = parser.parse_args()
 
 with open(args.changelog, "r") as changelog:
     lines = changelog.readlines()
 
+    changelog_last_release = ""
+    found_last_version = False
+
     # Find the latest version
     for line in lines:
         if not line.startswith("## ["):
+            changelog_last_release += line
             continue
+        elif not found_last_version:
+            changelog_last_release += line
+            found_last_version = True
+            version = line.strip().removeprefix("## [").split("]")[0]
+        else:
+            break
 
-        version = line.strip().removeprefix("## [").split("]")[0]
-        break
 
-    if args.print_latest_version:
+    if args.changelog_last_release:
+        print(changelog_last_release, end = "")
+        sys.exit(0)
+    elif args.print_latest_version:
         print(version, end = "")
         sys.exit(0)
     elif args.should_release:

.github/workflows/release.yml

@@ -105,12 +105,21 @@ jobs:
           CONTEXT=$(find . -name '*_srtool_output.json')
           SRTOOL() { <$(<<<$CONTEXT head -n1) jq -r .$1; }
           WASM() { <${JSON} jq -r ".runtimes.compressed.subwasm.$1"; }
+
+          # Copy the relevant parts of the changelog
+          .github/changelog-processor.py CHANGELOG.md --print-changelog-from-last-release > DRAFT
+
           tee -a DRAFT <<-EOF
-          EOF
-          tee -a DRAFT <CHANGELOG.md
-          tee -a DRAFT <<-EOF
-          ## Runtime info
+          # Runtime info
           *These runtimes were built with **$(SRTOOL rustc)** using **[$(SRTOOL gen)](https://github.com/paritytech/srtool)***
+
+          To replicate the build, use the following command:
+          ```sh
+          srtool build \
+                 --root --profile production \
+                 --package CRATE_NAME --runtime-dir PATH_TO_CRATE \
+                 --build-opts="--features=on-chain-release-build"
+          ```
           EOF
 
           for JSON in $(<<<$CONTEXT sort -sr)
@@ -127,7 +136,7 @@ jobs:
 
           tee -a DRAFT <<-EOF
 
-          ### $HEADING
+          ## $HEADING
           ~~~
           🏋️ Runtime Size:           $(numfmt --to iec-i --format "%.2f" $(WASM size)) ($(WASM size) bytes)
           🗜 Compressed:             $(WASM 'compression | if .compressed then "Yes: \(1 - .size_compressed / .size_decompressed | . * 10000 | round / 100)%" else "No" end')