Github workflow to automate release draft creation (#3978)

This PR introduces the github flow which will create a release draft
automatically when the rc tag is pushed. The flow contains the following
steps:

- Gets the info about rust version used to build the node
- Builds the runtimes using `srtool`
- Extracts the info about each runtime 
- Aggregates the changelog from the prdocs
- Creates the release draft containing all the info related to the
release (changelog, runtimes, rust versions)
- Attaches the runtimes to the draft
- Posts the message to the RelEng internal channel to inform that the
build is done.

Related to the #3295

---------

Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

scripts/release/build-changelogs.sh

@@ -2,11 +2,16 @@
 
 export PRODUCT=polkadot
 export VERSION=${VERSION:-1.5.0}
+export ENGINE=${ENGINE:-docker}
+export REF1=${REF1:-'HEAD'}
+export REF2=${REF2}
+export RUSTC_STABLE=${RUSTC_STABLE:-'1.0'}
+export RUSTC_NIGHTLY=${RUSTC_NIGHTLY:-'1.0'}
 
 PROJECT_ROOT=`git rev-parse --show-toplevel`
 echo $PROJECT_ROOT
 
-TMP=$(mktemp -d)
+TMP=${TMP:-$(mktemp -d)}
 TEMPLATE_AUDIENCE="${PROJECT_ROOT}/scripts/release/templates/audience.md.tera"
 TEMPLATE_CHANGELOG="${PROJECT_ROOT}/scripts/release/templates/changelog.md.tera"
 
@@ -21,7 +26,7 @@ OUTPUT="${TMP}/changelogs/$PRODUCT/$VERSION"
 echo -e "OUTPUT: \t\t$OUTPUT"
 mkdir -p $OUTPUT
 
-prdoc load -d "$PROJECT_ROOT/prdoc/$VERSION" --json > $DATA_JSON
+$ENGINE run --rm -v ${PROJECT_ROOT}:/repo paritytech/prdoc load -d "prdoc/$VERSION" --json > $DATA_JSON
 # ls -al $DATA_JSON
 
 cat $DATA_JSON | jq ' { "prdoc" : .}' > $CONTEXT_JSON
@@ -48,8 +53,58 @@ for audience in "${audiences[@]}"; do
     echo "Processing audience: $audience ($audience_id)"
     export TARGET_AUDIENCE=$audience
     tera -t "${TEMPLATE_AUDIENCE}" --env --env-key env "${CONTEXT_JSON}" > "$OUTPUT/relnote_${audience_id}.md"
-    cat "$OUTPUT/relnote_${audience_id}.md" >> "$OUTPUT/relnote_combined.md"
+    cat "$OUTPUT/relnote_${audience_id}.md" >> "$PROJECT_ROOT/scripts/release/templates/changelog.md"
 done
 
 # Show the files
 tree -s -h -c $OUTPUT/
+
+ASSET_HUB_ROCOCO_DIGEST=${ASSET_HUB_ROCOCO_DIGEST:-"$PROJECT_ROOT/scripts/release/digests/asset-hub-rococo-srtool-digest.json"}
+ASSET_HUB_WESTEND_DIGEST=${ASSET_HUB_WESTEND_DIGEST:-"$PROJECT_ROOT/scripts/release/digests/asset-hub-westend-srtool-digest.json"}
+BRIDGE_HUB_ROCOCO_DIGEST=${BRIDGE_HUB_ROCOCO_DIGEST:-"$PROJECT_ROOT/scripts/release/digests/bridge-hub-rococo-srtool-digest.json"}
+BRIDGE_HUB_WESTEND_DIGEST=${BRIDGE_HUB_WESTEND_DIGEST:-"$PROJECT_ROOT/scripts/release/digests/bridge-hub-westend-srtool-digest.json"}
+COLLECTIVES_WESTEND_DIGEST=${COLLECTIVES_WESTEND_DIGEST:-"$PROJECT_ROOT/scripts/release/digests/collectives-westend-srtool-digest.json"}
+CONTRACTS_ROCOCO_DIGEST=${CONTRACTS_ROCOCO_DIGEST:-"$PROJECT_ROOT/scripts/release/digests/contracts-rococo-srtool-digest.json"}
+CORETIME_ROCOCO_DIGEST=${CORETIME_ROCOCO_DIGEST:-"$PROJECT_ROOT/scripts/release/digests/coretime-rococo-srtool-digest.json"}
+CORETIME_WESTEND_DIGEST=${CORETIME_WESTEND_DIGEST:-"$PROJECT_ROOT/scripts/release/digests/coretime-westend-srtool-digest.json"}
+GLUTTON_WESTEND_DIGEST=${GLUTTON_WESTEND_DIGEST:-"$PROJECT_ROOT/scripts/release/digests/glutton-westend-srtool-digest.json"}
+PEOPLE_ROCOCO_DIGEST=${PEOPLE_ROCOCO_DIGEST:-"$PROJECT_ROOT/scripts/release/digests/people-rococo-srtool-digest.json"}
+PEOPLE_WESTEND_DIGEST=${PEOPLE_WESTEND_DIGEST:-"$PROJECT_ROOT/scripts/release/digests/people-westend-srtool-digest.json"}
+ROCOCO_DIGEST=${ROCOCO_DIGEST:-"$PROJECT_ROOT/scripts/release/digests/rococo-srtool-digest.json"}
+WESTEND_DIGEST=${WESTEND_DIGEST:-"$PROJECT_ROOT/scripts/release/digests/westend-srtool-digest.json"}
+
+jq \
+      --slurpfile srtool_asset_hub_rococo $ASSET_HUB_ROCOCO_DIGEST \
+      --slurpfile srtool_asset_hub_westend $ASSET_HUB_WESTEND_DIGEST \
+      --slurpfile srtool_bridge_hub_rococo $BRIDGE_HUB_ROCOCO_DIGEST \
+      --slurpfile srtool_bridge_hub_westend $BRIDGE_HUB_WESTEND_DIGEST \
+      --slurpfile srtool_collectives_westend $COLLECTIVES_WESTEND_DIGEST \
+      --slurpfile srtool_contracts_rococo $CONTRACTS_ROCOCO_DIGEST \
+      --slurpfile srtool_coretime_rococo $CORETIME_ROCOCO_DIGEST\
+      --slurpfile srtool_coretime_westend $CORETIME_WESTEND_DIGEST \
+      --slurpfile srtool_glutton_westend $GLUTTON_WESTEND_DIGEST \
+      --slurpfile srtool_people_rococ $PEOPLE_ROCOCO_DIGEST \
+      --slurpfile srtool_people_westend $PEOPLE_WESTEND_DIGEST \
+      --slurpfile srtool_rococo $ROCOCO_DIGEST \
+      --slurpfile srtool_westend $WESTEND_DIGEST \
+      -n '{
+          srtool: [
+            { order: 10, name: "Westend", data: $srtool_westend[0] },
+            { order: 11, name: "Westend AssetHub", data: $srtool_asset_hub_westend[0] },
+            { order: 12, name: "Westend BridgeHub", data: $srtool_bridge_hub_westend[0] },
+            { order: 13, name: "Westend Collectives", data: $srtool_collectives_westend[0] },
+            { order: 14, name: "Westend Coretime", data: $srtool_coretime_westend[0] },
+            { order: 15, name: "Westend Glutton", data: $srtool_glutton_westend[0] },
+            { order: 16, name: "Westend People", data: $srtool_people_westend[0] },
+            { order: 17, name: "Rococo", data: $srtool_rococo[0] },
+            { order: 18, name: "Rococo AssetHub", data: $srtool_asset_hub_rococo[0] },
+            { order: 19, name: "Rococo BridgeHub", data: $srtool_bridge_hub_rococo[0] },
+            { order: 20, name: "Rococo Contracts", data: $srtool_contracts_rococo[0] },
+            { order: 21, name: "Rococo Coretime", data: $srtool_coretime_rococo[0] },
+            { order: 22, name: "Rococo People", data: $srtool_people_rococ[0] }
+      ] }' > "$PROJECT_ROOT/scripts/release/context.json"
+
+RELEASE_DIR="$PROJECT_ROOT/scripts/release/"
+pushd $RELEASE_DIR >/dev/null
+tera --env --env-key env --include-path templates --template templates/template.md.tera context.json > RELEASE_DRAFT.md
+popd >/dev/null