Add custom gitlog action

.github/actions/gitlog/action.yaml

@@ -0,0 +1,20 @@
+name: Git log
+description: Mangles git log for change log
+inputs:
+  output-file:
+    description: File path where to place the content of the changed commits
+    required: true
+  crate:
+    description: Name of the crate to get git log for
+    required: true
+outputs:
+  last_release: 
+    description: Last release commit or first commit of history
+    value: ${{ steps.gitlog.outputs.last_release }}
+runs:
+  using: composite
+  steps:
+    - shell: bash 
+      id: gitlog
+      run: |
+        ${{ github.action_path }}/gitlog.sh --output-file ${{ inputs.output-file }} --crate ${{ inputs.crate }}

.github/actions/gitlog/gitlog.sh

@@ -0,0 +1,87 @@
+#!/bin/bash
+
+# This mangles git log entries for change lop purposes
+
+output_file=""
+crate=""
+while true; do
+  case $1 in
+    "--output-file")
+      shift
+      output_file="$1"
+      shift
+    ;;
+    "--crate")
+      shift
+      crate="$1"
+      shift
+    ;;
+    *)
+      break
+    ;;
+  esac
+done
+
+if [[ "$output_file" == "" ]]; then
+  echo "Missing --output-file <file> option argument, define path to file or - for stdout" && exit 1
+fi
+if [[ "$crate" == "" ]]; then
+  echo "Missing --crate <crate> option argument, need an explisit crate to get git log for" && exit 1
+fi
+
+from_commit=HEAD
+last_release=$(git tag --sort=-committerdate | grep -E "$crate-[0-9]*\.[0-9]*\.[0-9]*" | head -1)
+echo "Found tag: $last_release"
+if [[ "$last_release" == "" ]]; then
+  last_release=$(git tag --sort=-committerdate | head -1) # get last tag
+  echo "Using latest tag: $last_release"
+fi
+
+commit_range=""
+if [[ $last_release != "" ]]; then
+  commit_range="$from_commit...$last_release"
+else
+  commit_range="$from_commit"
+fi
+
+ancestry_path=""
+if [[ "$last_release" != "" ]]; then
+  ancestry_path="--ancestry-path"
+fi
+
+mapfile -t log_lines < <(git log --pretty=format:'(%h) %s' $ancestry_path $commit_range)
+
+function is_crate_related {
+  commit="$1"
+  changes="$(git diff --name-only "$commit"~ "$commit" | awk -F / '{print $1}' | xargs)"
+
+  is_related=false
+  if [[ "$changes" == *"$crate"* ]]; then
+    is_related=true
+  fi
+
+  echo $is_related
+}
+
+log=""
+for line in "${log_lines[@]}"; do
+  commit=$(echo "$line" | awk -F ' ' '{print $1}')
+  commit=${commit//[\(\)]/}
+
+  if [[ $(is_crate_related "$commit") == true ]]; then
+    log=$log"* $line\n"
+  fi
+done
+
+if [[ "$output_file" != "" ]]; then
+  if [[ "$output_file" == "-" ]]; then
+    echo -e "$log"
+  else
+    echo -e "$log" > "$output_file"
+  fi
+fi
+
+if [[ "$last_release" == "" ]]; then
+  last_release=$(git rev-list --reverse HEAD | head -1)
+fi
+echo "::set-output name=last_release::$last_release"