Add pipeline-lib branch update action

Signed-off-by: Brian J. Murrell <brian.murrell@intel.com>

Author: brianjmurrell

.github/actions/update_pipeline_lib_branch/Dockerfile

@@ -0,0 +1,7 @@
+FROM alpine:3.10
+
+COPY entrypoint.sh /entrypoint.sh
+
+RUN apk add --no-cache bash
+
+ENTRYPOINT ["/entrypoint.sh"]

.github/actions/update_pipeline_lib_branch/action.yml

@@ -0,0 +1,6 @@
+name: 'Update Pipeline Library Branch'
+description: 'Update the pipeline-lib Library reference to be the current branch'
+author: 'Brian J. Murrell'
+runs:
+  using: 'docker'
+  image: 'Dockerfile'

.github/actions/update_pipeline_lib_branch/entrypoint.sh

@@ -0,0 +1,28 @@
+#!/bin/bash -l
+
+set -eux
+
+my_branch=${GITHUB_REF#refs/heads/}
+my_branch_RE=${my_branch//\//\\/}
+
+if [ $my_branch = master ]; then
+    # landing, return to standard commented out hint
+    sed -i -e "/^@Library(value=\"pipeline-lib@/s/\(.*-lib@\).*\(\".*\)$/\/\/ \1my_pr_branch\2/" Jenkinsfile
+    exit 0
+fi
+
+if grep "^@Library(value=\"pipeline-lib@${my_branch_RE}\") _" Jenkinsfile; then
+    # already set, nothing to do
+    exit 0
+fi
+
+if grep "^@Library(value=\"pipeline-lib@" Jenkinsfile; then
+    # set to something else set, change it
+    sed -i -e "/^@Library(value=\"pipeline-lib@/s/\(lib@\).*\"/\1${my_branch_RE}\"/" Jenkinsfile
+    exit 0
+fi
+
+# not set at all, add it
+sed -i -e "s/^\/\/ \(@Library(value=\"pipeline-lib@\)my_pr_branch\(\") _\)/\1${my_branch_RE}\2/" Jenkinsfile
+
+exit 0

.github/workflows/update_pipeline_lib_branch.yml

@@ -0,0 +1,21 @@
+name: Set Pipeline Library Branch
+# This workflow is triggered on pushes to the master branch of the repository.
+on:
+  push:
+
+jobs:
+  update_pipeline_lib_branch:
+    name: Update Pipeline Library Branch
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        ref: ${{ github.head_ref }}
+    - uses: ./.github/actions/update_pipeline_lib_branch
+    - uses: stefanzweifel/git-auto-commit-action@v4
+      with:
+        commit_message: Update pipeline-lib branch
+        commit_options: '--signoff'
+      id: update_pipeline_lib_branch
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}