Add working directory support

This adds the option to change directory before building the gem.
Adds support for monorepos

Dockerfile

@@ -1,4 +1,4 @@
-FROM ruby:2.6-alpine
+FROM ruby:2.7-alpine
 
 RUN apk add --no-cache git
 

action.yml

@@ -11,9 +11,13 @@ inputs:
   owner:
     description: 'Name of the user or organization account that owns the repository containing your project.'
     required: true
+  working-directory:
+    description: 'An optional path to switch to before building the Gem.'
+    required: false
 runs:
   using: 'docker'
   image: 'Dockerfile'
   args:
     - ${{ inputs.token }}
     - ${{ inputs.owner }}
+    - ${{ inputs.working-directory }}

entrypoint.sh

@@ -2,6 +2,7 @@
 
 GITHUB_TOKEN=$1
 OWNER=$2
+WORKING_DIRECTORY=$3
 
 [ -z "${GITHUB_TOKEN}" ] && { echo "Missing input.token!"; exit 2; }
 [ -z "${OWNER}" ] && { echo "Missing input.owner!"; exit 2; }
@@ -13,6 +14,6 @@ chmod 600 ~/.gem/credentials
 echo ":github: Bearer ${GITHUB_TOKEN}" >> ~/.gem/credentials
 
 echo "Building the gem"
-gem build *.gemspec
+gem build ${WORKING_DIRECTORY:-.}/*.gemspec
 echo "Pushing the built gem to GitHub Package Registry"
-gem push --key github --host "https://rubygems.pkg.github.com/${OWNER}" *.gem
+gem push --key github --host "https://rubygems.pkg.github.com/${OWNER}" ./*.gem