Add hassfest action (#5)

Author: ludeeus

README.md

@@ -1,4 +1,5 @@
 # actions
+
 GitHub Actions for Home Assistant workflows
 
 ## JQ
@@ -11,3 +12,30 @@ GitHub Actions for Home Assistant workflows
 - `home-assistant/actions/py37-tox@master`
 - `home-assistant/actions/py36-tox@master`
 - `home-assistant/actions/py35-tox@master`
+
+## hassfest
+
+_Run hassfest to validate standalone integration repositories._
+
+**action**: `home-assistant/actions/hassfest@master`
+
+example implementation:
+
+```yaml
+name: Validate with hassfest
+
+on:
+  push:
+  pull_request:
+  schedule:
+    - cron:  '0 0 * * *'
+
+jobs:
+  validate:
+    runs-on: "ubuntu-latest"
+    steps:
+        - uses: "actions/checkout@v2"
+        - uses: home-assistant/actions/hassfest@master
+```
+
+This will run the `hassfest` action on every push and pull request to all branches, as well as every midnight.

hassfest/Dockerfile

@@ -0,0 +1,33 @@
+FROM python:3-alpine
+
+COPY entrypoint.sh /entrypoint.sh
+
+RUN \
+    apk add --no-cache \
+        python3-dev \
+        bash \
+        git \
+        gcc \
+        libc-dev \
+        libffi-dev \
+        openssl-dev \
+    \
+    && rm -rf /var/cache/apk/* \
+    \
+    && git clone --depth 1 https://github.com/home-assistant/core.git /core \
+    \
+    && python3 -m pip install --no-cache-dir -e /core \
+    \
+    && chmod +x /entrypoint.sh
+
+WORKDIR "/github/workspace"
+ENTRYPOINT ["/entrypoint.sh"]
+
+LABEL "name"="hassfest"
+LABEL "maintainer"="Home Assistant <hello@home-assistant.io>"
+LABEL "version"="1.0"
+
+LABEL "com.github.actions.name"="hassfest"
+LABEL "com.github.actions.description"="Run hassfest to validate standalone integration repositories"
+LABEL "com.github.actions.icon"="terminal"
+LABEL "com.github.actions.color"="gray-dark"

hassfest/entrypoint.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+set -e
+
+declare -a INTEGRATIONS
+
+for manifestfile in $(find $GITHUB_WORKSPACE -type f -name manifest.json); do
+    INTEGRATIONS+=(--integration-path)
+    INTEGRATIONS+=("$(dirname -- ${manifestfile})")
+done
+
+if [ "${INTEGRATIONS}" = "" ]; then
+    echo "No integrations found!"
+    exit 1
+fi
+echo "${INTEGRATIONS[@]}"
+python3 -m script.hassfest --action validate "${INTEGRATIONS[@]}"