feat: Helmfile composite GitHub actions (#7)

* feat: Helmfile composite GitHub actions

These are the scripts that ultimately make up a composite GitHub Action
for running helmfile while having status codes propagated in a more
intuitive way, on top of wrapping all of the edge cases for formatting
comment text back to a GH PR comment.

helmfile-actions/README.md

@@ -0,0 +1,35 @@
+# helmfile-actions
+
+There is a single `./main.sh` file that delegates down to other scripts based on the `command` that you pass in.
+
+## Inputs
+```yaml
+inputs:
+  command:
+    description: "The helmfile command to run"
+    required: true
+  working_directory:
+    description: "The directory to run all the commands in"
+    required: false
+    default: "."
+```
+
+## Examples
+Example usage of `helmfile diff`:
+```yaml
+- uses: iStreamPlanet/github-actions/helmfile-actions@main
+  if: github.event_name == 'pull_request'
+  env:
+    GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+  with:
+    command: diff
+    working_directory: helmfile/
+```
+
+Example usage of `helmfile apply`:
+```yaml
+- uses: iStreamPlanet/github-actions/helmfile-actions@main
+  with:
+    command: apply
+    working_directory: helmfile/
+```

helmfile-actions/action.yml

@@ -0,0 +1,19 @@
+name: "helmfile action"
+description: "A composite action wrapper around helmfile"
+inputs:
+  command:
+    description: "The helmfile command to run"
+    required: true
+  working_directory:
+    description: "The directory to run all the commands in"
+    required: false
+    default: "."
+outputs: {}
+runs:
+  using: "composite"
+  steps:
+    - name: helmfile
+      shell: bash
+      id: main
+      working-directory: ${{ inputs.working_directory }}
+      run: ${{ github.action_path }}/main.sh "${{ inputs.command }}" "${{ inputs.working_directory }}"

helmfile-actions/apply.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+
+function helmfileApply {
+  output=$(helmfile --no-color apply ${*} 2>&1)
+  exitCode=$?
+
+  if [ ${exitCode} -eq 0 ]; then
+    echo "Successfully ran helmfile apply command."
+  else
+    echo "Error: Failed to run helmfile diff"
+  fi
+
+  echo "${output}"
+  echo
+  exit ${exitCode}
+}

helmfile-actions/diff.sh

@@ -0,0 +1,61 @@
+#!/bin/bash
+
+function helmfileDiff {
+  output=$(helmfile --no-color diff --detailed-exitcode ${*} 2>&1)
+  exitCode=$?
+  hasChanges=false
+  commentStatus="Failed"
+
+  if [ ${exitCode} -eq 0 ]; then
+    echo "Successfully ran helmfile diff command. No changes were found"
+    echo "${output}"
+    echo
+    echo "::set-output name=has-changes::${hasChanges}"
+    exit ${exitCode}
+  fi
+
+  if [ ${exitCode} -eq 2 ]; then
+    # This should still be a success
+    exitCode=0
+    hasChanges=true
+    commentStatus="Success"
+
+    echo "Successfully ran helmfile diff command. Changes were found"
+    echo "${output}"
+    echo
+
+     # If output is longer than max length (65536 characters), keep last part
+    output=$(echo "${output}" | tail -c 65000 )
+  fi
+
+  if [ ${exitCode} -ne 0 ]; then
+    echo "Error: Failed to run helmfile diff"
+    echo "${output}"
+    echo
+  fi
+
+  if [ "$GITHUB_EVENT_NAME" == "pull_request" ] && ([ "${hasChanges}" == "true" ] || [ "${commentStatus}" == "Failed" ]); then
+    commentWrapper="#### \`helmfile diff\` ${commentStatus} for \`${workingDir}\`
+<details><summary>Show Output</summary>
+
+\`\`\`diff
+${output}
+\`\`\`
+
+</details>
+"
+
+    payload=$(echo "${commentWrapper}" | jq -R --slurp '{body: .}')
+    commentsURL=$(cat ${GITHUB_EVENT_PATH} | jq -r .pull_request.comments_url)
+    echo "${payload}" | curl -s -S -H "Authorization: token ${GITHUB_TOKEN}" --header "Content-Type: application/json" --data @- "${commentsURL}" > /dev/null
+  fi
+
+  echo "::set-output name=has-changes::${hasChanges}"
+
+  # https://github.community/t5/GitHub-Actions/set-output-Truncates-Multiline-Strings/m-p/38372/highlight/true#M3322
+  output="${output//'%'/'%25'}"
+  output="${output//$'\n'/'%0A'}"
+  output="${output//$'\r'/'%0D'}"
+  echo "::set-output name=output::${output}"
+  exit ${exitCode}
+}

helmfile-actions/main.sh

@@ -0,0 +1,29 @@
+#!/bin/bash
+
+if [ "$#" -ne 2 ]; then
+  echo 'Usage: ./main.sh $command $working_directory'
+  exit 1
+fi
+
+workingDir="$2"
+function main {
+  command="$1"
+  scriptDir=$(dirname ${0})
+  source ${scriptDir}/diff.sh
+  source ${scriptDir}/apply.sh
+
+  case "${command}" in
+    diff)
+      helmfileDiff
+      ;;
+    apply)
+      helmfileApply
+      ;;
+    *)
+      echo "Error: Unrecognized command ${command}"
+      exit 1
+      ;;
+  esac
+}
+
+main "$1"