add grafana-images capability

src/grafana.coffee

@@ -17,6 +17,8 @@
#   HUBOT_GRAFANA_S3_SECRET_ACCESS_KEY - Optional; Secret access key for S3
#   HUBOT_GRAFANA_S3_PREFIX - Optional; Bucket prefix (useful for shared buckets)
#   HUBOT_GRAFANA_S3_REGION - Optional; Bucket region (defaults to us-standard)
#   HUBOT_USE_GRAFANA_IMAGES - true|false, whether to use grafana-images
#   HUBOT_GRAFANA_IMAGES_HOST - The host where grafana images resides, e.g. 'http://grafana.example.com'
#
# Dependencies:
#   "knox": "^0.9.2"
@@ -41,6 +43,8 @@ module.exports = (robot) ->
  s3_prefix = process.env.HUBOT_GRAFANA_S3_PREFIX
  s3_region = 'us-standard'
  s3_region = process.env.HUBOT_GRAFANA_S3_REGION if process.env.HUBOT_GRAFANA_S3_REGION
  use_grafana_images = process.env.HUBOT_USE_GRAFANA_IMAGES
  grafana_images_host = if process.env.HUBOT_GRAFANA_IMAGES_HOST then process.env.HUBOT_GRAFANA_IMAGES_HOST else grafana_host

  # Get a specific dashboard with options
  robot.respond /(?:grafana|graph|graf) (?:dash|dashboard|db) ([A-Za-z0-9\-\:_]+)(.*)?/i, (msg) ->
@@ -135,7 +139,9 @@ module.exports = (robot) ->

          # Fork here for S3-based upload and non-S3
          if (s3_bucket && s3_access_key && s3_secret_key)
            fetchAndUpload msg, title, imageUrl, link  
            s3FetchAndUpload msg, title, imageUrl, link
          else if (use_grafana_images == "true")
            customFetchAndUpload msg, title, imageUrl, link
          else
            sendRobotResponse msg, title, imageUrl, link

@@ -166,6 +172,19 @@ module.exports = (robot) ->

      msg.send response

  # Show help text
  robot.respond /(?:grafana|graph|graf) help$/i, (msg) ->
    response = "grafana usage:\n"
    response += "  hubot graf list\n"
    response += "  hubot graf db cm-monitoring-default\n"
    response += "  hubot graf db cm-monitoring-default:8\n"
    response += "  hubot graf db cm-monitoring-default:swap\n"
    response += "  hubot graf db cm-monitoring-default now-12hr\n"
    response += "  hubot graf db cm-monitoring-default now-24hr now-12hr\n"
    response += "  hubot graf db cm-monitoring-default:8 now-8d now-1d\n"
    response += "  hubot graf db cm-monitoring-default:swap server=ncv-dashing now-1w\n"
    msg.send response

  # Handle generic errors
  sendError = (message, msg) ->
    robot.logger.error message
@@ -201,13 +220,40 @@ module.exports = (robot) ->
      data = JSON.parse(body)
      return callback(data)

  customFetchAndUpload = (msg, title, url, link) ->
    requestHeaders = {
      encoding: "utf8",
      Authorization: "Bearer #{grafana_api_key}",
      Accept: "application/json"
    }

    req_opts = {
      method: "POST",
      url: "#{grafana_images_host}/grafana-images",
      headers: requestHeaders,
      json: {
        imageUrl: url
      }
    }

    # post to grafana-images
    request req_opts, (err, res, json) ->
      robot.logger.debug "grafana-images POST: #{req_opts.url}, content-type[#{res.headers['content-type']}]"

      if res.statusCode == 200
        sendRobotResponse msg, title, json.pubImg, link
      else
        robot.logger.debug res
        robot.logger.error "Upload Error Code: #{res.statusCode}"
        msg.send "#{title} - [Access Error] - #{link}"

  # Pick a random filename
  uploadPath = () ->
  s3UploadPath = () ->
    prefix = s3_prefix || 'grafana'
    "#{prefix}/#{crypto.randomBytes(20).toString('hex')}.png"

  # Fetch an image from provided URL, upload it to S3, returning the resulting URL
  fetchAndUpload = (msg, title, url, link) ->
  s3FetchAndUpload = (msg, title, url, link) ->
    if grafana_api_key
        requestHeaders =
          encoding: null,
@@ -237,7 +283,7 @@ module.exports = (robot) ->
      'encoding'       : null
    }

    filename = uploadPath()
    filename = s3UploadPath()

    req = client.put(filename, headers)
    req.on 'response', (res) ->