feat(config): use LogDNA's env-config package

Replace current configuration with [@logdna/env-logdna](https://www.npmjs.com/package/@logdna/env-config)

Ref: #2
Semver: major

doc/env.md

@@ -0,0 +1,254 @@
+## Environment Variables
+
+### `BATCH_INTERVAL`
+
+> The number of milliseconds between sending each batch
+
+| Config | Value |
+| --- | --- |
+| Name | `batch-interval` |
+| Environment Variable | `BATCH_INTERVAL` |
+| Type | `number` |
+| Required | no |
+| Default | `50` |
+
+***
+
+### `BATCH_LIMIT`
+
+> The number of lines within each batch
+
+| Config | Value |
+| --- | --- |
+| Name | `batch-limit` |
+| Environment Variable | `BATCH_LIMIT` |
+| Type | `number` |
+| Required | no |
+| Default | `25` |
+
+***
+
+### `FREE_SOCKET_TIMEOUT`
+
+> The number of milliseconds to wait for inactivity before timing out
+
+| Config | Value |
+| --- | --- |
+| Name | `free-socket-timeout` |
+| Environment Variable | `FREE_SOCKET_TIMEOUT` |
+| Type | `number` |
+| Required | no |
+| Default | `300000` |
+
+***
+
+### `HOSTNAME`
+
+> Optionally, use alternative host name set through the environment
+
+| Config | Value |
+| --- | --- |
+| Name | `hostname` |
+| Environment Variable | `HOSTNAME` |
+| Type | `string` |
+| Required | no |
+| Default | `(none)` |
+
+***
+
+### `HTTP_PROXY`
+
+> An http:// proxy URL to pass through before going to LogDNA
+
+| Config | Value |
+| --- | --- |
+| Name | `http-proxy` |
+| Environment Variable | `HTTP_PROXY` |
+| Type | `string` |
+| Required | no |
+| Default | `(none)` |
+
+***
+
+### `HTTPS_PROXY`
+
+> A secure (https://) proxy URL to pass through before going to LogDNA
+
+| Config | Value |
+| --- | --- |
+| Name | `https-proxy` |
+| Environment Variable | `HTTPS_PROXY` |
+| Type | `string` |
+| Required | no |
+| Default | `(none)` |
+
+***
+
+### `INGESTION_ENDPOINT`
+
+> The endpoint for log ingestion at LogDNA
+
+| Config | Value |
+| --- | --- |
+| Name | `ingestion-endpoint` |
+| Environment Variable | `INGESTION_ENDPOINT` |
+| Type | `string` |
+| Required | no |
+| Default | `/logs/ingest` |
+
+***
+
+### `INGESTION_HOST`
+
+> The host for log ingestion
+
+| Config | Value |
+| --- | --- |
+| Name | `ingestion-host` |
+| Environment Variable | `INGESTION_HOST` |
+| Type | `string` |
+| Required | no |
+| Default | `logs.logdna.com` |
+
+***
+
+### `INGESTION_KEY`
+
+> LogDNA Ingestion Key to stream the logs from files
+
+| Config | Value |
+| --- | --- |
+| Name | `ingestion-key` |
+| Environment Variable | `INGESTION_KEY` |
+| Type | `string` |
+| Required | **yes** |
+| Default | `(none)` |
+
+***
+
+### `INGESTION_PORT`
+
+> The port for log ingestion
+
+| Config | Value |
+| --- | --- |
+| Name | `ingestion-port` |
+| Environment Variable | `INGESTION_PORT` |
+| Type | `number` |
+| Required | no |
+| Default | `443` |
+
+***
+
+### `MAX_REQUEST_RETRIES`
+
+> Maximum number of retries for sending each batch
+
+| Config | Value |
+| --- | --- |
+| Name | `max-request-retries` |
+| Environment Variable | `MAX_REQUEST_RETRIES` |
+| Type | `number` |
+| Required | no |
+| Default | `5` |
+
+***
+
+### `MAX_REQUEST_TIMEOUT`
+
+> Maximum request timeout in sending each batch
+
+| Config | Value |
+| --- | --- |
+| Name | `max-request-timeout` |
+| Environment Variable | `MAX_REQUEST_TIMEOUT` |
+| Type | `number` |
+| Required | no |
+| Default | `300` |
+
+***
+
+### `PROXY`
+
+> A full proxy URL (including protocol) to pass through before going to LogDNA
+
+| Config | Value |
+| --- | --- |
+| Name | `proxy` |
+| Environment Variable | `PROXY` |
+| Type | `string` |
+| Required | no |
+| Default | `(none)` |
+
+***
+
+### `REQUEST_RETRY_INTERVAL`
+
+> The number of milliseconds between each retry
+
+| Config | Value |
+| --- | --- |
+| Name | `request-retry-interval` |
+| Environment Variable | `REQUEST_RETRY_INTERVAL` |
+| Type | `number` |
+| Required | no |
+| Default | `100` |
+
+***
+
+### `SSL`
+
+> Use https:// for log ingestion
+
+| Config | Value |
+| --- | --- |
+| Name | `ssl` |
+| Environment Variable | `SSL` |
+| Type | `boolean` |
+| Required | no |
+| Default | `true` |
+
+***
+
+### `TAGS`
+
+> Optionally, use comma-separated tags set through the environment
+
+| Config | Value |
+| --- | --- |
+| Name | `tags` |
+| Environment Variable | `TAGS` |
+| Type | `string` |
+| Required | no |
+| Default | `(none)` |
+
+***
+
+### `URL`
+
+> *Combination of SSL, INGESTION_HOST, INGESTION_PORT, and INGESTION_ENDPOINT*
+
+| Config | Value |
+| --- | --- |
+| Name | `url` |
+| Environment Variable | `URL` |
+| Type | `string` |
+| Required | no |
+| Default | `https://logs.logdna.com/logs/ingest` |
+
+***
+
+### `USER_AGENT`
+
+> user-agent header value to use while sending logs
+
+| Config | Value |
+| --- | --- |
+| Name | `user-agent` |
+| Environment Variable | `USER_AGENT` |
+| Type | `string` |
+| Required | no |
+| Default | `logdna-s3/2.0.0` |
+
+***
+

index.js

@@ -2,36 +2,49 @@
 
 const async = require('async')
 
-const {getConfig} = require('./lib/config.js')
+const config = require('./lib/config.js')
 const {handleEvent} = require('./lib/event-handler.js')
 const {flush} = require('./lib/logger.js')
 const {getLogs, prepareLogs} = require('./lib/transformer.js')
 const {batchify, getProperty} = require('./lib/utils.js')
 
-const BATCH_INTERVAL = parseInt(process.env.LOGDNA_BATCH_INTERVAL) || 50
-const BATCH_LIMIT = parseInt(process.env.LOGDNA_BATCH_LIMIT) || 25
+const DOT_REGEXP = /\./g
 
 module.exports = {
   handler
 }
 
-function handler(event, context, callback) {
-  const config = getConfig(event)
+async function handler(event, context, callback) {
+  config.validateEnvVars()
+  const tags = config.get('tags')
+  if (tags) {
+    config.set('tags', tags.split(',').map((tag) => {
+      return tag.trim()
+    }).join(','))
+  }
+
   const eventData = handleEvent(event)
   const s3params = {
     Bucket: getProperty(eventData, 'meta.bucket.name')
   , Key: getProperty(eventData, 'meta.object.key')
   }
 
-  return getLogs(s3params, (error, lines) => {
-    if (error) return callback(error)
-
-    const logArrays = prepareLogs(lines, eventData)
-    const batches = batchify(logArrays, BATCH_LIMIT)
-    return async.everySeries(batches, (batch, next) => {
-      setTimeout(() => {
-        return flush(batch, config, next)
-      }, BATCH_INTERVAL)
-    }, callback)
-  })
+  let lines
+  try {
+    lines = getLogs(s3params)
+  } catch (e) {
+    return callback(e)
+  }
+
+  const logArrays = prepareLogs(lines, eventData)
+  const batches = batchify(logArrays, config.get('batch-limit'))
+  if (!config.get('hostname')) {
+    config.set('hostname', s3params.Bucket.replace(DOT_REGEXP, '_'))
+  }
+
+  async.everySeries(batches, (batch, next) => {
+    setTimeout(() => {
+      return flush(batch, config, next)
+    }, config.get('batch-interval'))
+  }, callback)
 }