Make a Fluentd sidecar image and example for sending logs from within a

pod's filesystem to Elasticsearch, copying liberally from the GCP version.

contrib/logging/fluentd-sidecar-gcp/Dockerfile

@@ -4,7 +4,7 @@
 # The environment variable that controls which log files are collected is
 # FILES_TO_COLLECT. Files specified in the environment variable should be
 # separated by whitespace, as in "/var/log/syslog /var/log/nginx/access.log".
-# This configuration assumes that the host performning the collection is a VM
+# This configuration assumes that the host performing the collection is a VM
 # that has been created with a logging.write scope and that the Logging API
 # has been enabled for the project in the Google Developer Console. 
 

contrib/logging/fluentd-sidecar-gcp/README.md

@@ -1,4 +1,6 @@
-# Collecting log files from within containers with Fluentd and sending to the Google Cloud Logging service.
+# Collecting log files from within containers with Fluentd and sending them to the Google Cloud Logging service.
+*Note that this only works for clusters running on GCE and whose VMs have the cloud-logging.write scope. If your cluster is logging to Elasticsearch instead, see [this guide](/contrib/logging/fluentd-sidecar-es/) instead.*
+
 This directory contains the source files needed to make a Docker image that collects log files from arbitrary files within a container using [Fluentd](http://www.fluentd.org/) and sends them to GCP.
 The image is designed to be used as a sidecar container as part of a pod.
 It lives in the Google Container Registry under the name `gcr.io/google_containers/fluentd-sidecar-gcp`.

contrib/logging/fluentd-sidecar-gcp/logging-sidecar-example.yaml

@@ -1,11 +1,11 @@
 apiVersion: v1beta3
 kind: Pod
-metadata: 
-  labels: 
+metadata:
+  labels:
     example: logging-sidecar
   name: logging-sidecar-example
-spec: 
-  containers: 
+spec:
+  containers:
   - name: synthetic-logger
     image: ubuntu:14.04
     command: ["bash", "-c", "i=\"0\"; while true; do echo \"`hostname`: $i \" >> /var/log/synthetic-count.log; date --rfc-3339 ns >> /var/log/synthetic-dates.log; sleep 4; i=$[$i+1]; done"]