Fix some codespell issues

See,
./README.md:164: plattform  ==> platform
./main.go:29: conains  ==> contains
./main.go:30: conains  ==> contains
./tls.go:12: irrelevent  ==> irrelevant
./examples/prometheus/elasticsearch.rules:1: filesytem  ==> filesystem

README.md

@@ -161,7 +161,7 @@ elasticsearch_exporter --help
 We provide examples for [Prometheus](http://prometheus.io) [alerts and recording rules](examples/prometheus/elasticsearch.rules) as well as an [Grafana](http://www.grafana.org) [Dashboard](examples/grafana/dashboard.json) and a [Kubernetes](http://kubernetes.io) [Deployment](examples/kubernetes/deployment.yml).
 
 The example dashboard needs the [node_exporter](https://github.com/prometheus/node_exporter) installed. In order to select the nodes that belong to the elastsearch cluster, we rely on a label `cluster`.
-Depending on your setup, it can derived from the plattform metadata:
+Depending on your setup, it can derived from the platform metadata:
 
 For example on [GCE](https://cloud.google.com)
 

examples/prometheus/elasticsearch.rules

@@ -1,4 +1,4 @@
-# calculate filesytem used and free percent
+# calculate filesystem used and free percent
 elasticsearch_filesystem_data_used_percent = 100 * (elasticsearch_filesystem_data_size_bytes - elasticsearch_filesystem_data_free_bytes) / elasticsearch_filesystem_data_size_bytes
 elasticsearch_filesystem_data_free_percent = 100 - elasticsearch_filesystem_data_used_percent
 

main.go

@@ -26,8 +26,8 @@ func main() {
 		esExportIndices      = flag.Bool("es.indices", false, "Export stats for indices in the cluster.")
 		esExportShards       = flag.Bool("es.shards", false, "Export stats for shards in the cluster (implies es.indices=true).")
 		esCA                 = flag.String("es.ca", "", "Path to PEM file that contains trusted CAs for the Elasticsearch connection.")
-		esClientPrivateKey   = flag.String("es.client-private-key", "", "Path to PEM file that conains the private key for client auth when connecting to Elasticsearch.")
-		esClientCert         = flag.String("es.client-cert", "", "Path to PEM file that conains the corresponding cert for the private key to connect to Elasticsearch.")
+		esClientPrivateKey   = flag.String("es.client-private-key", "", "Path to PEM file that contains the private key for client auth when connecting to Elasticsearch.")
+		esClientCert         = flag.String("es.client-cert", "", "Path to PEM file that contains the corresponding cert for the private key to connect to Elasticsearch.")
 		esInsecureSkipVerify = flag.Bool("es.ssl-skip-verify", false, "Skip SSL verification when connecting to Elasticsearch.")
 		logLevel             = flag.String("log.level", "info", "Sets the loglevel. Valid levels are debug, info, warn, error")
 		logFormat            = flag.String("log.format", "logfmt", "Sets the log format. Valid formats are json and logfmt")

tls.go

@@ -9,7 +9,7 @@ import (
 
 func createTLSConfig(pemFile, pemCertFile, pemPrivateKeyFile string, insecureSkipVerify bool) *tls.Config {
 	if insecureSkipVerify {
-		// pem settings are irrelevent if we're skipping verification anyway
+		// pem settings are irrelevant if we're skipping verification anyway
 		return &tls.Config{
 			InsecureSkipVerify: true,
 		}