add README.md for redis

plugins/inputs/redis/README.md

+# Telegraf Plugin: Redis
+
+### Configuration:
+
+```
+# Read Redis's basic status information
+[[inputs.redis]]
+  ## specify servers via a url matching:
+  ##  [protocol://][:password]@address[:port]
+  ##  e.g.
+  ##    tcp://localhost:6379
+  ##    tcp://:password@192.168.99.100
+  ##
+  ## If no servers are specified, then localhost is used as the host.
+  ## If no port is specified, 6379 is used
+  servers = ["tcp://localhost:6379"]
+```
+
+### Measurements & Fields:
+
+- Measurement
+    - uptime_in_seconds
+    - connected_clients
+    - used_memory
+    - used_memory_rss
+    - used_memory_peak
+    - used_memory_lua
+    - rdb_changes_since_last_save
+    - total_connections_received
+    - total_commands_processed
+    - instantaneous_ops_per_sec
+    - instantaneous_input_kbps
+    - instantaneous_output_kbps
+    - sync_full
+    - sync_partial_ok
+    - sync_partial_err
+    - expired_keys
+    - evicted_keys
+    - keyspace_hits
+    - keyspace_misses
+    - pubsub_channels
+    - pubsub_patterns
+    - latest_fork_usec
+    - connected_slaves
+    - master_repl_offset
+    - repl_backlog_active
+    - repl_backlog_size
+    - repl_backlog_histlen
+    - mem_fragmentation_ratio
+    - used_cpu_sys
+    - used_cpu_user
+    - used_cpu_sys_children
+    - used_cpu_user_children
+
+### Tags:
+
+- All measurements have the following tags:
+    - port
+    - server
+
+### Example Output:
+
+Using this configuration:
+```
+[[inputs.nginx]]
+  ## specify servers via a url matching:
+  ##  [protocol://][:password]@address[:port]
+  ##  e.g.
+  ##    tcp://localhost:6379
+  ##    tcp://:password@192.168.99.100
+  ##
+  ## If no servers are specified, then localhost is used as the host.
+  ## If no port is specified, 6379 is used
+  servers = ["tcp://localhost:6379"]
+```
+
+When run with:
+```
+./telegraf -config telegraf.conf -input-filter redis -test
+```
+
+It produces:
+```
+* Plugin: redis, Collection 1
+> redis,port=6379,server=localhost clients=1i,connected_slaves=0i,evicted_keys=0i,expired_keys=0i,instantaneous_ops_per_sec=0i,keyspace_hitrate=0,keyspace_hits=0i,keyspace_misses=2i,latest_fork_usec=0i,master_repl_offset=0i,mem_fragmentation_ratio=3.58,pubsub_channels=0i,pubsub_patterns=0i,rdb_changes_since_last_save=0i,repl_backlog_active=0i,repl_backlog_histlen=0i,repl_backlog_size=1048576i,sync_full=0i,sync_partial_err=0i,sync_partial_ok=0i,total_commands_processed=4i,total_connections_received=2i,uptime=869i,used_cpu_sys=0.07,used_cpu_sys_children=0,used_cpu_user=0.1,used_cpu_user_children=0,used_memory=502048i,used_memory_lua=33792i,used_memory_peak=501128i,used_memory_rss=1798144i 1457052084987848383
+```

plugins/inputs/redis/redis.go

@@ -19,6 +19,7 @@ type Redis struct {
 }
 
 var sampleConfig = `
+[[inputs.redis]]
   ## specify servers via a url matching:
   ##  [protocol://][:password]@address[:port]
   ##  e.g.