How to use FluentD as a buffer between Telegraf and InfluxDB - influxdb

Question

Is there any way to ship metrics gathered form Telegraf to FluentD, then into InfluxDB?
I know it's possible to write data from FluentD into InfluxDB; but how does one ship data from Telegraf into FluentD, basically using use FluentD as a buffer (as opposed to using Kafka or Redis)?

Answer 1

While it might be possible to do with FluentD using some of the available, although outdated output plugins, such as InfluxDB-Metrics, I couldn't get the plugin to work properly and it hasn't been updated in over six years, so it will probably not work with newer releases of FluentD.
Fluent Bit however, has an Influxdb output built right into it, so I was able to get it to work with that. The caveat is that it has no Telegraf plugin. So the solution I found was to setup a tcp input plugin in Fluent Bit, and set Telegraf to write JSON formatted data to it in it's output section.
The caveat of doing this, is that the JSON data is nested and not formatted properly for InfluxDB. The workaround is to use nest filters in Fluent Bit to 'lift' the nested data format, and re-format properly for InfluxDB.
Below is an example for disk-space, which is not a metric that is natively supported with Fluent Bit metrics but is natively supported with Telegraf:
#SET me=${HOST_HOSTNAME}
[INPUT] ## tcp recipe ## Collect data from telegraf
Name tcp
Listen 0.0.0.0
Port 5170
Tag telegraf.${me}
Chunk_Size 32
Buffer_Size 64
Format json
[FILTER] ## rename the three tags sent from Telegraf to prevent duplicates
Name modify
Match telegraf.*
Condition Key_Value_Equals name disk
Rename fields fieldsDisk
Rename name nameDisk
Rename tags tagsDisk
[FILTER] ## un-nest nested JSON formatted info under 'field' tag
Name nest
Match telegraf.*
Operation lift
Nested_under fieldsDisk
Add_prefix disk.
[FILTER] ## un-nest nested JSON formatted info under 'disk' tag
Name nest
Match telegraf.*
Operation lift
Nested_under tagsDisk
Add_prefix disk.
[OUTPUT] ## output properly formatted JSON info
Name influxdb
Match telegraf.*
Host influxdb.server.com
Port 8086
#HTTP_User whatever
#HTTP_Passwd whatever
Database telegraf.${me}
Sequence_Tag point_in_time
Auto_Tags On
NOTE: This is just a simple awkward config for my own proof of concept