bdclark/telegraf-consul repository overview

⁠telegraf-consul Docker image

Docker image that runs Telegraf⁠ with its configuration driven via Consul-Template⁠.

⁠NOTE

This image currently uses a patched build of consul-template (included with this repo) due to https://github.com/hashicorp/consul-template/pull/749⁠. This fix has been merged but not yet released. The included binary is 0.16.0 plus the fix.

⁠Environment Variables

Use TELEGRAF_CONF_KEY to set the key prefix where the telegraf configuration will be found in Consul. If not set, telegraf will be used.

Also, you must set CONSUL_HTTP_ADDR in order for consul-template to render any templates when the container runs. Any supported consul-template environment variables can be used, such as:

• CONSUL_HTTP_ADDR
• CONSUL_HTTP_TOKEN
• CONSUL_HTTP_AUTH
• CONSUL_HTTP_SSL
• CONSUL_HTTP_SSL_VERIFY

⁠Supported Consul keys

• <conf_key>/global_tags/* - global tag key/value pairs
• <conf_key>/agent/* - any valid agent key/value pairs
• <conf_key>/inputs/<input_type>/<input_name>/* - telegraf input(s)*
• <conf_key>/inputs/<output_type>/<output_name>/* - telegraf outputs(s)*

The keys/values will be converted to a TOML telegraf config.

⁠Inputs/Output Configurations

Since telegraf inputs/outputs are actually arrays (can have multiple of each type) and Consul K/Vs are a map, an (arbitrary) name is required for each input/output for uniqueness and to "array-ify" them.

⁠Value Types

Since Consul basically stores everything as strings and values in the telegraf TOML config may require strings, values, or arrays, Consul KV values are converted as follows:

• any value matching True, true, False, false will be treated as Boolean
• any value that can be converted to float will be treated as numeric
• any value beginning with [ and ending with ] will be treated as an array
• any value matching {} will be treated as an empty map
• anything else will be string

⁠Example

The following example Consul keys/values:

KEY                                                  VALUE
telegraf/agent/omit_hostname                         true
telegraf/outputs/influxdb/1/urls                     ["http://1.1.1.1:8086"]
telegraf/inputs/mongodb/cluster1/servers             ["mongo1.example.com:27017"]
telegraf/inputs/mongodb/cluster1/gather_perdb_stats  true
telegraf/inputs/mongodb/cluster2/servers             ["1.2.3.4:27017"]
telegraf/inputs/mem/foo                              {}

Will generate the following effective telegraf.conf:

[agent]
omit_hostname = true

[[outputs.influxdb]]
urls = ["http://1.1.1.1:8086"]

[[inputs.mongodb]]
servers = ["mongo1.example.com:27017"]
gather_perdb_stats = true

[[inputs.mongodb]]
servers = ["1.2.3.4:27017"]

[[inputs.mem]] # empty - no config necessary