Nest
The Nest Filter plugin allows you to operate on or with nested data. Its modes of operation are
nest- Take a set of records and place them in a maplift- Take a map by key and lift its records up
As an example using JSON notation, to nest keys matching the
Wildcard value Key* under a new key NestKey the transformation becomes,Example (input)
{
"Key1" : "Value1",
"Key2" : "Value2",
"OtherKey" : "Value3"
}
Example (output)
{
"OtherKey" : "Value3"
"NestKey" : {
"Key1" : "Value1",
"Key2" : "Value2",
}
}
As an example using JSON notation, to lift keys nested under the
Nested_under value NestKey* the transformation becomes,Example (input)
{
"OtherKey" : "Value3"
"NestKey" : {
"Key1" : "Value1",
"Key2" : "Value2",
}
}
Example (output)
{
"Key1" : "Value1",
"Key2" : "Value2",
"OtherKey" : "Value3"
}
The plugin supports the following configuration parameters:
Key | Value Format | Operation | Description |
|---|---|---|---|
Operation | ENUM [ nest or lift] | | Select the operation nest or lift |
Wildcard | FIELD WILDCARD | nest | Nest records which field matches the wildcard |
Nest_under | FIELD STRING | nest | Nest records matching the Wildcard under this key |
Nested_under | FIELD STRING | lift | Lift records nested under the Nested_under key |
Add_prefix | FIELD STRING | ANY | Prefix affected keys with this string |
Remove_prefix | FIELD STRING | ANY | Remove prefix from affected keys if it matches this string |
In order to start filtering records, you can run the filter from the command line or through the configuration file. The following invokes the Memory Usage Input Plugin, which outputs the following (example),
[0] memory: [1488543156, {"Mem.total"=>1016044, "Mem.used"=>841388, "Mem.free"=>174656, "Swap.total"=>2064380, "Swap.used"=>139888, "Swap.free"=>1924492}]
Note: Using the command line mode requires quotes parse the wildcard properly. The use of a configuration file is recommended.
The following command will load the mem plugin. Then the nest filter will match the wildcard rule to the keys and nest the keys matching
Mem.* under the new key NEST.$ bin/fluent-bit -i mem -p 'tag=mem.local' -F nest -p 'Operation=nest' -p 'Wildcard=Mem.*' -p 'Nest_under=Memstats' -p 'Remove_prefix=Mem.' -m '*' -o stdout
[INPUT]
Name mem
Tag mem.local
[OUTPUT]
Name stdout
Match *
[FILTER]
Name nest
Match *
Operation nest
Wildcard Mem.*
Nest_under Memstats
Remove_prefix Mem.
The output of both the command line and configuration invocations should be identical and result in the following output.
[2018/04/06 01:35:13] [ info] [engine] started
[0] mem.local: [1522978514.007359767, {"Swap.total"=>1046524, "Swap.used"=>0, "Swap.free"=>1046524, "Memstats"=>{"total"=>4050908, "used"=>714984, "free"=>3335924}}]
This example nests all
Mem.* and Swap,* items under the Stats key and then reverses these actions with a lift operation. The output appears unchanged.[INPUT]
Name mem
Tag mem.local
[OUTPUT]
Name stdout
Match *
[FILTER]
Name nest
Match *
Operation nest
Wildcard Mem.*
Wildcard Swap.*
Nest_under Stats
Add_prefix NESTED
[FILTER]
Name nest
Match *
Operation lift
Nested_under Stats
Remove_prefix NESTED
[2018/06/21 17:42:37] [ info] [engine] started (pid=17285)
[0] mem.local: [1529566958.000940636, {"Mem.total"=>8053656, "Mem.used"=>6940380, "Mem.free"=>1113276, "Swap.total"=>16532988, "Swap.used"=>1286772, "Swap.free"=>15246216}]
This example takes the keys starting with
Mem.* and nests them under LAYER1, which itself is then nested under LAYER2, which is nested under LAYER3.[INPUT]
Name mem
Tag mem.local
[OUTPUT]
Name stdout
Match *
[FILTER]
Name nest
Match *
Operation nest
Wildcard Mem.*
Nest_under LAYER1
[FILTER]
Name nest
Match *
Operation nest
Wildcard LAYER1*
Nest_under LAYER2
[FILTER]
Name nest
Match *
Operation nest
Wildcard LAYER2*
Nest_under LAYER3
[0] mem.local: [1524795923.009867831, {"Swap.total"=>1046524, "Swap.used"=>0, "Swap.free"=>1046524, "LAYER3"=>{"LAYER2"=>{"LAYER1"=>{"Mem.total"=>4050908, "Mem.used"=>1112036, "Mem.free"=>2938872}}}}]
{
"Swap.total"=>1046524,
"Swap.used"=>0,
"Swap.free"=>1046524,
"LAYER3"=>{
"LAYER2"=>{
"LAYER1"=>{
"Mem.total"=>4050908,
"Mem.used"=>1112036,
"Mem.free"=>2938872
}
}
}
}
This example starts with the 3-level deep nesting of Example 2 and applies the
lift filter three times to reverse the operations. The end result is that all records are at the top level, without nesting, again. One prefix is added for each level that is lifted.[INPUT]
Name mem
Tag mem.local
[OUTPUT]
Name stdout
Match *
[FILTER]
Name nest
Match *
Operation nest
Wildcard Mem.*
Nest_under LAYER1
[FILTER]
Name nest
Match *
Operation nest
Wildcard LAYER1*
Nest_under LAYER2
[FILTER]
Name nest
Match *
Operation nest
Wildcard LAYER2*
Nest_under LAYER3
[FILTER]
Name nest
Match *
Operation lift
Nested_under LAYER3
Add_prefix Lifted3_
[FILTER]
Name nest
Match *
Operation lift
Nested_under Lifted3_LAYER2
Add_prefix Lifted3_Lifted2_
[FILTER]
Name nest
Match *
Operation lift
Nested_under Lifted3_Lifted2_LAYER1
Add_prefix Lifted3_Lifted2_Lifted1_
[0] mem.local: [1524862951.013414798, {"Swap.total"=>1046524, "Swap.used"=>0, "Swap.free"=>1046524, "Lifted3_Lifted2_Lifted1_Mem.total"=>4050908, "Lifted3_Lifted2_Lifted1_Mem.used"=>1253912, "Lifted3_Lifted2_Lifted1_Mem.free"=>2796996}]
{
"Swap.total"=>1046524,
"Swap.used"=>0,
"Swap.free"=>1046524,
"Lifted3_Lifted2_Lifted1_Mem.total"=>4050908,
"Lifted3_Lifted2_Lifted1_Mem.used"=>1253912,
"Lifted3_Lifted2_Lifted1_Mem.free"=>2796996
}
Last modified 2mo ago