Documentation
¶
Overview ¶
Package transformer provides the means to mutate a container as part of a skogul.Handler, before it is passed on to a Sender.
Index ¶
Constants ¶
This section is empty.
Variables ¶
var Auto skogul.ModuleMap
Auto maps names to Transformers to allow auto configuration
Functions ¶
This section is empty.
Types ¶
type Case ¶ added in v0.3.0
type Case struct {
When string `doc:"Used as a conditional statement on a field"`
Is string `doc:"Used for the specific value (string) of the stated metadata field"`
Transformers []*skogul.TransformerRef `doc:"The transformers to run when the defined conditional is true"`
}
Case requires a field ("when") and a value ("is") to match for the set of transformers to run
type Data ¶
type Data struct {
Set map[string]interface{} `doc:"Set data fields to specific values."`
Require []string `doc:"Require the pressence of these data fields."`
Flatten [][]string `doc:"Flatten nested structures down to the root level"`
FlattenSeparator string `` /* 137-byte string literal not displayed */
Remove []string `doc:"Remove these data fields."`
Ban []string `doc:"Fail if any of these data fields are present"`
}
Data enforces a set of rules on data in all metrics, potentially changing the metric data.
type Metadata ¶
type Metadata struct {
Set map[string]interface{} `doc:"Set metadata fields to specific values."`
Require []string `doc:"Require the pressence of these fields."`
ExtractFromData []string `doc:"Extract a set of fields from Data and add it to Metadata. Removes the original."`
Remove []string `doc:"Remove these metadata fields."`
Ban []string `doc:"Fail if any of these fields are present"`
}
Metadata enforces a set of rules on metadata in all metrics, potentially changing the metric metadata.
type Replace ¶ added in v0.2.0
type Replace struct {
Source string `doc:"Metadata key to read from."`
Destination string `` /* 222-byte string literal not displayed */
Regex string `doc:"Regular expression to match."`
Replacement string `doc:"Replacement text. Can also use $1, $2, etc to reference sub-matches. Defaults to empty string - remove matching items."`
// contains filtered or unexported fields
}
Replace executes a regular expression replacement of metric metadata.
type Split ¶
type Split struct {
Field []string `doc:"Split into multiple metrics based on this field (each field denotes the path to a nested object element)."`
Fail bool `` /* 140-byte string literal not displayed */
}
Split is the configuration for the split transformer
type Switch ¶ added in v0.3.0
type Switch struct {
Cases []Case `doc:"A list of switch cases "`
}
Switch is a wrapper for a list of cases
type Templater ¶
type Templater struct{}
Templater iterates over all Metrics in a Skogul Container and fills in any missing template variable from the Template in the Container, so noone else has to.
Skogul Templates are shallow:
{
"template": {
"metadata": {
"foo": "bar",
"geo": {
"country": "Norway"
}
}
},
"metrics": [
{
"timestamp": "...",
"metadata": {
"name": "john",
"geo": {
"city": "Oslo"
}
},
"data": ...
},
{
"timestamp": "...",
"metadata": {
"name": "fred",
"foo": "BANANA"
},
"data": ...
}
]
}
Will result in:
{
"metrics": [
{
"timestamp": "...",
"metadata": {
"name": "john",
"foo", "bar",
"geo": {
"city": "Oslo"
}
},
"data": ...
},
{
"timestamp": "...",
"metadata": {
"name": "fred",
"foo": "BANANA",
"geo": {
"country": "Norway"
}
},
"data": ...
}
]
}
The template just checked if "geo" was present in metadata or not - it did not merge missing keys.
It is good practice to use a template for any common fields, particularly timestamps.
type Timestamp ¶ added in v0.4.0
type Timestamp struct {
Source []string `doc:"The source field of the timestamp"`
Format string `doc:"The format to use (default: RFC3339)"`
Fail bool `doc:"Propagate errors back to the caller. Useful if the timestamp is required for the container."`
// contains filtered or unexported fields
}
Timestamp is the configuration for extracing a timestamp from inside the data
Source Files