The enrich key field is being kept track in _meta field by the policy runner.
The ingest processor uses the field name defined in enrich index _meta field and
not in the policy. This will avoid problems if policy is changed without
a new enrich index being created.
This also complete decouples EnrichPolicy from ExactMatchProcessor.
The following scenario results in failure without this change:
1) Create policy
2) Execute policy
3) Create pipeline with enrich processor
4) Use pipeline
5) Update enrich key in policy
6) Use pipeline, which then fails.
The enrich processor performs a lookup in a locally allocated
enrich index shard using a field value from the document being enriched.
If there is a match then the _source of the enrich document is fetched.
The document being enriched then gets the decorate values from the
enrich document based on the configured decorate fields in the pipeline.
Note that the usage of the _source field is temporary until the enrich
source field that is part of #41521 is merged into the enrich branch.
Using the _source field involves significant decompression which not
desired for enrich use cases.
The policy contains the information what field in the enrich index
to query and what fields are available to decorate a document being
enriched with.
The enrich processor has the following configuration options:
* `policy_name` - the name of the policy this processor should use
* `enrich_key` - the field in the document being enriched that holds to lookup value
* `ignore_missing` - Whether to allow the key field to be missing
* `enrich_values` - a list of fields to decorate the document being enriched with.
Each entry holds a source field and a target field.
The source field indicates what decorate field to use that is available in the policy.
The target field controls the field name to use in the document being enriched.
The source and target fields can be the same.
Example pipeline config:
```
{
"processors": [
{
"policy_name": "my_policy",
"enrich_key": "host_name",
"enrich_values": [
{
"source": "globalRank",
"target": "global_rank"
}
]
}
]
}
```
In the above example documents are being enriched with a global rank value.
For each document that has match in the enrich index based on its host_name field,
the document gets an global rank field value, which is fetched from the `globalRank`
field in the enrich index and saved as `global_rank` in the document being enriched.
This is PR is part one of #41521
move put policy api yaml test to this rest module.
The main benefit is that all tests will then be run when running:
`./gradlew -p x-pack/plugin/enrich check`
The rest qa module starts a node with default distribution and basic
license.
This qa module will also be used for adding different rest tests (not yaml),
for example rest tests needed for #41532
Also when we are going to work on security integration then we can
add a security qa module under the qa folder. Also at some point
we should add a multi node qa module.
