Removes testing of Elasticsearch 6.x (#3667)

This stops testing Elasticsearch 6.x as Elastic themselves only support
7.x and 8.x. This also moves examples to use ES 8.x in preparation of
the next release.

Signed-off-by: Adrian Cole <adrian@tetrate.io>

README.md

@@ -129,7 +129,7 @@ Note: This store requires a [job to aggregate](https://github.com/openzipkin/zip
 
 ### Elasticsearch
 The [Elasticsearch](zipkin-server#elasticsearch-storage) component uses
-Elasticsearch 5+ features, but is tested against Elasticsearch 6-7.x.
+Elasticsearch 5+ features, but is tested against Elasticsearch 7-8.x.
 
 It stores spans as Zipkin v2 json so that integration with other tools is
 straightforward. To help with scale, this uses a combination of custom

docker/examples/README.md

@@ -54,7 +54,7 @@ $ docker-compose -f docker-compose-cassandra.yml run --rm --no-deps --entrypoint
 
 ## Elasticsearch
 
-You can store traces in [Elasticsearch](../test-images/zipkin-elasticsearch7/README.md) instead of memory,
+You can store traces in [Elasticsearch](../test-images/zipkin-elasticsearch8/README.md) instead of memory,
 using the `docker-compose-elasticsearch.yml` file. This configuration starts `zipkin`,
 `zipkin-elasticsearch` and `zipkin-dependencies` (cron job) in their own containers.
 

docker/examples/docker-compose-elasticsearch.yml

@@ -22,7 +22,7 @@ version: '2.4'
 
 services:
   storage:
-    image: ghcr.io/openzipkin/zipkin-elasticsearch7:${TAG:-latest}
+    image: ghcr.io/openzipkin/zipkin-elasticsearch8:${TAG:-latest}
     container_name: elasticsearch
     # Uncomment to expose the storage port for testing
     # ports:

zipkin-server/README.md

@@ -247,7 +247,7 @@ $ STORAGE_TYPE=cassandra3 java -jar zipkin.jar \
 
 ### Elasticsearch Storage
 Zipkin's [Elasticsearch storage component](../zipkin-storage/elasticsearch)
-supports versions 5-7.x and applies when `STORAGE_TYPE` is set to `elasticsearch`
+supports versions 7-8.x and applies when `STORAGE_TYPE` is set to `elasticsearch`
 
 The following apply when `STORAGE_TYPE` is set to `elasticsearch`:
 

zipkin-storage/elasticsearch/README.md

@@ -3,13 +3,13 @@
 This is a plugin to the Elasticsearch storage component, which uses
 HTTP by way of [Armeria](https://github.com/line/armeria) and
 [Jackson](https://github.com/FasterXML/jackson). This uses Elasticsearch 5+
-features, but is tested against Elasticsearch 6-7.x.
+features, but is tested against Elasticsearch 7-8.x.
 
 ## Multiple hosts
 Most users will supply a DNS name that's mapped to multiple A or AAAA
 records. For example, `http://elasticsearch:9200` will use normal host
 lookups to get the list of IP addresses, though you can alternatively supply
-a list of http base urls. In either case, all of the resolved IP addresses
+a list of http base urls. In either case, all the resolved IP addresses
 from all provided hosts will be iterated over round-robin, with requests made
 only to healthy addresses.