Remove unassigned Graylog2 index/shards with Bash in a loop - bash

Question

There were some disk issues on a Graylog2 server I use for debug logs. There are unassigned shards now:
curl -XGET http://host:9200/_cat/shards
graylog_292 1 p STARTED 751733 648.4mb 127.0.1.1 Doctor Leery
graylog_292 1 r UNASSIGNED
graylog_292 2 p STARTED 756663 653.2mb 127.0.1.1 Doctor Leery
graylog_292 2 r UNASSIGNED
graylog_290 0 p STARTED 299059 257.2mb 127.0.1.1 Doctor Leery
graylog_290 0 r UNASSIGNED
graylog_290 3 p STARTED 298759 257.1mb 127.0.1.1 Doctor Leery
graylog_290 3 r UNASSIGNED
graylog_290 1 p STARTED 298314 257.3mb 127.0.1.1 Doctor Leery
graylog_290 1 r UNASSIGNED
graylog_290 2 p STARTED 297722 257.1mb 127.0.1.1 Doctor Leery
graylog_290 2 r UNASSIGNED
....
It's over 400 shards. I can delete them without data loss, because it's a single node setup. In order to do this I need to loop over the index (graylog_xxx) and over the shard (1,2,...).
How do I loop over this (2 variables) with Bash? There are 2 variables for the deletion API call, which I need to replace (afaik):
curl -XPOST 'host:9200/_cluster/reroute' -d '{
"commands" : [ {
"allocate" : {
"index" : "$index",
"shard" : $shard,
"node" : "Doctor Leery",
"allow_primary" : true
}
}
]
}'
What also bothers me about this is, that the unassigned shards have no node. But in the API call I need to specify one.

Answer 1

Form the _cat/shards output you shared, it simply looks like those are unassigned replicas, which you can simply remove by updating the cluster settings and setting the replica count to 0, like this:
curl -XPUT 'localhost:9200/_settings' -d '{
"index" : {
"number_of_replicas" : 0
}
}'
After running the above curl, your cluster will be green again.