原英文版地址: https://www.elastic.co/guide/en/elasticsearch/reference/7.7/conditionals-with-regex.html, 原文档版权归 www.elastic.co 所有
本地英文版地址: ../en/conditionals-with-regex.html
本地英文版地址: ../en/conditionals-with-regex.html
重要: 此版本不会发布额外的bug修复或文档更新。最新信息请参考 当前版本文档。
Conditionals with the Regular Expressionsedit
The if conditional is implemented as a Painless script, which requires
explicit support for regular expressions.
script.painless.regex.enabled: true must be set in elasticsearch.yml to use regular
expressions in the if condition.
If regular expressions are enabled, operators such as =~ can be used against a /pattern/ for conditions.
For example:
PUT _ingest/pipeline/check_url
{
"processors": [
{
"set": {
"if": "ctx.href?.url =~ /^http[^s]/",
"field": "href.insecure",
"value": true
}
}
]
}
POST test/_doc/1?pipeline=check_url
{
"href": {
"url": "http://www.elastic.co/"
}
}
Results in:
{
"_index": "test",
"_type": "_doc",
"_id": "1",
"_version": 1,
"_seq_no": 60,
"_primary_term": 1,
"found": true,
"_source": {
"href": {
"insecure": true,
"url": "http://www.elastic.co/"
}
}
}
Regular expressions can be expensive and should be avoided if viable alternatives exist.
For example in this case startsWith can be used to get the same result
without using a regular expression:
PUT _ingest/pipeline/check_url
{
"processors": [
{
"set": {
"if": "ctx.href?.url != null && ctx.href.url.startsWith('http://')",
"field": "href.insecure",
"value": true
}
}
]
}