From cae4538b3e9cab8f9e5fd972f6c35eb4b002014d Mon Sep 17 00:00:00 2001
From: Matthias Rampke <mr@soundcloud.com>
Date: Fri, 1 Dec 2017 18:26:06 +0100
Subject: [PATCH] Docs: state that all regular expressions are RE2. (#3518)

We already mentioned that regular expressions are RE2 for
[relabeling][0], but left open what the regular expression syntax
anywhere else is.

In the querying examples and reference, make it explicit that _all_
regular expressions are RE2.

[0]: https://prometheus.io/docs/prometheus/latest/configuration/configuration/#relabel_config
---
 docs/querying/basics.md   | 3 +++
 docs/querying/examples.md | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/docs/querying/basics.md b/docs/querying/basics.md
index 062e2fe20..65798b74f 100644
--- a/docs/querying/basics.md
+++ b/docs/querying/basics.md
@@ -116,6 +116,9 @@ The following expression selects all metrics that have a name starting with `job
 
     {__name__=~"job:.*"}
 
+All regular expressions in Prometheus use [RE2
+syntax](https://github.com/google/re2/wiki/Syntax).
+
 ### Range Vector Selectors
 
 Range vector literals work like instant vector literals, except that they
diff --git a/docs/querying/examples.md b/docs/querying/examples.md
index 589d6bbca..5827ca5eb 100644
--- a/docs/querying/examples.md
+++ b/docs/querying/examples.md
@@ -31,6 +31,9 @@ Note that this does a substring match, not a full string match:
 
     http_requests_total{job=~".*server"}
 
+All regular expressions in Prometheus use [RE2
+syntax](https://github.com/google/re2/wiki/Syntax).
+
 To select all HTTP status codes except 4xx ones, you could run:
 
     http_requests_total{status!~"4.."}