Merge pull request #15379 from fionaliao/fix-migration-guide

docs: additional formatting fixes to 3.0 migration guide

docs/migration.md

@@ -18,26 +18,26 @@ This document offers guidance on migrating from Prometheus 2.x to Prometheus 3.0
   - `remote-write-receiver`
   - `new-service-discovery-manager`
   - `expand-external-labels`
-    Environment variable references `${var}` or `$var` in external label values 
+      - Environment variable references `${var}` or `$var` in external label values 
     are replaced according to the values of the current environment variables.  
-    References to undefined variables are replaced by the empty string.
+      - References to undefined variables are replaced by the empty string.
     The `$` character can be escaped by using `$$`.
   - `no-default-scrape-port`
-    Prometheus v3 will no longer add ports to scrape targets according to the 
+      - Prometheus v3 will no longer add ports to scrape targets according to the 
     specified scheme. Target will now appear in labels as configured.
-    If you rely on scrape targets like 
+      - If you rely on scrape targets like 
       `https://example.com/metrics` or `http://exmaple.com/metrics` to be 
       represented as `https://example.com/metrics:443` and 
       `http://example.com/metrics:80` respectively, add them to your target URLs
   - `agent`
-    Instead use the dedicated `--agent` CLI flag.
+      - Instead use the dedicated `--agent` CLI flag.
   - `auto-gomemlimit`
-    Prometheus v3 will automatically set `GOMEMLIMIT` to match the Linux 
+      - Prometheus v3 will automatically set `GOMEMLIMIT` to match the Linux 
       container memory limit. If there is no container limit, or the process is 
       running outside of containers, the system memory total is used. To disable 
       this, `--no-auto-gomemlimit` is available.
   - `auto-gomaxprocs`
-    Prometheus v3 will automatically set `GOMAXPROCS` to match the Linux 
+      - Prometheus v3 will automatically set `GOMAXPROCS` to match the Linux 
       container CPU quota. To disable this, `--no-auto-gomaxprocs` is available.
 
   Prometheus v3 will log a warning if you continue to pass these to 
@@ -62,17 +62,13 @@ This document offers guidance on migrating from Prometheus 2.x to Prometheus 3.0
 
 - The `.` pattern in regular expressions in PromQL matches newline characters. 
   With this change a regular expressions like `.*` matches strings that include 
-  `\n`. This applies to matchers in queries and relabel configs. For example the 
-  following regular expressions now match the accompanying strings, whereas in 
-  Prometheus v2 these combinations didn't match.
-
-  | Regex      | Additional matches  |
-  | -----      | ------              |
-  | ".*"       | "foo\n", "Foo\nBar" |
-  | "foo.?bar" | "foo\nbar"          |
-  | "foo.+bar" | "foo\nbar"          |
-
-  If you want Prometheus v3 to behave like v2 did, you will have to change your 
+  `\n`. This applies to matchers in queries and relabel configs.
+  - For example, the following regular expressions now match the accompanying
+  strings, whereas in Prometheus v2 these combinations didn't match.
+      - `.*` additionally matches `foo\n` and `Foo\nBar`
+      - `foo.?bar` additionally matches `foo\nbar`
+      - `foo.+bar` additionally matches `foo\nbar`
+  - If you want Prometheus v3 to behave like v2, you will have to change your
   regular expressions by replacing all `.` patterns with `[^\n]`, e.g.
   `foo[^\n]*`.
 - Lookback and range selectors are left open and right closed (previously left 
@@ -103,7 +99,7 @@ header was unparsable or unrecognised. This could lead to incorrect data being
 parsed in the scrape. Prometheus v3 will now fail the scrape in such cases.
 
 If a scrape target is not providing the correct Content-Type header the
-fallback protocol can be specified using the fallback_scrape_protocol
+fallback protocol can be specified using the `fallback_scrape_protocol`
 parameter. See [Prometheus scrape_config documentation.](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#scrape_config)
 
 This is a breaking change as scrapes that may have succeeded with Prometheus v2
@@ -157,6 +153,7 @@ scrape_configs:
 ### Log message format
 Prometheus v3 has adopted `log/slog` over the previous `go-kit/log`. This 
 results in a change of log message format. An example of the old log format is:
+
 ```
 ts=2024-10-23T22:01:06.074Z caller=main.go:627 level=info msg="No time or size retention was set so using the default time retention" duration=15d
 ts=2024-10-23T22:01:06.074Z caller=main.go:671 level=info msg="Starting Prometheus Server" mode=server version="(version=, branch=, revision=91d80252c3e528728b0f88d254dd720f6be07cb8-modified)"
@@ -165,6 +162,7 @@ ts=2024-10-23T22:01:06.074Z caller=main.go:677 level=info host_details="(Linux 5
 ```
 
 a similar sequence in the new log format looks like this:
+
 ```
 time=2024-10-24T00:03:07.542+02:00 level=INFO source=/home/user/go/src/github.com/prometheus/prometheus/cmd/prometheus/main.go:640 msg="No time or size retention was set so using the default time retention" duration=15d
 time=2024-10-24T00:03:07.542+02:00 level=INFO source=/home/user/go/src/github.com/prometheus/prometheus/cmd/prometheus/main.go:681 msg="Starting Prometheus Server" mode=server version="(version=, branch=, revision=7c7116fea8343795cae6da42960cacd0207a2af8)"