1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
|
---
title: Tagged logging
layout: gem-single
name: dry-logger
---
Tags allow you to mark log entries within a specific block, useful for grouping related operations or marking logs from specific components.
## Basic tagging
```ruby
logger = Dry.Logger(:my_app,
template: "[%<tags>s] %<message>s %<payload>s"
)
logger.tagged(:database) do
logger.info("Connection opened", pool_size: 5)
logger.info("Query executed", duration_ms: 23)
end
# [database] Connection opened pool_size=5
# [database] Query executed duration_ms=23
logger.info("Outside tagged block")
# [] Outside tagged block
```
## Multiple tags
```ruby
logger.tagged(:api, :production) do
logger.info("Request processed")
end
# [api production] Request processed
```
## Hash tags
Tags can be hashes for structured tagging:
```ruby
logger.tagged(component: "auth", version: "v2") do
logger.info("Authentication attempt")
end
# [component="auth" version="v2"] Authentication attempt
```
## Mixing tag types
```ruby
logger.tagged(:production, component: "database") do
logger.info("Slow query", duration_ms: 500)
end
# [production component="database"] Slow query duration_ms=500
```
## Filtering by tags
Tags are particularly powerful when combined with conditional logging:
```ruby
logger = Dry.Logger(:my_app, context: {}) do |setup|
# Only log database operations to this file
setup.add_backend(
stream: "logs/database.log",
log_if: -> (entry) { entry.tag?(:database) }
)
# Only log API operations to this file
setup.add_backend(
stream: "logs/api.log",
log_if: -> (entry) { entry.tag?(:api) }
)
# Everything goes to main log
setup.add_backend(stream: "logs/all.log")
end
logger.tagged(:database) do
logger.info("Query executed") # Goes to database.log and all.log
end
logger.tagged(:api) do
logger.info("Request received") # Goes to api.log and all.log
end
logger.info("General message") # Only goes to all.log
```
## Nested tags
Tags only apply within their block and don't nest:
```ruby
logger.tagged(:outer) do
logger.info("Outer") # [outer]
logger.tagged(:inner) do
logger.info("Inner") # [inner] (not [outer inner])
end
logger.info("Outer again") # [outer]
end
```
|
