Ecosyste.ms: Awesome
An open API service indexing awesome lists of open source software.
https://github.com/leodido/caddy-jsonselect-encoder
Pick what to log in JSON format
https://github.com/leodido/caddy-jsonselect-encoder
caddy encoder format formatter json logging output parse select
Last synced: 2 months ago
JSON representation
Pick what to log in JSON format
- Host: GitHub
- URL: https://github.com/leodido/caddy-jsonselect-encoder
- Owner: leodido
- License: apache-2.0
- Created: 2021-07-16T10:54:55.000Z (over 3 years ago)
- Default Branch: main
- Last Pushed: 2022-06-03T22:17:37.000Z (over 2 years ago)
- Last Synced: 2024-05-09T20:25:47.590Z (8 months ago)
- Topics: caddy, encoder, format, formatter, json, logging, output, parse, select
- Language: Go
- Homepage:
- Size: 144 KB
- Stars: 7
- Watchers: 2
- Forks: 0
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# caddy-jsonselect-encoder
> Select what you want to log
By using a selector you can choose what (and how) you want to emit your JSON logs.
## Module
The **module name** is `jsonselect`.
Its syntax is:
```caddyfile
jsonselect {
message_key
level_key
time_key
name_key
caller_key
stacktrace_key
line_ending
time_format
level_format
}
```
### Selector
A selector represents the JSON path of the log entry you want to select.
The syntax is heavily inspired by [buger/jsonparser](https://github.com/buger/jsonparser). With some additions...
So, you can write a selector like the following one to only output the HTTP status code and the logger name:
```caddyfile
{status} {logger}
```
Or you can even select deeper in the JSON log entry:
```caddyfile
{request>host} {request>method}
```
The resulting JSON will respect the hierarchy of the selector paths.
Thus, for a selector like `{request>method}` the resulting JSON log entry will look like this:
```json
{"request":{"method":"GET"}}
```
Notice that the parsing of selectors happens at provisioning time to do not impact encoding performances.
Finally, I extended the syntax to support the reshaping of the resulting JSON keys.
To define a key for a given selector, you can use the following syntax:
```caddyfile
{key:selector}
```
For example, to store the status of a log entry in a `httpRequest.responseStatus` JSON path you can write:
```caddyfile
{httpResponse>responseStatus:status}
```
Which will output the following JSON:
```json
{"httpRequest":{"responseStatus":404}}
```
This is particularly useful to adapt your log entries to different JSON structures like the Stackdriver one.
## Caddyfile
Log a JSON containing only the level, the timestamp, and the message of the log entry.
Also, use "mex" as a key for the message.
```console
log {
output stdout
format jsonselect "{level} {ts} {mex}" {
message_key mex
}
}
```
This will output:
```json
{"level":"info","ts":1626453781.3333929,"mex":"handled request"}
```
Log the host of the request and the duration:
```caddyfile
log {
output stdout
format jsonselect "{request>host} {duration}"
}
```
Which outputs something like the following JSON respecting the selector's path structure:
```json
{"request":{"host":"localhost:2015"},"duration":0.003321}
```
Maybe you wanna log for Stackdriver ...
```caddyfile
log {
format jsonselect "{severity} {timestamp} {logName}" {
level_key "severity"
level_format "upper"
time_key "timestamp"
time_format "rfc3339"
name_key "logName"
}
}
```
This outputs:
```json
{"severity":"ERROR","timestamp":"2021-07-16T12:55:10Z","logName":"http.log.access.log0"}
```
Even more, you can define keys for the resulting output to better match the [Stackdriver log entry format](https://cloud.google.com/logging/docs/reference/v2/rest/v2/LogEntry).
Like this:
```caddyfile
log {
format jsonselect "{severity:level} {timestamp:ts} {httpRequest>requestMethod:request>method} {httpRequest>protocol:request>proto} {httpRequest>status:status} {httpRequest>responseSize:size} {httpRequest>userAgent:request>headers>User-Agent>[0]}" {
time_format "rfc3339_nano"
level_format "upper"
}
}
```
Which outputs:
```json
{"severity":"INFO","timestamp":"2021-07-19T14:48:56.262966Z","httpRequest":{"protocol":"HTTP/2.0","requestMethod":"GET","responseSize":17604,"status":200,"userAgent":"Mozilla/5.0 ..."}}
```
## Try it out
From the root directoy of this project, run:
```console
xcaddy run
```
Then open , go on existing and non-existing pages, and observe the access logs.
To install xcaddy in case you need to, run:
```console
go get -u github.com/caddyserver/xcaddy/cmd/xcaddy
```
## Build
To build [Caddy](https://github.com/caddyserver/caddy) with this module in, execute:
```console
xcaddy build --with github.com/leodido/caddy-jsonselect-encoder
```
---
[](https://github.com/igrigorik/ga-beacon)