out_loki: allow sending unquoted strings#8814
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This patch adds a third value to `drop_single_key` - `raw`, which allows sending unquoted strings to Loki when using JSON as the `line_format`. While yes, for the output to be valid JSON, quotes would be expected, Loki does not support reading a plain quoted string with its JSON parser, complaining that it cannot find a `}` character. Instead, you need to use a combination of regexp and line_format expressions to unquote the log before running any other parsers over it. By adding a third value of `raw`, this ensures backwards compatibility for anyone that is already relying on the existing behaviour. Signed-off-by: Andrew Titmuss <iandrewt@icloud.com>
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Relates to fluent/fluent-bit#8814 Signed-off-by: Andrew Titmuss <iandrewt@icloud.com>
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Relates to fluent/fluent-bit#8814 Signed-off-by: Andrew Titmuss <iandrewt@icloud.com>
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Relates to fluent/fluent-bit#8814 Signed-off-by: Andrew Titmuss <iandrewt@icloud.com> Signed-off-by: Tom <yao.lin@siemens.com>
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This patch adds a third value to
drop_single_key-raw, which allows sending unquoted strings to Loki when using JSON as theline_format.While yes, for the output to be valid JSON, quotes would be expected, Loki does not support reading a plain quoted string with its JSON parser, complaining that it cannot find a
}character. Instead, you need to use a combination of regexp and line_format expressions to unquote the log before running any other parsers over it.By adding a third value of
raw, this ensures backwards compatibility for anyone that is already relying on the existing behaviour.An example query before this change for plaintext logs, to remove the quotes:
This is necessary to add before any other parsing for non-JSON logs, such as using Loki's
logfmtparser, as it will otherwise drop the first and last key/value pair due to the extraneous quotes. Given Loki by design does not care about the input format (there's a reason JSON parsing is optional in the first place!), I do think this should be the default behavior some day, but given the breaking nature of the change, having it as an option for now should be fine.Addresses #4353, #3005
Testing
Before we can approve your change; please submit the following in a comment:
Note that I sent this to a fake http server instead of a Loki instance for testing, hence the 200 response. The HTTP body my server received was this:
{"streams":[{"stream":{"job":"fluent-bit"},"values":[["1715344552991602966","value"]]}]}If this is a change to packaging of containers or native binaries then please confirm it works for all targets.
ok-package-testlabel to test for all targets (requires maintainer to do).Documentation
fluent/fluent-bit-docs#1368
Backporting
Fluent Bit is licensed under Apache 2.0, by submitting this pull request I understand that this code will be released under the terms of that license.