fluentbit
This crate aims to build output plugins for Fluent-bit. It is based on the Go interface for writting output plugins.
This crate is still in heavy development. At this point, Multiple-instance plugin is not supported but it would be added very soon.
Hello World
A simple Hello world example which prints data to stdout, it involves following three steps:
- Create a struct/enum with the data you might use for processing the incoming buffer from Fluent-bit
- Implement the trait FLBPluginMethods for that struct/enum.
- After steps 1 and 2, call the macro create_boilerplate!() which will generate the boilerplate code that every plugin should have, taking care of the unsafe safe code and abstracting it into a safe Rust style. This macro will accept as an argument any type which implements the FLBPluginMethods trait
And that's all. Compile your plugin as a dynamic library by adding this line to your Cargo.toml
[lib]
crate-type=["cdylib"]
Another thing that is worth to mention is that Fluent-bit should be able to load Go plugins even though your plugin was written in Rust. To enable external plugins' support you have to compile Fluent-bit with Goland support, e.g:
$ cd build/
$ cmake -DFLB_DEBUG=On -DFLB_PROXY_GO=On ../
$ make
Once compiled, you can see a new option in the binary -e which stands for external plugin, e.g:
$ bin/fluent-bit -h
Usage: fluent-bit [OPTION]
Available Options
-c --config=FILE specify an optional configuration file
-d, --daemon run Fluent Bit in background mode
-f, --flush=SECONDS flush timeout in seconds (default: 5)
-i, --input=INPUT set an input
-m, --match=MATCH set plugin match, same as '-p match=abc'
-o, --output=OUTPUT set an output
-p, --prop="A=B" set plugin configuration property
-e, --plugin=FILE load an external plugin (shared lib)
...
Now here is a simple output plugin
extern crate fluentbit;
use fluentbit::*;
#[derive(Default)]
struct MyPluginDemo{
num_flushes: u32,
}
impl FLBPluginMethods for MyPluginDemo{
fn plugin_register(&mut self, info: &mut PluginInfo) -> FLBResult {
info.name = "rustout".into();
info.description = "It is a default description".into();
Ok(())
}
fn plugin_init(&mut self) -> FLBResult {
Ok(())
}
fn plugin_flush(&mut self, data: &[u8]) -> FLBResult {
println!("data: {:?}", data);
self.num_flushes += 1;
println!("FLUSH NUMBER {}", self.num_flushes);
Ok(())
}
fn plugin_exit(&mut self) -> FLBResult {
println!("exiting");
Ok(())
}
}
create_boilerplate!(MyPluginDemo::default());
Test your plugin:
cargo build --release
fluent-bit -e target/release/libexample.so -i cpu -o "rustout"
License
fluentbit is licensed under either
- Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
- MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)
at your option.
Contribution
Any kinds of contributions are welcome as a pull request.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in fluentbit by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.