define-alpine-the-sequel/software/fluentbit.ts

import { constants, copyFile } from "node:fs/promises";
import { join } from "node:path";
import { Alpine } from "../alpine.js";
import { buildRepro, reproRun } from "../helpers/repro-run.js";

const parsersPath = "/etc/fluent-bit/parsers.conf";

export async function installFluentBit(alpine: Alpine): Promise<void> {
  const bin = await buildFluentBit();
  await saveParsers(alpine);
  await alpine.addPackages(["musl-fts", "yaml"]);
  await copyFile(
    bin,
    alpine.path("/usr/local/bin/fluent-bit"),
    constants.COPYFILE_FICLONE
  );
}

// ## Script generators

// Returns a logScript to be used with runit for logging to Loki
export function runitLokiLogger(parser: FluentBitParser, name: string): string {
  return `#!/bin/sh
exec chpst -u nobody:nobody /usr/local/bin/fluent-bit \
  --parser='${parsersPath}' \
  --input=stdin \
    --prop=parser='${parser}' \
  --output=loki \
    --prop=labels='job=fluentbit,stream=${name}'
`;
}

// ## Parsers

export enum FluentBitParser {
  Json = "json",
  Logfmt = "logfmt",
  // Raw toma todo lo que haya en una línea y lo guarda en `message`. No recomendado.
  Raw = "raw",

  Forgejo = "forgejo",
  Ntpsec = "ntpsec",
  Dhcpcd = "dhcpcd",
}

async function saveParsers(alpine: Alpine): Promise<void> {
  // https://github.com/fluent/fluent-bit/blob/master/conf/parsers.conf
  await alpine.writeFile(
    parsersPath,
    // https://rubular.com/
    `
[PARSER]
    name logfmt
    format logfmt

[PARSER]
    name raw
    format regex
    regex ^(?<message>.*?)$

[PARSER]
    name forgejo
    format regex
    regex ^((?<time>\\d{4}\\/\\d{2}\\/\\d{2} \\d{2}:\\d{2}:\\d{2}?) )?((?<trace>.+:.+:.+\\(\\)?) \\[(?<level>.?)\\] )?(?<message>.*?)$

[PARSER]
    name ntpsec
    format regex
    regex ^(?<time>\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}) (?<process>.+\\[\\d+\\]): (?<component>\\w+): (?<message>.+)$

[PARSER]
    name dhcpcd
    format regex
    regex ^((?<interface>\\w+): )?(?<message>.+)$
`
  );
}

// ## Build binary

function buildFluentBit(): Promise<string> {
  const version = "v2.0.9";
  return buildRepro(
    "fluentbit",
    version,
    `#!/bin/sh -e
runprint() {
  echo "==> $@"
  "$@"
}

runprint apk add --quiet \
    make gcc g++ patch musl-dev openssl-dev linux-headers \
    bison cmake flex musl-fts-dev gtest-dev yaml-dev zlib-dev

wget https://github.com/fluent/fluent-bit/archive/refs/tags/${version}.tar.gz -O- | tar zx
cd fluent-bit-*

patch --strip=1 <<'EOF'
--- a/lib/chunkio/src/CMakeLists.txt
+++ b/lib/chunkio/src/CMakeLists.txt
@@ -12,6 +12,7 @@
   )
 
 set(libs cio-crc32)
+set(libs \${libs} fts)
 
 if(\${CMAKE_SYSTEM_NAME} MATCHES "Windows")
   set(src
EOF
    
runprint cmake -B build \
	-DFLB_CORO_STACK_SIZE=24576 \
	.
runprint make -C build

ls build/bin/

mv build/bin/fluent-bit /fluent-bit
`,
    (dir) =>
      reproRun({
        cwd: dir,
        command: "/src/build",
        cache: [],
      }),
    (dir) => join(dir, "rootfs/fluent-bit")
  );
}