我們一起聊聊自定義 OpenTelemetry Collector 容器鏡像
OpenTelemetry Collector 有兩個(gè)官方發(fā)行版：Core 和 Contrib。
- Core 發(fā)行版是 Collector 的基礎(chǔ)發(fā)行版，供 OTel 開(kāi)發(fā)人員進(jìn)行開(kāi)發(fā)和測(cè)試。它包含一組基本的擴(kuò)展、連接器、接收器、處理器和導(dǎo)出器。
- Contrib 發(fā)行版供非 OTel 開(kāi)發(fā)人員進(jìn)行實(shí)驗(yàn)和學(xué)習(xí)。它還擴(kuò)展了 Core 發(fā)行版，并包含由第三方（包括供應(yīng)商和個(gè)人社區(qū)成員）創(chuàng)建的組件，這些組件對(duì)整個(gè) OpenTelemetry 社區(qū)非常有用。
不管 Core 還是 Contrib 都不應(yīng)該成為你生產(chǎn)工作負(fù)載的一部分。僅僅使用 Core 本身太過(guò)簡(jiǎn)單，無(wú)法滿足組織的需求（盡管它提供的組件都是必須的）；雖然 Contrib 中提供的組件足夠全面，然而并不是說(shuō)每個(gè)組件都是你所需要的，太多冗余的組件顯得過(guò)于臃腫，還增大的攻擊面。
那如何選擇你所需的發(fā)行版呢？答案就是構(gòu)建自己的發(fā)行版?？梢允褂霉俜教峁┑拿麨?OpenTelemetry Collector Builder (OCB) 的工具來(lái)自定義附件。
安裝 OCB
ocb 是個(gè)簡(jiǎn)單的 CLI，支持 Window/Linux/macOS 以及 x86 和 arm64 平臺(tái)。我們可以從 release 頁(yè)面[1] 下載 ocb 的 binary。
curl -o ocb -sL https://github.com/open-telemetry/opentelemetry-collector/releases/download/cmd%2Fbuilder%2Fv0.95.0/ocb_0.95.0_linux_amd64
chmod +x ocb可以通過(guò) ./ocb help 查看使用方法。
還可以通過(guò) go install 來(lái)安裝。
go install go.opentelemetry.io/collector/cmd/builder@latest要構(gòu)建自己的發(fā)行版，需要使用下面的命令，通過(guò) --config 指定配置文件，也就是下面要介紹的構(gòu)建清單。
./ocb --config=builder-config.yaml如果不提供，會(huì)使用 默認(rèn)的清單文件[2]。既然我們是要構(gòu)建自己的發(fā)行版，那接來(lái)看看如何配置構(gòu)建清單。
構(gòu)建清單
構(gòu)建清單是對(duì) OpenTelemetry Collector 的描述，通常包含如下幾個(gè)部分：
- dist：發(fā)行版的基本信息
- receivers：集成的 receiver[3] 列表
- exporters：集成的 exporter[4] 列表
- extensions：集成的 extension[5] 列表
- processors：集成的 processor[6] 列表
- connectors：集成的 receiver[7] 列表
從 GitHub 倉(cāng)庫(kù)中可以找到 core 發(fā)行版的構(gòu)建清單[8]，我們可以基于該版本進(jìn)行裁剪（去掉 replace 的部分）。
dist:
module: go.opentelemetry.io/collector/cmd/otelcorecol
name: otelcorecol
description: Local OpenTelemetry Collector binary, testing only.
version: 0.95.0-dev
otelcol_version: 0.95.0
output_path: /tmp/dist
exporters:
- gomod: go.opentelemetry.io/collector/exporter/debugexporter v0.95.0
- gomod: go.opentelemetry.io/collector/exporter/loggingexporter v0.95.0
- gomod: go.opentelemetry.io/collector/exporter/otlpexporter v0.95.0
- gomod: go.opentelemetry.io/collector/exporter/otlphttpexporter v0.95.0
extensions:
- gomod: go.opentelemetry.io/collector/extension/ballastextension v0.95.0
- gomod: go.opentelemetry.io/collector/extension/memorylimiterextension v0.95.0
- gomod: go.opentelemetry.io/collector/extension/zpagesextension v0.95.0
processors:
- gomod: go.opentelemetry.io/collector/processor/batchprocessor v0.95.0
- gomod: go.opentelemetry.io/collector/processor/memorylimiterprocessor v0.95.0
connectors:
- gomod: go.opentelemetry.io/collector/connector/forwardconnector v0.95.0現(xiàn)在為 開(kāi)頭提到的文章[9] 中可以找到更多的組件。
dist:
module: go.opentelemetry.io/collector/cmd/otelcorecol
name: otelcorecol
description: Local OpenTelemetry Collector binary, testing only.
version: 0.95.0-dev
otelcol_version: 0.95.0
output_path: /tmp/dist
receivers:
- gomod: go.opentelemetry.io/collector/receiver/otlpreceiver v0.95.0
exporters:
- gomod: go.opentelemetry.io/collector/exporter/debugexporter v0.95.0
- gomod: go.opentelemetry.io/collector/exporter/loggingexporter v0.95.0
- gomod: go.opentelemetry.io/collector/exporter/otlpexporter v0.95.0
- gomod: go.opentelemetry.io/collector/exporter/otlphttpexporter v0.95.0
- gomod: github.com/open-telemetry/opentelemetry-collector-contrib/exporter/lokiexporter v0.95.0
extensions:
- gomod: go.opentelemetry.io/collector/extension/ballastextension v0.95.0
- gomod: go.opentelemetry.io/collector/extension/memorylimiterextension v0.95.0
- gomod: go.opentelemetry.io/collector/extension/zpagesextension v0.95.0
processors:
- gomod: go.opentelemetry.io/collector/processor/batchprocessor v0.95.0
- gomod: go.opentelemetry.io/collector/processor/memorylimiterprocessor v0.95.0
- gomod: github.com/open-telemetry/opentelemetry-collector-contrib/processor/resourceprocessor v0.95.0
connectors:
- gomod: go.opentelemetry.io/collector/connector/forwardconnector v0.95.0這樣就準(zhǔn)備好了構(gòu)建清單，執(zhí)行下面的命令，然后在 dist.output_path 指定的目錄中可以到找構(gòu)建好的二進(jìn)制文件。
./ocb --config=builder-config.yaml構(gòu)建鏡像
通過(guò)上面的方法來(lái)構(gòu)建 collector 的二進(jìn)制文件，進(jìn)一步再構(gòu)建容器鏡像。
FROM golang:1.21 as build
ARG OTEL_VERSION=0.95.0
WORKDIR /app
COPY . .
RUN go install go.opentelemetry.io/collector/cmd/builder@v${OTEL_VERSION}
RUN CGO_ENABLED=0 builder --config=builder-config.yaml
FROM gcr.io/distroless/base-debian11
COPY --from=build /tmp/dist/otelcorecol /
# 4317 - default OTLP receiver
# 55678 - opencensus (tracing) receiver
# 55679 - zpages
EXPOSE 4317/tcp 55678/tcp 55679/tcp
CMD ["--config", "/etc/otelcol-contrib/config.yaml"]
ENTRYPOINT ["/otelcorecol"]我已經(jīng)構(gòu)建好了鏡像 addozhang/opentelemetry-collector:0.95.0 ，在創(chuàng)建 CR OpenTelemetryCollector 的時(shí)候，可以將鏡像修改為我們定制的鏡像。
參考資料
[1] release 頁(yè)面: https://github.com/open-telemetry/opentelemetry-collector/releases?q=builder
[2] 默認(rèn)的清單文件: https://github.com/open-telemetry/opentelemetry-collector/blob/main/cmd/builder/internal/config/default.yaml
[3] receiver: https://opentelemetry.io/docs/collector/configuration/#receivers
[4] exporter: https://opentelemetry.io/docs/collector/configuration/#exporters
[5] extension: https://opentelemetry.io/docs/collector/configuration/#extensions
[6] processor: https://opentelemetry.io/docs/collector/configuration/#processors
[7] receiver: https://opentelemetry.io/docs/collector/configuration/#connectors
[8] core 發(fā)行版的構(gòu)建清單: https://raw.githubusercontent.com/open-telemetry/opentelemetry-collector/main/cmd/otelcorecol/builder-config.yaml
[9] 開(kāi)頭提到的文章: https://mp.weixin.qq.com/s/DUUDYggjaVtFRbDF3rslhw/
