SpringBoot 容器映像更新只要200k，你敢信？？？

2024-05-14碼農

來源：juejin.cn/post/7268183236739383337

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導讀

基礎環境

基於傳統單個jar包構建模式

基礎Dockerfile

Base映像資訊

Base映像大小 622MB

Base映像history資訊

傳統構建方式

[構建後映像大小為基礎映像大小 622MB + 2*65M <= 757MB

成品構建history資訊

最佳化Dockerfile

基於spring boot 分層構建方式

探索基於分層構建原理

基於分層構建構建制品映像

驗證模擬開發推播程式碼更新映像

驗證映像

導讀

在容器化實踐中部署spring boot套用普遍采用基礎java映像再添加jar包層來構建套用映像制品。隨著公司業務大量上雲，每個變更日上傳到雲上映像日漸增多，導致本地機房到雲上頻寬壓力倍增。為解決映像上傳問題，調研了相關技術棧決定采用spring boot 2.3新增的映像分層構建功能。

基礎環境

spring boot version >= 2.3

java oracle jdk 8u201

docker version 20.10.13

基於傳統單個jar包構建模式

基礎Dockerfile

以下是我們基於基礎映像構建spring boot映像制品的Dockerfile，采用了比較傳統的COPY jar包。相信這也是大家普遍采用的模式。Dockefile如下，該Dockerfile存在一個坑，會在下邊闡述。

FROM registry.xxx.com/base/oracle-jdk:8u201 ENV TZ=Asia/Shanghai ENV LC_ALL en_US.utf8 WORKDIR /app ADD ./xxx-1.0.0.jar /app/lib/xxx-1.0.0.jar ADD ./entrypoint.sh /app/bin/entrypoint.sh ENTRYPOINT exec bash /app/bin/entrypoint.sh RUN ln -s /app/logs /app/log && chown 1001.1001 -R /app

Base映像資訊

我們base映像主要分三層添加了相關常用的工具如telnet netstat等以及安全修復

docker image inspect registry.xxx.com/base/oracle-jdk:8u201

分層資訊：

"RootFS": { "Type": "layers", "Layers": [ "sha256:174f5685490326fc0a1c0f5570b8663732189b327007e47ff13d2ca59673db02", "sha256:2105884a1756425b2188084cc1738d6a6b13293773af56f6727af1be979858ed", "sha256:c33745b350978d855171c996779055195b09e227844b7a03a1d795aee803dbb9" ] }

Base映像大小 622MB

映像大小 622MB 不算太小，對比友商有些基礎映像竟然1-2G😂 簡直有點離譜。

registry.xxx.com/base/oracle-jdk 8u201 1869b73a8999 2 years ago 622MB

Base映像history資訊

從構建歷史可以看出占用空間主要分為三層分別是

centos 7 基礎映像層

yum install 層

jdk 層

docker image history registry.xxx.com/base/oracle-jdk:8u201 IMAGE CREATED CREATED BY SIZE COMMENT 1869b73a8999 2 years ago /bin/sh -c set -ex; cd /tmp; curl -fsSLO… 302MB <missing> 2 years ago /bin/sh -c #(nop) ENV JAVA_VERSION=8 JAVA_U… 0B <missing> 2 years ago /bin/sh -c #(nop) ENV TZ=Asia/Shanghai LANG… 0B <missing> 2 years ago /bin/sh -c set -ex; yum update -y; yum i… 116MB <missing> 2 years ago /bin/sh -c #(nop) LABEL maintainer=… 0B <missing> 2 years ago /bin/sh -c #(nop) CMD ["/bin/bash"] 0B <missing> 2 years ago /bin/sh -c #(nop) LABEL org.label-schema.sc… 0B <missing> 2 years ago /bin/sh -c #(nop) ADD file:b3ebbe8bd304723d4… 204MB

傳統構建方式

docker build -t registry.xxx.com/layer/build:old . Sending build context to Docker daemon 67.45MB Step 1/8 : FROM registry.xxx.com/base/oracle-jdk:8u201 ---> 1869b73a8999 Step 2/8 : ENV TZ=Asia/Shanghai ---> Running in a67423d7246b Removing intermediate container a67423d7246b ---> 9304102c278e Step 3/8 : ENV LC_ALL en_US.utf8 ---> Running in 05bf14c10efd Removing intermediate container 05bf14c10efd ---> 63fb6c823893 Step 4/8 : WORKDIR /app ---> Running in 095764328d18 Removing intermediate container 095764328d18 ---> c057ab4a7d18 Step 5/8 : ADD ./xxx-1.0.0.jar /app/lib/xxx-1.0.0.jar ---> 08928447fafa Step 6/8 : ADD ./entrypoint.sh /app/bin/entrypoint.sh ---> 0902efa62157 Step 7/8 : ENTRYPOINT exec bash /app/bin/entrypoint.sh ---> Running in dc0eb814cfff Removing intermediate container dc0eb814cfff ---> 20679a170252 Step 8/8 : RUN ln -s /app/logs /app/log && chown 1001.1001 -R /app ---> Running in 34159dca7464 Removing intermediate container 34159dca7464 ---> b6043465c072 Successfully built b6043465c072 Successfully tagged registry.xxx.com/layer/build:old

**構建後映像大小為基礎映像大小 622MB + 2*65M <= 757MB**

構建後比我們預期的 jar包加基礎映像所占用的空間大😢 why?

#jar包大小 ls -lh xxx-1.0.0.jar -rw------- 1 root root 65M Aug 16 10:33 xxx-1.0.0.jar #映像大小 docker image ls |grep registry.xxx.com/layer/build registry.xxx.com/layer/build old b6043465c072 59 seconds ago 757MB

成品構建history資訊

檢視構建成品的映像層發現竟然有兩層一樣大小，也會被推播了兩遍。🥲離大譜。透過分析Dockerfile是因為 RUN ln -s /app/logs /app/log && chown 1001.1001 -R /app 導致的。為保證映像安全，生產環境執行統一采用了1001帳號執行。為了保證1001對workdir有絕對的讀寫許可權。對目錄遞迴授權導致檔內容發生改變。

在構建時認為檔發生變化產生一樣大小的兩層導致的。（這還是我自己當時最佳化引入的屎山😊）具體原因我也不太清楚docker構建時如何判定檔發生變化，我原本以為是基於MD5碼。實際上在對檔屬主屬組改變時MD5碼是不對變的。有知道的大神可以在評論區留言交流。

docker image history registry.xxx.com/layer/build:old IMAGE CREATED CREATED BY SIZE COMMENT b6043465c072 6 minutes ago /bin/sh -c ln -s /app/logs /app/log && chown… 67.4MB 20679a170252 6 minutes ago /bin/sh -c #(nop) ENTRYPOINT ["/bin/sh" "-c… 0B 0902efa62157 6 minutes ago /bin/sh -c #(nop) ADD file:9ac19caf793524884… 128B 08928447fafa 6 minutes ago /bin/sh -c #(nop) ADD file:c7624c195e7c047ee… 67.4MB c057ab4a7d18 6 minutes ago /bin/sh -c #(nop) WORKDIR /app 0B 63fb6c823893 6 minutes ago /bin/sh -c #(nop) ENV LC_ALL=en_US.utf8 0B 9304102c278e 6 minutes ago /bin/sh -c #(nop) ENV TZ=Asia/Shanghai 0B 1869b73a8999 2 years ago /bin/sh -c set -ex; cd /tmp; curl -fsSLO… 302MB <missing> 2 years ago /bin/sh -c #(nop) ENV JAVA_VERSION=8 JAVA_U… 0B <missing> 2 years ago /bin/sh -c #(nop) ENV TZ=Asia/Shanghai LANG… 0B <missing> 2 years ago /bin/sh -c set -ex; yum update -y; yum i… 116MB <missing> 2 years ago /bin/sh -c #(nop) LABEL maintainer=currycan… 0B <missing> 2 years ago /bin/sh -c #(nop) CMD ["/bin/bash"] 0B <missing> 2 years ago /bin/sh -c #(nop) LABEL org.label-schema.sc… 0B <missing> 2 years ago /bin/sh -c #(nop) ADD file:b3ebbe8bd304723d4… 204MB #映像也推播了兩層一樣大小 [root@localhost old-nochown]# docker push registry.xxx.com/layer/build:old The push refers to repository [registry.xxx.com/layer/build] bb35157fcb0b: Pushing [=============> ] 18.35MB/67.45MB 3c0641004863: Pushed 6ed0abaff975: Pushing [=====================> ] 28.38MB/67.45MB aa0794231b2c: Pushed c33745b35097: Layer already exists 2105884a1756: Layer already exists 174f56854903: Layer already exists

最佳化Dockerfile

原因知道了。最佳化思路是先建立目錄並遞迴授權。同時構建出來的jar的許可權可以透過COPY 指定1001屬主屬組。

FROM registry.xxx.com/base/oracle-jdk:8u201 ENV TZ=Asia/Shanghai ENV LC_ALL en_US.utf8 RUN mkdir -pv /app/{bin,lib,logs} && ln -s /app/logs /app/log && chown 1001:1001 -R /app WORKDIR /app COPY --chown=1001:1001 ./xxx-1.0.0.jar /app/lib/xxx-1.0.0.jar COPY --chown=1001:1001 ./entrypoint.sh /app/bin/entrypoint.sh ENTRYPOINT exec bash /app/bin/entrypoint.sh

最佳化後的映像只有COPY這一層的jar包了。

docker image history registry.xxx.com/layer/build:old-mkdir IMAGE CREATED CREATED BY SIZE COMMENT b9fc3a8a97f2 29 hours ago /bin/sh -c #(nop) ENTRYPOINT ["/bin/sh" "-c… 0B c823448f9582 29 hours ago /bin/sh -c #(nop) COPY --chown=1001:1001file… 128B 9a997f3962bf 29 hours ago /bin/sh -c #(nop) COPY --chown=1001:1001file… 67.4MB f272c4e64f87 29 hours ago /bin/sh -c #(nop) WORKDIR /app 0B 1a526d3df7c2 29 hours ago /bin/sh -c mkdir -pv /app/{bin,lib,logs} && … 9B 63fb6c823893 30 hours ago /bin/sh -c #(nop) ENV LC_ALL=en_US.utf8 0B 9304102c278e 30 hours ago /bin/sh -c #(nop) ENV TZ=Asia/Shanghai 0B 1869b73a8999 2 years ago /bin/sh -c set -ex; cd /tmp; curl -fsSLO… 302MB <missing> 2 years ago /bin/sh -c #(nop) ENV JAVA_VERSION=8 JAVA_U… 0B <missing> 2 years ago /bin/sh -c #(nop) ENV TZ=Asia/Shanghai LANG… 0B <missing> 2 years ago /bin/sh -c set -ex; yum update -y; yum i… 116MB <missing> 2 years ago /bin/sh -c #(nop) LABEL maintainer=currycan… 0B <missing> 2 years ago /bin/sh -c #(nop) CMD ["/bin/bash"] 0B <missing> 2 years ago /bin/sh -c #(nop) LABEL org.label-schema.sc… 0B <missing> 2 years ago /bin/sh -c #(nop) ADD file:b3ebbe8bd304723d4… 204MB

基於spring boot 分層構建方式

探索基於分層構建原理

直接上手官方文件的demo 把官方文件demo的多階段構建拆分一下。

cat Dockerfile FROM registry.xxx.com/base/oracle-jdk:8u201 as builder WORKDIR /app COPY --chown=1001:1001 ./xxx-1.0.0.jar /app/lib/xxx-1.0.0.jar RUN java -Djarmode=layertools -jar /app/lib/xxx-1.0.0.jar extract

一階段實際就是將jar解壓按照spring boot layers.idx檔中的分層方式將依賴和業務代分碼層。

- "dependencies": - BOOT-INF/lib/library1.jar - BOOT-INF/lib/library2.jar - "spring-boot-loader": - org/springframework/boot/loader/JarLauncher. class - org/springframework/boot/loader/jar/JarEntry. class - "snapshot-dependencies": - BOOT-INF/lib/library3-SNAPSHOT.jar - "application": - META-INF/MANIFEST.MF - BOOT-INF/ classes/a/b/C. class

進入到容器中可以看到被解壓為4個目錄：

[root@b762a63589c1 app]# ls application dependencies lib logs snapshot-dependencies spring-boot-loader

儲存占用如下：其中不出意外dependencies也就是依賴庫占用是最大的業務程式碼只有可憐的304K🤔。

[root@29d87aaf64b9 app]# du -lh --max-depth=1 304K ./application 65M ./dependencies 0 ./logs 20K ./snapshot-dependencies 420K ./spring-boot-loader 65M ./lib 130M .

基於分層構建構建制品映像

在官方的demo上修改得到完整的Dockerfile。其中最佳化了entrypoint指令碼，采用分層構建後啟動套用不能采用傳統的 java $JAVA_OPTS -jar xxx.jar 這方式啟動套用。要使用 java org.springframework.boot.loader.JarLauncher 啟動套用因此jvm參數需要透過指令碼接受容器的環境變量來傳入。

FROM registry.xxx.com/base/oracle-jdk:8u201 as builder WORKDIR /app COPY --chown=1001:1001 ./xxx-1.0.0.jar /app/lib/xxx-1.0.0.jar RUN java -Djarmode=layertools -jar /app/lib/xxx-1.0.0.jar extract FROM registry.xxx.com/base/oracle-jdk:8u201 ENV TZ=Asia/Shanghai ENV LC_ALL en_US.utf8 RUN mkdir -pv /app/logs && ln -s /app/logs /app/log && chown 1001:1001 -R /app WORKDIR /app COPY --chown=1001:1001 --from=builder /app/dependencies/ ./ COPY --chown=1001:1001 --from=builder /app/spring-boot-loader/ ./ COPY --chown=1001:1001 --from=builder /app/snapshot-dependencies/ ./ COPY --chown=1001:1001 --from=builder /app/application/ ./ CMD ["exec"] ENTRYPOINT ["bash","/app/entrypoint.sh"]

entrypoint.sh指令碼使用exec將java作為容器1號行程，避免無法接受linux 訊號導致java行程無法正常結束。

#!/bin/bash if [ -f /opt/cm/before.sh ]; then source /opt/cm/before.sh; fi exec java $JAVA_OPTS org.springframework.boot.loader.JarLauncher

構建映像

[root@localhost new]# docker build -t registry.xxx.com/layer/build:new . Sending build context to Docker daemon 67.45MB Step 1/14 : FROM registry.xxx.com/base/oracle-jdk:8u201 as builder ---> 1869b73a8999 Step 2/14 : WORKDIR /app ---> Using cache ---> 6973e49f31fa Step 3/14 : COPY --chown=1001:1001 ./xxx-1.0.0.jar /app/lib/xxx-1.0.0.jar ---> Using cache ---> c5a17d5969ea Step 4/14 : RUN java -Djarmode=layertools -jar /app/lib/xxx-1.0.0.jar extract ---> Using cache ---> 911074c3ef21 Step 5/14 : FROM registry.xxx.com/base/oracle-jdk:8u201 ---> 1869b73a8999 Step 6/14 : ENV TZ=Asia/Shanghai ---> Using cache ---> 9304102c278e Step 7/14 : ENV LC_ALL en_US.utf8 ---> Using cache ---> 63fb6c823893 Step 8/14 : RUN mkdir -pv /app/logs && ln -s /app/logs /app/log && chown 1001:1001 -R /app ---> Running in 9cac9cb86507 mkdir: created directory ‘/app’ mkdir: created directory ‘/app/logs’ Removing intermediate container 9cac9cb86507 ---> 858e77315e6b Step 9/14 : WORKDIR /app ---> Running in 81c7173692fc Removing intermediate container 81c7173692fc ---> 5c19ddda3114 Step 10/14 : COPY --chown=1001:1001 --from=builder /app/dependencies/ ./ ---> 078e3f4a199c Step 11/14 : COPY --chown=1001:1001 --from=builder /app/spring-boot-loader/ ./ ---> 1542209ccc8b Step 12/14 : COPY --chown=1001:1001 --from=builder /app/snapshot-dependencies/ ./ ---> 75a9584e0952 Step 13/14 : COPY --chown=1001:1001 --from=builder /app/application/ ./ ---> 555270edceea Step 14/14 : ENTRYPOINT ["java", "org.springframework.boot.loader.JarLauncher"] ---> Running in fe99278683a2 Removing intermediate container fe99278683a2 ---> 2cce0deab7e2 Successfully built 2cce0deab7e2 Successfully tagged registry.xxx.com/layer/build:new

檢視分層詳情，可以看到jar被拆分成4層分別由copy指令建立。

[root@localhost ~]# docker image history registry.xxx.com/layer/build:new IMAGE CREATED CREATED BY SIZE COMMENT 2cce0deab7e2 28 hours ago /bin/sh -c #(nop) ENTRYPOINT ["java" "org.s… 0B 555270edceea 28 hours ago /bin/sh -c #(nop) COPY dir:2f5975d11563ae449… 248kB 75a9584e0952 28 hours ago /bin/sh -c #(nop) COPY dir:a3bb0870001a0ef25… 18.5kB 1542209ccc8b 28 hours ago /bin/sh -c #(nop) COPY dir:16d00ea1f180914e2… 252kB 078e3f4a199c 28 hours ago /bin/sh -c #(nop) COPY dir:1d3190ed598b634a5… 67.1MB 5c19ddda3114 28 hours ago /bin/sh -c #(nop) WORKDIR /app 0B 858e77315e6b 28 hours ago /bin/sh -c mkdir -pv /app/logs && ln -s /app… 9B 63fb6c823893 30 hours ago /bin/sh -c #(nop) ENV LC_ALL=en_US.utf8 0B 9304102c278e 30 hours ago /bin/sh -c #(nop) ENV TZ=Asia/Shanghai 0B 1869b73a8999 2 years ago /bin/sh -c set -ex; cd /tmp; curl -fsSLO… 302MB <missing> 2 years ago /bin/sh -c #(nop) ENV JAVA_VERSION=8 JAVA_U… 0B <missing> 2 years ago /bin/sh -c #(nop) ENV TZ=Asia/Shanghai LANG… 0B <missing> 2 years ago /bin/sh -c set -ex; yum update -y; yum i… 116MB <missing> 2 years ago /bin/sh -c #(nop) LABEL maintainer=currycan… 0B <missing> 2 years ago /bin/sh -c #(nop) CMD ["/bin/bash"] 0B <missing> 2 years ago /bin/sh -c #(nop) LABEL org.label-schema.sc… 0B <missing> 2 years ago /bin/sh -c #(nop) ADD file:b3ebbe8bd304723d4… 204MB

對比發現jar包被拆分了。

[root@localhost new]# diff old.info new.info 1,16c1,18 < IMAGE CREATED CREATED BY SIZE COMMENT < b9fc3a8a97f2 About an hour ago /bin/sh -c #(nop) ENTRYPOINT ["/bin/sh" "-c… 0B < c823448f9582 About an hour ago /bin/sh -c #(nop) COPY --chown=1001:1001file… 128B < 9a997f3962bf About an hour ago /bin/sh -c #(nop) COPY --chown=1001:1001file… 67.4MB < f272c4e64f87 About an hour ago /bin/sh -c #(nop) WORKDIR /app 0B < 1a526d3df7c2 About an hour ago /bin/sh -c mkdir -pv /app/{bin,lib,logs} && … 9B < 63fb6c823893 2 hours ago /bin/sh -c #(nop) ENV LC_ALL=en_US.utf8 0B < 9304102c278e 2 hours ago /bin/sh -c #(nop) ENV TZ=Asia/Shanghai 0B < 1869b73a8999 2 years ago /bin/sh -c set -ex; cd /tmp; curl -fsSLO… 302MB < <missing> 2 years ago /bin/sh -c #(nop) ENV JAVA_VERSION=8 JAVA_U… 0B < <missing> 2 years ago /bin/sh -c #(nop) ENV TZ=Asia/Shanghai LANG… 0B < <missing> 2 years ago /bin/sh -c set -ex; yum update -y; yum i… 116MB < <missing> 2 years ago /bin/sh -c #(nop) LABEL maintainer=currycan… 0B < <missing> 2 years ago /bin/sh -c #(nop) CMD ["/bin/bash"] 0B < <missing> 2 years ago /bin/sh -c #(nop) LABEL org.label-schema.sc… 0B < <missing> 2 years ago /bin/sh -c #(nop) ADD file:b3ebbe8bd304723d4… 204MB --- > IMAGE CREATED CREATED BY SIZE COMMENT > 2cce0deab7e2 8 minutes ago /bin/sh -c #(nop) ENTRYPOINT ["java" "org.s… 0B > 555270edceea 8 minutes ago /bin/sh -c #(nop) COPY dir:2f5975d11563ae449… 248kB > 75a9584e0952 8 minutes ago /bin/sh -c #(nop) COPY dir:a3bb0870001a0ef25… 18.5kB > 1542209ccc8b 8 minutes ago /bin/sh -c #(nop) COPY dir:16d00ea1f180914e2… 252kB > 078e3f4a199c 8 minutes ago /bin/sh -c #(nop) COPY dir:1d3190ed598b634a5… 67.1MB > 5c19ddda3114 8 minutes ago /bin/sh -c #(nop) WORKDIR /app 0B > 858e77315e6b 8 minutes ago /bin/sh -c mkdir -pv /app/logs && ln -s /app… 9B > 63fb6c823893 2 hours ago /bin/sh -c #(nop) ENV LC_ALL=en_US.utf8 0B > 9304102c278e 2 hours ago /bin/sh -c #(nop) ENV TZ=Asia/Shanghai 0B > 1869b73a8999 2 years ago /bin/sh -c set -ex; cd /tmp; curl -fsSLO… 302MB > <missing> 2 years ago /bin/sh -c #(nop) ENV JAVA_VERSION=8 JAVA_U… 0B > <missing> 2 years ago /bin/sh -c #(nop) ENV TZ=Asia/Shanghai LANG… 0B > <missing> 2 years ago /bin/sh -c set -ex; yum update -y; yum i… 116MB > <missing> 2 years ago /bin/sh -c #(nop) LABEL maintainer=currycan… 0B > <missing> 2 years ago /bin/sh -c #(nop) CMD ["/bin/bash"] 0B > <missing> 2 years ago /bin/sh -c #(nop) LABEL org.label-schema.sc… 0B > <missing> 2 years ago /bin/sh -c #(nop) ADD file:b3ebbe8bd304723d4… 204MB

推播到倉庫

[root@localhost new]# docker push registry.xxx.com/layer/build:new The push refers to repository [registry.xxx.com/layer/build] e5409ea62302: Pushed 7167dfa406ea: Pushed cf7e94a2dc11: Pushed 8e261e1bae2c: Pushed 770c31a84800: Pushed c33745b35097: Layer already exists 2105884a1756: Layer already exists 174f56854903: Layer already exists new: digest: sha256:faef10681394c01d1c2973ed10c7c33e7289eec25f22c90d085f6eef96ce3bff size: 2001

驗證模擬開發推播程式碼更新映像

開發摸了一天🐟終於開發出新版本

[root@localhost new]# md5sum bc-1.0.1.jar bc-1.0.0.jar 3792d3178a4e07708052b7effa9b12f8 xxx-1.0.1.jar 8ee570b94977668631355cb49c5d7cf1 xxx-1.0.0.jar

構建新版本，構建過程階段二中使用了cache 僅更新了 application層

[root@localhost new]# docker image build -t registry.xxx.com/layer/build:new-1.0.1 . Sending build context to Docker daemon 134.9MB Step 1/16 : FROM registry.xxx.com/base/oracle-jdk:8u201 as builder ---> 1869b73a8999 Step 2/16 : WORKDIR /app ---> Using cache ---> 6973e49f31fa Step 3/16 : COPY --chown=1001:1001 ./xxx-1.0.1.jar /app/lib/xxx-1.0.1.jar ---> b219210fd8ab Step 4/16 : RUN java -Djarmode=layertools -jar /app/lib/xxx-1.0.1.jar extract ---> Running in d099c10b653c Removing intermediate container d099c10b653c ---> 66a8593b0291 Step 5/16 : FROM registry.xxx.com/base/oracle-jdk:8u201 ---> 1869b73a8999 Step 6/16 : ENV TZ=Asia/Shanghai ---> Using cache ---> 9304102c278e Step 7/16 : ENV LC_ALL en_US.utf8 ---> Using cache ---> 63fb6c823893 Step 8/16 : RUN mkdir -pv /app/logs && ln -s /app/logs /app/log && chown 1001:1001 -R /app ---> Using cache ---> 858e77315e6b Step 9/16 : WORKDIR /app ---> Using cache ---> 5c19ddda3114 Step 10/16 : COPY --chown=1001:1001 ./entrypoint.sh /app/entrypoint.sh ---> Using cache ---> c47b74bb8cf9 Step 11/16 : COPY --chown=1001:1001 --from=builder /app/dependencies/ ./ ---> Using cache ---> 078e3f4a199c Step 12/16 : COPY --chown=1001:1001 --from=builder /app/spring-boot-loader/ ./ ---> Using cache ---> 1542209ccc8b Step 13/16 : COPY --chown=1001:1001 --from=builder /app/snapshot-dependencies/ ./ ---> Using cache ---> 75a9584e0952 Step 14/16 : COPY --chown=1001:1001 --from=builder /app/application/ ./ ---> 0f138b106caf Step 15/16 : CMD ["exec"] ---> Using cache ---> a1170ae7a20e Step 16/16 : ENTRYPOINT ["bash","/app/entrypoint.sh"] ---> Using cache ---> 5a6bb7613fc8 Successfully built 5a6bb7613fc8 Successfully tagged registry.xxx.com/layer/build:new-1.0.1

推播到倉庫可以看到僅推播了application層只有300K

docker push registry.xxx.com/layer/build:new-1.0.1 The push refers to repository [registry.xxx.com/layer/build] c33a5c6456bd: Pushed 7167dfa406ea: Layer already exists cf7e94a2dc11: Layer already exists 8e261e1bae2c: Layer already exists 770c31a84800: Layer already exists c33745b35097: Layer already exists 2105884a1756: Layer already exists 174f56854903: Layer already exists new-1.0.1: digest: sha256:53647bb45f0f0bb5bb8d56f14cd40deb22f0d5e4fce1200fed1c225a516dddb5 size: 2001

驗證映像

[root@localhost new]# docker run -it --rm -u 1001:1001 -e JAVA_OPTS="-XX:+PrintGCDetails -XX:+PrintGCDateStamps -XX:+PrintHeapAtGC -XX:+PrintTenuringDistribution -XX:+PrintGCApplicationStoppedTime -XX:+PrintGCApplicationConcurrentTime -XX:+PrintCommandLineFlags" registry.xxx.com/layer/build:new-1.0.1

可以看到打印出了堆疊資訊（容器預設是不開啟的）套用成功啟動😋

[root@localhost ~]# docker run -it --rm -u 1001:1001 -e JAVA_OPTS="-XX:+PrintGCDetails -XX:+PrintGCDateStamps -XX:+PrintHeapAtGC -XX:+PrintTenuringDistribution -XX:+PrintGCApplicationStoppedTime -XX:+PrintGCApplicationConcurrentTime -XX:+PrintCommandLineFlags" registry.xxx.com/layer/build:new-1.0.1 -XX:InitialHeapSize=130478208 -XX:MaxHeapSize=2087651328 -XX:+PrintCommandLineFlags -XX:+PrintGCApplicationConcurrentTime -XX:+PrintGCApplicationStoppedTime -XX:+PrintGCDateStamps -XX:+PrintGCDetails -XX:+PrintHeapAtGC -XX:+PrintTenuringDistribution -XX:+UseCompressed classPointers -XX:+UseCompressedOops -XX:+UseParallelGC {Heap before GC invocations=1 (full 0): PSYoungGen total 37888K, used 32768K [0x00000000d6800000, 0x00000000d9200000, 0x0000000100000000) eden space 32768K, 100% used [0x00000000d6800000,0x00000000d8800000,0x00000000d8800000) from space 5120K, 0% used [0x00000000d8d00000,0x00000000d8d00000,0x00000000d9200000) to space 5120K, 0% used [0x00000000d8800000,0x00000000d8800000,0x00000000d8d00000) ParOldGen total 86016K, used 0K [0x0000000083800000, 0x0000000088c00000, 0x00000000d6800000) eden space 32768K, 0% used [0x00000000d6800000,0x00000000d6800000,0x00000000d8800000) from space 5120K, 72% used [0x00000000d8800000,0x00000000d8ba1748,0x00000000d8d00000) to space 5120K, 0% used [0x00000000dad00000,0x00000000dad00000,0x00000000db200000) ParOldGen total 86016K, used 8K [0x0000000083800000, 0x0000000088c00000, 0x00000000d6800000) object space 86016K, 0% used [0x0000000083800000,0x0000000083802000,0x0000000088c00000) Metaspace used 6799K, capacity 7074K, committed 7168K, reserved 1056768K class space used 820K, capacity 935K, committed 1024K, reserved 1048576K } ... 2023-08-17 20:50:42.253 INFO 1 --- [ main] org.springframework.boot.actuate.endpoint.web.EndpointLinksResolver.<init>(EndpointLinksResolver.java:58) - [] : Exposing 1 endpoint(s) beneath base path '/actuator' 2023-08-17 20:50:42.315 INFO 1 --- [ main] org.apache.juli.logging.DirectJDKLog.log(DirectJDKLog.java:173) - [] : Starting ProtocolHandler ["http-nio-8082"] 2023-08-17 20:50:42.349 INFO 1 --- [ main] org.springframework.boot.web.embedded.tomcat.TomcatWebServer.start(TomcatWebServer.java:220) - [] : Tomcat started on port(s): 8082 (http) with context path '/xxx' 2023-08-17 20:50:42.376 INFO 1 --- [ main] org.springframework.boot.StartupInfoLogger.logStarted(StartupInfoLogger.java:61) - [] : Started Application in 11.242 seconds (JVM running for 12.553)

對比兩個版本可以發現只有application成hash值不一樣程式碼量增加了 253kB-248kB=5KB

[root@localhost new]# docker image history registry.xxx.com/layer/build:new IMAGE CREATED CREATED BY SIZE COMMENT 2cce0deab7e2 About an hour ago /bin/sh -c #(nop) ENTRYPOINT ["java" "org.s… 0B 555270edceea About an hour ago /bin/sh -c #(nop) COPY dir:2f5975d11563ae449… 248kB 75a9584e0952 About an hour ago /bin/sh -c #(nop) COPY dir:a3bb0870001a0ef25… 18.5kB 1542209ccc8b About an hour ago /bin/sh -c #(nop) COPY dir:16d00ea1f180914e2… 252kB 078e3f4a199c About an hour ago /bin/sh -c #(nop) COPY dir:1d3190ed598b634a5… 67.1MB 5c19ddda3114 About an hour ago /bin/sh -c #(nop) WORKDIR /app 0B 858e77315e6b About an hour ago /bin/sh -c mkdir -pv /app/logs && ln -s /app… 9B 63fb6c823893 3 hours ago /bin/sh -c #(nop) ENV LC_ALL=en_US.utf8 0B 9304102c278e 3 hours ago /bin/sh -c #(nop) ENV TZ=Asia/Shanghai 0B 1869b73a8999 2 years ago /bin/sh -c set -ex; cd /tmp; curl -fsSLO… 302MB <missing> 2 years ago /bin/sh -c #(nop) ENV JAVA_VERSION=8 JAVA_U… 0B <missing> 2 years ago /bin/sh -c #(nop) ENV TZ=Asia/Shanghai LANG… 0B <missing> 2 years ago /bin/sh -c set -ex; yum update -y; yum i… 116MB <missing> 2 years ago /bin/sh -c #(nop) LABEL maintainer=currycan… 0B <missing> 2 years ago /bin/sh -c #(nop) CMD ["/bin/bash"] 0B <missing> 2 years ago /bin/sh -c #(nop) LABEL org.label-schema.sc… 0B <missing> 2 years ago /bin/sh -c #(nop) ADD file:b3ebbe8bd304723d4… 204MB [root@localhost new]# docker image history registry.xxx.com/layer/build:new-1.0.1 IMAGE CREATED CREATED BY SIZE COMMENT 76aa6233354a 40 minutes ago /bin/sh -c #(nop) ENTRYPOINT ["java" "org.s… 0B 0f138b106caf 40 minutes ago /bin/sh -c #(nop) COPY dir:4d21cc5ce0d92794b… 253kB 75a9584e0952 About an hour ago /bin/sh -c #(nop) COPY dir:a3bb0870001a0ef25… 18.5kB 1542209ccc8b About an hour ago /bin/sh -c #(nop) COPY dir:16d00ea1f180914e2… 252kB 078e3f4a199c About an hour ago /bin/sh -c #(nop) COPY dir:1d3190ed598b634a5… 67.1MB 5c19ddda3114 About an hour ago /bin/sh -c #(nop) WORKDIR /app 0B 858e77315e6b About an hour ago /bin/sh -c mkdir -pv /app/logs && ln -s /app… 9B 63fb6c823893 3 hours ago /bin/sh -c #(nop) ENV LC_ALL=en_US.utf8 0B 9304102c278e 3 hours ago /bin/sh -c #(nop) ENV TZ=Asia/Shanghai 0B 1869b73a8999 2 years ago /bin/sh -c set -ex; cd /tmp; curl -fsSLO… 302MB <missing> 2 years ago /bin/sh -c #(nop) ENV JAVA_VERSION=8 JAVA_U… 0B <missing> 2 years ago /bin/sh -c #(nop) ENV TZ=Asia/Shanghai LANG… 0B <missing> 2 years ago /bin/sh -c set -ex; yum update -y; yum i… 116MB <missing> 2 years ago /bin/sh -c #(nop) LABEL maintainer=currycan… 0B <missing> 2 years ago /bin/sh -c #(nop) CMD ["/bin/bash"] 0B <missing> 2 years ago /bin/sh -c #(nop) LABEL org.label-schema.sc… 0B <missing> 2 years ago /bin/sh -c #(nop) ADD file:b3ebbe8bd304723d4… 204MB