Instruction : https://spring.io/guides/gs/spring-boot-docker/
Docker : Linux container management toolkit, letting users publish container images and consume those published by others
Docker image: a recipe for running a containerized process
Init project - spring boot application
run app without docker container
./gradlew build && java -jar build/libs/testApp-0.0.1-SNAPSHOT.jar
→ localhost:8080 shows “Hello World from Spring Boot”
Containerize it
1. create Dockerfile
FROM openjdk:8-jdk-alpine ## first image
ARG JAR_FILE=target/*.jar ## build/*.jar 동일
COPY ${JAR_FILE} ./app.jar
ENTRYPOINT ["java","-jar","/app.jar"]2. build image and tags it as springio/shop-snapshot
docker build --build-arg JAR_FILE=./build/libs/*.jar -t springio/testApp-snapshot .PS C:\dev\source\bg-server\bg-shop> docker build --build-arg JAR_FILE=./build/libs/*.jar -t springio/testApp-snapshot .
[+] Building 5.2s (7/7) FINISHED
=> [internal] load build definition from Dockerfile 0.0s
=> => transferring dockerfile: 31B 0.0s
=> [internal] load .dockerignore 0.0s
=> => transferring context: 2B 0.0s
=> [internal] load metadata for docker.io/library/openjdk:8-jdk-alpine 1.0s
=> [internal] load build context 0.0s
=> => transferring context: 173B 0.0s
=> [1/2] FROM docker.io/library/openjdk:8-jdk-alpine@sha256:94792824df2df33402f201713f932b58cb9de94a0cd524164a0f2283343547b3 3.8s
=> => resolve docker.io/library/openjdk:8-jdk-alpine@sha256:94792824df2df33402f201713f932b58cb9de94a0cd524164a0f2283343547b3 0.0s
=> => sha256:a3562aa0b991a80cfe8172847c8be6dbf6e46340b759c2b782f8b8be45342717 3.40kB / 3.40kB 0.0s
=> => sha256:e7c96db7181be991f19a9fb6975cdbbd73c65f4a2681348e63a141a2192a5f10 2.76MB / 2.76MB 0.6s
=> => sha256:f910a506b6cb1dbec766725d70356f695ae2bf2bea6224dbe8c7c6ad4f3664a2 238B / 238B 0.3s
=> => sha256:c2274a1a0e2786ee9101b08f76111f9ab8019e368dce1e325d3c284a0ca33397 70.73MB / 70.73MB 2.9s
=> => sha256:94792824df2df33402f201713f932b58cb9de94a0cd524164a0f2283343547b3 1.64kB / 1.64kB 0.0s
=> => sha256:44b3cea369c947527e266275cee85c71a81f20fc5076f6ebb5a13f19015dce71 947B / 947B 0.0s
=> => extracting sha256:e7c96db7181be991f19a9fb6975cdbbd73c65f4a2681348e63a141a2192a5f10 0.1s
=> => extracting sha256:f910a506b6cb1dbec766725d70356f695ae2bf2bea6224dbe8c7c6ad4f3664a2 0.0s
=> => extracting sha256:c2274a1a0e2786ee9101b08f76111f9ab8019e368dce1e325d3c284a0ca33397 0.8s
=> [2/2] COPY ./build/libs/*.jar app.jar 0.1s
=> exporting to image 0.2s
=> => exporting layers 0.2s
=> => writing image sha256:130a2e258861b3b64de4ad4c9fcd6d924203e80ccaaed5dcae16a755588747af 0.0s
=> => naming to docker.io/springio/testApp-snapshot3. a spring boot app with just java and a jar file
docker build -t springio/testApp-snapshot
docker run -p 8080:8080 springio/testApp-snapshotcontainer name : 05791b92cae5
app.jar 는 컨테이너에 쉘을 실행시켜 접근해서 확인할 수 있음 (alpine image) https://spring.io/guides/topicals/spring-boot-docker → A Basic Dockerfile section linux - Starting a shell in the Docker Alpine container - Stack Overflow
# The alpine base container we used in the example does not have bash, so this is an ash shell. It has some but not all of the features of bash.
docker run -ti --entrypoint /bin/sh myorg/myapp
4. add user privileges and separate dependencies and application resources
FROM openjdk:8-jdk-alpine
RUN addgroup -S spring && adduser -S spring -G spring
USER spring:spring
ARG JAR_FILE=build/*.jar
COPY ${JAR_FILE} app.jar
ENTRYPOINT ["java","-jar","/app.jar"]
- build\dependency 폴더 만들기
mkdir -p build/dependency -
unpack jar
jar -xf ../libs/*.jarPS C:\dev\source\testApp\build\dependency> jar -xf ..\libs\testApp-0.0.1-SNAPSHOT.jar PS C:\dev\source\testApp\build\dependency> jar -xf ..\libs\testApp-0.0.1-SNAPSHOT-plain.jarlayers.idx → to separate code based on how likely it is to change between application builds e.g. library code is less likely to change between builds and re-use the layers from cache
- "dependencies": - "BOOT-INF/lib/" - "spring-boot-loader": - "org/" - "snapshot-dependencies": - "application": - "BOOT-INF/classes/" - "BOOT-INF/classpath.idx" - "BOOT-INF/layers.idx" - "META-INF/" -
도커 실행시켜 확인
docker build --build-arg DEPENDENCY=build/dependency -t springio/shop-snapshot .
5. Gradle build
./gradlew bootBuildImage --imageName=springio/gs-spring-boot-docker
6. Publish port to run (final)
-
dockerfile
FROM openjdk:8-jdk-alpine RUN addgroup -S spring && adduser -S spring -G spring USER spring:spring ARG JAR_FILE=build/*.jar COPY ${JAR_FILE} ./app.jar ARG DEPENDENCY=build/dependency WORKDIR app COPY ${DEPENDENCY}/BOOT-INF/classes BOOT-INF/classes COPY ${DEPENDENCY}/BOOT-INF/lib BOOT-INF/lib COPY ${DEPENDENCY}/META-INF META-INF COPY ${DEPENDENCY}/org org ENTRYPOINT ["java","-jar","/app.jar"] -
docker build 빌드 인자 두개 이상 일때
docker build --build-arg JAR_FILE=./build/libs/*.jar --build-arg DEPENDENCY=build/dependency -t springio/testApp-snapshot .PS C:\dev\source\testApp> docker build --build-arg JAR_FILE=./build/libs/*.jar --build-arg DEPENDENCY=build/dependency -t springio/testApp-snapshot . [+] Building 1.0s (13/13) FINISHED => [internal] load build definition from Dockerfile 0.0s => => transferring dockerfile: 32B 0.0s => [internal] load .dockerignore 0.0s => => transferring context: 2B 0.0s => [internal] load metadata for docker.io/library/openjdk:8-jdk-alpine 0.9s => [internal] load build context 0.0s => => transferring context: 14.47kB 0.0s => [1/8] FROM docker.io/library/openjdk:8-jdk-alpine@sha256:94792824df2df33402f201713f932b58cb9de94a0cd524164a0f2283343547b3 0.0s => CACHED [2/8] RUN addgroup -S spring && adduser -S spring -G spring 0.0s => CACHED [3/8] COPY ./build/libs/*.jar ./app.jar 0.0s => CACHED [4/8] WORKDIR app 0.0s => CACHED [5/8] COPY build/dependency/BOOT-INF/classes BOOT-INF/classes 0.0s => CACHED [6/8] COPY build/dependency/BOOT-INF/lib BOOT-INF/lib 0.0s => CACHED [7/8] COPY build/dependency/META-INF META-INF 0.0s => CACHED [8/8] COPY build/dependency/org org 0.0s => exporting to image 0.0s => => exporting layers 0.0s => => writing image sha256:1bae517ebc7079a5ab8d7243ff36225b1fc5f20b32b7a31821910fb327f79bd1 0.0s => => naming to docker.io/springio/shop-snapshot 0.0s Use 'docker scan' to run Snyk tests against images to find vulnerabilities and learn how to fix them -
docker run
PS C:\dev\source\testApp> docker run -p 8080:8080 springio/testApp-snapshot