Update cli docker base to eclipse-temurin:17-jre-alpine

[daveset]

PR checklist

• Read the contribution guidelines.
• Ran the shell script under ./bin/ to update Petstore sample so that CIs can verify the change. (For instance, only need to run ./bin/{LANG}-petstore.sh and ./bin/security/{LANG}-petstore.sh if updating the {LANG} (e.g. php, ruby, python, etc) code generator or {LANG} client's mustache templates). Windows batch files can be found in .\bin\windows\.
  N/A - not targeting a specific generator here and it doesn't appear any of these scripts use the docker image.
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  N/A - not targeting particular programming language

Description of the PR

This addresses the UnsupportedClassVersionError exceptions reported in issues #12240 and #12242 for the 3.0.0 branch.

The error can be reproduced simply by running the docker image with generate --help:

$ docker run --rm --volume "$(pwd)":/local swaggerapi/swagger-codegen-cli-v3:3.0.50 generate --help 
Exception in thread "main" java.lang.UnsupportedClassVersionError: ch/qos/logback/classic/spi/LogbackServiceProvider has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
        ...
        at java.util.ServiceLoader$1.next(ServiceLoader.java:480)
        at org.slf4j.LoggerFactory.safelyInstantiate(LoggerFactory.java:148)
        at org.slf4j.LoggerFactory.findServiceProviders(LoggerFactory.java:129)
        at org.slf4j.LoggerFactory.bind(LoggerFactory.java:190)

The UnsupportedClassVersionError is because the swaggerapi/swagger-generator-v3:3.0.50 docker image installs Java 8 (class version 52) as can be seen in the docker image history [1] and the Dockerfile itself [2]. The Logback library version 1.4.11 [3] used by swagger codegen is being built targeting Java 11 [4] (class file version 55).

The logback library could potentially be rolled back to a version built targeting Java 8 (1.3.x [4]). However, the codegen CLI is the only Dockerfile here on the 3.0.0 branch that is using a Java 8 runtime. The others are using Java 17 though from different base images:

• The top-level Dockerfile is based on openjdk:17-jdk-alpine:

  swagger-codegen/Dockerfile

  Line 1 in fc4e952

  FROM openjdk:17-jdk-alpine

• The swagger-generator module Dockerfile uses Java 17 via eclipse-temurin:17-jre:

  swagger-codegen/modules/swagger-generator/Dockerfile

  Line 9 in fc4e952

  COPY --from=eclipse-temurin:17-jre $JAVA_HOME $JAVA_HOME

• The swagger-codegen-cli module Dockerfile uses Java 8 via openjdk-8-jre-alpine:

  swagger-codegen/modules/swagger-codegen-cli/Dockerfile

  Line 1 in fc4e952

  FROM openjdk:8-jre-alpine

Given that, it seems reasonable to update swagger-codegen-cli to also use Java 17 which is the change I have made here.

I validated the change by manually building the image and testing generate --help and running a go client generation:

$ docker run --rm --volume "$(pwd)":/local swaggerapi/swagger-codegen-cli-v3:jre17-alpine generate --help 
usage: swagger-codegen generate [-h] [-v []] [-l] [-o] [-i] [-t]
                       [--template-version] [--template-engine] [-a] [-c]
                       [-D [ [ ...]]] [-s] [--api-package]
                       [--model-package] [--model-name-prefix]
                       ...

References:
[1] https://hub.docker.com/layers/swaggerapi/swagger-codegen-cli-v3/3.0.50/images/sha256-10f28ee6ef4dc6ad4871947b38347cd1fa61dea6537a87d0309605cd6f2b9185?context=explore
[2]

swagger-codegen/modules/swagger-codegen-cli/Dockerfile

Line 1 in fc4e952

FROM openjdk:8-jre-alpine

[3]

swagger-codegen/pom.docker.xml

Line 1136 in fc4e952

<logback-version>1.4.11</logback-version>

[4] https://github.com/qos-ch/logback/blob/master/README.md#java-ee-and-jakarta-ee-versions

[daveset]

@HugoMario it looks like you have made the latest commits on the 3.0.0 branch of this repo. Can you review this fix to the broken swagger-codegen-cli-v3 Docker image? If you are not the right person, can you forward to whoever is? Thanks!

[frantuma]

@daveset thanks a lot for analysis and fix!