如何使用docker-solrs图像扩展机制创建solr核心？

我想创建一个solr的docker镜像,在启动时创建一个核心.因此,我正在使用为solr docker容器描述的docker-entrypoint-initdb.d扩展机制.文件说

在启动时创建核心的第三种方法是使用下一节中介绍的图像扩展机制.

但它并没有解释如何实现这一目标.

我正在使用的Dockerfile是:

FROM solr:6.6

USER root

RUN mkdir /A12Core && chown -R solr:solr /A12Core

COPY --chown=solr:solr ./services-core/search/A12Core /A12Core/
COPY --chown=solr:solr ./create-a12core.sh /docker-entrypoint-initdb.d/

USER solr

RUN chmod -R a+X /A12Core

该文件夹A12Core包含核心的solr配置文件.create-a12core.sh创建核心的脚本是:

#!/bin/bash

solr-precreate A12Core /A12Core

该/A12Core目录包含以下文件:

./core.properties
./conf
./conf/update-script.js
./conf/mapping-ISOLatin1Accent.txt
./conf/schema.xml
./conf/spellings.txt
./conf/solrconfig.xml
./conf/currency.xml
./conf/mapping-FoldToASCII.txt
./conf/_schema_analysis_stopwords_english.json
./conf/stopwords.txt
./conf/synonyms.txt
./conf/elevate.xml
./conf/lang
./conf/lang/stopwords_en.txt
./conf/lang/stopwords_de.txt

但是,当使用上面的Dockerfile和脚本启动图像构建时,似乎会创建一个无限循环.输出是:

/opt/docker-solr/scripts/solr-foreground: running /docker-entrypoint-initdb.d/create-a12core.sh
Executing /opt/docker-solr/scripts/solr-precreate A12Core /A12Core
/opt/docker-solr/scripts/solr-precreate: running /docker-entrypoint-initdb.d/create-a12core.sh
Executing /opt/docker-solr/scripts/solr-precreate A12Core /A12Core
/opt/docker-solr/scripts/solr-precreate: running /docker-entrypoint-initdb.d/create-a12core.sh
Executing /opt/docker-solr/scripts/solr-precreate A12Core /A12Core
/opt/docker-solr/scripts/solr-precreate: running /docker-entrypoint-initdb.d/create-a12core.sh
...

如何使用docker-entrypoint-initdb.d扩展机制创建核心？