Docker容器内无法访问Eclipse下载站点（连接被拒绝）

以下是导致该问题的核心原因：

• 容器网络出站规则限制
  宿主机防火墙（如ufw、iptables）或Docker自身的网络策略，可能针对性拦截了容器对download.eclipse.org等域名的443端口请求。尽管容器能正常访问其他站点（如Oracle JDK下载地址），但部分域名的出站流量被规则阻断，导致连接被拒绝。

• DNS解析不一致
  容器内DNS服务解析download.eclipse.org得到的IP（如报错中的198.41.30.199）在当前容器网络环境下不可达，而主机的DNS解析结果为其他可用节点。可在容器内执行nslookup download.eclipse.org，与主机解析结果对比确认差异。

• 目标站点的IP封禁
  容器的出口IP（可能是宿主机公网IP或Docker NAT网络IP）被Eclipse官方下载站或镜像站的防火墙封禁。主机能正常访问是因为其IP不在封禁列表中，或镜像站对容器所属IP段有访问限制。

• Oomph的独立网络配置
  虽然容器本身能正常下载文件，但Oomph安装程序可能有独立的代理或网络设置，未继承容器的网络环境。比如主机配置了代理但容器内未同步，或Oomph内部网络参数错误，导致无法连接指定站点。

报错信息： #

!MESSAGE Connection to https://download.eclipse.org/releases/2023-03/202301131000/p2.index failed on Connect to https://download.eclipse.org:443 [download.eclipse.org/198.41.30.199] failed: Connection refused

!MESSAGE Connection to https://download.eclipse.org/oomph/updates/milestone/latest/compositeContent.jar failed on Connect to https://download.eclipse.org:443 [download.eclipse.org/198.41.30.199] failed: Connection refused. Retry attempt 0 started

!MESSAGE Connection to https://download.eclipse.org/oomph/updates/milestone/latest/compositeArtifacts.jar failed on Connect to https://download.eclipse.org:443 [download.eclipse.org/198.41.30.199] failed: Connection refused. Retry attempt 0 started

!MESSAGE Connection to https://download.eclipse.org/technology/epp/packages/2023-03/202301121200/features/org.eclipse.epp.package.common.feature_4.27.0.20230112-0751.jar failed on Connect to https://download.eclipse.org:443 [download.eclipse.org/198.41.30.199] failed: Connection refused. Retry attempt 0 started

!MESSAGE Connection to https://download.eclipse.org/technology/epp/packages/2023-03/202301121200/features/org.eclipse.epp.package.java.feature_4.27.0.20230112-0751.jar failed on Connect to https://download.eclipse.org:443 [download.eclipse.org/198.41.30.199] failed: Connection refused. Retry attempt 0 started

!MESSAGE Failure reporting download statistics to URL: https://download.eclipse.org/stats/technology/epp/packages/2023-03-M1/org.eclipse.epp.package.common/4.27.0.20230112-0751

!MESSAGE Unable to connect to repository https://download.eclipse.org/stats/technology/epp/packages/2023-03-M1/org.eclipse.epp.package.common/4.27.0.20230112-0751

!MESSAGE Connection to https://eclipse.mirror.rafal.ca/releases/2023-03/202301131000/plugins/org.eclipse.mylyn.wikitext.asciidoc.ui_3.0.42.202201072301.jar failed on Connect to https://eclipse.mirror.rafal.ca:443 [eclipse.mirror.rafal.ca/207.210.46.249] failed: Connection refused. Retry attempt 0 started

内容的提问来源于stack exchange，提问作者manu muraleedharan