Speeding Up Jenkins Plugin Downloads in China with the TUNA Mirror and Update‑Center Fixes

Jenkins' community infrastructure is hosted on overseas servers without a domestic CDN or load‑balancing, causing Chinese users to experience very slow or timed‑out plugin downloads despite the availability of over 1,500 plugins.

Developers, who naturally prefer quick solutions, often wonder why they must wait for data packets from the United States; many have already installed dozens of plugins. The TUNA (Tsinghua University) open‑source mirror site offers a convenient mirror for Jenkins resources.

https://mirrors.tuna.tsinghua.edu.cn/jenkins/

However, simply changing the Update Center URL in Jenkins' plugin manager does not fully resolve the slowness, even after switching networks or devices. The author opened an issue to investigate further.

https://github.com/tuna/issues/issues/659

While rsync can synchronize the 106 GB of plugin files, it does not eliminate the final‑mile latency problem.

The root cause lies in how Jenkins parses the update-center.json file: the official server signs the file with a private key, while a public key is bundled in the distribution. Only update-center.json files that pass this signature verification are used.

https://github.com/jenkins-infra/update-center2/pull/245

Knowing the issue, the Chinese Jenkins community prepared a three‑step fix that replaces the signed JSON URL and provides the correct public key, as illustrated in the following diagrams.

The solution and all its components (except the private signing key) are open source; no monetary cost is required, only existing compute and storage resources. The community also thanks TUNA, GitHub Actions, and Gitee Pages for their support.

https://github.com/jenkins-zh/mirror-adapter

The most important point, revealed at the end, is to use the Chinese localization plugin version 1.0.10 for the fastest installation experience.

https://plugins.jenkins.io/localization-zh-cn