开源项目Syncthing-Android环境搭建与编译

NAS - SyncthingAndroid

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NAS - SyncthingAndroid

之所以了解SyncthingAndroid 开源项目，是因为最近两年关注到一款产品 NAS产品，恰好有朋友在做这款产品，就去研究了一下基于NAS产品的一些技术实现。

国内已经有非常成熟的生产厂商了，也在大面积铺货。 从时间技术上 SyncthingAndroid 并不是唯一技术实现，服务端可以用samba或者webdav 文件挂载，穿透方案可以用
n2n,Android和ios 叫hin2n,国外用syncthing 开源整体方案来做。

这里针对 SyncthingAndroid 端来讲一下环境搭建问题。

参考资料

syncthing-android
syncthing-android-fdroid

这里将的是syncthing-android-fdroid 环境搭建，其实它就是基于 syncthing-android 实现的。

编译

其实开源软件已经说明了 用 Linux 或者 SSL 推荐的编译方式，且编译步骤已经说明了的。

Build on Debian Linux / WSL - recommended way
A Linux VM, for example running Debian, is recommended to build this.

Build SyncthingNative and the Syncthing-Android wrapper using the following commands:

#
# Install prerequisites.
apt-get -y install gcc git openjdk-17-jdk python3 unzip
#
# Clone repository.
mkdir -p ~/git && cd ~/git
git clone https://github.com/Catfriend1/syncthing-android.git --recursive
## git stash && git pull origin Catfriend1-patch-1 && git checkout Catfriend1-patch-1
#
# Build
cd ~/git/syncthing-android
python3 install_minimum_android_sdk_prerequisites.py
./gradlew buildNative
export ANDROID_HOME=~/git/syncthing-android-prereq
echo -e "\norg.gradle.jvmargs=-Xmx4096m" >> gradle.properties
./gradlew lintDebug
./gradlew assembleDebug

解决编译遇到的各种问题

上面Build 已经说明了步骤，但是实际操作中会遇到各种问题，下面一一例举并说明修改方案。
为什么会遇到这些问题？ 毕竟是在国内，开源项目会造成各种依赖条件不可达呗…

gradle 无法下载

root@wfc-VMware-Virtual-Platform:~/git/syncthing-android# ./gradlew buildNative
Downloading https://services.gradle.org/distributions/gradle-8.9-bin.zip

Exception in thread "main" java.io.IOException: Downloading from https://services.gradle.org/distributions/gradle-8.9-bin.zip failed: timeout

解决方案，替换成阿里镜像：
修改文件：syncthing-android/gradle/wrapper/gradle-wrapper.properties

#Thu Sep 29 21:34:28 CEST 2022
# https://gradle.org/release-checksums/
distributionBase=GRADLE_USER_HOME
distributionUrl=https\://mirrors.cloud.tencent.com/gradle/gradle-8.9-bin.zip
distributionPath=wrapper/dists
zipStorePath=wrapper/dists
#distributionSha256Sum=d725d707bfabd4dfdc958c624003b3c80accc03f7037b5122c4b1d0ef15cecab
zipStoreBase=GRADLE_USER_HOME

syncthing.git 访问不可达

具体报错如下：

./gradlew buildNative
Downloading https://mirrors.cloud.tencent.com/gradle/gradle-8.9-bin.zip
............10%.............20%.............30%.............40%.............50%.............60%.............70%.............80%.............90%.............100%

Welcome to Gradle 8.9!

Here are the highlights of this release:
 - Enhanced Error and Warning Messages
 - IDE Integration Improvements
 - Daemon JVM Information

For more details see https://docs.gradle.org/8.9/release-notes.html

Starting a Gradle Daemon (subsequent builds will be faster)

> Task :syncthing:checkPython
Using python 3.12.3 from /usr (python3)

> Task :syncthing:buildNative
[python] python3 -u ./build-syncthing.py
         git_bin='/usr/bin/git'
         Info: go is not available on the PATH. Trying install_go
         Downloading prebuilt-go to: /root/git/syncthing-android/syncthing/../../syncthing-android-prereq/go_1.24.1.tgz
         Downloaded prebuilt-go to: /root/git/syncthing-android/syncthing/../../syncthing-android-prereq/go_1.24.1.tgz
         SHA-256: /root/git/syncthing-android/syncthing/../../syncthing-android-prereq/go_1.24.1.tgz cb2396bae64183cdccf81a9a6df0aea3bce9511fc21469fb89a0c00470088073
         [ok] Checksum of /root/git/syncthing-android/syncthing/../../syncthing-android-prereq/go_1.24.1.tgz matches expected value.
         Extracting prebuilt-go ...
         Adding to PATH: /root/git/syncthing-android/syncthing/../../syncthing-android-prereq/go_1.24.1/bin
         go_bin='/root/git/syncthing-android/syncthing/../../syncthing-android-prereq/go_1.24.1/bin/go'
         ANDROID_NDK_HOME env var is not defined. Then, NDK_VERSION and ANDROID_SDK_ROOT env vars must be defined.
         Downloading NDK to: /root/git/syncthing-android/syncthing/../../syncthing-android-prereq/ndk_r28.zip
         Downloaded NDK to: /root/git/syncthing-android/syncthing/../../syncthing-android-prereq/ndk_r28.zip
         SHA-1: /root/git/syncthing-android/syncthing/../../syncthing-android-prereq/ndk_r28.zip 894f469c5192a116d21f412de27966140a530ebc
         [ok] Checksum of /root/git/syncthing-android/syncthing/../../syncthing-android-prereq/ndk_r28.zip matches expected value.
         Extracting NDK ...
         Adding ANDROID_NDK_HOME='/root/git/syncthing-android/syncthing/../../syncthing-android-prereq/android-ndk-r28'
         ANDROID_NDK_HOME='/root/git/syncthing-android/syncthing/../../syncthing-android-prereq/android-ndk-r28'
         Invoking git fetch ...
         fatal: unable to access 'https://github.com/syncthing/syncthing.git/': Recv failure: Connection reset by peer
         Traceback (most recent call last):
           File "/root/git/syncthing-android/syncthing/./build-syncthing.py", line 338, in <module>
             subprocess.check_call([
           File "/usr/lib/python3.12/subprocess.py", line 413, in check_call
             raise CalledProcessError(retcode, cmd)
         subprocess.CalledProcessError: Command '['git', '-C', '/root/git/syncthing-android/syncthing/src/github.com/syncthing/syncthing', 'fetch', '--tags']' returned non-zero exit status 128.

> Task :syncthing:buildNative FAILED

FAILURE: Build failed with an exception.

这里一定要看清问题的本质：是 访问不可达，而不是 python 脚本问题，这个问题自己在开源平台上咨询过都是答非所问…

 fatal: unable to access 'https://github.com/syncthing/syncthing.git/': Recv failure: Connection reset by peer

所以，要怎么分析问题和解决问题？
这里有个天坑 ，因为我是国内环境，ubuntu 无法访问github，这个才是问题的本质，这里也是为什么 github 的 syncthing.git 无法访问的原因。

尝试解决方案：更改DNS 路由

vim /etc/systemd/resolved.conf

nameserver 8.8.8.8
nameserver 1.1.1.1


 vim  /etc/resolv.conf
 nameserver 8.8.8.8
nameserver 1.1.1.1

然后尝试看看github 是否能访问，当然如果还是不行，尝试其它方法看看。

golang 访问不可达

报错日志如下：

root@wfc-VMware-Virtual-Platform:~/git/syncthing-android# ./gradlew buildNative

> Task :syncthing:checkPython
Using python 3.12.3 from /usr (python3)

> Task :syncthing:buildNative
[python] python3 -u ./build-syncthing.py
         git_bin='/usr/bin/git'
         Info: go is not available on the PATH. Trying install_go
         Downloaded prebuilt-go to: /root/git/syncthing-android/syncthing/../../syncthing-android-prereq/go_1.24.1.tgz
         SHA-256: /root/git/syncthing-android/syncthing/../../syncthing-android-prereq/go_1.24.1.tgz cb2396bae64183cdccf81a9a6df0aea3bce9511fc21469fb89a0c00470088073
         [ok] Checksum of /root/git/syncthing-android/syncthing/../../syncthing-android-prereq/go_1.24.1.tgz matches expected value.
         Adding to PATH: /root/git/syncthing-android/syncthing/../../syncthing-android-prereq/go_1.24.1/bin
         go_bin='/root/git/syncthing-android/syncthing/../../syncthing-android-prereq/go_1.24.1/bin/go'
         ANDROID_NDK_HOME env var is not defined. Then, NDK_VERSION and ANDROID_SDK_ROOT env vars must be defined.
         Downloaded NDK to: /root/git/syncthing-android/syncthing/../../syncthing-android-prereq/ndk_r28.zip
         SHA-1: /root/git/syncthing-android/syncthing/../../syncthing-android-prereq/ndk_r28.zip 894f469c5192a116d21f412de27966140a530ebc
         [ok] Checksum of /root/git/syncthing-android/syncthing/../../syncthing-android-prereq/ndk_r28.zip matches expected value.
         Adding ANDROID_NDK_HOME='/root/git/syncthing-android/syncthing/../../syncthing-android-prereq/android-ndk-r28'
         ANDROID_NDK_HOME='/root/git/syncthing-android/syncthing/../../syncthing-android-prereq/android-ndk-r28'
         Invoking git fetch ...
         From https://github.com/syncthing/syncthing
          + e2973ff2f...fa0d933e4 release-nightly -> origin/release-nightly  (forced update)
         Invoking git describe ...
         Cleaning go-build cache
         Building syncthing version v1.29.4
         
         *** Building for arm
         go: github.com/AudriusButkevicius/recli@v0.0.7-0.20220911121932-d000ce8fbf0f: Get "https://proxy.golang.org/github.com/%21audrius%21butkevicius/recli/@v/v0.0.7-0.20220911121932-d000ce8fbf0f.mod": dial tcp 142.250.217.113:443: connect: connection refused
         Traceback (most recent call last):
           File "/root/git/syncthing-android/syncthing/./build-syncthing.py", line 384, in <module>
             subprocess.check_call([go_bin, 'mod', 'download'], cwd=syncthing_dir)
           File "/usr/lib/python3.12/subprocess.py", line 413, in check_call
             raise CalledProcessError(retcode, cmd)
         subprocess.CalledProcessError: Command '['/root/git/syncthing-android/syncthing/../../syncthing-android-prereq/go_1.24.1/bin/go', 'mod', 'download']' returned non-zero exit status 1.

> Task :syncthing:buildNative FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':syncthing:buildNative'.
> Python call failed: python3 -u ./build-syncthing.py
  
        OUTPUT:
                git_bin='/usr/bin/git'
                Info: go is not available on the PATH. Trying install_go
                Downloaded prebuilt-go to: /root/git/syncthing-android/syncthing/../../syncthing-android-prereq/go_1.24.1.tgz
                SHA-256: /root/git/syncthing-android/syncthing/../../syncthing-android-prereq/go_1.24.1.tgz cb2396bae64183cdccf81a9a6df0aea3bce9511fc21469fb89a0c00470088073
                [ok] Checksum of /root/git/syncthing-android/syncthing/../../syncthing-android-prereq/go_1.24.1.tgz matches expected value.
                Adding to PATH: /root/git/syncthing-android/syncthing/../../syncthing-android-prereq/go_1.24.1/bin
                go_bin='/root/git/syncthing-android/syncthing/../../syncthing-android-prereq/go_1.24.1/bin/go'
                ANDROID_NDK_HOME env var is not defined. Then, NDK_VERSION and ANDROID_SDK_ROOT env vars must be defined.
                Downloaded NDK to: /root/git/syncthing-android/syncthing/../../syncthing-android-prereq/ndk_r28.zip
                SHA-1: /root/git/syncthing-android/syncthing/../../syncthing-android-prereq/ndk_r28.zip 894f469c5192a116d21f412de27966140a530ebc
                [ok] Checksum of /root/git/syncthing-android/syncthing/../../syncthing-android-prereq/ndk_r28.zip matches expected value.
                Adding ANDROID_NDK_HOME='/root/git/syncthing-android/syncthing/../../syncthing-android-prereq/android-ndk-r28'
                ANDROID_NDK_HOME='/root/git/syncthing-android/syncthing/../../syncthing-android-prereq/android-ndk-r28'
                Invoking git fetch ...
                From https://github.com/syncthing/syncthing
                 + e2973ff2f...fa0d933e4 release-nightly -> origin/release-nightly  (forced update)
                Invoking git describe ...
                Cleaning go-build cache
                Building syncthing version v1.29.4
                
                *** Building for arm
                go: github.com/AudriusButkevicius/recli@v0.0.7-0.20220911121932-d000ce8fbf0f: Get "https://proxy.golang.org/github.com/%21audrius%21butkevicius/recli/@v/v0.0.7-0.20220911121932-d000ce8fbf0f.mod": dial tcp 142.250.217.113:443: connect: connection refused
                Traceback (most recent call last):
                  File "/root/git/syncthing-android/syncthing/./build-syncthing.py", line 384, in <module>
                    subprocess.check_call([go_bin, 'mod', 'download'], cwd=syncthing_dir)
                  File "/usr/lib/python3.12/subprocess.py", line 413, in check_call
                    raise CalledProcessError(retcode, cmd)
                subprocess.CalledProcessError: Command '['/root/git/syncthing-android/syncthing/../../syncthing-android-prereq/go_1.24.1/bin/go', 'mod', 'download']' returned non-zero exit status 1.


* Try:
> Run with --stacktrace option to get the stack trace.
> Run with --info or --debug option to get more log output.
> Run with --scan to get full insights.
> Get more help at https://help.gradle.org.

BUILD FAILED in 17m 42s
2 actionable tasks: 2 executed

当我们满心欢喜声明问题已经解决，开始build arm ,结果又报错了：
dial tcp 142.250.217.113:443: connect: connection refused

这里是还有个坑，无法访问这个地址，go 相关的，千万不要理解为python 脚本问题了。

大家可以看看尝试 网上搜一搜解决方案， 最终我自己也是不断倒腾出来的，设置代理解决。 当然遇到无法解决，再次尝试其它方法

echo 'export GOPROXY=https://goproxy.cn' >> ~/.bashrc
source ~/.bashrc

go env -w GO111MODULE=on
go mod vendor
apt install udo

防坑

这里能不开代理软件千万不要开代理软件，比如会遇到 无法访问github 就去打开代理软件，虽然能访问github了，但是还是无法访问github中的其它资源了。 慎用

总结

自己花了好几周，找了好多资料，测试无数测最终解决了编译问题：其实就是两个大问题，需要看到具体日志，然后解决。

• github 依赖的资源无法访问，需要解决ubuntu 访问github 问题，修改dns 路由解决
• go 在编译过程中编译不成功，需要解决网络接口不可达，设置go 代理来解决。