我的Jenkins不在Docker容器中运行，只是传统安装到VPS。执行简单的测试项目时出现以下错误。我正在使用Ubuntu 14，java
7和稳定的Jenkins。我尝试了所有可以在Google上找到的方法，但无法正常工作。

我正在尝试执行此外壳

docker build --pull=true -t nick/hello-jenkins:$GIT_COMMIT .

代码更改后。

这是错误：

Got permission denied while trying to connect to the Docker daemon socket at unix: ....

Started by user nicolas xu
Building in workspace /var/lib/jenkins/workspace/hello-Jenkins
 > git rev-parse --is-inside-work-tree # timeout=10
Fetching changes from the remote Git repository
 > git config remote.origin.url https://github.com/nicolasxu/hello-nick-jenkins.git # timeout=10
Fetching upstream changes from https://github.com/nicolasxu/hello-nick-jenkins.git
 > git --version # timeout=10
 > git fetch --tags --progress https://github.com/nicolasxu/hello-nick-jenkins.git +refs/heads/*:refs/remotes/origin/*
 > git rev-parse refs/remotes/origin/master^{commit} # timeout=10
 > git rev-parse refs/remotes/origin/origin/master^{commit} # timeout=10
Checking out Revision d94ae21a8a2cf58ffc790dcad15bd851fb17df5a (refs/remotes/origin/master)
 > git config core.sparsecheckout # timeout=10
 > git checkout -f d94ae21a8a2cf58ffc790dcad15bd851fb17df5a
 > git rev-list d94ae21a8a2cf58ffc790dcad15bd851fb17df5a # timeout=10
[hello-Jenkins] $ /bin/sh -xe /tmp/hudson5076309502904684976.sh
+ docker build --pull=true -t nick/hello-jenkins:d94ae21a8a2cf58ffc790dcad15bd851fb17df5a .
Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Post http://%2Fvar%2Frun%2Fdocker.sock/v1.27/build?buildargs=%7B%7D&cachefrom=%5B%5D&cgroupparent=&cpuperiod=0&cpuquota=0&cpusetcpus=&cpusetmems=&cpushares=0&dockerfile=Dockerfile&labels=%7B%7D&memory=0&memswap=0&networkmode=default&pull=1&rm=1&shmsize=0&t=nick%2Fhello-jenkins%3Ad94ae21a8a2cf58ffc790dcad15bd851fb17df5a&ulimits=null: dial unix /var/run/docker.sock: connect: permission denied
Build step 'Execute shell' marked build as failure
Finished: FAILURE

我可以在控制台中以root身份运行“ docker”，这没问题，为什么jenkins无法尝试运行“
docker”的shell命令？到底是怎么回事？完全困惑.......