问题
使用 capistrano 部署 Rails 项目时遇到一个问题：运行 bin 目录下的文件，但是进程没起来。
配置文件及部署
在 deploy.rb 文件中新增了如下内容
on roles(:chasqui) do
execute "for i in $( ps ax | awk '/chasqui_start/ {print $1}' ); do kill ${i}; done"
execute <<-BASH.squish!
cd #{deploy_to}/current
&& nohup ruby ./bin/chasqui_start >/dev/null 2>&1 &
BASH
end
然后部署时相关结果如下：
...
INFO [397a5432] Running for i in $( ps ax | awk '/chasqui_start/ {print $1}' ); do kill ${i}; done as deploy@server_ip_a
DEBUG [397a5432] Command: for i in $( ps ax | awk '/chasqui_start/ {print $1}' ); do kill ${i}; done
INFO [aa096778] Running cd /home/deploy/project_name/current && nohup ruby ./bin/chasqui_start >/dev/null 2>&1 & as deploy@server_ip_a
DEBUG [aa096778] Command: cd /home/deploy/project_name/current && nohup ruby ./bin/chasqui_start >/dev/null 2>&1 &
INFO [aa096778] Finished in 0.065 seconds with exit status 0 (successful).
...
异常
部署成功之后，我上去对应服务器查看服务是否起来：
ps ax | awk '/bin\/chasqui_start/ {print $1}' 没有输出。
但如果上去服务器上执行，服务能够正常起来。
deploy@prime-server-1:~/project_name$ cd /home/deploy/project_name/current && nohup ruby ./bin/chasqui_start >/dev/null 2>&1 &
[2] 2460
[1] Done cd /home/deploy/project_name/current && nohup ruby ./bin/chasqui_start > /dev/null 2>&1
deploy@prime-server-1:~/project_name$ ps ax | awk '/bin\/chasqui_start/ {print $1}'
2500
另外，如果我手动在服务器上执行 bin/chasqui_start 之后，然后通过 capistrano 重新部署，chasqui_start 进程会挂掉，说明 execute "for i in $( ps ax | awk '/chasqui_start/ {print $1}' ); do kill ${i}; done" 还是会执行的，但是cd #{deploy_to}/current
&& nohup ruby ./bin/chasqui_start >/dev/null 2>&1 & 没有执行。
思索并搜索未果，故此一帖请教，多谢。
cd #{deploy_to}/current && nohup ruby ./bin/chasqui_start >/dev/null 2>&1 & 是这句没有指定 ruby 的版本？你可以把错误信息直接打印出来看看
hww
#3
2017年09月24日
感谢楼上两位；
在 @zouqilin 的指导下，应该是 nohup 还没有把服务成功启动，SSH 就退出了。
解决方法为，sleep x seconds
on roles(:chasqui) do
execute "for i in $( ps ax | awk '/chasqui_start/ {print $1}' ); do kill ${i}; done"
execute "bash -l -c 'cd #{deploy_to}/current && (nohup rvm use 2.2.4 do ruby bin/chasqui_start 2>&1 &) && sleep 2 && ps -ef | grep chasqui_start' "
end
部署结果
...
INFO [4926e2d3] Running for i in $( ps ax | awk '/chasqui_start/ {print $1}' ); do kill ${i}; done as deploy@server_a_ip
DEBUG [4926e2d3] Command: for i in $( ps ax | awk '/chasqui_start/ {print $1}' ); do kill ${i}; done
INFO [3bf1335b] Running bash -l -c 'cd /home/deploy/project_name/current && (nohup rvm use 2.2.4 do ruby bin/chasqui_start 2>&1 &) && sleep 2 && ps -ef | grep chasqui_start' as deploy@server_a_ip
DEBUG [3bf1335b] Command: bash -l -c 'cd /home/deploy/project_name/current && (nohup rvm use 2.2.4 do ruby bin/chasqui_start 2>&1 &) && sleep 2 && ps -ef | grep chasqui_start'
DEBUG [3bf1335b] nohup: appending output to ‘nohup.out’
DEBUG [3bf1335b] deploy 12008 1 0 23:57 ? 00:00:00 ruby bin/chasqui_start
DEBUG [3bf1335b] deploy 15134 12310 3 23:59 pts/0 00:00:00 bash -l -c cd /home/deploy/project_name/current && (nohup rvm use 2.2.4 do ruby bin/chasqui_start 2>&1 &) && sleep 2 && ps -ef | grep chasqui_start
deploy 15235 1 10 23:59 pts/0 00:00:00 ruby bin/chasqui_start
deploy 15449 15134 0 23:59 pts/0 00:00:00 grep chasqui_start
INFO [3bf1335b] Finished in 2.248 seconds with exit status 0 (successful).
...