Devstack — screen 調試工具的使用

目錄

目錄 為什麼要使用 screen 工具 啟動 screen screen 的切換常用 退出和重新串連 screen Restart Openstack Services screen 指令選項總覽 Openstack 重啟指令 glance-api glance-registry nova-api nova-conduter nova-crt nova-network nova-scheduter nova-novnc nova-cauth nova-cpu c-api c-sch c-vol

為什麼要使用 screen 工具 。

當 Devstack 編譯安裝完 OpenStack 後，我們是不能通過 init 指令碼或者 service 指令來與各個 Openstack Services 進行互動的。
也就是說我們無法像使用 RDO 安裝那樣可以通過 systemctl restart openstack-nova-api.serice 來重啟 nova-api 服務。
因為 Devstack 的設計初衷是便於 Openstack developers 開發和調試 Openstack 代碼，所以 Devstack 只能通過 screen 來啟動服務，而且每一個 Openstack Services 都是一個子 screen 。Devstack 部署的 Openstack 相信大家都會遇見一個問題，當物理機重啟後 Services 怎麼重啟，其實只需要執行 ./rejoin-stack.sh就好了，其原理跟啟動 screen 是一樣的，將沒有啟動的 Services 啟動，已經啟動的不會被覆蓋，啟動完成後自動進入 screen 。在 screen 中我們不僅僅可以啟動 Services ，我們還能夠非常清晰簡便的切換查看各個 Services 的 Log 。本篇主要介紹了 screen 的使用，應該是多有 Openstack 開發人員的必備技能吧。 啟動 screen

screen -x stack

注意：如果啟動失敗，可以嘗試在執行下面的指令之後在重新嘗試啟動：

script /dev/null

可以看見 Terminal 最下方有一串白色的字串，其中的每一個數字對應一個子 screen 也就是一個 Openstack services 。
我們可以通過快速鍵+數位組合來切換到對應的子 screen 。’ * ‘ 所在的處的位置表示當前的 screen 是該 Service 的 screen。EXAMPLE:

14$(L) c-api  15-$(L) c-sch   16$(L) c-vol*

screen 的切換(常用)

CTRL+a + number ：切換到數字 number 對應的子 screen 中(number == 0 ⇒ shell)

CTRL + a + ’ ⇒ 輸入number：當 number > 10 時，可以使用這種方法來切換，當然 number < 10 時，也可以使用。 推薦*

CTRL + a + n ：切換到下一個 screen

CTRL + a + p：切換到前一個 screen

CTRL + a + a：返回上一個 screen

CRTL + a + 稍等一秒 + shift + ‘：顯示所有的 screen 的列表

CTRL + [：開始滾動模式 ，然後可以使用上下左右鍵滾屏

CTRL + ]：退出滾動模式

CTRL + a + H ：儲存 screen 到記錄檔，再按一次停止儲存

CTRL + a + ?：擷取協助資訊 退出和重新串連 screen

退出： CRTL + a + ’ ⇒ 輸入 0 ，然後再輸入screen -d CRTL + a + d

重新串連：

#查看目前使用者啟動的 screenfanguiju@jmilkfan:~$ screen -ls   There is a screen on:    20569.stack (08/02/16 11:36:47) (Detached)1 Socket in /var/run/screen/S-fanguiju.#上一條指令的Outputfanguiju@jmilkfan:~$ screen -r 20569  

Restart Openstack Services

CTRL + c：終止一個 screen ，Stop the services

進入希望 Restart 的 Openstack Services 的 screen 中，然後輸入 CTRL + c 結束這個進程，輸入 ↑並重新執行上一條指令。
screen 指令選項總覽

fanguiju@fanguiju:~/devstack$ screen --help Use: screen [-opts] [cmd [args]] or: screen -r [host.tty]Options:-4            Resolve hostnames only to IPv4 addresses.-6            Resolve hostnames only to IPv6 addresses.-a            Force all capabilities into each window's termcap.-A -[r|R]     Adapt all windows to the new display width & height.-c file       Read configuration file instead of '.screenrc'.-d (-r)       Detach the elsewhere running screen (and reattach here).-dmS name     Start as daemon: Screen session in detached mode.-D (-r)       Detach and logout remote (and reattach here).-D -RR        Do whatever is needed to get a screen session.-e xy         Change command characters.-f            Flow control on, -fn = off, -fa = auto.-h lines      Set the size of the scrollback history buffer.-i            Interrupt output sooner when flow control is on.-l            Login mode on (update /var/run/utmp), -ln = off.-ls [match]   or -list. Do nothing, just list our SockDir [on possible matches].-L            Turn on output logging.-m            ignore $STY variable, do create a new screen session.-O            Choose optimal output rather than exact vt100 emulation.-p window     Preselect the named window if it exists.-q            Quiet startup. Exits with non-zero return code if unsuccessful.-r [session]  Reattach to a detached screen process.-R            Reattach if possible, otherwise start a new session.-s shell      Shell to execute rather than $SHELL.-S sockname   Name this session <pid>.sockname instead of <pid>.<tty>.<host>.-t title      Set title. (window's name).-T term       Use term as $TERM for windows, rather than "screen".-U            Tell screen to use UTF-8 encoding.-v            Print "Screen version 4.01.00devel (GNU) 2-May-06".-wipe [match] Do nothing, just clean up SockDir [on possible matches].-x            Attach to a not detached screen. (Multi display mode).-X            Execute <cmd> as a screen command in the specified session.

Openstack 重啟指令

screen 有一個非常不方便的地方就是，有些電腦不能通過 CTRL + [|] 來實現螢幕的滾動，這根本無法很好的觀察 Log ，所以建議將啟動指令 Copy 另外一個 Terminal 執行。
注意：下列的指令的/opt/stack/參數因各人的安裝路徑不同而異。
restart glance: glance-api

/usr/local/bin/glance-api --config-file=/etc/glance/glance-api.conf & echo $! >/opt/stack/status/stack/g-api.pid; fg || echo "g-api failed to start" | tee "/opt/stack/status/stack/g-api.failure"

glance-registry

/usr/local/bin/glance-registry --config-file=/etc/glance/glance-registry.conf & echo $! >/opt/stack/status/stack/g-reg.pid; fg || echo "g-reg failed to start" | tee "/opt/stack/status/stack/g-reg.failure"

nova-api

sudo /usr/local/bin/nova-api & echo $! >/opt/stack/status/stack/n-api.pid; fg || echo "n-api failed to start" | tee "/opt/stack/status/stack/n-api.failure"

nova-conduter

/usr/local/bin/nova-conductor --config-file /etc/nova/nova.conf & echo $! >/opt/stack/status/stack/n-cond.pid; fg || echo "n-cond failed to start" | tee "/opt/stack/status/stack/n-cond.failure"

nova-crt

/usr/local/bin/nova-cert --config-file /etc/nova/nova.conf & echo $! >/opt/stack/status/stack/n-crt.pid; fg || echo "n-crt failed to start" | tee "/opt/stack/status/stack/n-crt.failure"

nova-network

/usr/local/bin/nova-network --config-file /etc/nova/nova.conf & echo $! >/opt/stack/status/stack/n-net.pid; fg || echo "n-net failed to start" | tee "/opt/stack/status/stack/n-net.failure"

nova-scheduter

/usr/local/bin/nova-scheduler --config-file /etc/nova/nova.conf & echo $! >/opt/stack/status/stack/n-sch.pid; fg || echo "n-sch failed to start" | tee "/opt/stack/status/stack/n-sch.failure"

nova-novnc

/usr/local/bin/nova-novncproxy --config-file /etc/nova/nova.conf --web /opt/stack/noVNC & echo $! >/opt/stack/status/stack/n-novnc.pid; fg || echo "n-novnc failed to start" | tee "/opt/stack/status/stack/n-novnc.failure"

nova-cauth

/usr/local/bin/nova-consoleauth --config-file /etc/nova/nova.conf & echo $! >/opt/stack/status/stack/n-cauth.pid; fg || echo "n-cauth failed to start" | tee "/opt/stack/status/stack/n-cauth.failure"

nova-cpu

sg libvirtd '/usr/local/bin/nova-compute --config-file /etc/nova/nova.conf' & echo $! >/opt/stack/status/stack/n-cpu.pid; fg || echo "n-cpu failed to start" | tee "/opt/stack/status/stack/n-cpu.failure"

restart cinder: c-api

/usr/local/bin/cinder-api --config-file /etc/cinder/cinder.conf & echo $! >/opt/stack/status/stack/c-api.pid; fg || echo "c-api failed to start" | tee "/opt/stack/status/stack/c-api.failure"

c-sch

/usr/local/bin/cinder-scheduler --config-file /etc/cinder/cinder.conf & echo $! >/opt/stack/status/stack/c-sch.pid; fg || echo "c-sch failed to start" | tee "/opt/stack/status/stack/c-sch.failure"

c-vol

/usr/local/bin/cinder-volume --config-file /etc/cinder/cinder.conf & echo $! >/opt/stack/status/stack/c-vol.pid; fg || echo "c-vol failed to start" | tee "/opt/stack/status/stack/c-vol.failure"