記一次重裝nginx時遇到的問題

時間 2020-07-08

標籤一次重裝 nginx 遇到問題欄目 Nginx 简体版

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原由

以前在網上看文章提到說，經過 apt-get 的方式安裝 nginx，可能安裝不是最新版本的狀況，考慮到在 Ubuntu 下第一次安裝 nginx，之後確定會有卸載從新安裝新版本的需求，恰好剛開始學習 nginx，索性練習下卸載重裝的過程。html

安裝

使用 Ubuntu 下的包管理工具 apt 來安裝 nginxnginx

$ sudo apt-get install nginx
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卸載

一樣使用 apt 來卸載 nginxweb

$ sudo apt-get remove nginx
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sudo apt-get autoremove命令幫咱們卸載再也不須要的依賴包在這裏咱們卸載 nginx 相關的依賴包apache

$ sudo apt-get autoremove
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刪除 nginx 配置文件夾ubuntu

$ sudo rm -rf /etc/nginx
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從新安裝 nginx

# 更新源
$ sudo apt update
$ sudo apt-get install nginx
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然而控制檯報錯：bash

Job for nginx.service failed because the control process exited with error code. See "systemctl status nginx.service" and "journalctl -xe" for details.
invoke-rc.d: initscript nginx, action "start" failed.
dpkg: error processing package nginx-core (--configure):
 subprocess installed post-installation script returned error exit status 1
dpkg: dependency problems prevent configuration of nginx:
 nginx depends on nginx-core (>= 1.10.3-0ubuntu0.16.04.2) | nginx-full (>= 1.10.3-0ubuntu0.16.04.2) | nginx-light (>= 1.10.3-0ubuntu0.16.04.2) | nginx-extras (>= 1.10.3-0ubuntu0.16.04.2); however:
  Package nginx-core is not configured yet.
  Package nginx-full is not installed.
  Package nginx-light is not installed.
  Package nginx-extras is not installed.
 nginx depends on nginx-core (<< 1.10.3-0ubuntu0.16.04.2.1~) | nginx-full (<< 1.10.3-0ubuntu0.16.04.2.1~) | nginx-light (<< 1.10.3-0ubuntu0.16.04.2.1~) | nginx-extras (<< 1.10.3-0ubuntu0.16.04.2.1~); however:
  Package nginx-core is not configured yet.
 No apport report written because the error message indicates its a followup error from a previous failure.
 Package nginx-full is not installed.
  Package nginx-light is not installed.
  Package nginx-extras is not installed.

dpkg: error processing package nginx (--configure):
 dependency problems - leaving unconfigured
Processing triggers for libc-bin (2.23-0ubuntu9) ...
Errors were encountered while processing:
 nginx-core
 nginx
E: Sub-process /usr/bin/dpkg returned an error code (1)
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查看nginx.service狀態架構

$ systemctl status nginx.service
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● nginx.service - A high performance web server and a reverse proxy server
   Loaded: loaded (/lib/systemd/system/nginx.service; enabled; vendor preset: enabled)
   Active: failed (Result: exit-code) since Sat 2018-03-17 23:16:40 CST; 1min 18s ago
  Process: 26795 ExecStartPre=/usr/sbin/nginx -t -q -g daemon on; master_process on; (code=exited, status=1/FAILURE)
 Main PID: 18259 (code=exited, status=0/SUCCESS)

Mar 17 23:16:40 VM-0-5-ubuntu systemd[1]: Starting A high performance web server and a reverse proxy server...
Mar 17 23:16:40 VM-0-5-ubuntu nginx[26795]: nginx: [emerg] open() "/etc/nginx/nginx.conf" failed (2: No such file or direMar 17 23:16:40 VM-0-5-ubuntu nginx[26795]: nginx: configuration file /etc/nginx/nginx.conf test failed
Mar 17 23:16:40 VM-0-5-ubuntu systemd[1]: nginx.service: Control process exited, code=exited status=1
Mar 17 23:16:40 VM-0-5-ubuntu systemd[1]: Failed to start A high performance web server and a reverse proxy server.
Mar 17 23:16:40 VM-0-5-ubuntu systemd[1]: nginx.service: Unit entered failed state.
Mar 17 23:16:40 VM-0-5-ubuntu systemd[1]: nginx.service: Failed with result 'exit-code'.
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仔細看報錯信息，獲取到兩個信息點：app

Package nginx-core is not configured yet.
Package nginx-full/nginx-light/nginx-extras is not installed.

因而上網搜，網上找說多是apache佔用了80端口致使報錯ssh

查看端口占用狀況tcp

$ sudo netstat -nlp
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Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      1287/sshd
udp        0      0 0.0.0.0:68              0.0.0.0:*                           891/dhclient
udp        0      0 172.21.0.5:123          0.0.0.0:*                           1231/ntpd
udp        0      0 127.0.0.1:123           0.0.0.0:*                           1231/ntpd
udp        0      0 0.0.0.0:123             0.0.0.0:*                           1231/ntpd
udp6       0      0 :::123                  :::*                                1231/ntpd
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發現 80 端口沒被佔用，並且systemctl status nginx.service的提示信息也沒說起 80 端口被佔用，若是提示信息中說 80 端口被佔用，能夠執行如下兩步試試：

終止 apache 運行

$ sudo service apache2 stop
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從新安裝 nginx

$ sudo apt-get install nginx
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瞭解詳細信息請看askubuntu 上的提問

上述狀況與個人並不相符，因而換個思路，報錯信息中說起 nginx 的配置文件不存在，思考爲何卸載重裝 nginx，卻沒有生成配置文件？和第一次安裝的時候不同，而後百度上搜nginx卸載重裝後配置文件沒有從新生成，找到了相似的問題，給出了以下的操縱步驟：

卸載 nginx 不保留配置文件

$ sudo apt-get --purge remove nginx

Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
  fontconfig-config fonts-dejavu-core libfontconfig1 libgd3 libjbig0 libjpeg-turbo8 libjpeg8 libtiff5 libvpx3 libxpm4
  libxslt1.1 nginx-common nginx-core
Use 'sudo apt autoremove' to remove them.
The following packages will be REMOVED:
  nginx*
0 upgraded, 0 newly installed, 1 to remove and 205 not upgraded.
2 not fully installed or removed.
After this operation, 37.9 kB disk space will be freed.
Do you want to continue? [Y/n] y
(Reading database ... 66386 files and directories currently installed.)
Removing nginx (1.10.3-0ubuntu0.16.04.2) ...
Setting up nginx-core (1.10.3-0ubuntu0.16.04.2) ...
Job for nginx.service failed because the control process exited with error code. See "systemctl status nginx.service" and "journalctl -xe" for details.
invoke-rc.d: initscript nginx, action "start" failed.
dpkg: error processing package nginx-core (--configure):
 subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
 nginx-core
E: Sub-process /usr/bin/dpkg returned an error code (1)
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卸載自動安裝且再也不須要的依賴包

$ sudo apt-get autoremove

Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be REMOVED:
  fontconfig-config fonts-dejavu-core libfontconfig1 libgd3 libjbig0 libjpeg-turbo8 libjpeg8 libtiff5 libvpx3 libxpm4
  libxslt1.1 nginx-common nginx-core
0 upgraded, 0 newly installed, 13 to remove and 205 not upgraded.
1 not fully installed or removed.
After this operation, 9,745 kB disk space will be freed.
Do you want to continue? [Y/n] y
(Reading database ... 66383 files and directories currently installed.)
Removing nginx-core (1.10.3-0ubuntu0.16.04.2) ...
Removing libgd3:amd64 (2.1.1-4ubuntu0.16.04.8) ...
Removing libfontconfig1:amd64 (2.11.94-0ubuntu1.1) ...
Removing fontconfig-config (2.11.94-0ubuntu1.1) ...
Removing fonts-dejavu-core (2.35-1) ...
Removing libtiff5:amd64 (4.0.6-1ubuntu0.2) ...
Removing libjbig0:amd64 (2.1-3.1) ...
Removing libjpeg8:amd64 (8c-2ubuntu8) ...
Removing libjpeg-turbo8:amd64 (1.4.2-0ubuntu3) ...
Removing libvpx3:amd64 (1.5.0-2ubuntu1) ...
Removing libxpm4:amd64 (1:3.5.11-1ubuntu0.16.04.1) ...
Removing libxslt1.1:amd64 (1.1.28-2.1ubuntu0.1) ...
Removing nginx-common (1.10.3-0ubuntu0.16.04.2) ...
Processing triggers for libc-bin (2.23-0ubuntu9) ...
Processing triggers for man-db (2.7.5-1) ...
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篩選已安裝軟件包中與 nginx 有關的

$ dpkg --get-selections | grep nginx

nginx-common                                    deinstall
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卸載nginx-common不保留配置文件

$ sudo apt-get --purge remove nginx-common

Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be REMOVED:
  nginx-common*
0 upgraded, 0 newly installed, 1 to remove and 205 not upgraded.
After this operation, 0 B of additional disk space will be used.
Do you want to continue? [Y/n] y
(Reading database ... 66243 files and directories currently installed.)
Removing nginx-common (1.10.3-0ubuntu0.16.04.2) ...
Purging configuration files for nginx-common (1.10.3-0ubuntu0.16.04.2) ...
dpkg: warning: while removing nginx-common, directory '/var/www/html' not empty so not removed
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從新安裝 nginx

$ sudo apt-get install nginx
...
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查看版本號，執行 nginx 配置文件語法檢測

$ nginx -v
nginx version: nginx/1.10.3 (Ubuntu)

$ sudo nginx -t
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful
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雖然 nginx 已經重裝好了，可是一路下來還有幾個困惑：

apt-get autoremove 究竟是按什麼規則卸載軟件？
爲何 nginx-common 沒有在一開始的時候卸載？

1. apt-get autoremove 究竟是按什麼規則卸載軟件？

apt-get autoremove：刪除，自動安裝的，且再也不須要的（不被其餘軟件看成依賴的）軟件包

舉個栗子: 經過 apt-get 方式安裝 nginx 時，會經過引導自動安裝所需的依賴包（nginx-core），而當咱們卸載 nginx 後，那些自動安裝的依賴包就成爲再也不須要的軟件包（nginx-core），經過apt-get autoremove會自動清理它們

既然會自動刪除再也不須要的軟件包，那麼爲何 nginx-common 沒被刪除？

2. 爲何 nginx-common 沒有在`apt-get autoremove`的時候卸載？

不知道細心的童鞋發現沒，咱們在卸載 nginx 的時候，手動刪除了 nginx 的配置文件夾（sudo rm -rf /etc/nginx）。那這些配置文件夾和nginx-common軟件包有什麼關係呢？

經過查找 ubuntu packages，找到了Ubuntu16.0.4 下 nginx-common 軟件包的文件清單。

按照清單上的目錄手動排查，發現本機上除了手動刪除的/etc/nginx目錄不存在，文件清單內的其餘文件都沒有被刪除， ~~猜想多是 nginx-common 軟件包完整性被破壞，致使autoremove的時候沒有被刪除，固然這隻個人猜想。~~

問題回答後續補充:

整理徹底卸載 nginx 命令時，發現執行以下命令，ngnix 的配置文件並無被刪除

$ sudo apt-get remove --purge nginx
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查閱 ubuntu packages 發現，nginx 依賴 nginx-core，nginx-core 依賴 nginx-common，且其中 nginx 的配置文件屬於 nginx-common 軟件包配置文件的一部分。

執行以下命令進一步驗證

# 卸載nginx-common ，nginx配置文件不會被刪除
$ sudo apt-get remove nginx-common
...
# 卸載nginx-common，nginx配置文件已經被刪除（包括但不限於）
$ sudo apt-get remove --purge nginx-common
$ find /etc/nginx/
find: ‘/etc/nginx/’: No such file or directory
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推翻以前的猜想：

apt-get autoremove執行時，nginx-common軟件包已經被選擇用於卸載( deinstall )，可是實際尚未卸載。

$ dpkg --get-selections| grep nginx
nginx-common                                    deinstall
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瞭解更多關於 deinstall，點擊這裏，若是有知道爲何的同窗請不吝賜教。

命令彙總

# 徹底卸載nginx
$ sudo apt-get remove --purge nginx
$ sudo apt-get autoremove --purge

# 更新nginx，保留配置文件
# 親測nginx.conf不會被刪除和覆蓋，但保險起見仍是建議先備份
$ sudo apt-get remove nginx
$ sudo apt-get autoremove
$ sudo apt update
$ sudo apt-get install nginx

# 安裝軟件包
# sudo apt-get install 軟件包名稱`
# eg:
$ sudo apt-get install nginx

# 卸載軟件包
# sudo apt-get remove 軟件包名稱
# eg:
$ sudo apt-get remove nginx

# 卸載軟件包且不保留配置文件
# sudo apt-get remove --purge 軟件包名稱
# eg:
$ sudo apt-get remove --purge nginx

# 卸載自動安裝的軟件包且不保留配置文件
# sudo apt-get autoremove --purge

# 列出本地軟件包列表
# dpkg --get-selections [| grep 篩選關鍵字]
# eg:（列出本地全部軟件包）
$ dpkg --get-selections
# eg:（列出本地與ngnix有關的軟件包）
$ dpkg --get-selections | grep nginx

# 查看進程信息
# ps -ef [| grep 篩選關鍵字]
# eg:（列出全部進程信息）
$ ps -ef
# eg:（列出與nginx有關的進程信息）
$ ps -ef | grep nginx

# 查看端口占用信息
$ sudo netstat -nlp

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