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[wiki.git] / ubuntu.mdwn

diff --git a/ubuntu.mdwn b/ubuntu.mdwn
index 5384b41f12996e234816ad8d28cf9ad5e2b763fc..ce90e2df85ad04cc8e6b60d52660247aa47e843d 100644 (file)
--- a/ubuntu.mdwn
+++ b/ubuntu.mdwn
@@ -10,10 +10,19 @@ https://help.ubuntu.com/community/AptGet/Howto
     dpkg --list
 
     # show info for a package
-    dpkg --status package_name
+    dpkg --status foobar
 
-    # show files owned by a package
-    dpkg --listfiles package_name
+    # show files owned by an installed package
+    dpkg --listfiles foobar
+
+    # show files owned by an uninstalled package
+    apt-file list foobar
+
+    # show which package owns a file
+    dpkg -S /usr/bin/foobar
+
+    # show which package will own a file
+    apt-file find /usr/bin/foobar
 
     # resynchronize the package index files from their sources
     apt-get update
@@ -68,18 +77,72 @@ https://www.digitalocean.com/community/tutorials/how-to-add-delete-and-grant-sud
 
 ## iptables
 
+    # so that firewall rules load at boot
+    apt-get install iptables-persistent
+    # edit rules
+    vim /etc/iptables/rules.v4 
+    # reload rules
+    iptables-restore < /etc/iptables/rules.v4
+    # save rules
+    invoke-rc.d iptables-persistent save
+
+### Sample iptables firewall rules
+
+    root@server2:~# cat /etc/iptables/rules.v4
+    # Generated by iptables-save v1.4.21 on Wed Oct 14 22:17:08 2015
+    *filter
+    :INPUT ACCEPT [0:0]
+    :FORWARD ACCEPT [0:0]
+    :OUTPUT ACCEPT [72:34181]
+    -A INPUT -i lo -j ACCEPT
+    -A INPUT -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
+    -A INPUT -p tcp -m tcp --dport 22 -j ACCEPT
+    -A INPUT -p tcp -m tcp --dport 80 -j ACCEPT
+    -A INPUT -j DROP
+    COMMIT
+    # Completed on Wed Oct 14 22:17:08 2015
+    root@server2:~#
+
 https://help.ubuntu.com/community/IptablesHowTo
 
 https://www.digitalocean.com/community/tutorials/how-to-set-up-a-firewall-using-iptables-on-ubuntu-14-04
 
 ## Apache httpd
 
+Install Apache
+
     sudo apt-get install apache2
 
 https://www.digitalocean.com/community/tutorials/how-to-set-up-apache-virtual-hosts-on-ubuntu-14-04-lts
 
+Restart Apache
+
+    systemctl reload apache2
+
+Enable site
+
+    a2ensite data.greptilian.com
+
+Show enabled sites
+
+    apache2ctl -S
+
 ## MySQL
 
     sudo apt-get install mysql-server
 
 https://www.digitalocean.com/community/tutorials/a-basic-mysql-tutorial
+
+## Timezone
+
+    sudo timedatectl set-timezone America/New_York
+
+https://www.digitalocean.com/community/tutorials/how-to-set-up-time-synchronization-on-ubuntu-18-04
+
+## Grub
+
+On a new installation of Ubuntu 18.04 on Digital Ocean I ran `sudo apt-get dist-upgrade` and saw this message:
+
+"A new version of /boot/grub/menu.lst is available, but the version installed currently has been locally modified. What would you like to do about menu.lst?
+
+I selected the first option called "install the package maintainer's version" even though the second option called "keep the local version currently installed" was highlighted. Showing differences didn't work. I rebooted the server and it came back up. There's a related post at https://www.digitalocean.com/community/questions/ubuntu-new-boot-grub-menu-lst-after-apt-get-upgrade