Nick Weavers's questions

I have set my hostname like this:

$ sudo hostnamectl set-hostname dev.mydomain.com

and I see it got set when I do this:

$ hostnamectl status
   Static hostname: dev.mydomain.com
         Icon name: computer-vm
           Chassis: vm
        Machine ID: 3e729c2d7c094902af0333ce40564ffe
           Boot ID: 68ed2ed21a55493785c1b11e2e6f11dc
    Virtualization: kvm
  Operating System: CentOS Linux 8 (Core)
       CPE OS Name: cpe:/o:centos:centos:8
            Kernel: Linux 4.18.0-147.3.1.el8_1.x86_64
      Architecture: x86-64

But when I pin the server from somewhere else (my desktop, or another remote machine) I see this:

$ ping dev.mydomain.com
PING dev.mydomain.com (my-servers-ip-address) 56(84) bytes of data.
64 bytes from some-other-domain-name (my-servers-ip-address): icmp_seq=1 ttl=59 time=20.0 ms

So the first line returned by ping correctly references dev.mydomain.com and it's IP address, but then it gets some other domain for the "64 bytes from..." part of the message

Where is some-other-domain-name coming from?

The machine is vhosting a number of websites as subdomains, so could that be related somehow?

What config files should I be checking?

Thanks

I would like to have script that is doing automated migrations of websites from another be able to append Includes to the /etc/httpd/conf.d/vhosts.conf file.

However, when I try to use echo to put append a string to the end of the file I get this:

$ sudo echo "Include thing" >> /etc/httpd/conf.d/vhosts.conf
-bash: /etc/httpd/conf.d/vhosts.conf: Permission denied

and yet I can vi /etc/httpd/conf.d/vhosts.conf, add the line and :wq the file to save and close it.

What am I missing?

I followed the guide to installing vsftp here https://www.tecmint.com/install-ftp-server-in-rhel-8/

The daemon is running:

# systemctl status vsftpd
● vsftpd.service - Vsftpd ftp daemon
   Loaded: loaded (/usr/lib/systemd/system/vsftpd.service; enabled; vendor preset: disabled)
   Active: active (running) since Wed 2020-01-22 12:33:32 UTC; 5s ago
  Process: 11345 ExecStart=/usr/sbin/vsftpd /etc/vsftpd/vsftpd.conf (code=exited, status=0/SUCCESS)
 Main PID: 11346 (vsftpd)
    Tasks: 1 (limit: 26213)
   Memory: 724.0K
   CGroup: /system.slice/vsftpd.service

           └─11346 /usr/sbin/vsftpd /etc/vsftpd/vsftpd.conf

I have enable the SeLinux security boolean to allow ftpd_full_access

    # sudo getsebool -a | grep ftpd_full_access
    ftpd_full_access --> on

I have a trusted zone that is only accessible from our ofice VPN IP address and these are the rules and services associated with it:

 # firewall-cmd --list-all --zone=trusted
trusted (active)
  target: ACCEPT
  icmp-block-inversion: no
  interfaces:
  sources: <my office vpn ip address>
  services: ftp mysql ssh
  ports: 21/tcp 45073/tcp
  protocols:
  masquerade: no
  forward-ports:
  source-ports:
  icmp-blocks:
  rich rules:

My /etc/vsftpd/vsftpd.conf conf looks like this:

anonymous_enable=NO
local_enable=YES
write_enable=YES
local_umask=022
dirmessage_enable=YES
xferlog_enable=YES
connect_from_port_20=YES
xferlog_std_format=YES
chroot_local_user=YES
listen=YES
listen_ipv6=NO

pam_service_name=vsftpd
userlist_enable=YES
tcp_wrappers=YES
lock_upload_files=YES

But I can't connect from Filezilla on my desktop machine which is using the VPN IP address.

Status: Connecting to nn.nn.nn.nn... 
Response: fzSftp started, protocol_version=9 
Command: open "[email protected]" 22 
Command: Pass: ************ 
Status: Connected to nn.nn.nn.nn 
Error: Connection timed out after 20 seconds of inactivity 
Error: Could not connect to server

I can connect to the same server to get an ssh session.

I must be missing something, but I can't see what. Can anyone help?

I added a group called developers

sudo groupadd developers

then added myself to that group

$ sudo usermod -a -G developers nick.weavers

Then I issued the command groups to check I'd been added, but got this

$ groups
nick.weavers wheel

However, if I issued the groups command with the name of the user I wanted to check like this

$ groups nick.weavers
nick.weavers : nick.weavers wheel developers

I am show to be in the developers group, but am I? Why do the two commands show different results?

I am trying to configure an ec2 as my web server that will scale out under a load balancer, but as the httpd.conf comments say,

# It is usually good practice to create a dedicated user and group for
# running httpd, as with most system services.
#
User apache
Group apache

The default user and group for a standard Amazon Linux RMI are apache. I would like to change this to a user and group I have created, say, my-user.

As you'll know, the User/Data section of an ec2 can contain a bash script that will perform actions when the ec2 is provisioned. I have:

#!/bin/bash
yum install httpd24 mysql57 php71 php71-mysql\* -y

Is it possible to use CLI commands to change the httpd user and group from this bash script after installing httpd - or use environment variables in the httpd.conf?

an anyone help? I am trying to upgrade but a get error messages about nagios-nrpe-server and bind.

Here is the console output:

>apt-get upgrade
Reading package lists... Done
Building dependency tree       
Reading state information... Done
0 to upgrade, 0 to newly install, 0 to remove and 0 not to upgrade.
2 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Do you want to continue [Y/n]? y
Setting up nagios-nrpe-server (2.12-5ubuntu1.2) ...
invoke-rc.d: initscript nagios-nrpe-server, action "start" failed.
dpkg: error processing nagios-nrpe-server (--configure):
subprocess installed post-installation script returned error exit status 1
Setting up bind9 (1:9.8.1.dfsg.P1-4ubuntu0.8) ...
* Starting domain name service... bind9 [fail]                                                                   
invoke-rc.d: initscript bind9, action "start" failed.
dpkg: error processing bind9 (--configure):
subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
nagios-nrpe-server
bind9
E: Sub-process /usr/bin/dpkg returned an error code (1)

This is a live web server with several hundred domains hosted so I am very nervous about doing anything that will take it out. I have nightly backups but it's a real pain getting my hosting company to restore and can take several hours, so I'm really nervous taking risks.

TIA.