jmazaredo's questions

I have a reverse proxy setup nginx host -> nagios both on ubuntu 20.04 machines virtual these are like just default apt-get install not customized. I added selfsigned certificate just for test.

192.168.254.107 - nginx 192.168.254.200 - nagios

The problem is that the cgi-bin seems not redirected and is being served on nginx itself

Nginx config

server {
    listen 443 ssl;
    listen 80 default_server;
    ssl_certificate /etc/ssl/certs/nginx-selfsigned.crt;
    ssl_certificate_key /etc/ssl/private/nginx-selfsigned.key;
    ssl_session_cache shared:SSL:1m;
    ssl_session_timeout 2m;

    location /nagios4 {
        proxy_pass https://192.168.254.200/nagios4;
        proxy_set_header Host $host;
        proxy_redirect off;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto https;
    }
}

Error

2020/12/02 05:08:53 [error] 2307#2307: *21 open() "/usr/share/nginx/html/cgi-bin/nagios4/avail.cgi" failed (2: No such file or directory), client: 192.168.254.163, server: , request: "GET /cgi-bin/nagios4/avail.cgi HTTP/1.1", host: "192.168.254.107", referrer: "https://192.168.254.107/nagios4/side.php"
2020/12/02 05:08:58 [error] 2307#2307: *21 open() "/usr/share/nginx/html/cgi-bin/nagios4/extinfo.cgi" failed (2: No such file or directory), client: 192.168.254.163, server: , request: "GET /cgi-bin/nagios4/extinfo.cgi?type=3 HTTP/1.1", host: "192.168.254.107", referrer: "https://192.168.254.107/nagios4/side.php"
2020/12/02 05:09:02 [error] 2307#2307: *21 open() "/usr/share/nginx/html/cgi-bin/nagios4/extinfo.cgi" failed (2: No such file or directory), client: 192.168.254.163, server: , request: "GET /cgi-bin/nagios4/extinfo.cgi?type=6 HTTP/1.1", host: "192.168.254.107", referrer: "https://192.168.254.107/nagios4/side.php"
2020/12/02 05:09:02 [error] 2307#2307: *21 open() "/usr/share/nginx/html/cgi-bin/nagios4/extinfo.cgi" failed (2: No such file or directory), client: 192.168.254.163, server: , request: "GET /cgi-bin/nagios4/extinfo.cgi?type=0 HTTP/1.1", host: "192.168.254.107", referrer: "https://192.168.254.107/nagios4/side.php"
2020/12/02 05:09:03 [error] 2307#2307: *21 open() "/usr/share/nginx/html/cgi-bin/nagios4/extinfo.cgi" failed (2: No such file or directory), client: 192.168.254.163, server: , request: "GET /cgi-bin/nagios4/extinfo.cgi?type=4 HTTP/1.1", host: "192.168.254.107", referrer: "https://192.168.254.107/nagios4/side.php"

I noticed this when i tried open in another browser it goes and looks for the path on the nginx host...

https://192.168.254.107/cgi-bin/nagios4/status.cgi?hostgroup=all&style=hostdetail

If I have 500GB table size, how big should the temp folder be in order to alter table information? I will be configuring temp in my.cnf and, in this example, I have 64 GB physical ram.

I have Centos 6.10 Server with initial swap of 3.81 GB working ok no issue.

I noticed wrong swap today amount of 4kb. I tried removing the partition and recreate entry on fstab and remount but no avail. Also tried creating swapfile 8GB using fallocate -l 8G /home/swapfile and added on fstab swapon -a. Still doesn't work.

Below are some info on system:

mkswap command

I have noticed dropped packets on my Xen virtual guest. Checking with main server no dropped packets observed. What could be causing this?

Im using 4.9.112-32.el7.x86_64

Added new info :

I have a Postfix mail server.

The problem is it is sending spam. The logs showed the following:

538ED2BF7F2: client=unknown[103.214.xxx.xx]
538ED2BF7F2: message-id=<>
538ED2BF7F2: from=<[email protected]>, size=786, nrcpt=1 (queue active)
538ED2BF7F2: to=<[email protected]>, relay=gmail-smtp-in.l.google.com[74.125.204.27]:25, delay=4, delays=2.1/0.02/0.8/1, dsn=2.0.0, status=sent (250 2.0.0 OK 1501439317 91si6880315ply.391 - gsmtp)
538ED2BF7F2: removed

I have a wrapper for PHP & Apache and checked whether it was from a form or script on a website, but it wasn't: it was not being logged. And I checked HTTP logs for possible logins/post from the specific IP address, but nothing comes up.

Also I changed the password. The server is not open relay.

Any other ideas?

UPDATED XXX_Reject

smtpd_recipient_restrictions = permit_mynetworks permit_sasl_authenticated reject_unauth_destination check_sender_access hash:/etc/postfix/sender_access reject_rbl_client zen.spamhaus.org reject_rbl_client bl.spamcop.net reject_rbl_client cbl.abuseat.org permit
smtpd_sender_restrictions =
        permit_mynetworks,
        reject_non_fqdn_sender,
        reject_unknown_sender_domain,
        permit

smtpd_client_restrictions = permit_mynetworks permit_sasl_authenticated reject_unauth_destination  reject_rbl_client zen.spamhaus.org reject_unknown_reverse_client_hostname permit

Im trying to bypass authentication via

AuthUserFile /etc/nagios3/htpasswd.users
  AuthType Basic
  AuthName MySite
  Require valid-user
  Order allow,deny
  Allow from 111.111.111.111
  Satisfy any

Im able to bypass but i get a notification

It appears as though you do not have permission to view information for any of the services you requested...

If you believe this is an error, check the HTTP server authentication requirements for accessing this CGI and check the authorization options in your CGI configuration file.

cgi.cfg

authorized_for_system_information=*
authorized_for_configuration_information=*
authorized_for_system_commands=*
authorized_for_all_services=*
authorized_for_all_hosts=*
authorized_for_all_service_commands=*
authorized_for_all_host_commands=*

I notice login as ?

I need to know the last login yesterday and email it to me via crontab....

Since the last command shows all the login you need to scroll up. Using grep and cut might do the trick.

If I have two disk drives c and d and I image the c drive to d and leave it for a day; it is a form of backup, since I can revert to the day I mirrored it. But if I mirror it as RAID1, it is not a backup since I'm making it redundant?

What if my sole purpose is just to make the system alive and not reverting to any previous date whatever. Isn't that a form of backup?

I setup a centos freeradius mysql with the frontend daloradius using the steps on this site http://linuxdrops.com/install-freeradius-with-web-based-management-daloradius-on-centosrhel-debian-ubuntu/

The installation seems ok i tried telneting and passing username/password on the switch.

The question is will this be enough for mac authentication port based on cisco switch. (just by adding mac address on daloradius new user page mac address authentication.

(I'm a newbie on radius)

postfix master dead but subsys locked

I tried removing the files on /var/lock/subsys/ and restarted postfix, no error on logs and mail is working but when I check the postfix status it still says "master dead but subsys locked"

2.6.32-431.5.1.el6.i686

tcp        0      0 *:smtp                      *:*                         LISTEN      21290/master    

checking on status:

[root@smtp subsys]# service postfix status
master dead but subsys locked
[root@smtp subsys]# 

When message arrives from other mail server (yahoo/gmail) on my postfix server it gets denied and not being transported using the transport on my configuration. Been checking whole day can't find anything hope you guy can help me.

getting this error:

Mar 20 17:41:19 smtp postfix/smtpd[2103]: NOQUEUE: reject: RCPT from mail.com [xxx.xxx.xxx.xxx]: 554 5.7.1 user_at_transport.com: Relay access denied; from=sales_at_mail.com to=user_at_domain_on_transport.com proto=ESMTP helo= mail.com

queue_directory = /raid/postfix
command_directory = /usr/sbin
daemon_directory = /usr/libexec/postfix
mail_owner = postfix
myhostname = smtp.example.com

unknown_address_reject_code = 554
unknown_client_reject_code = 554
unknown_hostname_reject_code = 554

mynetworks = /etc/postfix/mynetworks
relay_domains = /etc/postfix/relay_domains
relay_recipient_maps = hash:/etc/postfix/relay_recipient_maps
virtual_maps = hash:/etc/postfix/virtual
transport_maps = hash:/etc/postfix/transport
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
mailbox_command = /usr/bin/procmail
header_checks = regexp:/etc/postfix/header_checks
mime_header_checks = regexp:/etc/postfix/header_checks
default_destination_concurrency_limit = 50
debug_peer_level = 2
debugger_command =
         PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin
         xxgdb $daemon_directory/$process_name $process_id & sleep 5
sendmail_path = /usr/sbin/sendmail
newaliases_path = /usr/bin/newaliases
mailq_path = /usr/bin/mailq
setgid_group = postdrop
manpage_directory = /usr/share/man
sample_directory = /usr/share/doc/postfix-2.2.10/samples
readme_directory = /usr/share/doc/postfix-2.2.10/README_FILES
lmtp_tcp_port = 2003
maximal_queue_lifetime = 7d
message_size_limit = 32000000
smtpd_client_restrictions = check_client_access hash:/etc/postfix/access
        reject_rbl_client b.barracudacentral.org
        reject_rbl_client cbl.abuseat.org
        reject_rbl_client zen.spamhaus.org
        reject_rbl_client rabl.nuclearelephant.com
        reject_rbl_client bl.spamcop.net
        permit_mynetworks
smtpd_helo_required = yes
smtpd_helo_restrictions = check_helo_access hash:/etc/postfix/access
        reject_unauth_pipelining
        reject_invalid_hostname    
smtpd_sender_restrictions = check_sender_access hash:/etc/postfix/access
        reject_non_fqdn_sender
        reject_unknown_sender_domain
smtpd_recipient_restrictions = check_recipient_access hash:/etc/postfix/recipient_access
        check_recipient_access hash:/etc/postfix/access
        reject_non_fqdn_recipient
        reject_unknown_recipient_domain
        permit_mx_backup
        permit_mynetworks
        reject_unauth_destination
smtpd_client_connection_count_limit = 5
smtpd_client_connection_rate_limit = 30
smtpd_client_connection_limit_exceptions = 202.xxx.xxx.xxx/24
smtpd_client_event_limit_exceptions = 202.xxx.xxx.xxx/24
permit_mx_backup_networks = /etc/postfix/mynetworks
                203.xxx.xxx.xxx/32
address_verify_map = hash:/etc/postfix/verify
address_verify_sender = [email protected]
address_verify_negative_cache = yes
address_verify_negative_refresh_time = 1d
disable_vrfy_command = yes
smtpd_banner = $myhostname 
smtpd_delay_reject = no
strict_rfc821_envelopes = yes
smtpd_error_sleep_time = 0s
smtpd_soft_error_limit = 5
smtpd_hard_error_limit = 10
html_directory = no
bounce_queue_lifetime = 60m
biff = no
unknown_local_recipient_reject_code = 450

smtp      inet  n       -       n       -       -       smtpd
  -o content_filter=smtp-amavis:127.0.0.1:10024
  -o receive_override_options=no_address_mappings
pickup    fifo  n       -       n       60      1       pickup
  -o content_filter=
  -o receive_override_options=no_header_body_checks
cleanup   unix  n       -       n       -       0       cleanup
qmgr      fifo  n       -       n       300     1       qmgr
#qmgr     fifo  n       -       n       300     1       oqmgr
tlsmgr    unix  -       -       n       1000?   1       tlsmgr
rewrite   unix  -       -       n       -       -       trivial-rewrite
bounce    unix  -       -       n       -       0       bounce
defer     unix  -       -       n       -       0       bounce
trace     unix  -       -       n       -       0       bounce
verify    unix  -       -       n       -       1       verify
flush     unix  n       -       n       1000?   0       flush
proxymap  unix  -       -       n       -       -       proxymap
smtp      unix  -       -       n       -       -       smtp
# When relaying mail as backup MX, disable fallback_relay to avoid MX loops
relay     unix  -       -       n       -       -       smtp
        -o fallback_relay=
#       -o smtp_helo_timeout=5 -o smtp_connect_timeout=5
showq     unix  n       -       n       -       -       showq
error     unix  -       -       n       -       -       error
discard   unix  -       -       n       -       -       discard
local     unix  -       n       n       -       -       local
virtual   unix  -       n       n       -       -       virtual
lmtp      unix  -       -       n       -       -       lmtp
anvil     unix  -       -       n       -       1       anvil
scache    unix  -       -       n       -       1       scache
maildrop  unix  -       n       n       -       -       pipe
  flags=DRhu user=vmail argv=/usr/local/bin/maildrop -d ${recipient}
uucp      unix  -       n       n       -       -       pipe
  flags=Fqhu user=uucp argv=uux -r -n -z -a$sender - $nexthop!rmail ($recipient)
ifmail    unix  -       n       n       -       -       pipe
  flags=F user=ftn argv=/usr/lib/ifmail/ifmail -r $nexthop ($recipient)
bsmtp     unix  -       n       n       -       -       pipe
  flags=Fq. user=foo argv=/usr/local/sbin/bsmtp -f $sender $nexthop $recipient
smtp-amavis  unix  -    -       y       -       2       smtp
  -o smtp_data_done_timeout=1200
  -o disable_dns_lookups=yes
  -o smtp_send_xforward_command=yes
127.0.0.1:10025 inet n  -       y       -       -       smtpd
  -o content_filter=
  -o smtpd_helo_restrictions=
  -o smtpd_sender_restrictions=
  -o smtpd_recipient_restrictions=permit_mynetworks,reject
  -o mynetworks=127.0.0.0/8
  -o smtpd_error_sleep_time=0
  -o smtpd_soft_error_limit=1001
  -o smtpd_hard_error_limit=1000
  -o receive_override_options=no_header_body_checks
  -o smtpd_bind_address=127.0.0.1
  -o smtpd_helo_required=no
  -o smtpd_client_restrictions=
  -o smtpd_restriction_classes=
  -o disable_vrfy_command=no
  -o strict_rfc821_envelopes=yes
dovecot   unix  -       n       n       -       -       pipe
  flags=DRhu user=vmail:mail argv=/usr/libexec/dovecot/deliver -d ${recipient}
vacation    unix  -       n       n       -       -       pipe
  flags=Rq user=vacation argv=/var/spool/vacation/vacation.pl -f ${sender} -- ${recipient}

mail -s "subject" $user

I'm sending email via command line using linux accounts but it is adding @mail.hostname.com

so the username becomes [email protected]

Is there are way that it just email using local accounts without @mail.hostname.com or change it automatically using @hostname.com

cd /home/dir/11   
du -m --max-depth=1 | sed 's/[./]//g' | while read space user 
do
    if [ $space -gt 100 ]
                   then

        mail -s "using over 100MB " $user <<MAIL
$user:
You are now using $space MB in your home directory.
The total amount of diskspace allowed is 100 MB.

MAIL
  fi

done

It is adding the hostname of the machine while sending mail [email protected] where it should be [email protected] , i cant change the local machine hostname since there are some other connections using it. The mail is bouncing back since address is wrong:

This is the Postfix program at host mail.hostname.com.

I'm sorry to have to inform you that your message could not be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to

If you do so, please include this problem report. You can delete your own text from the attached returned message.

               The Postfix program

(expanded from ): unknown user: "user1"