Major Productions's questions

As I'm getting more and more frustrated with attempting to use sendmail to send web app emails that won't be flagged as spam, I've turned my attention to using postfix instead. I've found this Linode guide describing how to use Gmail as a relay for postfix, and it seems to tick most of the boxes - I have a Gmail account, so I could easily allow it as an external app on my account.

My question is this: will this work with virtual domains? Meaning, if I have several web apps with their own limited (read: not in the sudo group) linux users, and these apps send emails out for various reasons, can I make it so that postfix's virtual domains/aliases work properly and that the emails' senders are [email protected] rather than [email protected], or, even worse, [email protected]?

I don't want to install and configure postfix in this way if it's not going to work the way I need it to.

Following the advice in this answer and the steps listed here, I've added the following to my /etc/mail/sendmail.mc file and compiled it with m4 /etc/mail/sendmail.mc > /etc/mail/sendmail.cf. The end of.mc file itself:

dnl # Default Mailer setup
dnl # Masquerading options
FEATURE(`always_add_domain')dnl
MASQUERADE_AS(`debian')dnl
FEATURE(`allmasquerade')dnl
FEATURE(`masquerade_envelope')dnl
FEATURE(`genericstable',`hash -o /etc/mail/genericstable.db')dnl
GENERICS_DOMAIN_FILE(`/etc/mail/generics-domains')dnl
MAILER_DEFINITIONS
MAILER(`local')dnl
MAILER(`smtp')dnl

I created the /etc/mail/generics-domains file with:

mylinodeboxdomain.com
avirtualdomain.com

And created the /etc/mail/genericstable file with:

virtualuser    [email protected]

And restarted the sendmail service. Despite that, emails sent by virtualuser still seem to be coming from virtualuser@localhost rather than the desired [email protected]:

Received: from www.avirtualdomain.com (virtualuser@localhost)
    by mylinodeboxdomain.com (8.15.2/8.15.2/Submit) with SMTP id x6QIOIYY002415
    for <[email protected]>; Fri, 26 Jul 2019 14:24:18 -0400

I'm guessing my config is messed up, but as this is all new to me, I'm unsure what to change/remove.

I have a Linode instance in which I'm going to host several small-ish LEMP apps. Each of these apps need to send emails to users (mostly for account registration... forums/comments and whatnot). I'd like to be able to just use sendmail to accomplish this as it's already installed on the system. Is that possible? I'm not expecting a lot of traffic/email use, so I'm using Google's SMTP server:

The idea is that sendmail will be a null client - it can send mail out (and I already get system notifications (OSSEC, Fail2ban) from it), but not receive incoming mail. Any app contact form/mechanism sends a message to the owner of the app itself, whereby they can then communicate directly with them via their own email. I have a few questions, however:

1. Is it possible to configure things so that each app has its own outgoing email address/identity? I've separated each app into its own linux user without sudo access. So (fictional names), Bob's Widget Emporium is its own separate user, as is Sally's Awesome Political Views. Each app has its own domain record(s) through Linode's cloud DNS manager due to virtual hosting.
2. What do I need to do to not have these emails considered spam? And would this configuration be done at the centralized box level, or per account?
3. What do I need to do to block incoming emails from external sources? My iptables are the following -

ipv4:

$ sudo iptables -vL
Chain INPUT (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination         
 8887  909K f2b-ssh    tcp  --  any    any     anywhere             anywhere             multiport dports ssh
 1282  128K ACCEPT     all  --  lo     any     anywhere             anywhere            
    0     0 REJECT     all  --  !lo    any     127.0.0.0/8          anywhere             reject-with icmp-port-unreachable
  162  5770 ACCEPT     icmp --  any    any     anywhere             anywhere             state NEW icmp echo-request
  668 38256 ACCEPT     tcp  --  any    any     anywhere             anywhere             tcp dpt:ssh state NEW
  355 19004 ACCEPT     tcp  --  any    any     anywhere             anywhere             tcp dpt:http state NEW
  424 22736 ACCEPT     tcp  --  any    any     anywhere             anywhere             tcp dpt:https state NEW
48568 4098K ACCEPT     all  --  any    any     anywhere             anywhere             state RELATED,ESTABLISHED
 6996  368K LOG        all  --  any    any     anywhere             anywhere             limit: avg 5/min burst 5 LOG level debug prefix "iptables_INPUT_denied: "
 7413  388K REJECT     all  --  any    any     anywhere             anywhere             reject-with icmp-port-unreachable

Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination         
    0     0 LOG        all  --  any    any     anywhere             anywhere             limit: avg 5/min burst 5 LOG level debug prefix "iptables_FORWARD_denied: "
    0     0 REJECT     all  --  any    any     anywhere             anywhere             reject-with icmp-port-unreachable

Chain OUTPUT (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination         

Chain f2b-ssh (1 references)
 pkts bytes target     prot opt in     out     source               destination         
 8531  881K RETURN     all  --  any    any     anywhere             anywhere

ipv6:

sudo ip6tables -vL
Chain INPUT (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination         
    0     0 ACCEPT     all      lo     any     anywhere             anywhere            
    0     0 REJECT     all      !lo    any     localhost            anywhere             reject-with icmp6-port-unreachable
67580 6991K ACCEPT     ipv6-icmp    any    any     anywhere             anywhere            
   31  2480 ACCEPT     tcp      any    any     anywhere             anywhere             tcp dpt:http state NEW
   33  2640 ACCEPT     tcp      any    any     anywhere             anywhere             tcp dpt:https state NEW
10922   50M ACCEPT     all      any    any     anywhere             anywhere             state RELATED,ESTABLISHED
    4  2956 LOG        all      any    any     anywhere             anywhere             limit: avg 5/min burst 5 LOG level debug prefix "ip6tables_INPUT_denied: "
    4  2956 REJECT     all      any    any     anywhere             anywhere             reject-with icmp6-port-unreachable

Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination         
    0     0 LOG        all      any    any     anywhere             anywhere             limit: avg 5/min burst 5 LOG level debug prefix "ip6tables_FORWARD_denied: "
    0     0 REJECT     all      any    any     anywhere             anywhere             reject-with icmp6-port-unreachable

Chain OUTPUT (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination

Given my instance can send emails out, I'm guessing it can currently receive them as well.

So, is it possible to do all this with just sendmail, and if so, how would I configure things? Or, if this is too broad a question, please let me know and I'll split it.

I have fail2ban setup and working on my system. In /etc/fail2ban/jail.local, I have the following for my destination email:

destemail = [email protected]

Yet, looking through my /var/log/mail.log file, I keep seeing:

Jul 23 21:19:04 picus sendmail[21205]: x6O1J489021205: from=fail2ban, size=210, class=0, nrcpts=1, msgid=<[email protected]>, relay=root@localhost
Jul 23 21:19:04 picus sm-mta[21207]: x6O1J4vh021207: from=<[email protected]>, size=461, class=0, nrcpts=1, msgid=<[email protected]>, proto=ESMTP, daemon=MTA-v4, relay=localhost [127.0.0.1]
Jul 23 21:19:04 picus sendmail[21205]: x6O1J489021205: to=root, delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30210, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (x6O1J4vh021207 Message accepted for delivery)
Jul 23 21:19:04 picus sm-mta[21208]: x6O1J4vh021207: to=linode, ctladdr=<[email protected]> (8/0), delay=00:00:00, mailer=local, pri=120461, dsn=5.1.1, stat=User unknown
Jul 23 21:19:04 picus sm-mta[21208]: x6O1J4vh021207: to=<[email protected]>, delay=00:00:00, mailer=local, pri=30680, dsn=5.1.1, stat=User unknown
Jul 23 21:19:04 picus sm-mta[21208]: x6O1J4vh021207: to=linode, ctladdr=root (8/0), delay=00:00:00, mailer=local, pri=30680, dsn=5.1.1, stat=User unknown
Jul 23 21:19:04 picus sm-mta[21208]: x6O1J4vh021207: x6O1J4vh021208: postmaster notify: User unknown
Jul 23 21:19:04 picus sm-mta[21208]: x6O1J4vh021208: to=linode, ctladdr=root (8/0), delay=00:00:00, mailer=local, pri=0, dsn=5.1.1, stat=User unknown
Jul 23 21:19:04 picus sm-mta[21208]: x6O1J4vh021208: to=linode, ctladdr=root (8/0), delay=00:00:00, mailer=local, pri=0, dsn=5.1.1, stat=User unknown
Jul 23 21:19:04 picus sm-mta[21208]: x6O1J4vh021208: x6O1J4vi021208: return to sender: User unknown
Jul 23 21:19:04 picus sm-mta[21208]: x6O1J4vi021208: to=linode, ctladdr=root (8/0), delay=00:00:00, mailer=local, pri=0, dsn=5.1.1, stat=User unknown
Jul 23 21:19:04 picus sm-mta[21208]: x6O1J4vh021208: Saved message in /var/lib/sendmail/dead.letter

It keeps trying to send it to the root account on my machine rather than my email address. Am I missing some configuration option somewhere?

EDIT: after a bit of tinkering, I've been able to somewhat correct the problem. I changed:

dest = root

to

dest = [email protected]

in /etc/fail2ban/action.d/mail.conf. With that change, I'm now receiving emails that pertain to my ssh/ssh-ddos jails. However, I'm still not receiving emails from my recidive jail. Looking at /etc/fail2ban/jail.local, I see that it invokes something that collates/formats various WHOIS data for banned accounts in that particular jail.

More digging in the various configuration files led me to /etc/fail2ban/action.d/sendmail-common.conf which, like the other various configuration files I looked at, has dest = root.

Now, I could tweak these various configuration files to all use my email address as the destination, but I'm getting the feeling that's more or less the equivalent of hammering a round peg into a square hole. Is there a better way to force fail2ban to just default to using my email as the destination address? Is there a potential configuration problem with my sendmail installation (I can receive emails from OSSEC and my web app with no issue)?

As a continuation of this question, I did some more research and found this answer on SuperUser which seems to have solved my issue with sendmail being unable to write a particular file. Specifically, stopping sendmail, checking for ongoing processes, killing them, and then restarting sendmail fixed that portion of my problem.

As a test, I attempted to send another email to myself from the command line: echo "Subject: sendmail test" | sudo sendmail /usr/sbin/sendmail -v [email protected]. The email did not send correctly, but I did get a bounced email from sendmail itself with the error(s):

From MAILER-DAEMON  Tue Jul 23 12:44:30 2019
Return-Path: <MAILER-DAEMON>
Received: from major-productions.com (localhost [127.0.0.1])
        by major-productions.com (8.15.2/8.15.2/Debian-12) with ESMTP id x6NGiUQO012820
        for <[email protected]>; Tue, 23 Jul 2019 12:44:30 -0400
Received: from localhost (localhost)
        by major-productions.com (8.15.2/8.15.2/Submit) id x6NGiUSL012819;
        Tue, 23 Jul 2019 12:44:30 -0400
Date: Tue, 23 Jul 2019 12:44:30 -0400
From: Mail Delivery Subsystem <MAILER-DAEMON@debian>
Message-Id: <[email protected]>
To: [email protected]
MIME-Version: 1.0
Content-Type: multipart/report; report-type=delivery-status;
        boundary="x6NGiUSL012819.1563900270/major-productions.com"
Subject: Returned mail: see transcript for details
Auto-Submitted: auto-generated (failure)

This is a MIME-encapsulated message

--x6NGiUSL012819.1563900270/major-productions.com

The original message was received at Tue, 23 Jul 2019 12:44:30 -0400
from root@localhost

----- The following addresses had permanent fatal errors -----
/usr/sbin/sendmail
    (reason: 550 5.7.1 </usr/sbin/[email protected]>... Cannot mail directly to files)
    (expanded from: /usr/sbin/sendmail)
-v
    (reason: 550 5.1.1 <[email protected]>... User unknown)
    (expanded from: -v)

   ----- Transcript of session follows -----
... while talking to [127.0.0.1]:
>>> DATA
<<< 550 5.1.1 <[email protected]>... User unknown
550 5.1.1 -v... User unknown
<<< 550 5.7.1 </usr/sbin/[email protected]>... Cannot mail directly to files
550 5.1.1 /usr/sbin/sendmail... User unknown

--x6NGiUSL012819.1563900270/major-productions.com
Content-Type: message/delivery-status

Reporting-MTA: dns; major-productions.com
Arrival-Date: Tue, 23 Jul 2019 12:44:30 -0400

Final-Recipient: RFC822; /usr/sbin/[email protected]
Action: failed
Status: 5.7.1
Remote-MTA: DNS; [127.0.0.1]
Diagnostic-Code: SMTP; 550 5.7.1 </usr/sbin/[email protected]>... Cannot mail directly to files
Last-Attempt-Date: Tue, 23 Jul 2019 12:44:30 -0400

Final-Recipient: RFC822; [email protected]
Action: failed
Status: 5.1.1
Remote-MTA: DNS; [127.0.0.1]
Diagnostic-Code: SMTP; 550 5.1.1 <[email protected]>... User unknown
Last-Attempt-Date: Tue, 23 Jul 2019 12:44:30 -0400

--x6NGiUSL012819.1563900270/major-productions.com
Content-Type: message/rfc822

Return-Path: <me>
Received: (from root@localhost)
        by major-productions.com (8.15.2/8.15.2/Submit) id x6NGiUSK012819;
        Tue, 23 Jul 2019 12:44:30 -0400
Date: Tue, 23 Jul 2019 12:44:30 -0400
From: Dude Guy <me>
Message-Id: <[email protected]>
Subject: sendmail test

--x6NGiUSL012819.1563900270/major-productions.com--

I'm guessing it's a config error, but have no idea where to look/what to change.

I followed this tutorial to upgrade my linode instance from Debian 8 to Stable. In the wake of that upgrade, I've had several errors/issues with sendmail.

1. $ which sendmail doesn't return anything. I do have sendmail installed. It's at /usr/sbin/sendmail.

2. Sendmail's permissions are as follows:

   $ ls -la /usr/sbin/sendmail lrwxrwxrwx 1 root root 26 Jul 17 12:41 /usr/sbin/sendmail -> /etc/alternatives/sendmail

   The link (/etc/alternatives/sendmail) is highlighted in red.

3. When I try to send a test email with sudo echo "Subject: sendmail test" | /usr/sbin/sendmail -v [email protected] I get the following error:

   can not write to queue directory /var/spool/mqueue-client/ (RunAsGid=115, required=0): Permission denied

   That directory's permissions are:

   $ ls -la /var/spool/mqueue-client drwxrwxr-x 2 root root 4096 Sep 15 2018 mqueue-client

So, I obviously have some sort of permission/ownership issue, but I also think there's something else going on given items 1 and 2. I need to be able to receive emails from the system's OSSEC and Fail2ban, so I can't really go without a working email client/server. I'm just not sure how to fix these issues.

My sendmail was simply installed with $ sudo apt-get install sendmail sendmail-bin, so it came direct from Debian's repos, which is why I'm a bit baffled by these issues... I assumed that whatever configuration was needed would be handled by the installation process.

EDIT: the output of ls -l /etc/alternatives/sendmail*

lrwxrwxrwx 1 root root 24 Jul 17 12:41 /etc/alternatives/sendmail -> /usr/lib/sm.bin/sendmail
lrwxrwxrwx 1 root root 42 Jul 17 12:41 /etc/alternatives/sendmail.8.gz -> /usr/share/man/man8/sendmail.sendmail.8.gz

lrwxrwxrwx 1 root root 24 Jul 17 12:41 /etc/alternatives/sendmail-msp -> /usr/lib/sm.bin/sendmail
lrwxrwxrwx 1 root root 42 Jul 17 12:41 /etc/alternatives/sendmail-msp.8.gz -> /usr/share/man/man8/sendmail.sendmail.8.gz

lrwxrwxrwx 1 root root 24 Jul 17 12:41 /etc/alternatives/sendmail-mta -> /usr/lib/sm.bin/sendmail
lrwxrwxrwx 1 root root 42 Jul 17 12:41 /etc/alternatives/sendmail-mta.8.gz -> /usr/share/man/man8/sendmail.sendmail.8.gz

Each pair ends in a different color, e.g. /usr/lib/sm.bin/sendmail is highlighted in amber, while /usr/share/man/man8/sendmail.sendmail.8.gz is highlighted in red. It's the same colors - amber and red - for each pair.

EDIT2: The output of (echo subject: test; echo ; echo test) | /usr/sbin/sendmail -d44.4 -i -v username (I used my real username, but have adjusted the resulting output for security):

$ (echo subject: test; echo ; echo test) | /usr/sbin/sendmail -d44.4 -i -v username
safefile(/etc/mail/submit.cf, uid=1000, gid=0, flags=6000, mode=400):
safedirpath(/etc/mail, uid=1000, gid=0, flags=6000, level=0, offset=0):
    [dir /etc/mail] OK
    [uid 0, nlink 1, stat 100644, mode 4]   OK
safefile(/etc/mail/relay-domains, uid=1000, gid=0, flags=6580, mode=400):
safedirpath(/etc/mail, uid=1000, gid=0, flags=6580, level=0, offset=0):
    [dir /etc/mail] OK
    No such file or directory
safefile(/etc/mail/service.switch, uid=1000, gid=115, flags=6480, mode=400):
safedirpath(/etc/mail, uid=1000, gid=115, flags=6580, level=0, offset=0):
    [dir /etc/mail] OK
    [uid 0, nlink 1, stat 100644, mode 4]   OK
safefile(/etc/mail/service.switch, uid=1000, gid=115, flags=6480, mode=400):
safedirpath(/etc/mail, uid=1000, gid=115, flags=6580, level=0, offset=0):
    [dir /etc/mail] OK
    [uid 0, nlink 1, stat 100644, mode 4]   OK
safefile( , uid=1000, gid=115, flags=40, mode=660):
safedirpath(., uid=1000, gid=115, flags=40, level=0, offset=0):
    [dir .] OK
    No such file or directory
    [final dir . uid 111 mode 42770] Success
safedirpath(/var/spool/mqueue-client, uid=1000, gid=115, flags=0, level=0, offset=0):
    [dir /var/spool/mqueue-client] OK
safefile(./dfx6MIGnM5005502, uid=1000, gid=115, flags=2040, mode=600):
safedirpath(., uid=1000, gid=115, flags=2040, level=0, offset=0):
    [dir .] OK
    No such file or directory
    [final dir . uid 111 mode 42770] Success
username... Connecting to [127.0.0.1] via relay...
220 major-productions.com ESMTP Sendmail 8.15.2/8.15.2/Debian-12; Mon, 22 Jul 2019 14:16:49 -0400; (No UCE/UBE) logging access from: localhost(OK)-localhost [127.0.0.1]
>>> EHLO major-productions.com
250-major-productions.com Hello localhost [127.0.0.1], pleased to meet you
250-ENHANCEDSTATUSCODES
250-PIPELINING
250-EXPN
250-VERB
250-8BITMIME
250-SIZE
250-DSN
250-ETRN
250-AUTH DIGEST-MD5 CRAM-MD5
250-DELIVERBY
250 HELP
>>> VERB
250 2.0.0 Verbose mode
>>> MAIL From:<[email protected]> SIZE=20 [email protected]
250 2.1.0 <[email protected]>... Sender ok
>>> RCPT To:<[email protected]>
>>> DATA
250 2.1.5 <[email protected]>... Recipient ok
354 Enter mail, end with "." on a line by itself
>>> .
421 4.3.0 collect: Cannot write ./dfx6MIGnHm005503 (bfcommit, uid=0, gid=115): No such file or directory
>>> QUIT
username... Deferred: 421 4.3.0 collect: Cannot write ./dfx6MIGnHm005503 (bfcommit, uid=0, gid=115): No such file or directory
safefile(/var/lib/sendmail/sm-client.st, uid=1000, gid=115, flags=2282, mode=600):
safedirpath(/var/lib/sendmail, uid=1000, gid=115, flags=2282, level=0, offset=0):
    [dir /var/lib/sendmail] OK
    No such file or directory
safefile(/var/lib/sendmail/sm-client.st, uid=1000, gid=115, flags=2282, mode=600):
safedirpath(/var/lib/sendmail, uid=1000, gid=115, flags=2282, level=0, offset=0):
    [dir /var/lib/sendmail] OK
    No such file or directory
Closing connection to [127.0.0.1]

EDIT 3: the output of (echo subject: test; echo ; echo test) | /usr/sbin/sendmail -Am -d44.4 -i -v username while logged in as root (with the username obfuscated as before):

# (echo subject: test; echo ; echo test) | /usr/sbin/sendmail -Am -d44.4 -i -v username
safefile(/etc/mail/sendmail.cf, uid=0, gid=0, flags=6000, mode=400):
safedirpath(/etc/mail, uid=0, gid=0, flags=6000, level=0, offset=0):
    [dir /etc/mail] OK
    [uid 0, nlink 1, stat 100644, mode 400]     OK
safefile(/etc/mail/local-host-names, uid=0, gid=0, flags=6580, mode=400):
safedirpath(/etc/mail, uid=0, gid=0, flags=6580, level=0, offset=0):
    [dir /etc/mail] OK
    [uid 0, nlink 1, stat 100644, mode 400]     OK
safefile(/etc/mail/relay-domains, uid=0, gid=0, flags=6580, mode=400):
safedirpath(/etc/mail, uid=0, gid=0, flags=6580, level=0, offset=0):
    [dir /etc/mail] OK
    No such file or directory
safefile(/etc/mail/service.switch, uid=0, gid=0, flags=6480, mode=400):
safedirpath(/etc/mail, uid=0, gid=0, flags=6580, level=0, offset=0):
    [dir /etc/mail] OK
    [uid 0, nlink 1, stat 100644, mode 400]     OK
safefile(/etc/mail/service.switch, uid=0, gid=0, flags=6480, mode=400):
safedirpath(/etc/mail, uid=0, gid=0, flags=6580, level=0, offset=0):
    [dir /etc/mail] OK
    [uid 0, nlink 1, stat 100644, mode 400]     OK
safedirpath(/var/spool/mqueue, uid=0, gid=0, flags=4, level=0, offset=0):
    [dir /var/spool/mqueue] OK
safefile(/etc/mail/service.switch, uid=0, gid=0, flags=6480, mode=400):
safedirpath(/etc/mail, uid=0, gid=0, flags=6580, level=0, offset=0):
    [dir /etc/mail] OK
    [uid 0, nlink 1, stat 100644, mode 400]     OK
safefile(/etc/mail/aliases.db, uid=0, gid=0, flags=584, mode=400):
safedirpath(/etc/mail, uid=0, gid=0, flags=584, level=0, offset=0):
    [dir /etc/mail] OK
    [uid 110, nlink 1, stat 100640, mode 400]   OK
safedirpath(/home/username, uid=1000, gid=1000, flags=1985, level=0, offset=0):
    [dir /home/username] OK
safefile(/home/username/.forward.major-productions, uid=1000, gid=1000, flags=1895, mode=400):
    No such file or directory
safedirpath(/home/username, uid=1000, gid=1000, flags=1985, level=0, offset=0):
    [dir /home/username] OK
safefile(/home/username/.forward, uid=1000, gid=1000, flags=1895, mode=400):
    No such file or directory
safefile(./dfx6MKLN6r006080, uid=0, gid=0, flags=2040, mode=600):
safedirpath(., uid=0, gid=0, flags=2040, level=0, offset=0):
    [dir .] OK
    No such file or directory
    [final dir . uid 0 mode 40700] Success
username... Connecting to local...
safefile(/usr/sbin/sensible-mda, uid=0, gid=0, flags=41904, mode=0):
safedirpath(/usr/sbin, uid=0, gid=0, flags=41904, level=0, offset=0):
    [dir /usr/sbin] OK
    [uid 0, nlink 1, stat 104755, mode 0]   OK
username... Sent
safefile(/var/lib/sendmail/sendmail.st, uid=0, gid=0, flags=2282, mode=600):
safedirpath(/var/lib/sendmail, uid=0, gid=0, flags=2282, level=0, offset=0):
    [dir /var/lib/sendmail] OK
    No such file or directory
safefile(/var/lib/sendmail/sendmail.st, uid=0, gid=0, flags=2282, mode=600):
safedirpath(/var/lib/sendmail, uid=0, gid=0, flags=2282, level=0, offset=0):
    [dir /var/lib/sendmail] OK
    No such file or directory

I'm attempting to upgrade my Linode Jessie instance to Stable by following this tutorial. I've upgraded my /etc/apt/sources.list file, and am up to the $ sudo apt update step. When I enter that command, I get the following:

Hit http://mirrors.linode.com stable InRelease
Hit http://mirrors.linode.com stable-updates InRelease                         
Ign http://nyc2.mirrors.digitalocean.com stable InRelease                      
Hit http://archive.debian.org jessie-backports InRelease                       
Ign http://nyc2.mirrors.digitalocean.com stable Release.gpg                    
Ign http://nyc2.mirrors.digitalocean.com stable Release                        
Get:1 http://security.debian.org stable/updates InRelease [39.1 kB]            
Get:2 https://packages.sury.org stable InRelease                        
Ign https://packages.sury.org stable InRelease                                 
Get:3 http://mirrors.linode.com stable/main Sources [7,827 kB]                 
W: There is no public key available for the following key IDs:                 
648ACFD622F3D138
 NO_PUBKEY DCC9EFBF77E11517
W: There is no public key available for the following key IDs:
648ACFD622F3D138
E: Release file for http://archive.debian.org/debian/dists/jessie-backports/InRelease is expired (invalid since 145d 4h 29min 16s). Updates for this repository will not be applied.

My aforementioned /etc/apt/sources.list file is:

# 

# deb cdrom:[Debian GNU/Linux 8.3.0 _Jessie_ - Official Multi-architecture amd6$

#deb cdrom:[Debian GNU/Linux 8.3.0 _Jessie_ - Official Multi-architecture amd64$

deb http://mirrors.linode.com/debian/ stable main
deb-src http://mirrors.linode.com/debian/ stable main

deb http://security.debian.org/ stable/updates main
deb-src http://security.debian.org/ stable/updates main

# jessie-updates, previously known as 'volatile'
deb http://mirrors.linode.com/debian/ stable-updates main
deb [arch=i386,ppc64el,amd64] http://nyc2.mirrors.digitalocean.com/mariadb/repo/10.2/debian stable main
# deb-src [arch=i386,ppc64el,amd64] http://nyc2.mirrors.digitalocean.com/mariadb/repo/10.2/debian stable main

deb-src http://mirrors.linode.com/debian/ stable-updates main

Doing some research on PPAs, I also updated my `/etc/apt/sources.list.d/php.list file to:

deb https://packages.sury.org/php/ stable main

But the error remains.

Is there a way to upgrade this PPA so it can be used with Debian Stable? Or is there some other way around this issue?

I've run into a weird issue. I have a custom configured and compiled version of NGINX (I wanted a couple extra compile time modules installed). For whatever reason, it's creating client_temp as a file rather than a directory, and that's causing a 500 internal server error whenever I try uploading a file.

My configuration:

--prefix=/opt/nginx --sbin-path=/usr/local/sbin/nginx 
--conf-path=/opt/nginx/nginx.conf 
--error-log-path=/var/log/nginx/error.log --http-log-path=/var/log/nginx/access.log 
--pid-path=/var/run/nginx.pid --lock-path=/var/run/nginx.lock 
--http-client-body-temp-path=/var/cache/nginx/client_temp 
--http-proxy-temp-path=/var/cache/nginx/proxy_temp 
--http-fastcgi-temp-path=/var/cache/nginx/fastcgi_temp 
--http-uwsgi-temp-path=/var/cache/nginx/uwsgi_temp 
--http-scgi-temp-path=/var/cache/nginx/scgi_temp --user=www-data --group=www-data 
--with-http_ssl_module --with-http_realip_module 
--with-http_gunzip_module --with-http_gzip_static_module --with-threads --with-file-aio 
--with-ipv6 --with-http_v2_module 
--with-cc-opt='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector 
--param=ssp-buffer-size=4 -m64 -mtune=native' --add-module=../ngx_cache_purge-2.3 
--add-module=../headers-more-nginx-module --add-module=../ModSecurity-nginx

As you can see, I do specify a path for client_temp: --http-client-body-temp-path=/var/cache/nginx/client_temp, yet it's a file rather than a directory.

Do I need to manually create client_temp as a directory and remove the file? Or is there another way to remedy the situation?

So, NGINX 1.13.2 was released today, and I'd like to update my 1.13.1 installation. I can't simply use something like $ apt-get install nginx because I'm using a few static modules in my build. Due to that, I have a few questions:

1. Should I overwrite the existing files completely? I originally extracted NGINX itself to /opt/nginx so should I just $ tar -xvzf nginx-1.13.2 -C /opt/nginx?
2. I'm guessing I'll need to run ./configure again with the same values as before. When I run make should I use $ make upgrade rather than $ make install?
3. Is there anything else I should be aware of? I know about using the USR2 and WINCH signals to gracefully shutdown the old master process and start the new one, but I'm assuming that's after steps 1 and 2. Anything more I should know?

Thanks!

Over at the official NGINX docs, they have the following configuration for production-level Symfony:

# PROD
location ~ ^/app\.php(/|$) {
    fastcgi_pass unix:/var/run/php5-fpm.sock;
    fastcgi_split_path_info ^(.+\.php)(/.*)$;
    include fastcgi_params;
   # When you are using symlinks to link the document root to the
   # current version of your application, you should pass the real
   # application path instead of the path to the symlink to PHP
   # FPM.
   # Otherwise, PHP's OPcache may not properly detect changes to
   # your PHP files (see https://github.com/zendtech/ZendOptimizerPlus/issues/126
   # for more information).
   fastcgi_param SCRIPT_FILENAME $realpath_root$fastcgi_script_name;
   fastcgi_param DOCUMENT_ROOT $realpath_root;
   # Prevents URIs that include the front controller. This will 404:
   # http://domain.tld/app.php/some-path
   # Remove the internal directive to allow URIs like this
   internal;
}

The full configuration file can be found here

What is internal actually redirecting to? The comments say that it removes the front controller from the URI, but I'm not entirely sure how.

I'm in the process of building a LEMP stack server and local development environment, largely following the tutorials that both Linode and DigitalOcean provide. I have installed all the disparate components, but I'm a bit confused about configuring NGINX to handle PHP. The tutorials describe editing a server {} block found in sites-available/default. The thing is, my default configuration file has two server blocks, and I'm not sure which one I should edit.

The first contains:

server {
   listen 80 default_server;
   listen [::]:80 default_server;

   # SSL configuration
   #
   # listen 443 ssl default_server;
   # listen [::]:443 ssl default_server;
   #
   # Note: You should disable gzip for SSL traffic.
   # See: https://bugs.debian.org/773332
   #
   # Read up on ssl_ciphers to ensure a secure configuration.
   # See: https://bugs.debian.org/765782
   #
   # Self signed certs generated by the ssl-cert package
   # Don't use them in a production server!
   #
   # include snippets/snakeoil.conf;

   root /var/www/html;

   # Add index.php to the list if you are using PHP
   index index.html index.htm index.nginx-debian.html;

   server_name _;

   location / {
      # First attempt to serve request as file, then
      # as directory, then fall back to displaying a 404.
      try_files $uri $uri/ =404;
   }

   # pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
   #
   #location ~ \.php$ {
   #   include snippets/fastcgi-php.conf;
   #
   #   # With php7.0-cgi alone:
   #   fastcgi_pass 127.0.0.1:9000;
   #   # With php7.0-fpm:
   #   fastcgi_pass unix:/run/php/php7.0-fpm.sock;
   #}

   # deny access to .htaccess files, if Apache's document root
   # concurs with nginx's one
   #
   #location ~ /\.ht {
   #   deny all;
   #}
}

While the second contains:

# Virtual Host configuration for example.com
#
# You can move that to a different file under sites-available/ and symlink that
# to sites-enabled/ to enable it.
#
#server {
#   listen 80;
#   listen [::]:80;
#
#   server_name example.com;
#
#   root /var/www/example.com;
#   index index.html;
#
#   location / {
#      try_files $uri $uri/ =404;
#   }
#}

Which should I edit? I will be working on/hosting multiple virtual hosted sites, if that makes a difference.

I originally set my web root in /etc/apache2/sites-available/000-default.conf to point to /home/me/www. Due to the requirements of a new project, I need to be able to set /home/me/www/vendor/www as its own virtual host as any local directory cruft in the request stemming from localhost/blah/blah/blah will currently cause it to fail (the site is pretty horrible, codewise, which is why I've been contracted to work on it).

I have the following config file in my /etc/apache2/sites-available -

project2.com.conf:

<VirtualHost *:80>
    ServerAdmin webmaster@localhost
    ServerName project2
    ServerAlias localcopy
    ServerRoot /home/me/www/vendor/www/
    DocumentRoot /home/me/www/vendor/www/
    <Directory /home/me/www/vendor/www>
        Header set Access-Control-Allow-Origin "*" 
            Options Indexes FollowSymLinks MultiViews
            AllowOverride All
        Require all granted
    </Directory>

    # Available loglevels: trace8, ..., trace1, debug, info, notice, warn,
    # error, crit, alert, emerg.
    # It is also possible to configure the loglevel for particular
    # modules, e.g.

    #LogLevel info ssl:warn

    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>

# vim: syntax=apache ts=4 sw=4 sts=4 sr noet

I also have the following entry in my /etc/hosts file:

127.0.0.1   localhost
127.0.1.1   Shevat
127.0.1.2   project2.com

# The following lines are desirable for IPv6 capable hosts
::1     ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters

However, when I attempt to access project2.com through my browser, it displays the contents of the /home/me/www directory instead because, like I said above, I set that as my global web root in /etc/apache2/sites-available/000-default.conf.

Is there a way to override the global web root/virtual host settings in this instance so project2.com is accessed properly?

I have a project coming up where one of the requirements will be to cache what's essentially read-only data in order to lessen the strain on the db. I'm just a bit confused on how caching works with a db.

How does caching work? I've seen something called query caching, but does that cache query results? Or just the queries? And isn't a view a form of caching anyway?

I'm just looking for a nudge in the right direction. The project will use MySQL 5.1 for the store, so any links that can clear up my confusion would be a big help. A general Google search has only provided me with query caching, and with my lack of knowledge in this area, I'm not sure if that's the direction I should go.

I'm nearing the end of site development, and am now facing transferring my table structure and data from my development machine to the live server. SQL Server 2008 R2 is already installed and ready to go on the live server, so at least that's out of the way, but I'm unsure how to proceed. Is there a build script, or something simpler than manually recreating the tables and inserting the data? And if there is, will it keep my db connection string the same, assuming the login info is the same?

I'm trying to install SQL Server 2008 R2 on my development laptop and am hitting a snag when it gets to the 'Server Configuration' phase. It's asking me for Windows user account information for the various servies it needs to run. I'm not sure what to put in, or how to create what it's looking for. I tried putting in custom account names and passwords in the hope it would create those accounts automatically, but I get an 'Invalid account name or password' error for each.

I know next to nothing when it comes to Windows from an IT perspective, so I'm lost right now. I found one MSDN link, but it's over my head. Any help would be greatly appreciated.

I think this falls into the category of 'never ask a developer to do a server administrator's job'.

I'm a developer writing a couple of ASP.NET MVC 2 sites. I've attempted to use the ASP.NET Configuration Tool to create some user roles, but it keeps giving me an error stating that it can't find my data store, and that the AspNetSqlProvider cannot connect to the db. I have run aspnet_regsql, but that only created the tables necessary for user management. It did nothing to help my connection problem. From what I can see, my connection strings are okay.

As a test, I fired up some MVC tutorial apps in the debugger. Both displayed and saved my inputed data, so it seems like the database is working to some extent.

Following that, I decided to test if I could attach some .mdf files to the db via the Management Studio. I tried both an 'empty' file (folder structure intact, but no tables) and one that I've fleshed out for one of my projects. In both cases, the Management Studio claimed it couldn't find the files, despite both existing and me manually entering their paths.

All of this seems to point to a permissions issue. I'm just not sure on which side the problem resides - db or files - or how to fix it. Any help would be greatly appreciated.

Note: all of this is happening on my Win 7 laptop, with Visual Studio 2010 Professional.