Cntlm proxy - my experience

When you work in a company where you have to use proxy, some things can get more complicated. In this article I'd like to summarize my settings and experience of using proxy on my linux Fedora27 laptop.

Linux - configuration of a proxy 

Settings of a proxy on linux machines differs per distribution. On some user friendly distributions you can use a Graphical interface and on others, you do it in a configuration file.

The easiest way to find it out for your distribution is to put a phrase like "Fedora 24 proxy configuration" into google, where you replace Fedora 24 with your distribution ;)

For example I use for my proxy configuration file /etc/profile.d/proxy.sh
And it looks almost like the first example file which you'll find via google.

MY_PROXY_URL="http://prox.srv.world:3128/"
HTTP_PROXY=$MY_PROXY_URL
HTTPS_PROXY=$MY_PROXY_URL
FTP_PROXY=$MY_PROXY_URL
http_proxy=$MY_PROXY_URL
https_proxy=$MY_PROXY_URL
ftp_proxy=$MY_PROXY_URL
export HTTP_PROXY HTTPS_PROXY FTP_PROXY http_proxy https_proxy ftp_proxy
export no_proxy="localhost,127.0.0.1,localaddress,.localdomain.com"

Additionaly (in Fedora) you have to specify proxy for dnf in a separate file - /etc/dnf/dnf.conf
For those who don't know dnf is a package manager - similar to apt-get in debian-like distributions.

Cntlm daemon restart is slow (Fedora23)

Everything started with 

$ sudo systemctl restart cntlm.service being very slow - it takes a minute or more.

So I started digging why.
I simply tried to stop it and then check how it looks during stopping.

Reproduced in Fedora23 and Fedora24

Running:

$ sudo systemctl start cntlm.service

$ sudo systemctl status cntlm.service -l
● cntlm.service - CNTLM HTTP Accelerator For NTLM Secured Proxies Authenticator
   Loaded: loaded (/usr/lib/systemd/system/cntlm.service; enabled; vendor preset: disabled)
   Active: active (running) since Tue 2016-10-25 12:34:33 CEST; 6min ago
  Process: 23537 ExecStart=/usr/sbin/cntlm -c /etc/cntlm.conf -U cntlm -P /run/cntlm/cntlmd.pid (code=exited, status=0/SUCCESS)
 Main PID: 23540 (cntlm)
   Memory: 2.5M
      CPU: 257ms
  CGroup: /system.slice/cntlm.service
           └─23540 /usr/sbin/cntlm -c /etc/cntlm.conf -U cntlm -P /run/cntlm/cntlmd.pid

Oct 25 12:39:23 mylaptop cntlm[23540]: 127.0.0.1 CONNECT ssl.gstatic.com:443
Oct 25 12:39:24 mylaptop cntlm[23540]: 127.0.0.1 CONNECT lh5.googleusercontent.com:443
Oct 25 12:39:24 mylaptop cntlm[23540]: 127.0.0.1 CONNECT csi.gstatic.com:443
Oct 25 12:39:24 mylaptop cntlm[23540]: 127.0.0.1 CONNECT plus.google.com:443
Oct 25 12:39:25 mylaptop cntlm[23540]: 127.0.0.1 CONNECT i18n-cloud.appspot.com:443
Oct 25 12:39:26 mylaptop cntlm[23540]: 127.0.0.1 CONNECT play.google.com:443
Oct 25 12:39:27 mylaptop cntlm[23540]: 127.0.0.1 CONNECT play.google.com:443
Oct 25 12:39:40 mylaptop cntlm[23540]: 127.0.0.1 CONNECT webpoolam30e10.infra.lync.com:443
Oct 25 12:40:35 mylaptop cntlm[23540]: 127.0.0.1 CONNECT accounts.google.com:443
Oct 25 12:40:36 mylaptop cntlm[23540]: 127.0.0.1 CONNECT beacons.gvt2.com:443

After recieving stop signal:

$ sudo systemctl stop cntlm.service

$ sudo systemctl status cntlm.service -l

● cntlm.service - CNTLM HTTP Accelerator For NTLM Secured Proxies Authenticator
   Loaded: loaded (/usr/lib/systemd/system/cntlm.service; enabled; vendor preset: disabled)
   Active: deactivating (stop-sigterm) since Tue 2016-10-25 12:41:10 CEST; 11s ago
  Process: 23537 ExecStart=/usr/sbin/cntlm -c /etc/cntlm.conf -U cntlm -P /run/cntlm/cntlmd.pid (code=exited, status=0/SUCCESS)
 Main PID: 23540 (cntlm)
   Memory: 2.5M
      CPU: 260ms
   CGroup: /system.slice/cntlm.service
           └─23540 /usr/sbin/cntlm -c /etc/cntlm.conf -U cntlm -P /run/cntlm/cntlmd.pid
Oct 25 12:39:24 mylaptop cntlm[23540]: 127.0.0.1 CONNECT csi.gstatic.com:443
Oct 25 12:39:24 mylaptop cntlm[23540]: 127.0.0.1 CONNECT plus.google.com:443
Oct 25 12:39:25 mylaptop cntlm[23540]: 127.0.0.1 CONNECT i18n-cloud.appspot.com:443
Oct 25 12:39:26 mylaptop cntlm[23540]: 127.0.0.1 CONNECT play.google.com:443
Oct 25 12:39:27 mylaptop cntlm[23540]: 127.0.0.1 CONNECT play.google.com:443
Oct 25 12:39:40 mylaptop cntlm[23540]: 127.0.0.1 CONNECT webpoolam30e10.infra.lync.com:443
Oct 25 12:40:35 mylaptop cntlm[23540]: 127.0.0.1 CONNECT accounts.google.com:443
Oct 25 12:40:36 mylaptop cntlm[23540]: 127.0.0.1 CONNECT beacons.gvt2.com:443
Oct 25 12:41:10 mylaptop systemd[1]: Stopping CNTLM HTTP Accelerator For NTLM Secured Proxies Authenticator...
Oct 25 12:41:10 mylaptop cntlm[23540]: Signal 15 received, issuing clean shutdown

After waiting a minute or more: