MailHog Standalone Installation / Systemd service script

script.sh

# -r, --system                  create a system account
# -m, --create-home             create the user's home directory (by default no home created for system accounts)
# -s, --shell SHELL             login shell of the new account (Do system accounts get nologin by default anyway?)
sudo useradd -r -m -s /usr/sbin/nologin mailhog

# https://github.com/mailhog/MailHog/releases
wget https://github.com/mailhog/MailHog/releases/download/v1.0.0/MailHog_linux_amd64 -O /home/mailhog/MailHog_linux_amd64

# make exec.
# I like to keep the binary non-writeable by the executing user.
chmod +x /home/mailhog/MailHog_linux_amd64

# Optional, lets this specific binary listen to privilaged ports (ie 25) while running as an un-privilaged user.
setcap CAP_NET_BIND_SERVICE=+eip /home/mailhog/MailHog_linux_amd64

# create systemd service file
echo "[Unit]
Description=MailHog Email Catcher
After=syslog.target network.target

[Service]
User=mailhog
Group=mailhog
Environment=MH_API_BIND_ADDR=0.0.0.0:80
Environment=MH_UI_BIND_ADDR=0.0.0.0:80
Environment=MH_SMTP_BIND_ADDR=0.0.0.0:25
Type=simple
ExecStart=/home/mailhog/MailHog_linux_amd64
StandardOutput=journal
Restart=on-failure

[Install]
WantedBy=multi-user.target" > /etc/systemd/system/mailhog.service

# enable and start the service
systemctl enable mailhog
systemctl start mailhog

yeet

root@mailhog:~# ps -auxf
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
mailhog    563  0.0  0.7  10588  7624 ?        Ssl  16:16   0:00 /home/mailhog/MailHog_linux_amd64

root@mailhog:~# ss -tulpn
Netid  State   Recv-Q  Send-Q   Local Address:Port   Peer Address:Port
tcp    LISTEN  0       128                  *:25                *:*      users:(("MailHog_linux_a",pid=682,fd=3))
tcp    LISTEN  0       128                  *:80                *:*      users:(("MailHog_linux_a",pid=682,fd=5))