Send email on testing docker container with php and sendmail

It works.

In Dockerfile :

# sendmail config
############################################

RUN apt-get install -q -y ssmtp mailutils

# root is the person who gets all mail for userids < 1000
RUN echo "[email protected]" >> /etc/ssmtp/ssmtp.conf

# Here is the gmail configuration (or change it to your private smtp server)
RUN echo "mailhub=smtp.gmail.com:587" >> /etc/ssmtp/ssmtp.conf
RUN echo "[email protected]" >> /etc/ssmtp/ssmtp.conf
RUN echo "AuthPass=yourGmailPass" >> /etc/ssmtp/ssmtp.conf

RUN echo "UseTLS=YES" >> /etc/ssmtp/ssmtp.conf
RUN echo "UseSTARTTLS=YES" >> /etc/ssmtp/ssmtp.conf


# Set up php sendmail config
RUN echo "sendmail_path=sendmail -i -t" >> /usr/local/etc/php/conf.d/php-sendmail.ini

For testing inside php sendmail container :

echo "Un message de test" | mail -s "sujet de test" [email protected]

I succeed with the help of this two documents :

• https://unix.stackexchange.com/questions/36982/can-i-set-up-system-mail-to-use-an-external-smtp-server
• https://github.com/cmaessen/docker-php-sendmail/blob/master/Dockerfile

If it says:

"Package 'ssmtp' has no installation candidate"

You can use msmtp instead.

Add the following to your dockerfile

# sendmail config
#################
ARG SMTP_PASSWORD=not_provided
# install
RUN apt-get install -q -y msmtp mailutils
# config
COPY msmtprc /etc/msmtprc
RUN chmod 600 /etc/msmtprc
RUN chown www-data:www-data /etc/msmtprc
ARG SMTP_PASSWORD=not_provided
RUN sed -i "s|YourAwesomeStr0ngP4zzw0rd|$SMTP_PASSWORD|g" /etc/msmtprc
# Set up php sendmail config
RUN echo "sendmail_path=/usr/bin/msmtp -t" >> /etc/php/7.3/apache2/conf.d/php-sendmail.ini

Add a msmtprc file to your docker build context:

account default
host mail.yoursmtpserver.com
port 587
tls on
tls_starttls on
tls_trust_file /etc/ssl/certs/ca-certificates.crt
tls_certcheck on
auth on
user [email protected]
password "YourAwesomeStr0ngP4zzw0rd"
from "[email protected]"
logfile /var/log/msmtp.log

note: Some changes were made in order to make it work with my particular setup (branching FROM eboraas/apache-php). This applies particularily to the lines:

• ARG SMTP_PASSWORD=not_provided
• RUN chown www-data:www-data /etc/msmtprc
• RUN sed -i "s|YourAwesomeStr0ngP4zzw0rd|$SMTP_PASSWORD |g" /etc/msmtprc
• RUN echo "sendmail_path=/usr/bin/msmtp -t" >> /etc/php/7.3/apache2/conf.d/php-sendmail.ini

You may need to adapt paths, passwords and so on to fit your needs. Keep in mind to set the SMTP_PASSWORD build argument from environment (e.g. SMTP_PASSWORD=<secret> docker-compose build) if you want to use this solution straight away.

Useful resources:

• https://wiki.debian.org/msmtp
• https://owendavies.net/articles/setting-up-msmtp/
• https://wiki.archlinux.org/index.php/msmtp#Send_mail_with_PHP_using_msmtp
• linux msmtp configuration sends from shell but fails from PHP/apache