Added config folder for Postfix

[jkarlosb]

Feature #29

[jkarlosb]

First, I created a volume with postfix config folder. Second, Into postifix container start.sh I added a script to verify optional main.cf and if it exist, override the entries through postconf e flag. Next, the script checks if some .map file exist (e.g. transport.map, sasl_passwd.map, etc.), it copies to /etc/postfix folder, executes postmap and configures its perms. Example config files for basic SES config:

/freeposte/config/postfix/main.cf:

relayhost = [email-smtp.eu-west-1.amazonaws.com]:25
smtp_sasl_auth_enable = yes
smtp_sasl_security_options = noanonymous
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd.map
smtp_use_tls = yes
smtp_tls_security_level = encrypt
smtp_tls_note_starttls_offer = yes
smtp_tls_CAfile = /etc/ssl/certs/ca-certificates.crt

/freeposte/config/postfix/sasl_passwd.map:

[email-smtp.eu-west-1.amazonaws.com]:25 USER:PASSWORD

[kaiyou]

Sounds very good.

Because we have very few configuration files for each service, I am thinking about gathering them all in something like /freeposte/overrides (or anything that clearly states that these are overrides, not the actual configuration files) and overriding on a filename basis with proper documentation to avoid having too many directories and different mount points.

The documentation could state something like "create a main.cf to override the postfix configuration", and maybe use some more meaningful names like postfix.conf, dovecot.conf, etc.

The only problem I see would be confidentiality between containers for password maps for instance. Does not sound like too much of a risk. What do you think?

[jkarlosb]

Ok, It seems perfect for me, to avoid having too many mount points. About the confidentiality between containers I think this isn't a risk for now.

[kaiyou]

Sounds perfect. Let's go for master, I will test it tonight. Thanks!