Switch to python and Jinja2 for the dovecot container

dovecot/conf/dovecot.conf

@@ -52,27 +52,11 @@ namespace inbox {
   }
 }
 
-###############
-# TLS
-###############
-ssl = yes
-ssl_cert = </certs/cert.pem
-ssl_key = </certs/key.pem
-# This will be enabled once 2.3 is released
-# ssl_dh = </certs/dhparam.pem
-# In the meanwhile:
-ssl_dh_parameters_length = 2048
-# TLS hardening is based on the following documentation:
-# https://bettercrypto.org/static/applied-crypto-hardening.pdf
-ssl_protocols=!SSLv3 !SSLv2
-ssl_cipher_list = EDH+CAMELLIA:EDH+aRSA:EECDH+aRSA+AESGCM:EECDH+aRSA+SHA256:EECDH:+CAMELLIA128:+AES128:+SSLv3:!aNULL:!eNULL:!LOW:!3DES:!MD5:!EXP:!PSK:!DSS:!RC4:!SEED:!IDEA:!ECDSA:kEDH:CAMELLIA128-SHA:AES128-SHA
-ssl_prefer_server_ciphers = yes
-ssl_options = no_compression
-
 ###############
 # Authentication
 ###############
 auth_mechanisms = plain login
+disable_plaintext_auth = no
 
 passdb {
   driver = sql
@@ -88,10 +72,6 @@ service auth {
   user = dovecot
   unix_listener auth-userdb {
   }
-
-  inet_listener {
-    port = 2102
-  }
 }
 
 service auth-worker {
@@ -119,9 +99,6 @@ service imap-login {
   inet_listener imap {
     port = 143
   }
-  inet_listener imaps {
-    port = 993
-  }
 }
 
 ###############
@@ -149,7 +126,7 @@ plugin {
 ###############
 
 service managesieve-login {
-	inet_listener sieve {
+  inet_listener sieve {
     port = 4190
   }
 }
@@ -158,12 +135,12 @@ service managesieve {
 }
 
 plugin {
-	sieve = file:~/sieve;active=~/.dovecot.sieve
+  sieve = file:~/sieve;active=~/.dovecot.sieve
   sieve_plugins = sieve_extdata sieve_imapsieve sieve_extprograms
   sieve_global_extensions = +vnd.dovecot.extdata +spamtest +spamtestplus +vnd.dovecot.execute
-	sieve_before = /var/lib/dovecot/before.sieve
-	sieve_default = /var/lib/dovecot/default.sieve
-	sieve_after = /var/lib/dovecot/after.sieve
+  sieve_before = /var/lib/dovecot/before.sieve
+  sieve_default = /var/lib/dovecot/default.sieve
+  sieve_after = /var/lib/dovecot/after.sieve
   sieve_extdata_dict_uri = proxy::sieve
 
   # Sieve execute