docker-kopano/README.md

The mlan/kopano repository

This (unofficial) repository provides dockerized web mail service as well as ActiveSync, ICAL, IMAP and POP3 service. It is based on Kopano core components, as well as the Kopano WebApp and Z-Push. The image uses nightly built packages which are provided by the Kopano community.

Hopefully this repository can be retired once the Kopano community make official images available. There is some evidence of such activity on dockerhub:kopano.

Feature overview

Brief feature list follows below

• Groupware server Kopano WebApp
• ActiveSync server Z-Push
• Multi-staged build providing the images -full , -debugtools , -core and -webapp
• Configuration using environment variables
• Log directed to docker daemon with configurable level
• Built in utility script conf helping configuring Kopano components, WebApp and Z-Push
• Health check
• Hook for theming

Tags overview

The mlan/kopano repository contains a multi staged built. You select which build using the appropriate tag.

The version part of the tag is latest or the combined revision numbers of the nightly kopano-core and kopano-webapp package suits that was available when building this image. For example, 8.7.80-3.5.2 indicates that the image was built using the 8.7.80 version of Kopano core and 3.5.2 version of Kopano webapp.

The build part of the tag is one of -full , -debugtools , -core and soon also -webapp. The image with tag ending in -full or without ending contain Kopano core components, as well as, the Kopano webapp and z-push. The image with tag ending in -debugtools also contains some debug tools. The image with tag ending in -core contains the kopano-core components proving the server and imap, pop3 and ical access. The image with tag ending in -webapp contains the Kopano webapp and z-push proving web and active sync service which will depend on a kopano server running in a separate container or elsewhere.

To exemplify the usage of the tags, lets assume that the latest version tag is 8.7.80-3.5.2. In this case latest, 8.7.80-3.5.2, latest-full and 8.7.80-3.5.2-full all identify the same image.

Usage

In most use cases the mlan/kopano container also needs a SQL database (e.g., MySQL or MariaDB), Mail Transfer Agent (e.g., Postfix) and authentication (e.g., OpenLDAP). Docker images of such services are available. The docker compose example below is used to demonstrate how to configure these services.

docker run -d --name mail-app -p 80:80 mlan/kopano

Docker compose example

An example of how to configure an web mail server using docker compose is given below. It defines four services, mail-app, mail-mta, mail-db and auth, which are the web mail server, the mail transfer agent, the SQL database and authentication respectively.

version: '3.7'

services:
  mail-app:
    image: mlan/kopano:8.7.80-3.5.2
    restart: unless-stopped
    networks:
      - backend
    ports:
      - "80:80"
    labels:
      - traefik.enable=true
      - traefik.frontend.rule=Host:mail.${DOMAIN-docker.localhost}
      - traefik.docker.network=${COMPOSE_PROJECT_NAME}_proxy
      - traefik.port=80
    depends_on:
      - auth
      - mail-db
      - mail-mta
    environment:
      - USER_PLUGIN=ldap
      - LDAP_HOST=auth
      - MYSQL_HOST=mail-db
      - SMTP_SERVER=mail-mta
      - LDAP_SEARCH_BASE=${LDAP_BASE}
      - LDAP_USER_TYPE_ATTRIBUTE_VALUE=kopano-user
      - LDAP_GROUP_TYPE_ATTRIBUTE_VALUE=kopano-group
      - LDAP_USER_SEARCH_FILTER=(kopanoAccount=1)
      - SYSLOG_LEVEL=4
    env_file:
      - .init.env
    volumes:
      - mail-conf:/etc/kopano
      - mail-atch:/var/lib/kopano/attachments
      - mail-sync:/var/lib/z-push

  mail-mta:
    image: mlan/postfix-amavis:3.8
    restart: unless-stopped
    hostname: ${MAIL_SRV-mx}.${MAIL_DOMAIN-docker.localhost}
    networks:
      - backend
    ports:
      - "25:25"
    depends_on:
      - auth
    environment:
      - LDAP_HOST=auth
      - DAGENT_TRANSPORT=lmtp:mail-app:2003
      - SMTP_RELAY_HOSTAUTH=${SMTP_RELAY_HOSTAUTH}
      - SMTP_TLS_SECURITY_LEVEL=${SMTP_TLS_SECURITY_LEVEL-}
      - SMTP_TLS_WRAPPERMODE=${SMTP_TLS_WRAPPERMODE-no}
      - LDAP_USER_BASE=${LDAP_USEROU},${LDAP_BASE}
      - LDAP_GROUP_BASE=${LDAP_GROUPOU},${LDAP_BASE}
      - LDAP_QUERY_FILTER_USER=(&(kopanoAccount=1)(mail=%s))
      - LDAP_QUERY_FILTER_ALIAS=(&(kopanoAccount=1)(kopanoAliases=%s))
      - LDAP_QUERY_FILTER_GROUP=(&(objectclass=kopano-group)(mail=%s))
      - LDAP_QUERY_FILTER_EXPAND=(&(objectclass=kopano-user)(uid=%s))
      - DKIM_SELECTOR=${DKIM_SELECTOR-default}
      - SYSLOG_LEVEL=5
    env_file:
      - .init.env
    volumes:
      - mail-mta:/var
      - proxy-acme:/acme

  mail-db:
    image: mariadb
    restart: unless-stopped
    command: ['--log_warnings=1']
    networks:
      - backend
    environment:
      - LANG=C.UTF-8
    env_file:
      - .init.env
    volumes:
      - mail-db:/var/lib/mysql

  auth:
    image: mlan/openldap:1.0
    restart: unless-stopped
    networks:
      - backend
    environment:
      - LDAP_LOGLEVEL=parse
    volumes:
      - auth-conf:/srv/conf
      - auth-data:/srv/data

networks:
  backend:

volumes:
  mail-conf:
  mail-atch:
  mail-db:
  mail-mta:
  mail-sync:

Environment variables

When you create the mlan/kopano container, you can adjust the configuration of the Kopano server by passing one or more environment variables or on the docker run command line. Note that any pre-existing configuration files within the container will be left untouched.

To see all available configuration variables you can run man within the container, for example like this:

docker exec mail-app man kopano-server.cfg

If you do, you will notice that configuration variable names are all lower case, but they will be matched with all uppercase environment variables by the container entrypoint script.

SQL database configuration

The Kopano server uses a SQL database, which needs to be initiated, see below. Once the SQL database has been initiated you can create the Kopano container and configure it to use the SQL database using environment variables.

MYSQL_HOST

The hostname of the MySQL server to use. Default MYSQL_HOST=localhost.

MYSQL_PORT

The port of the MySQL server to use. Default MYSQL_PORT=3306

MYSQL_USER

The user under which we connect with MySQL. Default MYSQL_USER=root. For security reasons it is probably wise not to use the root user. Use the same name as was used when initiating the SQL database, see below.

MYSQL_PASSWORD

The password to use for MySQL. It is possible to leave it empty for no password, but that is advised against. Default MYSQL_PASSWORD=. Use the same password as was used when initiating the SQL database, see below.

MYSQL_DATABASE

The MySQL database to connect to. Default MYSQL_DATABASE=kopano. Use the same database name as was used when initiating the SQL database, see below.

ATTACHMENT_STORAGE

The location where attachments are stored. This can be in the MySQL database, or as separate files. The drawback of database is that the large data of attachment will push useful data from the MySQL cache. The drawback of separate files is that a mysqldump is not enough for a full disaster recovery. Possible values: database, files, files_v2 (experimental). Default: ATTACHMENT_STORAGE=files

ATTACHMENT_COMPRESSION

When the attachment_storage option is ATTACHMENT_STORAGE=files, this option controls the compression level for the attachments. Higher compression levels will compress data better, but at the cost of CPU usage. Lower compression levels will require less CPU but will compress data less. Setting the compression level to 0 will effectively disable compression completely. Changing the compression level, or switching it on or off, will not affect any existing attachments, and will remain accessible as normal. Set to 0 to disable compression completely. The maximum compression level is 9. Default: ATTACHMENT_COMPRESSION=6

SQL Database initialization

When creating the SQL container you can use environment variables to initiate it. For example, MYSQL_ROOT_PASSWORD=topsecret, MYSQL_DATABASE=kopano, MYSQL_USER=kopano and MYSQL_PASSWORD=verysecret.

Persistent data

There are at least three directories which should be considered mounted; the configuration files, /etc/kopano, the mail attachments, if they are kept in files, /var/lib/kopano/attachments and the active sync device states, if they are kept in files, /var/lib/z-push.

Authentication USER_PLUGIN

Kopano supports three different ways to manage user authentication. Use the USER_PLUGIN environment variable to select the source of the user base. Possible values are: db (default), ldap and unix.

db: Retrieve the users from the Kopano database. Use the kopano-admin tool to create users and groups. There are no additional settings for this plugin.

ldap: Retrieve the users and groups information from an LDAP server. All additional LDAP settings are needed see below

unix: Retrieve the users and groups information from the Linux password files. This option is probably not interesting here.

LDAP authentication

An LDAP server with user accounts configured to be used with Kopano is needed, but how to set one up is out of our scope here, instead see: Kopano Knowledge Base/Install and optimize OpenLDAP for use with Kopano Groupware Core.

Once the LDAP server is up and running, the mlan/kopano container can be configured to use it using environment variables. In addition to the variables discussed below also set USER_PLUGIN=ldap.

LDAP_HOST, LDAP_PORT, LDAP_PROTOCOL

These directives specify a single LDAP server to use. Defaults: LDAP_HOST=localhost, LDAP_PORT=389, LDAP_PROTOCOL=ldap

LDAP_SEARCH_BASE

This is the subtree entry where all objects are defined in the LDAP server. Default: LDAP_SEARCH_BASE=dc=kopano,dc=com

LDAP_USER_TYPE_ATTRIBUTE_VALUE

This variable determines what defines a valid Kopano user. Default: LDAP_USER_TYPE_ATTRIBUTE_VALUE=posixAccount

LDAP_GROUP_TYPE_ATTRIBUTE_VALUE

This variable determines what defines a valid Kopano group. Default: LDAP_GROUP_TYPE_ATTRIBUTE_VALUE=posixGroup

LDAP_USER_SEARCH_FILTER

Adds an extra filter to the user search. Default LDAP_USER_SEARCH_FILTER=

Hint: Use the kopanoAccount attribute in the filter to differentiate between non-kopano and kopano users.

Enabling IMAP and POP3 DISABLED_FEATURES

By default the imap and pop3 services are disabled for all users. You can set the environment variable DISABLED_FEATURES= to enable both imap and pop3. In this list you can disable certain features for users. This list is space separated, and currently may contain the following features: imap, pop3. Default: DISABLED_FEATURES=imap pop3

Logging LOG_LEVEL

The level of output for logging in the range from 0 to 6. 0 means no logging, 1 for critical messages only, 2 for error or worse, 3 for warning or worse, 4 for notice or worse, 5 for info or worse, 6 debug. Default: LOG_LEVEL=3

Custom themes

You can easily customize the Kopano WebApp see New! JSON themes in Kopano WebApp. Once you have the files you can install them in your docker container using the receipt below, where we assume that the container name is mail-app and that the directory mytheme contains the theme.json and the other file defining the theme.

$ docker cp mytheme/. mail-app:/etc/kopano/theme/Custom
$ docker exec mail-app chown -R root:root /etc/kopano/theme
$ docker exec mail-app conf replace /etc/kopano/webapp/config.php 'define("THEME", \x27\x27);' 'define("THEME", \x27Custom\x27);'

Please note that it is not possible to rename the directory /etc/kopano/theme/Custom within the container without further modifications.

Mail transfer agent interaction

Environment variables can be used to configure where Kopano find the Mail Transfer Agent, such as Postfix. Likewise the Mail Transfer Agent need to know where to forward emails to.

SMTP_SERVER

Hostname or IP address of the outgoing SMTP server. This server needs to relay mail for your server. Default: SMTP_SERVER=localhost

SMTP_PORT

TCP Port number for smtp_server. Default: SMTP_PORT=25

Configuring postfix

The Kopano server listens to the port 2003 and expect the LMTP protocol. For Postfix you can define DAGENT_TRANSPORT=lmtp:mail-app:2003 assuming the mlan/kopano container is named mail-app