icinga2

This repository contains the source for the icinga2 docker image.

The dockerhub-repository is located at https://hub.docker.com/r/jordan/icinga2/.

This build is automated by push for the git-repo. Just pull it via:

docker pull jordan/icinga2

Image details

1. Based on debian:bullseye
2. Key-Features:
   • icinga2
   • icingacli
   • icingaweb2
   • icingaweb2-director module
   • icingaweb2-graphite module
   • icingaweb2-module-aws
   • ssmtp
   • MySQL
   • Supervisor
   • Apache2
   • SSL Support
   • Custom CA support
3. No SSH. Use docker exec or nsenter
4. If passwords are not supplied, they will be randomly generated and shown via stdout.

Usage

Start a new container and bind to host's port 80

docker run -p 80:80 -h icinga2 -t jordan/icinga2:latest

docker-compose

Clone the repository and create a file secrets_sql.env, which contains the MYSQL_ROOT_PASSWORD variable.

git clone https://github.com/jjethwa/icinga2.git
cd icinga2
echo "MYSQL_ROOT_PASSWORD=<password>" > secrets_sql.env
docker-compose up

This boots up an icinga(web)2 container with another MySQL container reachable on http://localhost with the default credentials icingaadmin:icinga.

Persistence

To ensure restarts, you should set:

DEFAULT_MYSQL_PASS - The database password for the icinga2 user

MYSQL_ROOT_PASSWORD - This is the root (admin) password for the database. The container will try to reset the password for the icinga2 database user if this is available

This is particularly important when using the /var/lib/mysql volume or an external database

Icinga Web 2

Icinga Web 2 can be accessed at http://localhost/icingaweb2 with the credentials icingaadmin:icinga (if not set differently via variables). When using a volume for /etc/icingaweb2, make sure to set ICINGAWEB2_ADMIN_USER and ICINGAWEB2_ADMIN_PASS

Saving PHP Sessions

If you want to save your php-sessions over multiple boots, mount /var/lib/php/sessions/ into your container. Session files will get saved there.

example:

docker run [...] -v $PWD/icingaweb2-sessions:/var/lib/php/sessions/ jordan/icinga2

Graphite

The graphite writer can be enabled by setting the ICINGA2_FEATURE_GRAPHITE variable to true or 1 and also supplying values for ICINGA2_FEATURE_GRAPHITE_HOST and ICINGA2_FEATURE_GRAPHITE_PORT. This container does not have graphite and the carbon daemons installed so ICINGA2_FEATURE_GRAPHITE_HOST should not be set to localhost.

Example:

docker run -t \
  --link graphite:graphite \
  -e ICINGA2_FEATURE_GRAPHITE=true \
  -e ICINGA2_FEATURE_GRAPHITE_HOST=graphite \
  -e ICINGA2_FEATURE_GRAPHITE_PORT=2003 \
  jordan/icinga2:latest

You will need to modify the retention policy as detailed here: https://github.com/jjethwa/icinga2/issues/275#issuecomment-1046892058

Icinga Director

The Icinga Director Icinga Web 2 module is installed and enabled by default. You can disable the automatic kickstart when the container starts by setting the DIRECTOR_KICKSTART variable to false. To customize the kickstart settings, modify the /etc/icingaweb2/modules/director/kickstart.ini.

API Master

The container gets automatically configured as an API master. But it has some caveats. Please make sure:

• Set the container's hostname (-h or hostname)
  • The hostname has to match the name, your sattelites are configured to access the master.
• Forward the 5665 port
• Mount both volumes: /etc/icinga2, /var/lib/icinga2

Sending Notification Mails

The container has msmtp installed, which forwards mails to a preconfigured SMTP server (MTA).

The full documentation for msmtp is found here.

You have to edit the file msmtp/msmtprc for general configuration and msmtp/aliases (mapping from local Unix-user to mail-address). Please note that the example file can be heavily changed and secured, so read the msmtp docs listed above

# msmtp/msmtprc
defaults
auth           on
tls            on
tls_trust_file /etc/ssl/certs/ca-certificates.crt
logfile        /var/log/msmtp.log
aliases        /etc/aliases

# Gmail
account        gmail
host           smtp.gmail.com
port           587
from           <your-email-address@gmail.com>
user           <your-email-address@gmail.com>
password       <your-password-or-eval-command-to-gpg-file>

# Set a default account
account default: gmail

Note that Gmail has become very restrictive, the preparation and config must be done in Gmail's settings. If you can't get it to work, consider another SMTP service.

msmtp/aliases follows the format: Unix-user: e-mail-address.

# msmtp/aliases
root:<YOUR_MAILBOX>
default:<YOUR_MAILBOX>

As a last config change, edit the data/icinga/etc/icinga2/conf.d/users.conf and change the e-mail address root@localhost to either root or a valid external address. This must be done as msmtp interprets all addresses with an at-sign as external and the transport will fail. If the address is changed to root the aliasing feature will use your root alias instead.

These files have to be mounted into the container. Add these flags to your docker run-command:

-v $(pwd)/msmtp/aliases:/etc/aliases:ro
-v $(pwd)/msmtp/msmtprc:/etc/msmtprc:ro

If you are using the docker-compose file, uncomment the settings for these files under the icinga2 node and rebuild.

SSL Support

For enabling of SSL support, just add a volume to /etc/apache2/ssl, which contains these files:

• icinga2.crt: The certificate file for apache
• icinga2.key: The corresponding private key
• icinga2.chain (optional): If a certificate chain is needed, add this file. Consult your CA-vendor for additional info.

For https-redirection or http/https dualstack consult APACHE2_HTTP env-variable.

Custom CA Support

In the case where you need to trust a non-default CA, add the certificate(s) as .crt files to a volume to be mounted at /usr/local/share/ca-certificates/.

Any certificates that are CA certificates with a .crt extension in that volume will automatically be added to the CA store at startup.

Adding own modules

To use your own modules, you're able to install these into enabledModules-folder of your /etc/icingaweb2 volume.

MySQL connections

The container has support to run a MySQL server inside or access some external resources. By default, the MySQL server inside the container is setup, but when using the docker-compose.yml project, the server is located inside an extra container. Future releases will have this as the default and require an external MySQL/MariaDB container.

If you use the image plain or the docker-compose.yml project, you don't have to worry about anything for MySQL. Only, if you want to split the container from the MySQL server, it's necessary to give some variables.

External MySQL servers

If you have the image running plain or use the docker-compose.yml project, there is no necessity to fool around with these variables.

To connect the container with the MySQL server, you have fine granular control via environment variables. For every necessary database, there is a set of variables, which describe the connection to it. In theory, the databases could get distributed over multiple hosts.

All variables are a combination of the service and the property with the format <SERVICE>_MYSQL_<PROPERTY>, while

• <SERVICE> can be one of ICINGA2_IDO, ICINGAWEB2, ICINGAWEB2_DIRECTOR
• <PROPERTY> can be one of HOST, PORT, DATA, USER, PASS

The container creates all databases for you by default, but you can skip this auto creation for each of the three databases. By creating the databases yourself you won't have to provide the MYSQL_ROOT_PASSWORD and it improves overall security and flexibility.

The variables default their respective DEFAULT service variable.

• DEFAULT_MYSQL_HOST: The server hostname (defaults to localhost)
• DEFAULT_MYSQL_PORT: The server port (defaults to 3306)
• DEFAULT_MYSQL_DATA: The database (defaults to unset, the specific services have separate DBs)
  • ICINGA2_IDO_MYSQL_DATA: The database for icinga2 IDO (defaults to icinga2idomysql)
  • ICINGAWEB2_MYSQL_DATA: The database for icingaweb2 (defaults to icingaweb2)
  • ICINGAWEB2_DIRECTOR_MYSQL_DATA: The database for icingaweb2 director (defaults to icingaweb2_director)
• DEFAULT_MYSQL_USER: The MySQL user to access the database (defaults to icinga2)
• DEFAULT_MYSQL_PASS: The password for the MySQL user. (defaults to randomly generated string) - It is recommended that you set this value to ensure container restarts work as expected.
• ICINGA2_IDO_MYSQL_SKIP_DB_CREATION: This can be set to true if you already created the IDO database (defaults to false)
• ICINGAWEB2_MYSQL_SKIP_DB_CREATION: This can be set to true if you already created the Icingaweb2 database (defaults to false)
• ICINGAWEB2_DIRECTOR_MYSQL_SKIP_DB_CREATION: This can be set to true if you already created the Director database (defaults to false)

Note: Please do not use special chars like ! in mysql user/password because it breaks your director database connection. The director authentication.ini cannot handle it.

Moving to separate MySQL-container

1. Start your current container as always.
2. Run docker exec <container> i2-port-mysqldb
3. Shutdown the container
4. Copy the MySQL datafolder from the icinga2 container to your new mariadb container.
5. Change the environment variable DEFAULT_MYSQL_HOST to point to your new MySQL container.
6. Add the environment variable MYSQL_ROOT_PASSWORD to the icinga2 container, with the value of your password you currently set.
7. Start your containers.

Reference

Environment variables Reference

Volume Reference

All these folders are configured and able to get mounted as volume. The bottom ones are not quite necessary.