Docker configuration for building a standalone Metacat install

WORK IN PROGRESS: This Docker configuration is not yet complete, and should not be relied upon. The configuration currently includes some locally hardcoded data specific to my system, which will be replaced.

Using docker-compose

Metacat ships with a docker-compose.yaml file that configures metacat to be run in docker containers using the default containers from docker hub for Tomcat and Postgres. Configuration information for usernames and passwords to be used is passed in from environment variables, which are configured in the metacat.env file. You must edit that file to set proper values first, and then on a machine on which Docker is installed, Metacat can be launched and shut down using the following command:

#########################################################
#                                                       #
# First, edit metacat.env to set configuration options! #
#                                                       #
#########################################################

# Next, startup the Metacat webapp
$ docker-compose -p metacat up -d

# Visit https://${HOST}/metacat/admin to configure metacat
# The HOST varible and others were configured in metacat.env
# Use the ADMINPASS and PGPASS as appropriate in the configuration fields for metacat
# Use 'postgres' as the name of the host in the JDBC connect string
# Correct the deployLocation to remove the trailing 'metacat', so it reads '/usr/local/tomcat/webapps'

# Now restart the webapp to load indexing properly
$ docker restart metacat_webapp_1

# Now you can search the catalog via MetacatUI at https://${HOST}/metacatui
# By default, no data is loaded, so the catalog will be empty

# When all done, bring down the metacat server containers
$ docker-compose -p metacat down

Using standalone docker containers

The docker-compose utility is useful for configuring multiple containers. The sections below explain the manual approach to bringing up those same containers.

Network

• create a bridge network for all containers to communicate over

docker network create --driver bridge mc-net

Postgres

This creates a data-only volume called 'mc-data' to contain the data for postgres, which is then mounted and used with the volume command. When the mc-postgres container starts, it uses the mc-data volume. Even if the mc-postgres container is completely deleted, it is completely restartable because of the persistence of the data container.

docker volume create --name mc-pgdata
docker run --name mc-postgres --net=mc-net -p 5432:5432 -v mc-pgdata:/pgdata -e POSTGRES_PASSWORD=db-password-goes-here -e POSTGRES_USER=metacat -e POSTGRES_DB=metacat -e PGDATA=/pgdata -d postgres

• Connect with: psql -h {docker-machine-ip} metacat metacat
• Logs: docker logs mc-postgres | more

Tomcat

Same idea with tomcat. Mount a data-only volume container for the /var/metacat partition.

docker volume create --name mc-data
docker run --name mc-tomcat --net=mc-net -v mc-data:/var/metacat -p 8080:8080 -v ${HOME}/tomcat/apache-tomcat-8.0.30/webapps:/usr/local/tomcat/webapps -d tomcat:8.0

• Connect to http://${docker-machine-ip}:8080
• Errors to be fixed:
  • DataONE Config: Cannot locate configuration source file:///etc/dataone/node.properties

Configure Metacat

• Run password utility from local webapps dir, copy password.xml file into webapps dir
• From mc-tomcat, copy password.xml file to /var/metacat/users
• MetacatUI is at: http://${docker-machine-ip}:8080/metacatui