Consul¶

In an on-premise installation, the configuration of PLOSSYS Output Engine is kept in a Consul key value store. In a cloud environment, the container-orchestration system is used for this.

Consul in a Cluster¶

If Consul is running in a cluster, the settings stored in the key value store are distributed. Therefore, a failure of a Consul node does not affect the integrity of the key value store.

For how to configure Consul in a cluster, refer to Configure Consul in a Cluster.

Hint - cluster

In a cluster, a key has to be added or changed on one server only. The key value stores on the other servers are synchronized automatically.

Consul Web Interface¶

For Consul, a Web interface is available. In order to open the Consul Web Interface, enter the following URL into your Web browser:

https://<plossys_server>:8500

Hint - no Internet Explorer 11

Do not use Internet Explorer 11 for changing the configuration in Consul due to Internet Explorer 11 displays the previous setting even after it has been changed successfully in Consul.

Keys and Values¶

The keys in the key value store are structured hierarchically. For example, the settings of a PLOSSYS Output Engine system begin with dc/home/env, the settings for the stamping begin with dc/home/plossys.

For each service instance, both the service name and one or more tags are specified. A tag is any text without blanks. Both specifications can be used for identifying the instance to which the setting applies. Each setting is saved under /service/<service_name>/tag/<tag_name>.

Example - all services

dc/home/env/service/any/tag/any

Example - service instance for PLOSSYS Administrator

dc/home/env/service/plossysadmin/tag/any

The name of the key is appended to the path.

Example - log level for all instances

dc/home/env/service/any/tag/any/LOG_LEVEL

The keys available for PLOSSYS Output Engine and their values are listed in Service Keys.

Change the Value of an Existent Key¶

In the Consul Web interface, click KEY/VALUE on the top of the page.
In the tree view on the left, navigate to the level of the key, for example, dc/home/env/service/any/tag/any.
For changing an existent key, select the key, for example, CONSUL_TOKEN and specify its new value.
Click UPDATE.

Hint - service restart

After starting a server instance, envconsul monitors the configuration changes in the key value store. After a setting has been changed, envconsul restarts the service instances with the updated settings. Changes in the key value store not regarding to the service instance are ignored.

Add a New Key Value Pair¶

In the Consul Web interface, click KEY/VALUE on the top of the page.
In the tree view on the left, navigate to the level where the new key is to be created, for example, dc/home/env/service/operator-server/tag/any/.
For adding a new key value pair, extend the level by the key, for example, LOG_LEVEL and specify its value, for example, DEBUG.
Click CREATE.

Hint - service restart

After starting a server instance, envconsul monitors the configuration changes in the key value store. After a setting has been changed, envconsul restarts the service instances with the updated settings. Changes in the key value store not regarding to the service instance are ignored.

Change the Configuration Via PLOSSYS CLI¶

With PLOSSYS CLI, you can export the complete configuration from Consul to a YAML file and import a YAML file into Consul again. Additionally, you can set or get the value of a specific key.

For more information about the PLOSSYS CLI commands, refer to Administrate the System Configuration.

Restart after Change¶

After a key specified under dc/home/env/ has been changed, the correspondent Output Engine service is restarted automatically. With any, all Output Engine services are restarted automatically.

With keys specified in locations different to dc/home/env/ (for example, dc/home/plossys/convert-sapgof/GRIBS74_PDF_DB), the correspondent service (here: seal-convert-sapgof) has to be restarted after the change.

Secure Consul¶

For how to secure Consul, refer to Secure Consul on Windows or Secure Consul on Linux.