Injecting Parameters to Integration Solutions

When deploying integration artifacts in different environments, it is necessary to change the synapse parameters used in the artifacts according to the environment. For example, the 'endpoint URL' may be different in each environment. Without this feature, you need to create and maintain separate artifacts for each environment. This feature allows you to deploy the same integration solution to multiple environments (DEV, PROD, etc.) and then inject separate parameter values to the different environments.

This feature is particularly useful for container deployments, where we need to dynamically inject the parameter values to the container.

There are two ways to dynamically inject parameters to your integration solutions:

Injecting parameters as environment variables

If you want to inject parameter values as environment variables, follow the steps given below.

Configuring the synapse artifacts

Define your synapse artifacts using "$SYSTEM:<place_holder_value>" as the parameter value. Note that <place_holder_value> represents a place holder representing the parameter. For example, shown below is an endpoint artifact, where the endpoint uri configured for this feature:

<?xml version="1.0" encoding="UTF-8"?>
<endpoint xmlns="http://ws.apache.org/ns/synapse" name="StockQuoteEndPoint">
  <address uri="$SYSTEM:stockQuoteEP"/>
</endpoint>

Injecting parameter values

In a VM deployment, you can export the variables as shown below. Here VAR is the url you need to have set as environment property.

export VAR=http://localhost:61616/...

Injecting parameters using a configuration file

Use separate configuration files to load the parameter values for each environment. For example, a file named dev.properties can be used to inject parameter values to the development environment and a file named prod.properties can be used to inject parameter values to the production environment. It is possible to use a file in an NFS mount as the file path and it is useful for container deployment. We can use the environment specific configuration from the file in NFS mount and inject the parameter values to the docker container. With this feature, it is possible to inject the parameters by using the $FILE: prefix followed by the relevant key used to map the original value.

Configuring the synapse artifacts

Define your synapse artifacts using "$FILE:<place_holder_value>" as the parameter value. Note that <place_holder_value> represents a place holder representing the parameter. For example, shown below is an endpoint artifact, where the endpoint uri configured for this feature:

<?xml version="1.0" encoding="UTF-8"?>
<endpoint xmlns="http://ws.apache.org/ns/synapse" name="StockQuoteEndPoint">
  <address uri="$FILE:stockQuoteEP"/>
</endpoint>

Setting up the configuration file

Open the configuration file (such as dev.properties or prod.properties) and enter the parameter and value as a key value pair.

stockQuoteEP=http://localhost:9000/services/SimpleStockQuoteService

Injecting parameter values

The file path with the name should be defined in the properties.file.path system variable.

In the the product startup scripts (integrator.sh and integrator.bat file), which are available in the <EI_HOME>/bin directory, a system variable is defined as follows and the value is set to default.
```
-Dproperties.file.path=default 
```
When the above value set to default, the system reads the parameters from the file.properties file that is available in the <EI_HOME>/conf directory. Parameters can define as key-value pair in the file.properties file.
Instead of using the file.properties file, you are allowed to use the user defined configuration file similar to the file.properties file and configure the particular file path in the integrator.sh or integrator.bat file as shown below.

Supported parameters

Endpoint parameters

Configure the Endpoint parameters in your synapse configuration as shown below.

Endpoint Type	Parameters
Address Endpoint	`uri`
HTTP Endpoint	`uri`
Loadbalance Endpoint	`hostname` and `port`
RecipientList Endpoint	`hostname` and `port`
Template Endpoint	`uri`
WSDL Endpoint	`wsdlURI`

Data service parameters

Driver
URL
Username
Password

Scheduled Task parameters

The pinned servers parameter can be set as an environment variable for a scheduled task or proxy service. See the examples given below.

Inbound Endpoint parameters

See the list of properties that can be defined as environment variables:

Injecting proxy service parameters

The pinned servers parameter as well as all the service-level transport parameters:

Injecting Message Store parameters

Message Store Type	Parameters
JMS Message Store	`store.jms.username` `store.jms.password` `store.jms.connection.factory`
WSO2 MB Message Store
RabbitMQ Message Store	`store.rabbitmq.host.name` `store.rabbitmq.host.port` `store.rabbitmq.username` `store.rabbitmq.password`
JDBC Message Store	`store.jdbc.drive` `store.jdbc.connection.url` `store.jdbc.username` `store.jdbc.password`
Resequence Message Store