Triggering Maven profiles from Heroku configured Environment Variables - maven

Question

I am trying to activate a profile in my maven pom as follows:-
<profile>
<id>test</id>
</properties>
<activation>
<property>
<name>env.SITE</name>
<value>test</value>
</property>
</activation>
</profile>
Now i am configuring heroku to have the environment variable SITE as follows:-
heroku config:add SITE=test.
I expect the environment variable to trigger the profile when code is pushed. However this is not happening.

Answer 1

You can do this without a custom build pack.
Use this snippet in your pom.xml to display all properties available on Heroku and pick one that is not in your local: http://florianlr.wordpress.com/2012/04/24/16/
I used env.DYNO
<profile>
<id>heroku</id>
<activation>
<property>
<name>env.DYNO</name>
</property>
</activation>
...
</profile>
...
Works like a charm:)

Answer 2

You can specify the maven profile using the environment variable MAVEN_CUSTOM_OPTS.
In your pom define maven profile activation to be based off the presence of a property. The below example uses the development profile if you specify it and defaults to production if you don't. reference
<profiles>
<profile>
<id>production</id>
<activation>
<property>
<name>!profile-development</name>
</property>
</activation>
</profile>
<profile>
<id>development</id>
<activation>
<property>
<name>profile-development</name>
</property>
</activation>
</profile>
</profiles>
In Heroku set the MAVEN_CUSTOM_OPTS environment variable to use the profile. Note that this variable overrides the default option -DskipTests. reference
MAVEN_CUSTOM_OPTS=-DskipTests -Dprofile-development
In this example the production profile would not need MAVEN_CUSTOM_OPTS declared.

Answer 3

Or you can introduce your own customized Maven settings.xml file, e.g. heroku-settings.xml:
<?xml version="1.0" encoding="UTF-8"?>
<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0 http://maven.apache.org/xsd/settings-1.0.0.xsd">
<!-- activate by setting the MAVEN_SETTINGS_PATH config var to heroku-settings.xml in Heroku project settings tab.
See https://devcenter.heroku.com/articles/using-a-custom-maven-settings-xml for more details.
-->
<activeProfiles>
<activeProfile>production</activeProfile>
</activeProfiles>
</settings>
Then activate the settings by setting the MAVEN_SETTINGS_PATH config var to heroku-settings.xml in Heroku project settings tab

Answer 4

The config vars aren't currently available at compile time. To change the Maven profile you will need to fork the Heroku Java Buildpack.

Answer 5

I solved my problem by adding Heroku Environment like below:
MAVEN_CUSTOM_OPTS=-P<profile_id>
and cut out "activation" tag from pom.xml.
Btw I don't know why this doesn't work (in Heroku I have ENVIRONMENT=test)
<profile>
<id>test</id>
<activation>
<property>
<name>env.ENVIRONMENT</name>
<value>test</value>
</property>
</activation>
...
</profile>