eviaas

environment variables injector as a service for tsuru

About

This service allows easily exposing external services to tsuru applications. It works simply by injecting some predefined environment variables in the application after binding.

Example

Let's assume you have an external logging service running at udp://my.log.service:9976 and you want to expose this value to applications without hardcoding it in them (as the twelve factor methodology advises).

First you will have to create the eviaas service application and add it to tsuru:

$ git clone https://github.com/tsuru/eviaas.git

$ cd eviaas

$ tsuru app-create my-log-service-api python

$ tsuru env-set -a my-log-service-api EVI_ENVIRONS='{"MYLOG_PROTOCOL": "udp", "MYLOG_ADDRESS": "my.log.service:9976"}'

$ git push git@192.168.50.4:my-log-service-api.git master

$ cat >service_descriptor.yaml <<EOF
> id: my-log-service
> password: 1234
> team: my_team
> endpoint:
>   production: http://my-log-service-api.192.168.50.4.nip.io
> EOF

$ tsuru service-create service_descriptor.yaml

Now your tsuru has a new service called my-log-service and you can create instances:

$ tsuru service-instance-add my-log-service my-log-instance

$ tsuru service-list
+----------------+-----------------+
| Services       | Instances       |
+----------------+-----------------+
| my-log-service | my-log-instance |
+----------------+-----------------+

And bind apps to it:

$ tsuru service-instance-bind my-log-service my-log-instance -a my-app
Instance "my-log-instance" is now bound to the app "my-app".

The following environment variables are now available for use in your app:

- MYLOG_PROTOCOL
- MYLOG_ADDRESS

For info about what happens when you bind a service to an application, see http://docs.tsuru.io/en/latest/services/api.html#binding-an-app-to-a-service-instance