A helper application for grabbing and parsing CloudFoundry Environment Variables.
A small application for parsing and retrieving VCAP_SERVICES
, and
VCAP_APPLICATION.
> MyApp.Env.service_credentials("dynamo-db")
%{"database" => "dynamo", "accessKeyId" => "abcd", "secretAccessKey" => "defg",
"tableName" => "test-table" }
Or grabbing the current application name.
iex(1)> MyApp.Env.app_name()
"test_app"
See the documentation for other api examples.
CFEnv is no longer an application, but a process started within your application, with functions created as a macro. All functionality is present, but CFEnv.Services and CFEnv.Application have been combined. See usage instructions below, and the CFEnv
module.
You'll need to add cf_env as a dependancy to your mix.exs file, along with a
module for parsing json. CFEnv
supports Poison
and Jason
by
default, though custom JSON adapters can be provided. See CFEnv.Adapters.JSON
for details.
def deps do
[
{:cf_env, "~> 1.0"},
{:jason, "~> 1.1"},
# or, if you prefer poison
{:poison, "~> 3.0"}
]
end
Then, fetch your dependencies:
$ mix deps.get
You'll need to create a module that represents your service bindings.
defmodule MyApp.Env do
use CFEnv,
otp_app: :my_app,
json_engine: Jason
...
Finally, add the process to your supervision tree:
# For Elixir v1.5 and later
{MyApp.Env, [ default_bindings: %{} ]}
# For Elixir v1.4 and earlier
supervisor(MyApp.Env, [ default_bindings: %{}])
You can provide options as application config, or with runtime config. Runtime config always overrides application config.
config :my_app, MyApp.Env
json_engine: Jason,
default_services: %{
"some_db" => %{
"username" => System.get_env("TEST_USER"),
"password" => System.get_env("TEST_PASSWORD")
}
}
...
options = [
json_engine: Jason,
default_services: %{
"some_db" => %{
"username" => System.get_env("TEST_USER"),
"password" => System.get_env("TEST_PASSWORD")
}
}]
# explicit start
MyApp.Env.start_link(])
# supervisor start
children = [
{MyApp.Env, [options]}
]
Working with VCAP_SERVICES can be a pain. Instead, default services bindings can be passed in as a map from configuration, where each key is a string. You can provide reasonable defaults for local development this way.
config :cf_env,
default_services:
%{ "service_name" => %{
"username" => "u5er",
"password" => "pa$$w0rd"
}
}
On init, VCAP_SERVICES
and VCAP_APPLICATION
are parsed from JSON.
And each value is transformed into a map. If an alias key is present on the credentials, the service will be mapped to use that name instead. This is useful for updating the bindings for an application, without having to implement a code change, or affect other services using this binding.
Every map created this way is merged back into the provided default service map, with parsed CF services overwriting defaults, if any.
Currently only user-provided
services are supported.
The following list of services:
{
"user-provided": [
{
"name": "cf-env-test",
"label": "user-provided",
"tags": [],
"credentials": {
"database": "database",
"password": "passw0rd",
"url": "https://example.com/",
"username": "userid"
},
"syslog_drain_url": "http://example.com/syslog"
},
{
"name": "dynamo-db",
"label": "user-provided",
"tags": [],
"credentials": {
"alias": "alias-name",
"database": "dynamo",
"accessKeyId": "abcd",
"secretAccessKey": "defg"
"tableName": "test-table",
},
"syslog_drain_url": "http://example.com/syslog"
}
]
}
is reduced to the following map:
%{
# using the name
"cf-env-test" => %{
"name" => "cf-env-test",
"label" => "user-provided",
"tags" => [],
"credentials" => %{
"database" => "database",
"password" => "passw0rd",
"url" => "https://example.com/",
"username" => "userid"
},
"syslog_drain_url" => "http://example.com/syslog"
},
# using the provided alias
"another-cf-env-test" => %{
"name" => "another-cf-env-test",
"label" => "user-provided",
"tags" => [],
"credentials" => %{
"alias" => "alias-name",
"database" => "dynamo",
"accessKeyId" => "abcd",
"secretAccessKey" => "defg"
"tableName" => "test-table",
},
"syslog_drain_url": "http://example.com/syslog"
}
}
Use the .env
file to set up your local environment before testing.