After you create a service instance and bind it to an application, you must configure the application to connect to the service.
The cf-app-utils
gem allows your application to search for credentials from the VCAP_SERVICES
environment variable by name, tag, or label.
At runtime, Cloud Foundry creates a DATABASE_URL
environment variable for every application based on the VCAP_SERVICES environment variable.
Example VCAP_SERVICES
:
VCAP_SERVICES =
{
"postgresql-10-odb": [
{
"name": "postgresql-10-odb-c6c60",
"label": "postgresql-10-odb",
"credentials": {
"uri": "postgres://exampleuser:[email protected]:5432/exampledb"
}
}
]
}
Based on this VCAP_SERVICES
, Cloud Foundry creates the following DATABASE_URL
environment variable:
DATABASE_URL = postgres://exampleuser:[email protected]:5432/exampledb
Cloud Foundry uses the structure of the VCAP_SERVICES
environment variable to populate DATABASE_URL
. Any service containing a JSON object with the following form is recognized by Cloud Foundry as a candidate for DATABASE_URL
:
{
"some-service": [
{
"credentials": {
"uri": "<some database URL>"
}
}
]
}
Cloud Foundry uses the first candidate found to populate DATABASE_URL
.
Non Rails applications can also access the DATABASE_URL
variable.
If you have more than one service with credentials, only the first is populated into DATABASE_URL
. To access other credentials, you can inspect the VCAP_SERVICES
environment variable.
vcap_services = JSON.parse(ENV['VCAP_SERVICES'])
Use the hash key for the service to obtain the connection credentials from VCAP_SERVICES
.
For services that use the v2 format, the hash key is the name of the service.
For services that use the v1 format, the hash key is formed by combining the service provider and version, in the format PROVIDER-VERSION.
For example, the service provider “p-mysql” with version “n/a” forms the hash key p-mysql-n/a
.
Before you can use your database the first time, you must create and populate, or migrate it.
For more information about migrating database schemas, see Services Overview.
To aid in troubleshooting issues connecting to your service, you can examine the environment variables and log messages Cloud Foundry records for your application.
Use the cf env
command to view the Cloud Foundry environment variables for your application. cf env
displays the following environment variables:
VCAP_SERVICES
variables existing in the container environmentcf set-env
command$ cf env my-app Getting env variables for app my-app in org My-Org / space development as admin... OK System-Provided: { "VCAP_SERVICES": { "p-mysql-n/a": [ { "credentials": { "uri":"postgres://lrra:[email protected]:5432/lraa }, "label": "p-mysql-n/a", "name": "p-mysql", "syslog_drain_url": "", "tags": ["postgres","postgresql","relational"] } ] } } User-Provided: my-env-var: 100 my-drain: http://drain.example.com
Use the cf logs
command to view the Cloud Foundry log messages for your application. You can direct current logging to standard output, or you can dump the most recent logs to standard output.
Run cf logs APPNAME
to direct current logging to standard output:
$ cf logs my-app Connected, tailing logs for app my-app in org My-Org / space development as admin... 1:27:19.72 [App/0] OUT [CONTAINER] org.apache.coyote.http11.Http11Protocol INFO Starting ProtocolHandler ["http-bio-61013"] 1:27:19.77 [App/0] OUT [CONTAINER] org.apache.catalina.startup.Catalina INFO Server startup in 10427 ms
Run cf logs APPNAME --recent
to dump the most recent logs to standard output:
$ cf logs my-app --recent Connected, dumping recent logs for app my-app in org My-Org / space development as admin... 1:27:15.93 [App/0] OUT 15,935 INFO EmbeddedDatabaseFactory:124 - Creating embedded database 'SkyNet' 1:27:16.31 [App/0] OUT 16,318 INFO LocalEntityManagerFactory:287 - Building TM container EntityManagerFactory for unit 'default' 1:27:16.50 [App/0] OUT 16,505 INFO Version:37 - HCANN001: Hibernate Commons Annotations {4.0.1.Final} 1:27:16.51 [App/0] OUT 16,517 INFO Version:41 - HHH412: Hibernate Core {4.1.9.Final} 1:27:16.95 [App/0] OUT 16,957 INFO SkyNet-Online:73 - HHH268: Transaction strategy: org.hibernate.internal.TransactionFactory 1:27:16.96 [App/0] OUT 16,963 INFO InintiateTerminatorT1000Deployment:48 - HHH000397: Using TranslatorFactory 1:27:17.02 [App/0] OUT 17,026 INFO Version:27 - HV001: Hibernate Validator 4.3.0.Final
If you encounter the error, “A fatal error has occurred. Please see the Bundler troubleshooting documentation,” update your version of bundler and run bundle install
.
$ gem update bundler $ gem update --system $ bundle install