Exporting function logs to remote syslog service

Fn allows you to push the function logs to a syslog endpoint. This is an example of how to configure it and test it our using Papertrail

step 0

create a Papertrail account

Papertrail is a hosted log management service. You can sign up for a free account for the purposes of this tutorial

create log destination

Go to Settings (top right hand corner) and click on Log Destinations. Create a log destination.

make a note of your destination

On the Papertrail Settings choose Log Destinations (from the options in the left) and copy the endpoint - you'll use this in subsequent steps

For TCP, unselect TLS and select Plain Text

As shown below ... Settings > Log Destination > my.papertrail.com:4242 > Settings

For TCP > Unselect TLS and Select Plain Text

Create application

• Get the latest version of Fn CLI - curl -LSs https://raw.githubusercontent.com/fnproject/cli/master/install | sh
• Create an application with syslog endpoint info - fn create app fn-syslog-app --annotation oracle.com/oci/subnetIds=<SUBNETS> --syslog-url tcp://<your papertrail syslog endpoint> e.g. fn create app fn-syslog-app --syslog-url tcp://my.papertrail.com:4242
• Switch to the context for Oracle Functions - fn use context <context-name>

If you already have an existing application...

.. you can just configure that to use the papertrail syslog endpoint as well.

Using the Fn CLI

It is as simple as

fn update app <app-name> --syslog-url tcp://<your papertrail syslog endpoint> e.g.fn update app my-existing-app --syslog-url tcp://my.papertrail.com:4242

Using the Oracle Functions console

Open your application from the Applications page and click Edit Application

Enter the syslog endpoint and click Save

You should now see the updated value

Deploy

• Clone or download this repo
• cd fn-syslog-example
• fn -v deploy --app fn-syslog-app

Your function should now be deployed. Check it

fn inspect app fn-syslog-app

You will see something similar to this - notice the syslog_url configuration

{
            .....
        "created_at": "2018-08-13T11:39:48.943Z",
        "id": "01CMSHBGTFNG8G00GZJ0000001",
        "name": "fn-syslog-app",
        "syslog_url": "tcp://my.papertrailapp.com:4242",
        "updated_at": "2018-08-13T11:39:48.943Z"
            .....
}

Test

Test using Fn CLI with fn invoke command

Invoke

• fn invoke fn-syslog-app fn-syslog-func
• echo -n 'fun with fn!' | fn invoke fn-syslog-app fn-syslog-func

You can repeat this multiple times

Check your Papertrail a/c

Hop over to your Papertrail dashboard and click Events (top right) to see the logs