This article covers some basic troubleshooting tips to test communication with the Snaplex.

To verify if outbound requests are permitted from the Snaplex node, run:

...

curl https://elastic.snaplogic.com/status

A response with status OK indicates successful completion.

If this request hangs or fails, then a proxy is required. Request the HTTP proxy information from your network operations team.

To check access through a proxy, run:

...

curl -x myproxy.mydomain.com:3128 https://elastic.snaplogic.com/status

If this request fails with a 407 (Proxy Authentication Required), then you need to specify the authentication information in the proxy.

To check the proxy authentication, run:

...

curl -x myproxy.mydomain.com:3128 --proxy-user "proxyuser:proxypasswd" https://elastic.snaplogic.com/status

The -v option can be added to curl to get detailed messages.

...

Configuring the Script Snap to Use a HTTP Proxy

HTTP-compatible Snap Packs can use a HTTP proxy configured in the Node Proxies configuration tab of a Snaplex within SnapLogic Manager. However, the Script Snap allows you to write scripts that call external processes (for example: curl) and these scripts will not be aware of proxy configurations within the SnapLogic application. 

You can use curl to configure a proxy directly via the --proxy argument. To enforce proxy usage across all usages of the Script Snap, set the http_proxy and/or https_proxy environment variables within the following file:

/etc/sysconfig/jcc. 

Environment variables declared within the /etc/sysconfig/jcc file are visible to the Snaplex application (OS-level environment variables are not visible). If the /etc/sysconfig directory and /etc/sysconfig/jcc file does not exist in your Snaplex, run the following command with your own username/password (if authentication is required), proxy-ip-address, and port (you could also add https_proxy) to create them:

sudo mkdir -p /etc/sysconfig; sudo sh -c"echo 'export http_proxy=username:password@proxy-ip-address:port' >> /etc/sysconfig/jcc"

After the file and its directory are created, run one of the following commands to restart the Snaplex application:

/opt/snaplogic/bin/jcc.sh restart
 
c:\opt\snaplogic\bin\jcc.bat restart

The http_proxy/https_proxy environment variable is now active within the SnapLogic product. You can now run your script to call the external process.

For example, the following Script Snap uses the subprocess library to execute curl and adds the response body to the output document.

# Import the interface required by the Script snap.
from com.snaplogic.scripting.language import ScriptHook
import subprocess

class TransformScript(ScriptHook):
    def __init__(self, input, output, error, log):
        self.input = input
        self.output = output
        self.error = error
        self.log = log

    # The "execute()" method is called once when the pipeline is started
    # and allowed to process its inputs or just send data to its outputs.
    def execute(self):
        self.log.info("Executing Transform script")
        while self.input.hasNext():
            try:
                # Read the next input document, store it in a new dictionary, and write this as an output document.
                inDoc = self.input.next()
                proc = subprocess.Popen(['curl','https://www.snaplogic.com'], stdout=subprocess.PIPE)
                (out, err) = proc.communicate()
                outDoc = {
                    'original' : out
                }
                self.output.write(inDoc, outDoc)
            except Exception as e:
                errDoc = {
                    'error' : str(e)
                }
                self.log.error("Error in python script")
                self.error.write(errDoc)

        self.log.info("Script executed")

    # The "cleanup()" method is called after the snap has exited the execute() method
    def cleanup(self):
        self.log.info("Cleaning up")

# The Script Snap will look for a ScriptHook object in the "hook" variable. The snap will then call the hook's "execute" method.
hook = TransformScript(input, output, error, log)

On execution, the proxy access log shows the request being routed through the proxy.