Debug SOAP Requests

When a SOAP request fails, the most useful thing you can do is see exactly what was sent and received. Savon gives you a few tools for this.

Enable request/response logging

Pass log: true and pretty_print_xml: true when creating the client:

client = Savon.client(
  wsdl: "http://example.com/service?wsdl",
  log: true,
  pretty_print_xml: true
)

With these options set, every request and response is printed to $stdout. The output looks something like this:

<!-- Savon sending a request to http://example.com/service -->
<?xml version="1.0" encoding="UTF-8"?>
<env:Envelope xmlns:env="http://schemas.xmlsoap.org/soap/envelope/" xmlns:tns="http://example.com/">
  <env:Body>
    <tns:findUser>
      <id>42</id>
    </tns:findUser>
  </env:Body>
</env:Envelope>

<!-- Savon received the following response -->
<?xml version="1.0" encoding="UTF-8"?>
<env:Envelope xmlns:env="http://schemas.xmlsoap.org/soap/envelope/">
  <env:Body>
    <tns:findUserResponse>
      <user>
        <id>42</id>
        <name>Luke</name>
      </user>
    </tns:findUserResponse>
  </env:Body>
</env:Envelope>

In a Rails app, point logging at the Rails logger so output goes to your normal log stream:

client = Savon.client(
  wsdl: "...",
  logger: Rails.logger,
  log_level: :debug,
  pretty_print_xml: true
)

Filter sensitive values

Savon redacts any message parameters you list in filters before writing to the log:

client = Savon.client(
  wsdl: "...",
  log: true,
  pretty_print_xml: true,
  filters: [:password, :credit_card_number]
)

Filtered fields appear as ***FILTERED*** in both the request and response log output.

Inspect the response directly

If you want to examine the raw response in code rather than through logs:

response = client.call(:find_user, message: { id: 42 })

response.to_xml      # raw XML string as received from the server
response.http.code   # HTTP status code, e.g. 200
response.http.body   # raw HTTP response body
response.body        # parsed Hash (after namespace stripping and key conversion)

response.doc returns a Nokogiri::XML::Document if you want to run XPath queries against the raw response before any of Savon’s transformations:

response.doc.xpath("//user/name").map(&:text)

Common failure patterns

Response body keys don’t match what you expect By default, Savon strips namespaces and converts XML tags to snakecase Symbols. If the raw XML has <ns2:FindUserResponse>, response.body will have find_user_response:. Use log: true to see the raw XML, then trace how the keys are transformed. If the defaults don’t work for your service, see strip_namespaces and convert_response_tags_to on the Globals page.

Request XML looks wrong (wrong tag names, missing namespaces) Compare the logged request XML against what the service expects. If the tag casing is off, adjust convert_request_keys_to. See the Globals page for all options.

Request rejected with a WSSE auth error despite correct credentials Add wsse_timestamp: true. Many services require a WS-Security timestamp alongside credentials but don’t document it. See the Globals page.

Connection errors or timeouts fetching the WSDL Some services put the WSDL behind the same auth as the service itself. Download the WSDL manually and pass it as a local file path or a String:

Savon.client(wsdl: File.read("service.wsdl"), endpoint: "http://example.com/service")