Functions can be turned into "web actions" which return HTTP content without use of an API Gateway. This feature is enabled by setting an annotation (web-export) in the configuration file.
functions:
my_function:
handler: index.main
annotations:
web-export: true
Functions with this annotation can be invoked through a URL template with the following parameters.
https://{APIHOST}/api/v1/experimental/web/{USER_NAMESPACE}/{PACKAGE}/{ACTION_NAME}.{TYPE}
- APIHOST - platform endpoint e.g. openwhisk.ng.bluemix.net.
- USER_NAMESPACE - this must be an explicit namespace and cannot use the default namespace (_).
- PACKAGE - action package or
default. - ACTION_NAME - default form
${servicename}-${space}-${name}. - TYPE -
.json,.html,.textor.http.
Return values from the function are used to construct the HTTP response. The following parameters are supported.
headers: a JSON object where the keys are header-names and the values are string values for those headers (default is no headers).code: a valid HTTP status code (default is 200 OK).body: a string which is either plain text or a base64 encoded string (for binary data).
Here is an example of returning HTML content:
function main(args) {
var msg = "you didn't tell me who you are."
if (args.name) {
msg = `hello ${args.name}!`
}
return {body:
`<html><body><h3><center>${msg}</center></h3></body></html>`}
}Here is an example of returning binary data:
function main() {
let png = <base 64 encoded string>
return {
headers: { "Content-Type": "image/png" },
body: png };
}Functions can access request parameters using the following environment variables.
**__ow_meta_verb:**the HTTP method of the request.**__ow_meta_headers:**the request headers.**__ow_meta_path:**the unmatched path of the request.
Full details on this new feature are available in this blog post.
*IMPORTANT: Web Actions is currently experimental and may be subject to breaking changes.*