How to get SAM template of lambda function deployed via UI?

Question

I wrote a bash script similar to this one: Download an already uploaded Lambda function

Everything is fine with all lambda functions that have been deployed via SAM template files. However, when I retrieve the deployment package of a lambda function (application) that has been deployed via the web UI of AWS, all I get is the index.js file in the deployment package of that function.

Anyway, it is possible to generate a SAM yaml file that describes the architecture of the given lambda application by selecting it over the Lambda Management Console via Actions > Export Function > Download AWS SAM file. Consequently, there should be a possibility to do this via aws-cli or is that not possible at all?

score 1 · Answer 1 · answered Jun 28 '19 at 12:39

You can get function configuration with awscli https://docs.aws.amazon.com/cli/latest/reference/lambda/get-function-configuration.html and the response will contain a Code section with a link to the function package https://docs.aws.amazon.com/lambda/latest/dg/API_FunctionCodeLocation.html

Also, you can create a CloudFormation stack from the existing infrastructure with CloudFormer https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/cfn-using-cloudformer.html

Having a CloudFormation template you can get the resource description. https://docs.aws.amazon.com/cli/latest/reference/cloudformation/describe-stack-resources.html with the link to the function source code on S3.

See more on this in https://stackoverflow.com/a/55764927/6628583

However, when I get the link to the function package, there is only the handler function since there was never a SAM template used when the function was deployed via UI. I need a way to get this infrastructure as code representation just like in the web-ui in order to retrieve a SAM template of the deployed function.. — nymvno, Jul 01 '19 at 15:02

Darren Weber · Answer 2 · 2020-07-24T20:59:13.810

This is a clue, not a complete answer, sorry. There should be, but there is not yet, an aws-cli to get this SAM content. The URI in the browser is obtuse with some obscure network calls, e.g.

https://us-west-2.console.aws.amazon.com/p/log/1/lambda/1/OP/&k0=feevc&m0=1&d0=%7B%22s_fid%22:%2233SNIPPEDC66-34SNIPPED7FE5B%22%7D&p0=exportSAM&cb=1595621538378&proxy-rid=7c6a6a31SNIPPEDf1a400b457cc

There seems to be no easy way to construct that URI to GET the exportSAM download.

The browser lambda.js is not much help, e.g.

        var A = Object(p.connect)((function(e) {
            return {
                blueprint: Object(v.b)(e).query.exportBp,
                integrationConfigs: h.c.getNodes(e),
                downloadMessages: h.c.getDownloadMessages(e),
                isOpen: !!Object(v.b)(e).query.exportModal,
                exporting: h.c.getExporting(e)
            }
        }
        ), (function(e) {
            return {
                downloadSam: function(t) {
                    return e((n = t,
                    {
                        type: b.f.EXPORT_BLUEPRINT_TO_FLOURISH,
                        blueprintName: n
                    }));
                    var n
                },
                close: function() {
                    return e(Object(m.c)({
                        query: {
                            exportModal: void 0,
                            exportBp: void 0
                        }
                    }, {
                        persistQuery: !0
                    }))
                }
            }
        }
        ), (function(e, t, n) {
            return S(S(S(S({}, n), e), t), {}, {
                downloadSam: function() {
                    return t.downloadSam(e.blueprint)
                }
            })
        }

How to get SAM template of lambda function deployed via UI?

2 Answers2