5 ms·

Show HN: Deploy a Go Lambda to Ping a Site in 20 Seconds

75 points by frankcash 9y ago

tamrix 9y ago
That's a bit long really.
- frankcash 9y ago
  Ah, I'm sorry then :( .
- spraak 9y ago
  That's not the function invocation time (i.e. cold start etc) but rather time to build and deploy (and then maybe imvoke?)
sonaltr 9y ago
Looks nice! 1. Why go? (nothing wrong with it in itself, but last I had checked (before go on lambda was released)...Python was supposed the fastest of the bunch available) 1 a. Python can be embedded into a CF template...meaning deployment is slightly nicer (maybe not recommended though?) 2. I think the ability to change the time (20 secs) based on an SSM parameter would be cool!
- frankcash 9y ago
  1. I chose go since Lambda support was recently added for it. I have a lot of experience using Python and Node.js with Lambdas. 2. Sorry, I include the "20 Seconds" as a symbol of how easy it is to deploy!
ohyoutravel 9y ago
Nice! Is there a use case for this, or is this just a go/terraform example? Either way, pretty cool!
- frankcash 9y ago
  I created this as a terraform example and chose go since it was recently added to Lambda. I have a personal use case of this: pinging my heroku "dev" tier instance so it stays alive a bit longer.
isuckatcoding 9y ago
Pretty neat. Instead of hard coding the url, you could provide it as parameter to the main. Pretty sure it’s possible (at least using the node and c# Lambda it was).
- frankcash 9y ago
  I could definitely look into this, thanks for the suggestion!
  - davewongillies 9y ago
    I raised a PR to just that: https://github.com/frankcash/go-lambda-ping/pull/1 https://github.com/frankcash/go-lambda-ping/pull/1 The URL is set in terraform.tfvars, which then gets passed to the lambda resource.
- RileyJames 9y ago
  url could be set via an environmental variable: https://docs.aws.amazon.com/lambda/latest/dg/go-programming-model-env-variables.html https://docs.aws.amazon.com/lambda/latest/dg/go-programming-...
dpeck 9y ago
Dumb question, never used lambda before, how often is this triggered? I can’t tell at first look through the code.
- shironineja 9y ago
  The lambda doesn't have a schedule within because doing so would split the concerns poorly; rather you would hit this lambda on your own schedule.
  - dpeck 9y ago
    Ah, so you ping the lambda to have it ping the coded in website?
    - shironineja 9y ago
      .. as a service!
    - mali9 9y ago
      Or you could invoke the lambda on a schedule using Cloudwatch https://docs.aws.amazon.com/lambda/latest/dg/with-scheduled-events.html https://docs.aws.amazon.com/lambda/latest/dg/with-scheduled-...
      - frankcash 9y ago
        Yup! Didn't want to include the TF to do the scheduling (for simplicity) but I could add it if people want.
laci27 9y ago
This is amazing! Does anyone know a good resource to learn more about Lambda and how to setup small projects like this?
- nzoschke 9y ago
  I’m working on a comprehensive resource for running Lambda Go projects here: https://github.com/nzoschke/gofaas https://github.com/nzoschke/gofaas The guide on periodicnworker functions is how I would build this pinger. https://github.com/nzoschke/gofaas/blob/master/docs/worker-functions.md https://github.com/nzoschke/gofaas/blob/master/docs/worker-f...
joosters 9y ago
An actual ping would be more impressive :) Perhaps to be less wasteful, the HTTP request should be a HEAD instead of GET? There’s little point downloading a whole page if you are going to just throw away the contents...
- laci27 9y ago
  actually, it's not. We create a special page, with PHP and one with nodejs, that just replies '1', so besides status, we also get a notice if nodejs or PHP malfunctions (which does happen on some servers, 1-2 time a year).
  - giancarlostoro 9y ago
    HEAD is still less wasteful and just as effective.
  - mbrumlow 9y ago
    You can still do all that with HEAD, the only difference is you don't return a message body, thus saving 1 byte plus a few in the actual header you would not need any more. For example; you would do a head request and node.js and php would still need to be configured to handled the HEAD request but instead of its handler returning "1" it would simply return.
alexellisuk 9y ago
Kind of a shame to have to hack on the source-code and inject a new URL - would have been better to have used a parameter. Anyway - here's how to do it with OpenFaaS and Python from August 2017 :-) https://blog.alexellis.io/first-faas-python-function/ https://blog.alexellis.io/first-faas-python-function/
- mrmondo 9y ago
  Much nicer example I think and no AWS tax / lock-in.
  - dblooman 9y ago
    What are the main benefits of using OpenFaaS except for vendor lock in? 99% of the time, I want a kinesis stream, or S3 event to start my lambdas, which it seems I would have to wire up myself
ivanhoe 9y ago
What's approx. monthly cost of running something like this on lambda e.g. every 5 minutes?
- codegladiator 9y ago
  Zero http://serverlesscalc.com/ http://serverlesscalc.com/
- alexellisuk 9y ago
  If you want to access it over HTTP you will have to pay for "AWS API Gateway" which is not free.
  - misframer 9y ago
    API Gateway isn't much at that rate. (1 month) / (5 minutes) = 8760 "$3.50 per million API calls received, plus the cost of data transfer out, in gigabytes." [0] 8760 * ($3.50 / 1000000) = $0.03. [0] https://aws.amazon.com/api-gateway/pricing/ https://aws.amazon.com/api-gateway/pricing/
ericfrederich 9y ago
I'm curious about how AWS handles lambdas written in Go. Go produces statically linked Linux binaries. What is it about Go that is supported? What is it about binaries written in other languages that isn't supported?
nickromano 9y ago
I built a python version recently, it uses the serverless library to deploy to AWS. https://github.com/nickromano/serverless-ping https://github.com/nickromano/serverless-ping

75 points by frankcash 9y ago

tamrix 9y ago

That's a bit long really.

frankcash 9y ago
Ah, I'm sorry then :( .
spraak 9y ago
That's not the function invocation time (i.e. cold start etc) but rather time to build and deploy (and then maybe imvoke?)

sonaltr 9y ago

Looks nice! 1. Why go? (nothing wrong with it in itself, but last I had checked (before go on lambda was released)...Python was supposed the fastest of the bunch available) 1 a. Python can be embedded into a CF template...meaning deployment is slightly nicer (maybe not recommended though?) 2. I think the ability to change the time (20 secs) based on an SSM parameter would be cool!

frankcash 9y ago
1. I chose go since Lambda support was recently added for it. I have a lot of experience using Python and Node.js with Lambdas. 2. Sorry, I include the "20 Seconds" as a symbol of how easy it is to deploy!

ohyoutravel 9y ago

Nice! Is there a use case for this, or is this just a go/terraform example? Either way, pretty cool!

frankcash 9y ago
I created this as a terraform example and chose go since it was recently added to Lambda. I have a personal use case of this: pinging my heroku "dev" tier instance so it stays alive a bit longer.

isuckatcoding 9y ago

Pretty neat. Instead of hard coding the url, you could provide it as parameter to the main. Pretty sure it’s possible (at least using the node and c# Lambda it was).

frankcash 9y ago
I could definitely look into this, thanks for the suggestion!
- davewongillies 9y ago
  I raised a PR to just that: https://github.com/frankcash/go-lambda-ping/pull/1 https://github.com/frankcash/go-lambda-ping/pull/1 The URL is set in terraform.tfvars, which then gets passed to the lambda resource.
RileyJames 9y ago
url could be set via an environmental variable: https://docs.aws.amazon.com/lambda/latest/dg/go-programming-model-env-variables.html https://docs.aws.amazon.com/lambda/latest/dg/go-programming-...

dpeck 9y ago

Dumb question, never used lambda before, how often is this triggered? I can’t tell at first look through the code.

shironineja 9y ago
The lambda doesn't have a schedule within because doing so would split the concerns poorly; rather you would hit this lambda on your own schedule.
- dpeck 9y ago
  Ah, so you ping the lambda to have it ping the coded in website?
  - shironineja 9y ago
    .. as a service!
  - mali9 9y ago
    Or you could invoke the lambda on a schedule using Cloudwatch https://docs.aws.amazon.com/lambda/latest/dg/with-scheduled-events.html https://docs.aws.amazon.com/lambda/latest/dg/with-scheduled-...
    - frankcash 9y ago
      Yup! Didn't want to include the TF to do the scheduling (for simplicity) but I could add it if people want.

laci27 9y ago

This is amazing! Does anyone know a good resource to learn more about Lambda and how to setup small projects like this?

nzoschke 9y ago
I’m working on a comprehensive resource for running Lambda Go projects here: https://github.com/nzoschke/gofaas https://github.com/nzoschke/gofaas The guide on periodicnworker functions is how I would build this pinger. https://github.com/nzoschke/gofaas/blob/master/docs/worker-functions.md https://github.com/nzoschke/gofaas/blob/master/docs/worker-f...

joosters 9y ago

An actual ping would be more impressive :) Perhaps to be less wasteful, the HTTP request should be a HEAD instead of GET? There’s little point downloading a whole page if you are going to just throw away the contents...

laci27 9y ago
actually, it's not. We create a special page, with PHP and one with nodejs, that just replies '1', so besides status, we also get a notice if nodejs or PHP malfunctions (which does happen on some servers, 1-2 time a year).
- giancarlostoro 9y ago
  HEAD is still less wasteful and just as effective.
- mbrumlow 9y ago
  You can still do all that with HEAD, the only difference is you don't return a message body, thus saving 1 byte plus a few in the actual header you would not need any more. For example; you would do a head request and node.js and php would still need to be configured to handled the HEAD request but instead of its handler returning "1" it would simply return.

alexellisuk 9y ago

Kind of a shame to have to hack on the source-code and inject a new URL - would have been better to have used a parameter. Anyway - here's how to do it with OpenFaaS and Python from August 2017 :-) https://blog.alexellis.io/first-faas-python-function/ https://blog.alexellis.io/first-faas-python-function/

mrmondo 9y ago
Much nicer example I think and no AWS tax / lock-in.
- dblooman 9y ago
  What are the main benefits of using OpenFaaS except for vendor lock in? 99% of the time, I want a kinesis stream, or S3 event to start my lambdas, which it seems I would have to wire up myself

ivanhoe 9y ago

What's approx. monthly cost of running something like this on lambda e.g. every 5 minutes?

codegladiator 9y ago
Zero http://serverlesscalc.com/ http://serverlesscalc.com/
alexellisuk 9y ago
If you want to access it over HTTP you will have to pay for "AWS API Gateway" which is not free.
- misframer 9y ago
  API Gateway isn't much at that rate. (1 month) / (5 minutes) = 8760 "$3.50 per million API calls received, plus the cost of data transfer out, in gigabytes." [0] 8760 * ($3.50 / 1000000) = $0.03. [0] https://aws.amazon.com/api-gateway/pricing/ https://aws.amazon.com/api-gateway/pricing/

ericfrederich 9y ago

I'm curious about how AWS handles lambdas written in Go. Go produces statically linked Linux binaries. What is it about Go that is supported? What is it about binaries written in other languages that isn't supported?

nickromano 9y ago

I built a python version recently, it uses the serverless library to deploy to AWS. https://github.com/nickromano/serverless-ping https://github.com/nickromano/serverless-ping