Building a Serverless Go App on Google Cloud
Inspired by Laurent Picard’s Building a serverless Python app in minutes with GCP, this is a similar set of steps, but uses a Go application and App Engine’s Flexible Environment.
The web app lists authors and uses the Google Books APIs to search for the author’s published works.
tl;dr
The few commands that’ll be slightly more elaborated, below.
PROJECT=my-project-name
# create a project
# cloud.google.com/sdk/gcloud/reference/alpha/projects/create
gcloud alpha projects create $PROJECT# set the project as default
gcloud config set core/project $PROJECT#
# write your code, test it locally
#
mkdir $GOPATH/src/github.com/you/$PROJECT
cd $GOPATH/src/github.com/you/$PROJECT# create an app.yaml to define deployment
# ref cloud.google.com/appengine/docs/flexible/go/configuring-your-app-with-app-yaml
vi app.yaml# deploy!
gcloud app deploy
Prerequisite: Install the Google Cloud SDK cli
Install the Google Cloud SDK command-line tool — this’ll be used throughout.
Create a Google Cloud Project
Using the gcloud alpha create command, create a new project. Note, this is an “alpha release” command, so it may change in the future. The non-alpha way is to use the web-based cloud console: https://console.cloud.google.com.
$ gcloud alpha projects create go-serverless
Create in progress for [https://cloudresourcemanager.googleapis.com/v1/projects/go-serverless].
Waiting for [operations/pc.7509198304344852511] to finish…done.List the existing projects
If this isn’t your first Google Cloud project, you may have multiple projects already, so here’s a useful command for checking what projects you have
$ gcloud projects list
PROJECT_ID NAME PROJECT_NUMBER
bespokemirrorapi bespokemirrorapi 811093430365
gdgnoco-fortune gdgnoco-fortune 861018601285
go-serverless go-serverless 49448245715
…Set a default project
Subsequent gcloud commands will be associated with a project, so it’s useful to set the default project to our newly created project. Creating a new project doesn’t automatically set it to the default one.
List all the current project configs with gcloud config list and set a config item with gcloud set ….
Set the core/project property to go-serverless:
$ gcloud config set core/project go-serverless
Updated property [core/project].
$ gcloud config list
[compute]
zone = us-central1-c
[core]
account = ghchinoy@gmail.com
disable_usage_reporting = False
project = go-serverlessYour active configuration is: [default]
Create an app locally
- Create a project directory
- Create a deployment file
app.yaml
Go projects, by convention, go into a folder under $GOPATH\src, typically associated with a repository. Here, I create a project using my github as a path and change to the created directory:
$ mkdir -p $GOPATH/src/github.com/ghchinoy/go-serverless
$ cd $GOPATH/src/github.com/ghchinoy/go-serverless
Add a new file called app.yaml — this defines a deployment on App Engine’s Flexible Environment (ref app.yaml for aeflex)
runtime: go
env: flex
api_version: 1skip_files:
- README.md
Add code, snippet of main.go (see source for full code)
Test locally
Run the app locally; view at http://localhost:8080
$ go run main.go template.go
2017/03/30 15:55:21 booklist
127.0.0.1 — — [30/Mar/2017:15:55:24 -0600] “GET / HTTP/1.1” 200 1584 “” “Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3056.0 Safari/537.36”
…
Deploy
Make sure the project has been configured for billing, visit https://console.developers.google.com/project/go-serverless/settings in a browser, substituting the project name go-serverless with your own.
$ gcloud app deploy
You are creating an app for project [go-serverless].
WARNING: Creating an App Engine application for a project is irreversible and the region
cannot be changed. More information about regions is at
https://cloud.google.com/appengine/docs/locations.Please choose the region where you want your App Engine application
located:[1] europe-west (supports standard and flexible)
[2] us-east1 (supports standard and flexible)
[3] us-central (supports standard and flexible)
[4] asia-northeast1 (supports standard and flexible)
[5] cancel
Please enter your numeric choice: 3Creating App Engine application in project [go-serverless] and region [us-central]….done.
You are about to deploy the following services:
— go-serverless/default/20170330t205543 (from [/Users/ghc/dev/go/src/github.com/ghchinoy/go-serverless/app.yaml])
Deploying to URL: [https://go-serverless.appspot.com]Do you want to continue (Y/n)? YIf this is your first deployment, this may take a while…done.Beginning deployment of service [default]…
Building and pushing image for service [default]
Some files were skipped. Pass ` — verbosity=info` to see which ones…Updating service [default]…done.
Deployed service [default] to [https://go-serverless.appspot.com]You can stream logs from the command line by running:
$ gcloud app logs tail -s defaultTo view your application in the web browser run:
$ gcloud app browse
Deployed!
https://go-serverless.appspot.com/
