pgpin
is an open-source example app showing how to build
a database-backed service in Go.
The example is a clone of Heroku Dataclips, basically a "pastebin for SQL queries".
In working through this example app we hope to learn:
-
How to build database-backed services in idiomatic Go, with an eye towards robustness and operability.
-
How developing such services in Go compares to other stacks, such as Ruby/Sinatra/Sequel.
Work on pgpin
is ongoing. The current version of the app has some
but not all of the user-facing features and robustness properties we
eventually want. See FEATURES.md and
TODO.md.
A Vagrant development environment is provided. Install a recent version of Vagrant and Virtualbox and run:
$ vagrant up
$ vagrant ssh
To start a development version of app:
$ cat migrations/* | psql $DATABASE_URL
$ godep go install
$ goreman start
An environment variable is provided to make testing with curl easy:
$ curl -i $PGPIN_URL/status
To apply code changes:
$ godep go install
$ goreman start
We suggest a git pre-commit hook to verify adherence to Go coding standards:
$ cat > .git/hooks/pre-commit <<EOF
#!/bin/bash
gofmt -d **/*.go 2>&1 | tee /tmp/pgpin-pre-commit
if [ $(wc -l < /tmp/pgpin-pre-commit) -gt "0" ]; then
exit 1
fi
go vet github.com/mmcgrana/pgpin || exit 1
errcheck -ignore 'fmt:a^' github.com/mmcgrana/pgpin || exit 1
EOF
$ chmod +x .git/hooks/pre-commit
To run tests:
$ cat migrations/* | psql $TEST_DATABASE_URL
$ godep go test
By default logs are silenced during tests. Turn them on with:
$ TEST_LOGS=true godep go test
To write and run one-off scripts that use the pgpin
app code:
$ cat > script/count_pins.go <<EOF
package main
import (
"log"
pgpin "../../pgpin"
)
func main() {
pgpin.PgStart()
count, _ := pgpin.PgCount("SELECT count(*) from pins")
log.Printf("pins.count total=%d", count)
}
EOF
$ godep go run script/count_pins.go
To an instance of pgpin
to Heroku:
$ export DEPLOY=... (e.g. "production", or your username)
$ bin/deploy-setup
$ curl -i https://pgpin-$DEPLOY.herokuapp.com/status
To tear it down:
$ bin/deploy-teardown
See LICENSE.md.
Some other projects we've looked to in writing the pgpin
example app:
We are interested in collecting other examples of non-trivial, open-source, database-backed (Postgres or otherwise) services written in Go. Please send suggestions to the author.