GoServ

Boilerplate for how I like to write a backend web service

Build

Goreleaser

See https://webinstall.dev/goreleaser

Local-only

goreleaser --snapshot --skip-publish --rm-dist

Publish

# Get a token at https://github.com/settings/tokens
export GITHUB_TOKEN=xxxxxxx

# Remove --snapshot to error on non-clean releases
goreleaser --snapshot --rm-dist

The platform, publish URL, and token file can be changed in .goreleaser.yml:

env_files:
    gitea_token: ~/.config/goreleaser/gitea_token
gitea_urls:
    api: https://try.gitea.io/api/v1/

Manually

git clone ssh://gitea@git.coolaj86.com:22042/coolaj86/goserv.git ./goserv
pushd ./goserv
bash ./examples/build.sh

export GOFLAGS="-mod=vendor"
go mod tidy
go mod vendor
go generate -mod=vendor ./...
go build -mod=vendor -o dist/goserv .

To build for another platform (such as Raspberry Pi) set GOOS and GOARCH`:

GOOS=linux GOARCH=arm64 go build -mod=vendor -o dist/goserv-linux-arm64 .

Run

./dist/goserv run --listen :3000 --trust-proxy --serve-path ./overrides

Examples and Config Templates

The example files are located in ./examples

• Caddyfile (web server config)
• .env (environment variables)
• build.sh

export BASE_URL=https://example.com

Authentication

You can use an OIDC provider or sign your own tokens.

go install -mod=vendor git.rootprojects.org/root/keypairs/cmd/keypairs

# Generate a keypair
keypairs gen -o key.jwk.json --pub pub.jwk.json

Create an Admin token:

# Sign an Admin token
echo '{ "sub": "random_ppid", "email": "me@example.com", "iss": "'"${BASE_URL}"'" }' \
    > admin.claims.json
keypairs sign --exp 1h ./key.jwk.json ./admin.claims.json > admin.jwt.txt 2> admin.jws.json

# verify the Admin token
keypairs verify ./pub.jwk.json ./admin.jwt.txt

Create a User token:

# Sign a User token
echo '{ "sub": "random_ppid", "email": "me@example.com", "iss": "'"${BASE_URL}"'" }' \
    > user.claims.json
keypairs sign --exp 1h ./key.jwk.json ./user.claims.json > user.jwt.txt 2> user.jws.json

# verify the User token
keypairs verify ./pub.jwk.json ./user.jwt.txt

Impersonation can be accomplished by appending the token sub (aka PPID) to the url as ?user_id=.

REST API

All routes require authentication, except for those at /api/public.

Authentication: Bearer <token>

Here’s the API, in brief:

Base URL looks like https://example.com/api.

# Demo Mode Only
DELETE /public/reset                                    Drop database and re-initialize

# Public
GET  /public/ping                                       Health Check
POST /public/setup                  <= (none)           Bootstrap

# Admin-only
GET  /admin/ping                                        (authenticated) Health Check

# User
GET  /user/ping                                         (authenticated) Health Check

When you GET anything, it will be wrapped in the result.

Bootstrapping

The first user to hit the /api/setup endpoint will be the admin:

export TOKEN=$(cat admin.jwt.txt)

curl -X POST "${BASE_URL}/api/public/setup" -H "Authorization: Bearer ${TOKEN}"

Then the setup endpoint will be disabled:

curl -X POST "${BASE_URL}/api/public/setup" -H "Authorization: Bearer ${TOKEN}"

GoDoc

If the documentation is not public hosted you can view it with GoDoc:

godoc --http :6060

• http://localhost:6060/pkg/git.example.com/example/goserv/
• http://localhost:6060/pkg/git.example.com/example/goserv/internal/api
• http://localhost:6060/pkg/git.example.com/example/goserv/internal/db

You can see abbreviated documentation with go's built-in doc, for example:

go doc git.example.com/example/goserv/internal/api

http://localhost:6060

Test

Create a test database. It must have test in the name.

DROP DATABASE "goserv_test"; CREATE DATABASE "goserv_test";

Run the tests:

export TEST_DATABASE_URL='postgres://postgres:postgres@localhost:5432/goserv_test'
go test -mod=vendor ./...

Dependencies

This setup can be run on a VPS, such as Digital Ocean, OVH, or Scaleway for $5/month with minimal dependencies:

• VPS
• Caddy
• PostgreSQL
• Serviceman

Mac, Linux:

curl -fsS https://webinstall.dev | bash
export PATH="$HOME:/.local/bin:$PATH"

webi caddy serviceman postgres

VPS Setup

You should have a domain pointing to a VPS and create a user account named app (because that’s a common convention). This script will create an app user, copying the authorized_keys from the root account.

my_vps='example.com'
ssh root@"$my_vps" 'curl -sS https://webinstall.dev/ssh-adduser | bash'

You can then login as a normal user.

ssh app@"$my_vps"

It is now safe to disable the root account.

Caddy (Automatic HTTPS Server)

curl -fsS https://webinstall.dev/caddy | bash

You can start Caddy as a system service under the app user like this:

sudo setcap 'cap_net_bind_service=+ep' "$(readlink $(command -v caddy))"

sudo env PATH="$PATH" \
    serviceman add --name caddy --username app \
    caddy run --config ./Caddyfile

See the Cheat Sheets at https://webinstall.dev/caddy and https://webinstall.dev/serviceman

PostgreSQL (Database)

curl -fsS https://webinstall.dev/postgres | bash

You can start Postgres as a system service under the app user like this:

sudo env PATH="$PATH" \
    serviceman add --name postgres --username app -- \
    postgres -D /home/app/.local/share/postgres/var -p 5432

Username and password are set to ‘postgres’ by default:

psql 'postgres://postgres:postgres@localhost:5432/postgres'

See the Cheat Sheets at https://webinstall.dev/postgres and https://webinstall.dev/serviceman

Licenses

Copyright 2020 The GoServ Authors. All rights reserved.

Exceptions

• countries.json LGPL, taken from https://github.com/stefangabos/world_countries
• flags.json MIT, taken from https://github.com/matiassingers/emoji-flags

These are probably also in the Public Domain.
(gathering the official data from any source would yield the same dataset)