131 lines
3.5 KiB
Go
131 lines
3.5 KiB
Go
// Copyright 2019 Google LLC
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License"); you may not
|
|
// use this file except in compliance with the License. You may obtain a copy of
|
|
// the License at
|
|
//
|
|
// https://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
// License for the specific language governing permissions and limitations under
|
|
// the License.
|
|
|
|
// Package config implements structures to store Nixery's configuration at
|
|
// runtime as well as the logic for instantiating this configuration from the
|
|
// environment.
|
|
package config
|
|
|
|
import (
|
|
"fmt"
|
|
"io/ioutil"
|
|
"log"
|
|
"os"
|
|
|
|
"cloud.google.com/go/storage"
|
|
)
|
|
|
|
// pkgSource represents the source from which the Nix package set used
|
|
// by Nixery is imported. Users configure the source by setting one of
|
|
// the supported environment variables.
|
|
type PkgSource struct {
|
|
srcType string
|
|
args string
|
|
}
|
|
|
|
// Convert the package source into the representation required by Nix.
|
|
func (p *PkgSource) Render(tag string) string {
|
|
// The 'git' source requires a tag to be present.
|
|
if p.srcType == "git" {
|
|
if tag == "latest" || tag == "" {
|
|
tag = "master"
|
|
}
|
|
|
|
return fmt.Sprintf("git!%s!%s", p.args, tag)
|
|
}
|
|
|
|
return fmt.Sprintf("%s!%s", p.srcType, p.args)
|
|
}
|
|
|
|
// Retrieve a package source from the environment. If no source is
|
|
// specified, the Nix code will default to a recent NixOS channel.
|
|
func pkgSourceFromEnv() *PkgSource {
|
|
if channel := os.Getenv("NIXERY_CHANNEL"); channel != "" {
|
|
log.Printf("Using Nix package set from Nix channel %q\n", channel)
|
|
return &PkgSource{
|
|
srcType: "nixpkgs",
|
|
args: channel,
|
|
}
|
|
}
|
|
|
|
if git := os.Getenv("NIXERY_PKGS_REPO"); git != "" {
|
|
log.Printf("Using Nix package set from git repository at %q\n", git)
|
|
return &PkgSource{
|
|
srcType: "git",
|
|
args: git,
|
|
}
|
|
}
|
|
|
|
if path := os.Getenv("NIXERY_PKGS_PATH"); path != "" {
|
|
log.Printf("Using Nix package set from path %q\n", path)
|
|
return &PkgSource{
|
|
srcType: "path",
|
|
args: path,
|
|
}
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// Load (optional) GCS bucket signing data from the GCS_SIGNING_KEY and
|
|
// GCS_SIGNING_ACCOUNT envvars.
|
|
func signingOptsFromEnv() *storage.SignedURLOptions {
|
|
path := os.Getenv("GCS_SIGNING_KEY")
|
|
id := os.Getenv("GCS_SIGNING_ACCOUNT")
|
|
|
|
if path == "" || id == "" {
|
|
log.Println("GCS URL signing disabled")
|
|
return nil
|
|
}
|
|
|
|
log.Printf("GCS URL signing enabled with account %q\n", id)
|
|
k, err := ioutil.ReadFile(path)
|
|
if err != nil {
|
|
log.Fatalf("Failed to read GCS signing key: %s\n", err)
|
|
}
|
|
|
|
return &storage.SignedURLOptions{
|
|
GoogleAccessID: id,
|
|
PrivateKey: k,
|
|
Method: "GET",
|
|
}
|
|
}
|
|
|
|
func getConfig(key, desc string) string {
|
|
value := os.Getenv(key)
|
|
if value == "" {
|
|
log.Fatalln(desc + " must be specified")
|
|
}
|
|
|
|
return value
|
|
}
|
|
|
|
// config holds the Nixery configuration options.
|
|
type Config struct {
|
|
Bucket string // GCS bucket to cache & serve layers
|
|
Signing *storage.SignedURLOptions // Signing options to use for GCS URLs
|
|
Port string // Port on which to launch HTTP server
|
|
Pkgs *PkgSource // Source for Nix package set
|
|
WebDir string
|
|
}
|
|
|
|
func FromEnv() *Config {
|
|
return &Config{
|
|
Bucket: getConfig("BUCKET", "GCS bucket for layer storage"),
|
|
Port: getConfig("PORT", "HTTP port"),
|
|
Pkgs: pkgSourceFromEnv(),
|
|
Signing: signingOptsFromEnv(),
|
|
WebDir: getConfig("WEB_DIR", "Static web file dir"),
|
|
}
|
|
}
|