From 2b82f1b71a50b8b1473421cce0eec1a0d7ddc360 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Mon, 11 Nov 2019 21:07:16 +0000 Subject: refactor: Reshuffle file structure for better code layout This gets rid of the package called "server" and instead moves everything into the project root, such that Go actually builds us a binary called `nixery`. This is the first step towards factoring out CLI-based functionality for Nixery. --- tools/nixery/config/config.go | 84 +++++++++++++++++++++ tools/nixery/config/pkgsource.go | 159 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 243 insertions(+) create mode 100644 tools/nixery/config/config.go create mode 100644 tools/nixery/config/pkgsource.go (limited to 'tools/nixery/config') diff --git a/tools/nixery/config/config.go b/tools/nixery/config/config.go new file mode 100644 index 000000000000..7ec102bd6cee --- /dev/null +++ b/tools/nixery/config/config.go @@ -0,0 +1,84 @@ +// 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 ( + "os" + + log "github.com/sirupsen/logrus" +) + +func getConfig(key, desc, def string) string { + value := os.Getenv(key) + if value == "" && def == "" { + log.WithFields(log.Fields{ + "option": key, + "description": desc, + }).Fatal("missing required configuration envvar") + } else if value == "" { + return def + } + + return value +} + +// Backend represents the possible storage backend types +type Backend int + +const ( + GCS = iota + FileSystem +) + +// Config holds the Nixery configuration options. +type Config struct { + Port string // Port on which to launch HTTP server + Pkgs PkgSource // Source for Nix package set + Timeout string // Timeout for a single Nix builder (seconds) + WebDir string // Directory with static web assets + PopUrl string // URL to the Nix package popularity count + Backend Backend // Storage backend to use for Nixery +} + +func FromEnv() (Config, error) { + pkgs, err := pkgSourceFromEnv() + if err != nil { + return Config{}, err + } + + var b Backend + switch os.Getenv("NIXERY_STORAGE_BACKEND") { + case "gcs": + b = GCS + case "filesystem": + b = FileSystem + default: + log.WithField("values", []string{ + "gcs", + }).Fatal("NIXERY_STORAGE_BUCKET must be set to a supported value") + } + + return Config{ + Port: getConfig("PORT", "HTTP port", ""), + Pkgs: pkgs, + Timeout: getConfig("NIX_TIMEOUT", "Nix builder timeout", "60"), + WebDir: getConfig("WEB_DIR", "Static web file dir", ""), + PopUrl: os.Getenv("NIX_POPULARITY_URL"), + Backend: b, + }, nil +} diff --git a/tools/nixery/config/pkgsource.go b/tools/nixery/config/pkgsource.go new file mode 100644 index 000000000000..95236c4b0d15 --- /dev/null +++ b/tools/nixery/config/pkgsource.go @@ -0,0 +1,159 @@ +// 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 + +import ( + "crypto/sha1" + "encoding/json" + "fmt" + "os" + "regexp" + "strings" + + log "github.com/sirupsen/logrus" +) + +// 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 interface { + // Convert the package source into the representation required + // for calling Nix. + Render(tag string) (string, string) + + // Create a key by which builds for this source and iamge + // combination can be cached. + // + // The empty string means that this value is not cacheable due + // to the package source being a moving target (such as a + // channel). + CacheKey(pkgs []string, tag string) string +} + +type GitSource struct { + repository string +} + +// Regex to determine whether a git reference is a commit hash or +// something else (branch/tag). +// +// Used to check whether a git reference is cacheable, and to pass the +// correct git structure to Nix. +// +// Note: If a user creates a branch or tag with the name of a commit +// and references it intentionally, this heuristic will fail. +var commitRegex = regexp.MustCompile(`^[0-9a-f]{40}$`) + +func (g *GitSource) Render(tag string) (string, string) { + args := map[string]string{ + "url": g.repository, + } + + // The 'git' source requires a tag to be present. If the user + // has not specified one, it is assumed that the default + // 'master' branch should be used. + if tag == "latest" || tag == "" { + tag = "master" + } + + if commitRegex.MatchString(tag) { + args["rev"] = tag + } else { + args["ref"] = tag + } + + j, _ := json.Marshal(args) + + return "git", string(j) +} + +func (g *GitSource) CacheKey(pkgs []string, tag string) string { + // Only full commit hashes can be used for caching, as + // everything else is potentially a moving target. + if !commitRegex.MatchString(tag) { + return "" + } + + unhashed := strings.Join(pkgs, "") + tag + hashed := fmt.Sprintf("%x", sha1.Sum([]byte(unhashed))) + + return hashed +} + +type NixChannel struct { + channel string +} + +func (n *NixChannel) Render(tag string) (string, string) { + return "nixpkgs", n.channel +} + +func (n *NixChannel) CacheKey(pkgs []string, tag string) string { + // Since Nix channels are downloaded from the nixpkgs-channels + // Github, users can specify full commit hashes as the + // "channel", in which case builds are cacheable. + if !commitRegex.MatchString(n.channel) { + return "" + } + + unhashed := strings.Join(pkgs, "") + n.channel + hashed := fmt.Sprintf("%x", sha1.Sum([]byte(unhashed))) + + return hashed +} + +type PkgsPath struct { + path string +} + +func (p *PkgsPath) Render(tag string) (string, string) { + return "path", p.path +} + +func (p *PkgsPath) CacheKey(pkgs []string, tag string) string { + // Path-based builds are not currently cacheable because we + // have no local hash of the package folder's state easily + // available. + return "" +} + +// 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, error) { + if channel := os.Getenv("NIXERY_CHANNEL"); channel != "" { + log.WithField("channel", channel).Info("using Nix package set from Nix channel or commit") + + return &NixChannel{ + channel: channel, + }, nil + } + + if git := os.Getenv("NIXERY_PKGS_REPO"); git != "" { + log.WithField("repo", git).Info("using NIx package set from git repository") + + return &GitSource{ + repository: git, + }, nil + } + + if path := os.Getenv("NIXERY_PKGS_PATH"); path != "" { + log.WithField("path", path).Info("using Nix package set at local path") + + return &PkgsPath{ + path: path, + }, nil + } + + return nil, fmt.Errorf("no valid package source has been specified") +} -- cgit 1.4.1