| 1 | package hostenv |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "errors" |
| 6 | "flag" |
| 7 | "fmt" |
| 8 | "io" |
| 9 | "os" |
| 10 | "path/filepath" |
| 11 | ) |
| 12 | |
| 13 | // carlos system host-env write|seed (region HA spec 2 §5 step 2). |
| 14 | // |
| 15 | // - write is the start-up script's step: as root, it assembles host.env |
| 16 | // from the deployment's parameters and writes it 0600. A missing |
| 17 | // required value stops it, and the file is left as it was. |
| 18 | // - seed is the operator's: it writes a box's existing host.env into |
| 19 | // the parameter layout, once per region. |
| 20 | |
| 21 | const hostEnvUsage = `usage: carlos system host-env write --deployment <name> --region <code> [--aws-region <region>] |
| 22 | carlos system host-env seed --deployment <name> --region <code> --kms-key <key> [--aws-region <region>] [--from <path>] |
| 23 | |
| 24 | write build host.env from the deployment's parameters (root) |
| 25 | seed copy a box's host.env into the deployment's parameters |
| 26 | ` |
| 27 | |
| 28 | // hostEnvRoot is the root write's fixed path is under: "/" on a box. |
| 29 | // Tests point it at a directory of their own; there is no flag. |
| 30 | var hostEnvRoot = "/" |
| 31 | |
| 32 | // openParams is the parameter store: the AWS adapter's (awsssm.go). |
| 33 | // kmsKey is the key seed encrypts with; write passes "". |
| 34 | var openParams = openSSMParams |
| 35 | |
| 36 | // RunSystemHostEnv is `carlos system host-env`. |
| 37 | func RunSystemHostEnv(args []string) { |
| 38 | if err := runHostEnv(context.Background(), args, os.Stdout, os.Geteuid(), openParams); err != nil { |
| 39 | fmt.Fprintln(os.Stderr, err) |
| 40 | os.Exit(1) |
| 41 | } |
| 42 | } |
| 43 | |
| 44 | func runHostEnv(ctx context.Context, args []string, out io.Writer, euid int, open func(ctx context.Context, awsRegion, kmsKey string) (Params, error)) error { |
| 45 | if len(args) == 0 || (args[0] != "write" && args[0] != "seed") { |
| 46 | return usageError() |
| 47 | } |
| 48 | verb := args[0] |
| 49 | fs := flag.NewFlagSet("system host-env "+verb, flag.ContinueOnError) |
| 50 | fs.SetOutput(io.Discard) |
| 51 | deployment := fs.String("deployment", "", "") |
| 52 | region := fs.String("region", "", "") |
| 53 | awsRegion := fs.String("aws-region", "", "") |
| 54 | kmsKey := fs.String("kms-key", "", "") |
| 55 | from := fs.String("from", Path, "") |
| 56 | if err := fs.Parse(args[1:]); err != nil || fs.NArg() != 0 || *deployment == "" || *region == "" { |
| 57 | return usageError() |
| 58 | } |
| 59 | switch verb { |
| 60 | case "write": |
| 61 | if euid != 0 { |
| 62 | return errors.New("carlos system host-env write runs as root: it writes a root-owned file") |
| 63 | } |
| 64 | p, err := open(ctx, *awsRegion, "") |
| 65 | if err != nil { |
| 66 | return err |
| 67 | } |
| 68 | body, err := Fetch(ctx, p, *deployment, *region) |
| 69 | if err != nil { |
| 70 | return fmt.Errorf("host.env was not written: %w", err) |
| 71 | } |
| 72 | // The path is fixed, /etc/carlos/host.env, and the file is written |
| 73 | // only through directories proved to be root's alone, then |
| 74 | // replaced whole (writeHostEnv). |
| 75 | if err := writeHostEnv(hostEnvRoot, body); err != nil { |
| 76 | return fmt.Errorf("host.env was not written: %w", err) |
| 77 | } |
| 78 | fmt.Fprintln(out, wroteFileLine(filepath.Join(hostEnvRoot, Path), *region)) |
| 79 | return nil |
| 80 | default: |
| 81 | if *kmsKey == "" { |
| 82 | return usageError() |
| 83 | } |
| 84 | body, err := os.ReadFile(*from) |
| 85 | if err != nil { |
| 86 | return err |
| 87 | } |
| 88 | env, err := Parse(body) |
| 89 | if err != nil { |
| 90 | return fmt.Errorf("%s: %w", *from, err) |
| 91 | } |
| 92 | p, err := open(ctx, *awsRegion, *kmsKey) |
| 93 | if err != nil { |
| 94 | return err |
| 95 | } |
| 96 | s, err := Seed(ctx, p, *deployment, *region, env) |
| 97 | if err != nil { |
| 98 | return fmt.Errorf("the parameters were not all written: %w", err) |
| 99 | } |
| 100 | fmt.Fprintln(out, seededLine(s)) |
| 101 | return nil |
| 102 | } |
| 103 | } |
| 104 | |
| 105 | func usageError() error { return errors.New(hostEnvUsage) } |
| 106 | |
| 107 | // wroteFileLine is what write says once host.env is in place. |
| 108 | func wroteFileLine(path, region string) string { |
| 109 | return fmt.Sprintf("wrote %s from the parameters for %s", path, region) |
| 110 | } |
| 111 | |
| 112 | // seededLine is what seed says once the parameters are written. |
| 113 | func seededLine(s Seeded) string { |
| 114 | return fmt.Sprintf("wrote %d parameters under %s and %d under %s", s.Regional, s.RegionPrefix, s.Shared, s.SharedPrefix) |
| 115 | } |
| 116 | |
amadan