| 1 | package bootstrap |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "fmt" |
| 6 | "strings" |
| 7 | ) |
| 8 | |
| 9 | // Environment the launched serve reads to reach the desktop browser broker. |
| 10 | // Both travel in the process environment only: the token rotates with every |
| 11 | // SSH connection generation, so nothing on disk may outlive it. |
| 12 | const ( |
| 13 | BrowserBrokerEnv = "REASONIX_BROWSER_BROKER" |
| 14 | BrowserTokenEnv = "REASONIX_BROWSER_TOKEN" |
| 15 | ) |
| 16 | |
| 17 | // ServeBrowserBrokerMarker is the `serve --help` flag name that advertises a |
| 18 | // binary able to use a desktop browser broker. Unlike the required capability |
| 19 | // markers it is optional: a serve without it launches untouched. |
| 20 | const ServeBrowserBrokerMarker = "browser-broker" |
| 21 | |
| 22 | // BrowserBrokerOptions hands a launching serve the desktop browser broker: |
| 23 | // the reverse-forwarded loopback endpoint on the REMOTE host and the bearer |
| 24 | // token of the current connection generation. |
| 25 | type BrowserBrokerOptions struct { |
| 26 | BaseURL string |
| 27 | Token string |
| 28 | } |
| 29 | |
| 30 | // BrowserBrokerSupportedCommand prints "yes" when bin's serve command |
| 31 | // advertises ServeBrowserBrokerMarker, "no" otherwise. |
| 32 | func BrowserBrokerSupportedCommand(bin string) string { |
| 33 | return fmt.Sprintf( |
| 34 | "if %s serve --help 2>&1 | grep -q -- %s; then echo yes; else echo no; fi", |
| 35 | shellQuote(bin), shellQuote(ServeBrowserBrokerMarker), |
| 36 | ) |
| 37 | } |
| 38 | |
| 39 | // browserEnvPrefix renders the environment assignments placed before the |
| 40 | // serve command; empty when no broker is configured. |
| 41 | func browserEnvPrefix(opts *BrowserBrokerOptions) string { |
| 42 | if opts == nil || strings.TrimSpace(opts.BaseURL) == "" || strings.TrimSpace(opts.Token) == "" { |
| 43 | return "" |
| 44 | } |
| 45 | return BrowserBrokerEnv + "=" + shellQuote(strings.TrimSpace(opts.BaseURL)) + " " + |
| 46 | BrowserTokenEnv + "=" + shellQuote(strings.TrimSpace(opts.Token)) + " " |
| 47 | } |
| 48 | |
| 49 | // resolveBrowserBroker asks the desktop for broker options right before a |
| 50 | // fresh launch, and only when bin advertises the capability, so the reverse |
| 51 | // forward is never installed for a serve that cannot use it. A broker that |
| 52 | // cannot be prepared degrades to a launch without browser access. |
| 53 | func resolveBrowserBroker(ctx context.Context, conn Conn, bin string, opts Options) *BrowserBrokerOptions { |
| 54 | if opts.BrowserBroker == nil { |
| 55 | return nil |
| 56 | } |
| 57 | res, err := conn.Exec(ctx, BrowserBrokerSupportedCommand(bin)) |
| 58 | if err != nil || strings.TrimSpace(string(res.Stdout)) != "yes" { |
| 59 | return nil |
| 60 | } |
| 61 | broker, err := opts.BrowserBroker(ctx) |
| 62 | if err != nil { |
| 63 | opts.progress("browser_broker", "unavailable: "+err.Error()) |
| 64 | return nil |
| 65 | } |
| 66 | if browserEnvPrefix(broker) == "" { |
| 67 | return nil |
| 68 | } |
| 69 | return broker |
| 70 | } |
| 71 |