WIP upgrade

3 files changed, 38 insertions, 2 deletions

diff --git a/TODO.txt b/TODO.txt
index f0dba8d..e8b167f 100644
--- a/TODO.txt
+++ b/TODO.txt
@@ -1,3 +1,7 @@
 [ ] Add metrics
 [ ] Log sessions to DB table
 [ ] Email on new session (maybe?)
+[ ] Automatically upgrade client
+[ ] Server driven session max TTL
+[ ] Rate limit tokens
+[ ] Rate limit CA
diff --git a/cmd/client/autoupdate.go b/cmd/client/autoupdate.go
new file mode 100644
index 0000000..feb272e
--- /dev/null
+++ b/cmd/client/autoupdate.go
@@ -0,0 +1,28 @@
+package client
+
+import (
+        "context"
+        "log"
+        "os"
+)
+
+// TODO:
+// Check the Server header from the host and if the second part does not match
+// - Use HEAD, ignore 404
+// Download the latest client for this os/arch (remap GOARCH=amd64 to x86_64)
+// Re-execute the client in the same process so the latest client is used
+// Log some output to let the user know this happened
+// Verify SHA256 based on server ETag
+func upgradeAndRestartClient(ctx context.Context, version, host string) error {
+        // Download, chmod, verify, unlink original, rename old to new, exec new
+        exec, err := os.Executable()
+        if err != nil {
+                return err
+        }
+
+        // Refuse if any path segment starts with go-build.*
+
+        log.Printf("Executable is %s", exec)
+
+        return nil
+}
diff --git a/cmd/client/client.go b/cmd/client/client.go
index b72003d..afc7a1d 100644
--- a/cmd/client/client.go
+++ b/cmd/client/client.go
@@ -37,7 +37,7 @@ func NewClientCommand(appVersion string) *cobra.Command {
                 Run: func(c *cobra.Command, args []string) {
                         cfg := app.Config{}
                         cli.MustGetConfig(c, &cfg)
-                        clientMain(cfg, args[0], args[1], args[2])
+                        clientMain(cfg, appVersion, args[0], args[1], args[2])
                 },
         }
         cli.AddFlags(clientCmd, &app.Config{}, app.DefaultConfig, "client")
@@ -202,12 +202,16 @@ func fetchOauthToken(ctx context.Context, clientId, proxyHost string) (string, e
         return tokenResponse.AccessToken, nil
 }
 
-func clientMain(cfg app.Config, host, port, username string) {
+func clientMain(cfg app.Config, appVersion, host, port, username string) {
         log.SetOutput(os.Stderr)
 
         ctx, cancel := context.WithCancel(context.Background())
         defer cancel()
 
+        if err := upgradeAndRestartClient(ctx, appVersion, cfg.ClientHost); err != nil {
+                log.Fatalf("Error attempting to upgrade client: %s", err)
+        }
+
         agentConn, err := connectToAgent()
         if err != nil {
                 log.Fatalf("Error connecting to agent, is it started?")