Refactor installation and runner scripts for enhanced usability and security

- Updated the installation script to clarify that production wrappers do not include fixed test secrets, improving user guidance for local testing.
- Modified the jiggablend-manager and jiggablend-runner scripts to remove fixed test configurations, emphasizing the use of local test credentials via `make init-test`.
- Enhanced error handling in the runner script to ensure that an API key is provided, improving security and user feedback.
- Added new flags and options for the runner, including sandboxing capabilities and GPU ray tracing control, enhancing flexibility for users.
- Improved README documentation to reflect changes in usage and configuration, ensuring users have clear instructions for setup and execution.

internal/auth/jobtoken.go

@@ -7,11 +7,54 @@ import (
 	"encoding/base64"
 	"encoding/json"
 	"fmt"
+	"sync"
 	"time"
 )
 
-// JobTokenDuration is the validity period for job tokens
-const JobTokenDuration = 1 * time.Hour
+// DefaultJobTokenDuration is the minimum validity period for job tokens.
+const DefaultJobTokenDuration = 1 * time.Hour
+
+// JobTokenSkew is extra lifetime added beyond configured task timeouts.
+const JobTokenSkew = 15 * time.Minute
+
+// JobTokenDuration is the current validity period for newly issued job tokens.
+// Prefer JobTokenTTL() / SetJobTokenTTL; this var remains for backward-compatible reads.
+var (
+	jobTokenTTL   = DefaultJobTokenDuration
+	jobTokenTTLMu sync.RWMutex
+)
+
+// JobTokenTTL returns the current job token lifetime used when minting tokens.
+func JobTokenTTL() time.Duration {
+	jobTokenTTLMu.RLock()
+	defer jobTokenTTLMu.RUnlock()
+	return jobTokenTTL
+}
+
+// SetJobTokenTTL sets the lifetime for newly issued job tokens.
+// Values below DefaultJobTokenDuration are raised to the default.
+func SetJobTokenTTL(d time.Duration) {
+	if d < DefaultJobTokenDuration {
+		d = DefaultJobTokenDuration
+	}
+	jobTokenTTLMu.Lock()
+	jobTokenTTL = d
+	jobTokenTTLMu.Unlock()
+}
+
+// ConfigureJobTokenTTLFromTimeouts sets token lifetime from the longest of the
+// given task timeouts (seconds) plus JobTokenSkew, floored at DefaultJobTokenDuration.
+func ConfigureJobTokenTTLFromTimeouts(timeoutSeconds ...int) time.Duration {
+	maxSec := 0
+	for _, s := range timeoutSeconds {
+		if s > maxSec {
+			maxSec = s
+		}
+	}
+	d := time.Duration(maxSec)*time.Second + JobTokenSkew
+	SetJobTokenTTL(d)
+	return JobTokenTTL()
+}
 
 // JobTokenClaims represents the claims in a job token
 type JobTokenClaims struct {
@@ -41,7 +84,7 @@ func GenerateJobToken(jobID, runnerID, taskID int64) (string, error) {
 		JobID:    jobID,
 		RunnerID: runnerID,
 		TaskID:   taskID,
-		Exp:      time.Now().Add(JobTokenDuration).Unix(),
+		Exp:      time.Now().Add(JobTokenTTL()).Unix(),
 	}
 
 	// Encode claims to JSON
@@ -112,4 +155,3 @@ func ValidateJobToken(token string) (*JobTokenClaims, error) {
 
 	return &claims, nil
 }
-