fix panic due to nil execution store (#4501)

The problem is we we don't fail the node properly when we fail to open
execution store's boltdb, which can happen if we already have a node
running using the same repo. This can be easily reproduced by running
two nodes on separate ports but using the same rep, or just trying to
run a node while devstack is running:

```
bacalhau serve --compute --orchestrator --api-port 1122

bacalhau serve --compute --orchestrator --api-port 2233
```

Now we get a clearer error of why we failed to start. It is not the best
error as it exposes implementation details and doesn't tell exactly what
is happning and how to fix things, but at better than a panic at least
and time is tight to improve the propagation of this error for now

```
failed to configure compute node: failed to create execution store: timed out while opening database, file "/Users/walid/.bacalhau/compute/state_boltdb.db" might be in use
```

Closes #4491

cmd/cli/serve/util.go

@@ -31,6 +31,9 @@ func GetComputeConfig(
 			return node.ComputeConfig{}, err
 		}
 		executionStore, err = boltdb.NewStore(ctx, executionStoreDBPath)
+		if err != nil {
+			return node.ComputeConfig{}, pkgerrors.Wrapf(err, "failed to create execution store")
+		}
 	}
 
 	executionsPath, err := cfg.ExecutionDir()

pkg/compute/store/boltdb/store.go

@@ -115,6 +115,10 @@ func NewStore(ctx context.Context, dbPath string) (*Store, error) {
 		boltdb_watcher.WithEventSerializer(eventObjectSerializer),
 	)
 
+	if err != nil {
+		return nil, fmt.Errorf("failed to create event store: %w", err)
+	}
+
 	return &Store{
 		database:   database,
 		marshaller: marshaller.NewJSONMarshaller(),

pkg/node/config_compute.go

@@ -16,6 +16,7 @@ import (
 	"github.com/bacalhau-project/bacalhau/pkg/compute/store"
 	"github.com/bacalhau-project/bacalhau/pkg/config/types"
 	legacy_types "github.com/bacalhau-project/bacalhau/pkg/config_legacy/types"
+	"github.com/bacalhau-project/bacalhau/pkg/lib/validate"
 	"github.com/bacalhau-project/bacalhau/pkg/models"
 )
 
@@ -244,3 +245,10 @@ func validateConfig(config ComputeConfig, physicalResources models.Resources) er
 
 	return err
 }
+
+func (c *ComputeConfig) Validate() error {
+	// TODO: add more validations
+	var mErr error
+	mErr = errors.Join(mErr, validate.NotNil(c.ExecutionStore, "execution store is required"))
+	return mErr
+}

pkg/node/node.go

@@ -17,6 +17,7 @@ import (
 	legacy_types "github.com/bacalhau-project/bacalhau/pkg/config_legacy/types"
 	baccrypto "github.com/bacalhau-project/bacalhau/pkg/lib/crypto"
 	"github.com/bacalhau-project/bacalhau/pkg/lib/policy"
+	"github.com/bacalhau-project/bacalhau/pkg/lib/validate"
 	"github.com/bacalhau-project/bacalhau/pkg/models"
 	nats_transport "github.com/bacalhau-project/bacalhau/pkg/nats/transport"
 	"github.com/bacalhau-project/bacalhau/pkg/node/metrics"
@@ -52,7 +53,6 @@ type NodeConfig struct {
 	RequesterNodeConfig         RequesterConfig
 	APIServerConfig             publicapi.Config
 	AuthConfig                  types.AuthConfig
-	NodeType                    models.NodeType
 	IsRequesterNode             bool
 	IsComputeNode               bool
 	Labels                      map[string]string
@@ -64,7 +64,11 @@ type NodeConfig struct {
 func (c *NodeConfig) Validate() error {
 	// TODO: add more validations
 	var mErr error
+	mErr = errors.Join(mErr, validate.NotBlank(c.NodeID, "node id is required"))
 	mErr = errors.Join(mErr, c.NetworkConfig.Validate())
+	if c.IsComputeNode {
+		mErr = errors.Join(mErr, c.ComputeConfig.Validate())
+	}
 	return mErr
 }