Allow connection of BFG to another BFG for L2 Keystone Notifications/Querying

README.md

@@ -140,6 +140,28 @@ go run ./integrationtest
 - A **PostgreSQL database**, bfgd expects the sql scripts in `./database/bfgd/scripts/` to be run to set up your schema.
 - A **connection to an Electrs node** on the proper Bitcoin network (testnet or mainnet).
 
+### Running your own Bitcoin Finality Governor (bfgd) and PoP mining with it
+
+If you'd like to run your own `bfgd` and don't want to rely on Hemi Labs (or any third party) for _broadcasting transactions_, you may run `bfgd` and connect it to a _trusted_ `bfgd` run by a third party to _receive l2 keystones only_ (l2 keystones represent l2 state and are what are mined in PoP transactions).  In this case, the third party `bfgd` will only send you l2 keystones, your `bfgd` can notify your local pop miner and this will broadcast them to your Electrs+bitcoind setup so you don't rely on Hemi Labs--or any third party--which may be congested.
+
+You'll need the following running to do this:
+* bitcoind
+* electrs
+* postgres
+* bfgd
+
+_Note: make sure you run all of the *.sql files for bfg in `database/bfgd/postgres/scripts`_
+
+When running BFG, you'll want the following env variables set:
+
+* `BFG_BFG_URL`: the _trusted_ `bfgd`'s websocket url that you will connect to
+* `BFG_BTC_PRIVKEY`: your btc private key.  note that this can be an unfunded private key and you'll still receive l2 keystones to mine
+* `BFG_POSTGRES_URI`: the connection URI for your postgres instance
+* `BFG_BTC_START_HEIGHT`: when your db is empty, bfgd will need a starting point to parse btc blocks at, set this to the tip of the bitcoin chain at first deploy
+* `BFG_EXBTC_ADDRESS`: your electrs rpc address
+
+You may then connect your local `popmd` to your aforementioned local `bfgd` via the `POPM_BFG_URL` env variable
+
 ## ▶️ Running bssd
 
 ### 🏁 Prerequisites

cmd/bfgd/bfgd.go

@@ -123,6 +123,18 @@ var (
 			Help:         "list of headers used to obtain the client IP address (requires trusted proxies)",
 			Print:        config.PrintAll,
 		},
+		"BFG_BFG_URL": config.Config{
+			Value:        &cfg.BFGURL,
+			DefaultValue: "",
+			Help:         "public websocket address of another BFG you'd like to receive L2Keystones from",
+			Print:        config.PrintAll,
+		},
+		"BFG_BTC_PRIVKEY": config.Config{
+			Value:        &cfg.BTCPrivateKey,
+			DefaultValue: "",
+			Help:         "a btc private key, this is only needed when connecting to another BFG",
+			Print:        config.PrintSecret,
+		},
 	}
 )
 

database/bfgd/database_ext_test.go

@@ -11,6 +11,7 @@ import (
 	"encoding/hex"
 	"errors"
 	"fmt"
+	"log"
 	mathrand "math/rand/v2"
 	"net/url"
 	"os"
@@ -475,6 +476,79 @@ func TestL2KeystoneInsertMultipleSuccess(t *testing.T) {
 	}
 }
 
+func TestL2KeystoneInsertIgnoreDuplicates(t *testing.T) {
+	ctx, cancel := defaultTestContext()
+	defer cancel()
+
+	db, sdb, cleanup := createTestDB(ctx, t)
+	defer func() {
+		db.Close()
+		sdb.Close()
+		cleanup()
+	}()
+
+	l2Keystone := bfgd.L2Keystone{
+		Version:            1,
+		L1BlockNumber:      11,
+		L2BlockNumber:      22,
+		ParentEPHash:       fillOutBytes("parentephash", 32),
+		PrevKeystoneEPHash: fillOutBytes("prevkeystoneephash", 32),
+		StateRoot:          fillOutBytes("stateroot", 32),
+		EPHash:             fillOutBytes("ephash", 32),
+		Hash:               fillOutBytes("mockhash", 32),
+	}
+
+	otherL2Keystone := bfgd.L2Keystone{
+		Version:            1,
+		L1BlockNumber:      11,
+		L2BlockNumber:      22,
+		ParentEPHash:       fillOutBytes("parentephash", 32),
+		PrevKeystoneEPHash: fillOutBytes("prevkeystoneephash", 32),
+		StateRoot:          fillOutBytes("stateroot", 32),
+		EPHash:             fillOutBytes("ephash", 32),
+		Hash:               fillOutBytes("mockhashz", 32),
+	}
+
+	err := db.L2KeystonesInsert(ctx, []bfgd.L2Keystone{l2Keystone, otherL2Keystone})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = db.L2KeystonesInsert(ctx, []bfgd.L2Keystone{l2Keystone, otherL2Keystone})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	saved, err := db.L2KeystoneByAbrevHash(ctx, [32]byte(l2Keystone.Hash))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	diff := deep.Equal(saved, &l2Keystone)
+	if len(diff) != 0 {
+		t.Fatalf("unexpected diff %s", diff)
+	}
+
+	otherSaved, err := db.L2KeystoneByAbrevHash(ctx, [32]byte(otherL2Keystone.Hash))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	diff = deep.Equal(otherSaved, &otherL2Keystone)
+	if len(diff) != 0 {
+		t.Fatalf("unexpected diff %s", diff)
+	}
+
+	count, err := l2KeystonesCount(ctx, sdb)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if count != 2 {
+		t.Fatalf("unexpected count %d", count)
+	}
+}
+
 func TestL2KeystoneInsertInvalidHashLength(t *testing.T) {
 	ctx, cancel := defaultTestContext()
 	defer cancel()
@@ -915,7 +989,7 @@ func TestL2KeystoneInsertMultipleAtomicFailure(t *testing.T) {
 	}
 }
 
-func TestL2KeystoneInsertMultipleDuplicateError(t *testing.T) {
+func TestL2KeystoneInsertDuplicateOK(t *testing.T) {
 	ctx, cancel := defaultTestContext()
 	defer cancel()
 
@@ -949,9 +1023,18 @@ func TestL2KeystoneInsertMultipleDuplicateError(t *testing.T) {
 	}
 
 	err := db.L2KeystonesInsert(ctx, []bfgd.L2Keystone{l2Keystone, otherL2Keystone})
-	if err == nil || errors.Is(err, database.DuplicateError("")) == false {
+	if err != nil {
 		t.Fatalf("received unexpected error: %s", err)
 	}
+
+	l2Keystones, err := db.L2KeystonesMostRecentN(ctx, 5)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if diff := deep.Equal([]bfgd.L2Keystone{l2Keystone}, l2Keystones); len(diff) != 0 {
+		log.Fatalf("unexpected diff %v", diff)
+	}
 }
 
 func TestPopBasisInsertNilMerklePath(t *testing.T) {

database/bfgd/postgres/postgres.go

@@ -133,10 +133,12 @@ func (p *pgdb) L2KeystonesInsert(ctx context.Context, l2ks []bfgd.L2Keystone) er
 		)
 
 		VALUES ($1, $2, $3, $4, $5, $6, $7, $8)
+
+		ON CONFLICT DO NOTHING
 	`
 
 	for _, v := range l2ks {
-		result, err := tx.ExecContext(ctx, qInsertL2Keystone, v.Hash,
+		_, err := tx.ExecContext(ctx, qInsertL2Keystone, v.Hash,
 			v.L1BlockNumber, v.L2BlockNumber, v.ParentEPHash,
 			v.PrevKeystoneEPHash, v.StateRoot, v.EPHash, v.Version)
 		if err != nil {
@@ -156,13 +158,6 @@ func (p *pgdb) L2KeystonesInsert(ctx context.Context, l2ks []bfgd.L2Keystone) er
 			}
 			return fmt.Errorf("insert l2 keystone: %w", err)
 		}
-		rows, err := result.RowsAffected()
-		if err != nil {
-			return fmt.Errorf("insert l2 keystone rows affected: %w", err)
-		}
-		if rows < 1 {
-			return fmt.Errorf("insert l2 keystone rows: %v", rows)
-		}
 	}
 
 	err = tx.Commit()