Auto load all wallets when start up

Question

Every time I restart my bitcoind, all the wallets will need to be reloaded:

$ bitcoin-cli listwallets
[
  ""
]
$ bitcoin-cli loadwallet test01
$ bitcoin-cli listwallets
[
  "",
  "test01"
]

So I was wondering that is there any ways to auto load all the wallet under path /home/ubuntu/.bitcoin/testnet3/wallets when startup? I have tried adding some config in bitcoin.config, but all didn't work for me:

wallet=/home/ubuntu/.bitcoin/testnet3/wallets
wallet=/home/ubuntu/.bitcoin/testnet3/wallets/test01
wallet=1

bitcoin core version: v0.18.1

Answer 1

If you're using a systemd service, here's a way to auto load wallets using ExecStartPost.
This is what I added to my bitcoind.service file:

ExecStartPost=/bin/bash -c "sleep 60 && ls PATH_TO_YOUR_WALLETS_FOLDER -I database -I wallet.dat -I db.log | xargs -r -L 1 PATH_TO_YOUR_BITCON_CLI/bitcoin-cli loadwallet"

It waits 60 seconds after bitcoind starts, to give it a chance to load the block index first. Then looks for wallet directories and loads each one using bitcoin-cli loadwallet WALLET_NAME command.

---

Alternatively, if you just want to load specific wallets on Bitcoin Core restart, add this to bitcoin.conf before restarting:

wallet=
wallet=wallet_name
wallet=another_wallet

Full path isn't required if you created the wallets in the default directory (aka datadir).
A wallet name is the name of the directory the corresponding wallet.dat is in.
The wallet= line is needed to also load the default wallet.
Make sure to add the lines in the [test] section if you're on testnet.

Answer 2

You can specify the wallet options multiple times.

I.e. specifying:

wallet=/home/ubuntu/.bitcoin/testnet3/wallets/wallet01
wallet=/home/ubuntu/.bitcoin/testnet3/wallets/wallet02
wallet=/home/ubuntu/.bitcoin/testnet3/wallets/wallet03

in your bitcoin.conf will load wallet01, wallet02, wallet03.

Answer 3

If we suppose that the count of wallets are a lot, we can't load them manually. I use a Python script which loads wallets:

import subprocess
import os

def load_wallets():
    wallets = os.listdir(wallets_dir)
    for wallet in wallets:
        try:
            x = subprocess.check_output('bitcoin-cli -testnet loadwallet ' + wallet, shell=True)
        except Exception:
            pass

Some files may be in the wallets directory which are not wallet dirs and script will pass them inside except block.

Change -testnet parameter if needed.