config: allow changing the default root directory

[liv-io]

Background

For some reason, I am not able to define alternative directories via CLI arguments.

• Arguments that work:

  --configfile=
  --logdir=
  

• Argument that does not work:

  --datadir=
  

Your environment

• version of btcd

  btcd version 0.24.0-beta
  

• which operating system (uname -a on *Nix)

  Linux pod_lnd 6.1.0-13-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.55-1 (2023-09-29) x86_64 GNU/Linux
  

• any other relevant environment details

  btcd is running as read-only* Podman container
  
  (*except for data directories of course)
  

• Containerfile

• Entrypoint/cmd

Steps to reproduce

• The command I am using is:

  mkdir -p /var/local/btcd/config /var/local/btcd/data /var/local/btcd/log
  
  /usr/local/bin/btcd --configfile=/var/local/btcd/config/btcd.conf --datadir=/var/local/btcd/data --debuglevel=info --externalip=1.2.3.4 --listen=0.0.0.0:8333 --logdir=/var/local/btcd/log --rpclisten=0.0.0.0:8334 --rpcpass=nakamoto --rpcuser=satoshi
  

Expected behaviour

• I expect btcd to write its output to the respective directories.

Actual behaviour

• btcd immediately exits and complains about the home directory being read-only. Even when overwriting the default --datadir= location, it still points to the home directory /home/btcd/.btcd/db:

  2024-01-20 19:05:57.634 [INF] BTCD: Version 0.24.0-beta
  2024-01-20 19:05:57.636 [ERR] BTCD: unlinkat /home/btcd/.btcd/db: read-only file system
  2024-01-20 19:05:57.637 [INF] BTCD: Shutdown complete
  

[liv-io]

@guggero Thanks again for your support on the lnd issue.

I quickly ran two more tests with btcd.

• In a read-only environment, btcd immediately stops as it tries to create the .btcd directory in the user's home.

  2024-01-22 11:51:44.252 [INF] BTCD: Version 0.24.0-beta
  2024-01-22 11:51:44.252 [ERR] BTCD: unlinkat /home/btcd/.btcd/db: read-only file system
  2024-01-22 11:51:44.252 [INF] BTCD: Shutdown complete
  

• In a read-write environment, btcd starts successfully and creates the .btcd directory and rpc.cert, rpc.key files. All other output is written to the defined paths.

  /home/btcd/.btcd
  /home/btcd/.btcd/rpc.cert
  /home/btcd/.btcd/rpc.key
  

• With the --rpccert= and --rpckey= options defined, it only creates the .btcd directory.

  /home/btcd/.btcd
  

• The command I've used is:

  /usr/local/bin/btcd --addpeer=10.10.10.11:8333 10.10.10.12:8333 --debuglevel=info --externalip=1.2.3.4 --listen=0.0.0.0:8333 --rpclisten=0.0.0.0:8334 --rpcpass=info --rpcuser=satoshi \
  --configfile=/var/local/btcd/other/config/btcd.conf \
  --datadir=/var/local/btcd/db \
  --logdir=/var/local/btcd/other/log/
  

  • Is there a "global" option for all output as in lnd (i.e. --lnddir=)?

Thanks!

[guggero]

It looks like there is indeed no global option in btcd and the default home directory is always being created. We should probably fix that, going to change the title to make it more clear what needs to be done.

[guggero]

Problem is here: https://github.com/btcsuite/btcd/blob/master/config.go#L529

[liv-io]

Thank you very much!

[theedtron]

Hello, I would like to jump on this.

[theedtron]

Hello @guggero,
Are you able to assist me with info on how flags are added in btcd?

For my approach , I want to add a flag for global home directory that installs everything in the specified path. I'll do a check whether the global flag exists and if true it will replace the path of the default home directory.

[guggero]

See https://github.com/btcsuite/btcd/blob/master/config.go#L99, those are all flags.

[theedtron]

See https://github.com/btcsuite/btcd/blob/master/config.go#L99, those are all flags.

@guggero Thanks for pointing me in the right direction.