Validate config and provide good error messages if something is wrong

[thiagodelgado111]

• Version: 0.27.7
• Platform:
  ProductName: Mac OS X
  ProductVersion: 10.12.6
  BuildVersion: 16G1114

Type: Bug

Severity: Medium

Description:

If an invalid protocol is specified in Ipfs' config constructor argument, it will be persisted and then pre-start keeps failing due to the invalid protocol – even after changing the config.

Steps to reproduce the error:

› node src/index.js

Swarm listening on /ip4/127.0.0.1/tcp/4001/ipfs/YYYYYYYYYY
I am ready!
Waiting for peers...
peers:  [ '/ip4/127.0.0.1/tcp/9999/ws/ipfs/XXXXXXXXXX' ]

Protocol used on Addresses.Swarm config list /ip6/::/etcp/4001

› node src/index.js

/Users/thiagodelgado/code/ipfs-playground/node_modules/multiaddr/src/protocols-table.js:17
    throw new Error('no protocol with name: ' + proto)
    ^

Error: no protocol with name: etcp

After fixing the config object

› node src/index.js

/Users/thiagodelgado/code/ipfs-playground/node_modules/multiaddr/src/protocols-table.js:17
    throw new Error('no protocol with name: ' + proto)
    ^

Error: no protocol with name: etcp

Same error even though not using that protocol anymore. Editing .jsipfs/config file removing the bad line solved it.

› node src/index.js

Swarm listening on /ip4/127.0.0.1/tcp/4001/ipfs/YYYYYYYYYY
I am ready!
Waiting for peers...
peers:  [ '/ip4/127.0.0.1/tcp/9999/ws/ipfs/XXXXXXXXXX' ]

[dryajov]

@thiagodelgado111 I'm not sure if I understand - removing the non existent protocol etcp fixed it, or did you run into some other issue? I believe that the behavior is expected (tho perhaps no very user friendly?) - multiaddr will throw if it can't recognise a protocol.

[thiagodelgado111]

removing the non existent protocol etcp fixed it, or did you run into some other issue?

Hi @dryajov, thanks for helping! So, removing the non-existent protocol from the config file fixed it!

Nevertheless, It took me a while to figure out the problem was in the config file though, would it be possible to either validate the config object before writing it, ignore the version read from disk if it fails and use the config object or ask users to check the config file when it happens?

[dryajov]

Thanks for clarifying @thiagodelgado111 - I agree ipfs should behave in a more user-friendly way when handling issues like this. Perhaps this is a good place to start a discussion around this? //cc @hacdias @daviddias @richardshneider @victorbjelkholm

[daviddias]

No need for discussion, @thiagodelgado111 is right. The API should empower the developer by providing good error messages and validate inputs. That's how we get good UX.

[alanshaw]

A config error cannot be caught, or listened for and will cause the process to exit.

const IPFS = require('ipfs')

console.log('IPFS node starting')
let node

try {
  node = new IPFS({
    "config": {
      "Addresses": {
        "Swarm": [ "rekt" ]
      }
    }
  })
  console.log('invalid config did not throw')
} catch (err) {
  console.log('invalid config threw error')
  throw err
}

node.once('ready', () => {
  console.log('IPFS node ready...')
})

node.on('error', (err) => {
  console.log('invalid config emitted error', err)
})

process.on('uncaughtException', (err) => {
  console.log('invalid config caused uncaughtException')
  throw err
})

Output:

$ npm ls ipfs && node ipfs-config-bug.js 
/Users/alan/Desktop/test
└── [email protected] 

IPFS node starting
invalid config did not throw
invalid config caused uncaughtException
/Users/alan/Desktop/test/ipfs-config-bug.js:30
  throw err
  ^

Error: no protocol with name: rekt
    at Protocols (/Users/alan/Desktop/test/node_modules/multiaddr/src/protocols-table.js:17:11)
    at stringToStringTuples (/Users/alan/Desktop/test/node_modules/multiaddr/src/codec.js:45:19)
    at stringToBuffer (/Users/alan/Desktop/test/node_modules/multiaddr/src/codec.js:170:13)
    at Object.fromString (/Users/alan/Desktop/test/node_modules/multiaddr/src/codec.js:178:10)
    at new Multiaddr (/Users/alan/Desktop/test/node_modules/multiaddr/src/index.js:39:25)
    at Multiaddr (/Users/alan/Desktop/test/node_modules/multiaddr/src/index.js:27:12)
    at config.Addresses.Swarm.forEach (/Users/alan/Desktop/test/node_modules/ipfs/src/core/components/pre-start.js:27:22)
    at Array.forEach (<anonymous>)
    at waterfall (/Users/alan/Desktop/test/node_modules/ipfs/src/core/components/pre-start.js:26:34)
    at nextTask (/Users/alan/Desktop/test/node_modules/async/waterfall.js:16:14)