Control by disableUnsafeDebugFlag

[kjeom]

Proposed changes

• This is a follow-up PR to debug namespace enhancement #1672
• This PR introduces the rpc.unsafe-debug.disable flag
• If you set the rpc.unsafe-debug.disable flag,
  • can use only a subset of debug APIs. Refer to Further Comments for the full list
  • cannot use the javascript-based tracing for VM tracing APIs, but only pre-defined tracers are allowed (e.g., revertTracer)
• How to set the flag
  • add ADDITIONAL="--rpc.unsafe-debug.disable" in kxxd.conf file

Types of changes

Please put an x in the boxes related to your change.

• Bugfix
• New feature or enhancement
• Others

Checklist

Put an x in the boxes that apply. You can also fill these out after creating the PR. If you're unsure about any of them, don't hesitate to ask. We're here to help! This is simply a reminder of what we are going to look for before merging your code.

• I have read the CONTRIBUTING GUIDELINES doc
• I have signed the CLA
• Lint and unit tests pass locally with my changes ($ make test)
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)
• Any dependent changes have been merged and published in downstream modules

Further comments

Why this new flag rpc.unsafe-debug.disable is introduced and why some debug APIs are disabled by that flag?

• The debug APIs are for private use in nature, however some public ENs provide debug namespace over RPC for user convenience
• Some debug APIs are vulnerable. Some debug APIs are too heavy/costly. Some debug APIs are meaningless to be provided over RPC.
• Nevertheless, we don't want to discourage public ENs to provide some useful & relatively safe debug APIs (e.g., debug_traceTransaction)

Full list of APIs affected

• debug APIs that are disabled when rpc.unsafe-debug.disable flag was set

  • debug_printBlock
  • debug_setHead
  • debug_startWarmUp, debug_startContractWarmUp, debug_stopWarmUp
  • debug_startCollectingTrieStats
  • debug_chaindbProperty, debug_chaindbCompact
  • debug_verbosity, debug_verbosityByName, debug_verbosityByID
  • debug_vmodule, debug_backtraceAt, debug_stacks, debug_freeOSMemory, debug_setGCPercent, debug_memStats, debug_gcStats, debug_startPProf, debug_stopPProf, debug_isPProfRunning, debug_cpuProfile, debug_startCPUProfile, debug_stopCPUProfile
  • debug_goTrace, debug_startGoTrace, debug_stopGoTrace
  • debug_blockProfile, debug_setBlockProfileRate, debug_writeBlockProfile, debug_mutexProfile, debug_setMutexProfileRate, debug_writeMutexProfile, debug_writeMemProfile
  • debug_standardTraceBadBlockToFile, debug_standardTraceBlockToFile
  • debug_preimage
  • debug_storageRangeAt
  • debug_setVMLogTarget

• debug APIs that are NOT disabled even if rpc.unsafe-debug.disable flag was set

  • VM tracing APIs, however with limited functionality (only pre-defined tracers are allowed)
    • debug_traceBadBlock, debug_traceBlock, debug_traceBlockByHash, debug_traceBlockByNumber, debug_traceBlockByNumberRange, debug_traceBlockFromFile, debug_traceTransaction, debug_traceChain
  • debug_dumpBlock, debug_dumpStateTrie, debug_getBlockRlp, debug_getModifiedAccountsByHash, debug_getModifiedAccountsByNumber, debug_getBadBlocks, debug_getModifiedStorageNodesByNumber
  • debug_metrics

[kjeom]

@2dvorak I think we need to test #1676 (comment) again.

[blukat29]

Please fix cmd/utils/nodecmd/consolecmd_test.go:ipcAPIs as well.
To check the fix, you'll have to manually run test (because nodecmd is ignored in make test-others).

env GOPATH=$(go env GOPATH) GO111MODULE=on go run build/ci.go test -p 1 ./cmd/utils/nodecmd/

[2dvorak]

Although the --rpc.unsafe-debug.disable flag was set and unsafe-debug APIs are blocked, the node console still shows all debug API list. Can we fix that too?

> debug
{
  backtraceAt: function(),
  blockProfile: function(),
  chaindbCompact: function(),

... more list ...

  writeMemProfile: function(),
  writeMutexProfile: function()
}
> debug.backtraceAt("")
Error: the method debug_backtraceAt does not exist/is not available
    at web3.js:3278:20
    at web3.js:6810:15
    at web3.js:5221:36
    at <anonymous>:1:1

[aidan-kwon]

LGTM except for minors