etherparty/explorer Issues – How to Allow Access to Geth and Refresh the Page for Private Blockchain

explorersgo-ethereumjson-rpcparityprivate-blockchain

Does anyone here have experience with the etherparty/explorer blockchain explorer? I am having trouble connecting. I keep getting the error message

"Allow Access to Geth and Refresh the Page"

when I access localhost:8000.

I was running geth and had the same error messages, but now I am running parity. Here is how I invoke parity:

parity --chain dev  --dapps-apis-all --jsonrpc-cors "http://localhost:8000" --jsonrpc-apis "web3, eth" --jsonrpc-hosts="all" --networkid="<private-number>" --force-ui --ui-no-validation

Here is how etherparty/explorer says to invoke geth:

geth --rpc --rpccorsdomain "http://localhost:8000"

The RPC port is available at localhost:8545.

EDIT: I have since tested with geth, using the main net. I get the same error. So I am trying other things. Maybe it's how I'm installing (or failing to install) web3?

Best Answer

Not a complete answer, but might help...

Poking around at their code, the error is output when this part is run:

    if(!web3.isConnected()) {
        $('#connectwarning').modal({keyboard:false,backdrop:'static'}) 
        $('#connectwarning').modal('show') 
    }

Which implies there's a failure in the following code:

var eth_node_url = 'http://localhost:8545'; // TODO: remote URL
web3.setProvider(new web3.providers.HttpProvider(eth_node_url));

Related Solutions

[Ethereum] Browser will not connect to running Geth: NS_ERROR_UNKNOWN_PROTOCOL

I fixed it. UI front-end now works, pulling contract data through to the browser.

I was not careful with my port references between geth/cors, http-server, and the one referenced in my UI javascript as Péter Szilágyi sniffed out. I list my working steps below to help others trace similar problems:

First: start geth using: geth --rpc --rpccorsdomain="http://localhost:3000" //presuming the UI will be run on port 3000

Second: Launch the http server on the above referenced port. In my case, used the npm installed module 'http-server': http-server -p 3000 //must match the port referenced in rpccorsdomain above.

Third: Made sure web3 was installed with npm. Linked app.js to index.html and included this code at the top:

 var Web3 = require('web3');

// Initialize connection
 var web3 = new Web3(new Web3.providers.HttpProvider('http://127.0.0.1:8545'));  //may want to test for non-existence first per docs
 var ABI = [...]
 var greeterAddress = "..."
 var greeter = web3.eth.contract(ABI).at(greeterAddress);

[Ethereum] How to connect IPC with Parity

The RPC standard is an unsecured (usually) webserver that communicates via standard HTTP messages (GET/POST/PUT/etc). If unsecured (and maybe parity provides the ability to secure it with certs of some kind), this means anyone who can access the port it's listening on will be able to control all functions exposed by that RPC.

The IPC endpoint, on the other hand, is a named pipe on the filesystem, that is protected through all the normal filesystem permissions means. This means if the user/group lacks permissions to the file handle for the pipe, they won't be able to read/write it. You could even configure the IPC pipe to be read-only for some users, and read/write for others.

Parity allows you to configure the IPC interface via a configuration file at the very least, and likely through command line flags, as well. From the web3 side, you would replace Web3.providers.HttpProvider("http://localhost:8545") with Web3.providers.IpcProvider("/path/to/ipc", net), where net is a reference to the nodejs net lib (e.g. var net = require('net');).

It's also worth pointing out that Parity appears to let you configure the interface that the RPC listens on, which allows you to limit it to just the "local" interface, by default. This puts it closer to the level of security (potentially) offered by the IPC endpoint, by restricting access to only local users. However, it still doesn't offer the per-user/per-group level of control that the IPC interface provides.

Best Answer

Related Solutions

[Ethereum] Browser will not connect to running Geth: NS_ERROR_UNKNOWN_PROTOCOL

[Ethereum] How to connect IPC with Parity

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