error while accessing Hyperldger explorer "Cannot GET /" - node.js

Question

I have configured our Fabric network (v1.4) with Explorer (latest version).
node --version v8.16.0
No errors in db log
No application level errors
Explorer syncing process is going on continuously for the network
Able to view the updated data in DB
http://localhost:8080/api-docs/ (Explorer Swagger) works fine.
However while accessing http://localhost:8080/ i am getting
Cannot GET / error.
Chrome inspect logs -
Failed to load resource: the server responded with a status of http://localhost:8080/ 404 (Not Found)
console logs -
[2020-01-28T22:30:53.167] [INFO] PgService - SSL to Postgresql disabled
[2020-01-28T22:30:53.167] [INFO] PgService - connecting to Postgresql postgres://hppoc:******#127.0.0.1:5432/fabricexplorer
[2020-01-28T22:30:54.285] [INFO] Platform - client_configs.name first-network client_configs.profile ./connection-profile/first-network.json
[2020-01-28T22:30:54.285] [INFO] Platform - FabricUtils.createFabricClient
[2020-01-28T22:30:54.286] [INFO] FabricConfig - config.client.tlsEnable true
[2020-01-28T22:30:54.287] [INFO] FabricGateway - peer0.org1.example.com
[2020-01-28T22:30:54.287] [INFO] FabricGateway - /path/fabric-samples/first-network/crypto-config/peerOrganizations/org1.example.com/users/Admin#org1.example.com/msp/signcerts/Admin#org1.example.com-cert.pem
adminPrivateKeyPath /path/fabric-samples/first-network/crypto-config/peerOrganizations/org1.example.com/users/Admin#org1.example.com/msp/keystore/e65fa2dd29a69b2b28f9e439d1a8d555d411e9906e5a20d0a7341207a3a46424_sk
[2020-01-28T22:30:54.287] [INFO] FabricConfig - FabricConfig, this.config.channels mychannel
[2020-01-28T22:30:54.607] [INFO] FabricClient - FabricClient.discover_results endpoint { host: 'orderer.example.com', port: 7050 }
[2020-01-28T22:30:54.638] [INFO] Platform - FabricUtils.createDetachClient
[2020-01-28T22:30:54.640] [INFO] Platform - initializeListener, client_name, client first-network { name: 'first-network',
profile: './connection-profile/first-network.json' }
[2020-01-28T22:30:54.646] [INFO] main - Please open web browser to access ：http://localhost:8080/
[2020-01-28T22:30:54.646] [INFO] main - pid is 18213
[2020-01-28T22:30:54.782] [INFO] PgService - SSL to Postgresql disabled
[2020-01-28T22:30:54.782] [INFO] PgService - connecting to Postgresql postgres://hppoc:******#127.0.0.1:5432/fabricexplorer
[2020-01-28T22:30:55.397] [INFO] SyncPlatform - Updating the client network and other details to DB
[2020-01-28T22:30:55.404] [INFO] SyncServices - SyncServices.synchNetworkConfigToDB client first-network channel_name mychannel
[2020-01-28T22:30:55.427] [INFO] FabricClient - FabricClient.discover_results endpoint { host: 'orderer.example.com', port: 7050 }
[2020-01-28T22:30:55.528] [INFO] SyncPlatform - Sync process is started for the network : [first-network] and client : [first-network]
[2020-01-28T22:30:55.530] [INFO] FabricConfig - config.client.tlsEnable true
[2020-01-28T22:30:55.530] [INFO] FabricGateway - peer0.org1.example.com
[2020-01-28T22:30:55.530] [INFO] FabricGateway - /path/fabric-samples/first-network/crypto-config/peerOrganizations/org1.example.com/users/Admin#org1.example.com/msp/signcerts/Admin#org1.example.com-cert.pem
adminPrivateKeyPath /path/fabric-samples/first-network/crypto-config/peerOrganizations/org1.example.com/users/Admin#org1.example.com/msp/keystore/e65fa2dd29a69b2b28f9e439d1a8d555d411e9906e5a20d0a7341207a3a46424_sk
[2020-01-28T22:30:55.530] [INFO] FabricConfig - FabricConfig, this.config.channels mychannel
[2020-01-28T22:30:55.798] [INFO] FabricClient - FabricClient.discover_results endpoint { host: 'orderer.example.com', port: 7050 }
[2020-01-28T22:30:55.833] [INFO] SyncServices - SyncServices.synchNetworkConfigToDB client first-network channel_name mychannel
[2020-01-28T22:30:55.865] [INFO] FabricClient - FabricClient.discover_results endpoint { host: 'orderer.example.com', port: 7050 }
[2020-01-28T22:30:55.883] [INFO] Sync - Synchronizer pid is 18220
[2020-01-28T22:30:55.901] [INFO] SyncServices - block_row.blocknum 4
[2020-01-28T22:30:58.200] [INFO] SyncPlatform - Updating the client network and other details to DB
[2020-01-28T22:30:58.209] [INFO] SyncServices - SyncServices.synchNetworkConfigToDB client first-network channel_name mychannel
[2020-01-28T22:30:58.241] [INFO] FabricClient - FabricClient.discover_results endpoint { host: 'orderer.example.com', port: 7050 }

Answer 1

So, I found the answer to the problem -
Weirdly the problem was it shows everywhere that it serves on localhost:8080 but after a lot of research found out that node js cannot serve static pages which hyperledger explorer is on port 8080.
So, needs to use "serve" to build and serve that page. I had did that 2 days back, it starts on port 5000 and it`s own IP address, but I was getting error on web browser for violation of "control security policy".
Solution :
$ cd ~/Hyperledger/blockchain-explorer/client
$ npm install
$ npm test -- -u --coverage
$ npm run build
$ npm install -g serve
$ serve -s build
Now it will show you the output something like :
┌────────────────────────────────────────────────────┐
│ │
│ Serving! │
│ │
│ - Local: http://localhost:5000 │
│ - On Your Network: http://160.33.244.178:5000 │
│ │
│ Copied local address to clipboard! │
│ │
└────────────────────────────────────────────────────┘
If you open up : http://localhost:5000 it will not show anything and in the network logs on inspect window will show you - "control security policy violation".
so use port 8080 instead like this :
- Local: http://localhost:8080 │
- On Your Network: http://160.33.244.178:8080
Also, you would need to start the hyperldger explorer server :
$ cd ~/<YourPath>/blockchain-explorer
$ ./start.sh
You will see login page with first network selected.
Use :
"adminUser" is the the admin user of the network, in this case it's fabric CA or an identity user.
"adminPassword" is the password for the admin user.
and you are in !

Answer 2

If you start explorer using docker compose, that is in root of repo, then check your 8090 port, cause docker map 8080 port of container to 8090 port of your machine.
See github:hyperledger/blockain-explorer/docker-compose.yaml