Known hosts error

[lifwanian]

I keep getting a knownHosts error on boot. Is this just a warning that the directory doesnt exists and that its being created? Is this a folder we can create ourselves? Or am I missing something?

Driver:

var neo4j = require('neo4j-driver').v1;
var driver = neo4j.driver(_URI_, neo4j.auth.basic(_USER_, _PASS_), {
    trust: 'TRUST_ON_FIRST_USE',
    encrypted: true
});
var session = driver.session();

Error:

[Error: ENOENT: no such file or directory, open '/app/.neo4j/known_hosts']
errno: -2,
code: 'ENOENT',
syscall: 'open',
path: '/app/.neo4j/known_hosts'

Running:

node: 4.4.5
npm: 2.15.5
neo4j: 3.0.2
neo4j-driver: 1.0.2

[bkapicka]

I can't comment on what introduced the error or if we are expected to create the folder/file by design, but I found that creating a blank known_hosts at the path in the error ('/app/.neo4j/known_hosts' in your case) resolved the error.

A similar issue was outlined here: http://www.markhneedham.com/blog/2016/07/11/neo4j-3-0-drivers-failed-to-save-the-server-id-and-the-certificate-received-from-the-server/

[lifwanian]

Hmm, interesting... Just tried it and everything seemed to be fine for a few calls, then all of a sudden things started blowing up. Tried both root folder and /.neo4j like in example:

/app/node_modules/neo4j-driver/lib/v1/internal/ch-node.js:214
      for (var i = 0; i < pending.length; i++) {
                                 ^

TypeError: Cannot read property 'length' of null
    at /app/node_modules/neo4j-driver/lib/v1/internal/ch-node.js:214:34
    at /app/node_modules/neo4j-driver/lib/v1/internal/ch-node.js:141:11
    at Interface.<anonymous> (/app/node_modules/neo4j-driver/lib/v1/internal/ch-node.js:76:7)
    at emitOne (events.js:77:13)
    at Interface.emit (events.js:169:7)
    at Interface._onLine (readline.js:211:10)
    at Interface.<anonymous> (readline.js:341:12)
    at Array.forEach (native)
    at Interface._normalWrite (readline.js:340:11)
    at ReadStream.ondata (readline.js:87:10)
    at emitOne (events.js:77:13)
    at ReadStream.emit (events.js:169:7)
    at readableAddChunk (_stream_readable.js:153:18)
    at ReadStream.Readable.push (_stream_readable.js:111:10)
    at onread (fs.js:1739:12)
    at FSReqWrap.wrapper [as oncomplete] (fs.js:576:17)

[jgkim]

I have the same issue with @lifwanian. Any workaround?

[legraphista]

Same issue here.

I solved it by creating the folder {...}/.neo4j/ and letting the driver create it's own known_hosts file instead of me creating a blank file.

Hope it helps.

[jgkim]

@legraphista, does making the driver known_hosts instead of me creating a blank file make a difference?

[legraphista]

@jgkim if you create a blank file, the driver will try to parse it, then something bad happens and it will error out.
If the driver doesn't see the file, it will create a new one and not do the parsing. You just have to make sure the known_hosts can be created and the folder is there.

[jgkim]

@legraphista Thank you for the info! 👍

[legraphista]

I'm glad to be of help

[oskarhane]

This should now be fixed with this commit c09ab5b

[dan-kez]

I've recently started receiving this error again when using my app within a docker container. I've put my docker-compose.yaml file below.

I was able to fix this temporarily by running the following. It looks like the docker user can't create this directory and that's the issue.

 docker exec -it testapi_app_1 mkdir /root/.neo4j

version: '2'

services:
  neo4j:
    image: neo4j/neo4j-experimental:3.1.0-M13-beta3
    environment:
      NEO4J_AUTH: none
    ports:
      - "17474:7473"
    volumes:
      - ./db/plugins:/plugins
      # If you want data to persist between sessions uncomment the following line
#      - ./db/data:/data

  app:
    image: node:6.9
    volumes:          ## adds app folder to the container
     - .:/app
    links:            ## connects neo4j to app container
     - neo4j
    ports:            ## publish ports
     - "3000:3000"
    working_dir: /app         ## uses work dir /app
    entrypoint: npm run dev  ## starts application

EDIT: Specific Error Text:

app_1    | { Error: ENOENT: no such file or directory, open '/root/.neo4j/known_hosts'
app_1    |     at Error (native)
app_1    |   errno: -2,
app_1    |   code: 'ENOENT',
app_1    |   syscall: 'open',
app_1    |   path: '/root/.neo4j/known_hosts' }