Fix Error Parsing YAML Config File with yaml-cpp

mongodbmongodb-3.0

I'm using the following command (Windows machine) with the MongoDB shell version: 3.0.7:

mongod --config "G:\NodeApps\mongod.cfg" --install

Contents of mongod.cfg file are given below:

systemLog:
    destination: file
    path:"G:\NodeApps\data\log"
storage:
    dbPath:"G:\NodeApps\data"

Getting the below error:

Error parsing YAML config file: yaml-cpp: error at line 4, column 8: illegal map value
try 'mongod --help' for more information

Similar questions doesn't have the solutions for this.

What I've already tried:

I'm using spaces (not tabs)
I'tried by saving the file in ASCII format, as It was mentioned in one of the posts that Mongod config file shouldn't be saved in non-ACSII format. Not even in UTF-8.

Please help me with this.

Best Answer

The error messages indicate the specific line and column where the YAML parser is having an issue with your configuration file, but if you're not familiar with the format it can be difficult to work out what is expected.

Two sets of changes are required to make your config valid YAML:

Add a "space" between the systemLog.path and storage.dbPath keys and their values

YAML requires a space between key/value pairs, so reports: "error at line 4, column 8: illegal map value".
Remove the double quotes from your path values

YAML interprets backslashes inside quoted strings as introducing an escape character, so reports: "error at line 3, column 16: unknown escape character". As an alternative, you could also leave the path quoted but either escape the backslashes (\\) or use forward slashes.

The following config should work (assuming "G:\NodeApps\data\" has the correct directory and file permissions):

systemLog:
    destination: file
    path: G:\NodeApps\data\log
storage:
    dbPath: G:\NodeApps\data

There are several online testers for YAML syntax that can be useful to troubleshoot problems (eg: YAML Lint).

Related Solutions

Mongodb – “ERROR: could not read from config file” MongoDB

First, assuming you are actually specifying where to read the file from, make sure that you have permission read that file with the current user (cat /usr/local/Cellar/mongodb/2.4.6/mongod.conf - or use less/vi/editor of choice). Assuming that works (and if it does not, adjust your permissions), then the next thing you need to do is make sure you are actually pointing at the correct file.

However, if you are not specifying where to read the file from, by default, if you just run mongod using the brew installation it will attempt to read from:

/usr/local/etc/mongod.conf

I verified this by installing 2.4.6 with brew and then checking the logs when it starts up:

Tue Oct 22 17:17:30.695 [initandlisten] options: { bind_ip: "127.0.0.1", config: "/usr/local/etc/mongod.conf", dbpath: "/usr/local/var/mongodb", logappend: "true", logpath: "/usr/local/var/log/mongodb/mongo.log" }

You can either modify that file (/usr/local/etc/mongod.conf) to look the way you want in your example, and make sure you have permissions to get to it, or you can run this instead to specify the original file:

mongod -f /usr/local/Cellar/mongodb/2.4.6/mongod.conf

MongoDB – Resolving YAML File Issues on Windows

I was not able to replicate, so here's my successful YAML config file (Windows 7 64 bit, MongoDB 2.6.1):

replication:
    replSetName: "rs1"
    oplogSizeMB: 512
storage:
    dbPath: "data"
    smallFiles: true
systemLog:
    destination: file
    path: "data/mongod.log"

How I started it:

C:\Users\Adam\mongo\2.6.1\bin>mongod.exe -f mongod-yaml.conf
2014-06-03T23:23:12.528+0100 log file "C:\Users\Adam\mongo\2.6.1\bin\data/mongod
.log" exists; moved to "C:\Users\Adam\mongo\2.6.1\bin\data/mongod.log.2014-06-03
T22-23-12".

And then (after an rs.initiate()):

rs1:PRIMARY> db.serverCmdLineOpts()
{
        "argv" : [
                "mongod.exe",
                "-f",
                "mongod-yaml.conf"
        ],
        "parsed" : {
                "config" : "mongod-yaml.conf",
                "replication" : {
                        "oplogSizeMB" : 512,
                        "replSetName" : "rs1"
                },
                "storage" : {
                        "dbPath" : "data",
                        "smallFiles" : true
                },
                "systemLog" : {
                        "destination" : "file",
                        "path" : "data/mongod.log"
                }
        },
        "ok" : 1
}

Note that I had issues when I used tabs to indent, which were resolved when using spaces. Case sensitivity was also a problem, but mainly due to muscle memory from the old config options.

Best Answer

Related Solutions

Mongodb – “ERROR: could not read from config file” MongoDB

MongoDB – Resolving YAML File Issues on Windows

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