CODEWITHSUNDEEP
mongodbhttptcp
Luís Brito
Luís Brito

Reputation: 1772

Simple HTTP/TCP health check for MongoDB

I need to create a Health Check for a MongoDB instance inside a Docker container.

Although I can make a workaround and use the Mongo Ping using the CLI, the best option is to create a simple HTTP or TCP testing. There is no response in the default 27017 port in standard ping testings.

Is there any trustworthy way to do it?

Upvotes: 36

Views: 64101

Answers (5)

JulBeg
JulBeg

Reputation: 271

For MongoDB > 6.0 the health check test could simply be:

mongosh --eval 'db.runCommand("ping")'
{ ok: 1 }

mongosh --eval 'db.runCommand("ping")' --quiet
{ ok: 1 }

mongosh --eval 'db.runCommand("ping").ok'
1

mongosh --eval 'db.runCommand("ping").ok' --quiet
1

Upvotes: 3

Wernfried Domscheit
Wernfried Domscheit

Reputation: 59563

If you need only a simple "ping" then you can also use curl:

curl --connect-timeout 10 --silent --show-error hostname:27017

If you get the "error" It looks like you are trying to access MongoDB over HTTP on the native driver port. then your MongoDB is running and replies.

Or use one of these

mongosh --norc --quiet --host=hostname:27017 <<< "db.getMongo()"
mongosh --norc --quiet --host=hostname:27017 --eval "db.getMongo()" 
echo "db.getMongo()" | mongosh --norc --quiet --host=hostname:27017

One benefit against db.stats(): Command db.getMongo() works without authentication, i.e. you don't need any credentials.

Just a note, if you run your MongoDB with SSL/TLS enabled and set net.tls.mode: requireTLS then you must also provide according certificates, otherwise you cannot run db.getMongo(), db.runCommand("ping") or db.stats(). The curl command is most generic and works in any case.

Upvotes: 22

Felipe Berretella
Felipe Berretella

Reputation: 69

telnet mongodb_server_name 28017

If the connection is successful, you will receive the following similar output from the command.

Trying 9.30.252.5...
Connected to 9.30.252.5.
Escape character is '^]'.

If the connection is failed, you will receive the following similar output from the terminal.

Trying 9.30.252.5...
telnet: connect to address 9.30.252.5: Connection refused
telnet: Unable to connect to remote host

Font

Upvotes: 0

Shawyeok
Shawyeok

Reputation: 1238

I've created a simple health check for mongodb, it uses the mongo client to send a simple query request (eg. db.stats()) to the server.

$ mongo 192.168.5.51:30000/test

MongoDB shell version: 3.2.3
connecting to: 192.168.5.51:30000/test

mongos> db.stats()
{
    "raw" : {
        "set1/192.168.5.52:27000,192.168.5.53:27000" : {
            "db" : "test",
            "collections" : 8,
            "objects" : 50,
            "avgObjSize" : 73.12,
            "dataSize" : 3656,
            "storageSize" : 53248,
            "numExtents" : 8,
            "indexes" : 8,
            "indexSize" : 65408,
            "fileSize" : 469762048,
            "nsSizeMB" : 16,
            "dataFileVersion" : {
                "major" : 4,
                "minor" : 6
            },
            "extentFreeList" : {
                "num" : 28,
                "totalSize" : 184807424
            },
            "ok" : 1
        }
    },
    "objects" : 50,
    "avgObjSize" : 73,
    "dataSize" : 3656,
    "storageSize" : 53248,
    "numExtents" : 8,
    "indexes" : 8,
    "indexSize" : 65408,
    "fileSize" : 469762048,
    "extentFreeList" : {
        "num" : 28,
        "totalSize" : 184807424
    },
    "ok" : 1
}

You can also do this in one line:

$ echo 'db.stats().ok' | mongo 192.168.5.51:30000/test --quiet
1

Hope it's help.

UPDATE:

As @luckydonald said, the ping command is better, so you can do it like:

$ mongo --eval 'db.runCommand("ping").ok' localhost:27017/test --quiet
1

Thanks for @luckydonald.

Upvotes: 40

Lucas Cimon
Lucas Cimon

Reputation: 2053

One solution is to use a minimal MongoDB client written in a script language for which there is an interpreter in your container.

For example, here is a zero-dependency one in Python: mongo_ping_client.py

Upvotes: 7

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