shell script - check mongod server is running

Question

I have a shell script to do some mongo db actions:

e.g. mongo testdb --eval "db.dropDatabase()"

BUT, if the mongod server is not running, I get:

MongoDB shell version: 2.0.4
connecting to: testdb
Tue May 14 04:33:58 Error: couldn't connect to server 127.0.0.1 shell/mongo.js:84

Is there a way in mongo I can check the connection status? Eventually I want something like:

if(mongod is running):
    mongo testdb --eval "db.dropDatabase()"
else:
    echo "pls make sure your mongod is running"
    exit 1

Answer 1

You should be able to create a bash script like this:

mongo --eval "db.stats()"  # do a simple harmless command of some sort

RESULT=$?   # returns 0 if mongo eval succeeds

if [ $RESULT -ne 0 ]; then
    echo "mongodb not running"
    exit 1
else
    echo "mongodb running!"
fi

Answer 2

try running this in your shell script:-

pgrep mongod

If the value is numeric you know that the process is running, if you get an empty value, flag it as service not running...