Mongorestore in a Dockerfile

Question

I want to create a Docker image that starts a mongo server and automatically restores from a previous mongodump on startup.

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Here is my Dockerfile for the image:

 FROM mongo

 COPY dump /home/dump

 CMD mongorestore /home/dump

When I run this, I run into this error:

Failed: error connecting to db server: no reachable servers

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Is there any way to get the mongorestore command to run through Docker?

Solution 1

With help from this answer, Marc Young's answer, and the Dockerfile reference I was able to get this working.

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Dockerfile

FROM mongo

COPY dump /home/dump
COPY mongo.sh /home/mongo.sh
RUN chmod 777 /home/mongo.sh

CMD /home/mongo.sh

mongo.sh

#!/bin/bash

# Initialize a mongo data folder and logfile
mkdir -p /data/db
touch /var/log/mongodb.log
chmod 777 /var/log/mongodb.log

# Start mongodb with logging
# --logpath    Without this mongod will output all log information to the standard output.
# --logappend  Ensure mongod appends new entries to the end of the logfile. We create it first so that the below tail always finds something
/entrypoint.sh mongod --logpath /var/log/mongodb.log --logappend &

# Wait until mongo logs that it's ready (or timeout after 60s)
COUNTER=0
grep -q 'waiting for connections on port' /var/log/mongodb.log
while [[ $? -ne 0 && $COUNTER -lt 60 ]] ; do
    sleep 2
    let COUNTER+=2
    echo "Waiting for mongo to initialize... ($COUNTER seconds so far)"
    grep -q 'waiting for connections on port' /var/log/mongodb.log
done

# Restore from dump
mongorestore --drop /home/dump

# Keep container running
tail -f /dev/null

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Solution 2

A similar solution to RyanNHG's, but without an sh file.

Dockerfile

FROM mongo:3.6.8

COPY dump/ /tmp/dump/

CMD mongod --fork --logpath /var/log/mongodb.log; \
    mongorestore /tmp/dump/; \
    mongod --shutdown; \
    docker-entrypoint.sh mongod

Solution 3

This is an old question and the solution above could still work but in later versions, you can add .sh and .js scripts in /docker-entrypoint-initdb.d/, which will be executed in case the instance is first loading (/data/db is empty).

Now, Dockerfile could look something like:

FROM mongo

COPY ./data-dump/ /tmp/dump/mydb/

COPY ./import_data.sh /docker-entrypoint-initdb.d/import_data.sh

CMD chmod 777 /docker-entrypoint-initdb.d/import_data.sh #this is probably too permissive

With that, whatever is in import_data.sh will be run (or whatever other file(s) you have there) first time the container is started.

# change the mongorestore command to match your case, adding user/password and other options.
mongorestore /tmp/dump # note we can possibly restore many DBs. 

It is documented here under Initializing a fresh instance section

Solution 4

the problem isn't with docker.

If you look at the dockerfile for mongo it runs CMD ["mongod"] which starts the mongo service.

You said FROM MONGO but you overwrote the CMD line. this means mongo never started via mongod. so try CMD mongod; mongorestore /home/dump

View more solutions

Comments

[RyanNHG]

Thank you for your reply! And you're correct, I took a look at that file earlier tonight and realized that only the last CMD will run. However, with CMD mongod; mongorestore /home/dump, the mongorestore command never runs. I tried mongod & mongorestore /home/dump and got a little bit closer. Still no luck though.

[Eugen Mayer]

mongod & mongorestore /home/dump will not work since mongod is running in the foreground and thus is blocking. Use the answer from ryanHNG

[Augustin Riedinger]

I moved the mongorestore command to the Dockerfile to make the script more reusable: eval $MONGORESTORE_CMD in mongo.sh and RUN MONGORESTORE_CMD='mongorestore --drop /home/dump' in the Dockerfile. I thought it made sense also to call the script /entrypoint-with-mongorestore.sh finally.

[Ashu Joshi]

Does the database have to be restored everytime the image is created? Shouldn't this be a "RUN" instead of a CMD? ["CMD /home/mongo.sh"]

[Laizer]

In trying this approach, I get /entrypoint.sh: No such file or directory. Changing ./entrypoint.sh to docker-entrypoint.sh (note the change from absolute to relative) did the trick.

[Gaurav]

This works like a charm Thanks @hisener. I have been struggling for whole day then found this with little tweaks to this it helped me a lot.

[Rafid Aslam]

I also think the same as @AshuJoshi, wouldn't this restore the database every time the image is run?

[Justin]

Works, but the /data/db files are all deleted after running mongod --shutdown

[Justin]

Was able to get it working within a multi-stage build by copying /data/db to /tmp/db before mongod --shutdown, then within the second stage, copying from the build-stage's /tmp/db to /data/db.