I am trying to run two commands in the docker cmd
following the instruction here this is my docker file
FROM mongo:5.0.14
CMD mongod;touch /tmp/testfile
Actually, I am trying to override the CMD in here
The reason I am trying to do this experiment is that I want to seed my mongodb without having another helper container as explained here
I want to run the mongoimport in the docker run stage
however, what I explained above is not working. what is the problem?
Related
As other answers have noted, I'm trying to run multiple commands in docker-compose, but my container exits without any errors being logged. I've tried numerous variations of this in my docker-compose file:
command: echo "the_string_for_the_file" > ./datahub-frontend/conf/user.props && datahub-frontend/bin/datahub-frontend
The Dockerfile command is:
CMD ["datahub-frontend/bin/datahub-frontend"]
My Real Goal
Before the application starts, I need to create a file named user.props in a location ./datahub-frontend/conf/ and add some text to that file.
Annoying Constraints
I cannot edit the Dockerfile
I cannot use a volume + some init file to do my bidding
Why? DataHub is an open source project for documenting data. I'm trying to create a very easy way for non-developers to get an instance of DataHub hosted in the cloud. The hosting we're using (AWS Elastic Beanstalk) is cool in that it will accept a docker-compose file to create a web application, but it cannot take other files (e.g. an init script). Even if it could, I want to make it really simple for folks to spin up the container: just a single docker-compose file.
Reference:
The container image is located here:
https://registry.hub.docker.com/layers/datahub-frontend-react/linkedin/datahub-frontend-react/465e2c6/images/sha256-e043edfab9526b6e7c73628fb240ca13b170fabc85ad62d9d29d800400ba9fa5?context=explore
Thanks!
You can use bash -c if your docker image has bash
Something like this should work:
command: bash -c "echo \"the_string_for_the_file\" > ./datahub-frontend/conf/user.props && datahub-frontend/bin/datahub-frontend"
mongo docker image can be started using some command like this:
docker run --name some-mongo -d mongo --auth
This works fine, but now my cloud service provider is using docker-compose, and I don't have access to docker run, all I can do is to modify that .yml file that used with docker-compose.
So my question is how can I pass that --auth command line arg to docker-compose using that .yml config file? Or do I understand this in a totally wrong way? Anyway I just want to start my mongo image with auth enabled.
This was answered earlier here(how to add --auth for mongodb image when using docker-compose?). auth here is an option to mongo container. In docker compose, we can specify the same in "command" parameter.
I'm new to docker and mongoDB, so I expect I'm missing some steps. Here's what I have in my Dockerfile so far:
FROM python:2.7
RUN apt-get update \
&& apt-get install -y mongodb \
&& rm -rf /var/lib/apt/lists/*
RUN mkdir -p /data/db
RUN service mongodb start
RUN mongod --fork --logpath /var/log/mongodb.log
RUN mongo db --eval 'db.createUser({user:"dbuser",pwd:"dbpass",roles:["readWrite","dbAdmin"]})'
The connection fails on the last command:
Error: couldn't connect to server 127.0.0.1:27017 at src/mongo/shell/mongo.js:145
exception: connect failed`.
How can I connect successfully? Should I change the host/IP, and to what, in which commands?
Several things going wrong here. First are the commands you're running:
RUN service mongodb start
RUN mongod --fork --logpath /var/log/mongodb.log
Each of these will run to create a layer in docker. And once the command being run returns, the temporary container that was started is stopped and any files changed in the container are captured to make a new layer. There are no persistent processes that last between these commands.
These commands are also running the background version of the startup commands. In docker, you'll find this to be problematic since when you use this as your container's command, you'll find the container dies as soon as the command finishes. Pid 1 on the container has the same role of pid 1 on a linux OS, once it dies, so does everything else.
The second issue I'm seeing is mixing data with your container in the form of initializing the database with the last RUN command. This fails since there's no database running (see above). I'd recommend instead to make an entrypoint that configures the database if one does not already exist, and then use a volume in your docker-compose.yml or on your docker run commandline to persist data between containers.
If you absolutely must initialize the data as part of your image, then you can try merging the various commands into a single run:
RUN mongod --fork --logpath /var/log/mongodb.log \
&& mongo db --eval 'db.createUser({user:"dbuser",pwd:"dbpass",roles:["readWrite","dbAdmin"]})'
I think you misunderstood what Dockerfiles are used for.
As Dockerfile reference points out, a
Dockerfile is a text document that contains all the commands a user could call on the command line to assemble an image.
The whole concept of an image is to derive running container from it which are then filled with data and queried (in case of a database) or are beeing called by an external container / host (in case of an web service) or many other possible usages.
To answer your question I'll assume that:
You want to use a mongo database to store data.
You have some pyhton code which needs to have access to mongo.
You want some initial data in your database.
To do so:
Run a mongo database
docker run --name my-mongo -d mongo
Note: There is no need to write a custom image. Use the official mongo image!
Create a python image which contains your script
a) Write your Dockerfile
FROM python:3-alpine
ADD my_script.py /
RUN pip install any-dependency-you-might-need
CMD [ "python", "./my_script.py" ]
b) Write your my_script.py
Insert your application stuff here. It will be executed in the python container. And as mongo will be linked, you can use s.th. like client = MongoClient('mongodb://mongo:27017/') to get started.
Run your python container with a link to mongo
a) Build it:
docker build -t my-pyhthon-magic .
b) Run it:
docker run -d --name python-magic-container --link my-mongo:mongo my-python-magic
Note: The --link here links a running container named my-mongo to be reached internally in my-python-magic-container as mongo. That`s why you can use it in your python script.
I hope this helped you - don't hesitate to ask or modify your question if I misunderstood you.
I need to do a dataimport from a PostgreSQL container running inside docker to a Solr server also running inside of Docker.
In my docker run command I specify the --link option which creates the environment variable $POSTGRESQL_PORT_5432_TCP_ADDR inside the solr docker container, and I need to pass this into Solr to use in my solrconfig.xml file.
I've heard that this is possible by passing JVM environment variables to the Solr startup command, but docker run starts Solr automatically. The only workaround I've found is doing something like:
docker run --name solr -d -p 8983:8983 --link postgresql --volumes-from solr_cores makuk66/docker-solr /bin/true
Starting the container with bin/true so it does nothing, and then
docker exec -it solr /bin/bash
to get into the container, finally running the solr startup command myself with the flag
-Dsolr.database.ip=$POSTGRESQL_PORT_5432_TCP_ADDR
However this is an involved manual process, and I'm wondering if there's a better way.
Looking on the page Taking Solr to Production you see
The bin/solr script simply passes options starting with -D on to the JVM during startup. For running in production, we recommend setting these properties in the SOLR_OPTS variable defined in the include file. Keeping with our soft-commit example, in /var/solr/solr.in.sh, you would do:
SOLR_OPTS="$SOLR_OPTS -Dsolr.autoSoftCommit.maxTime=10000"
So all you need to do is edit the SOLR_OPTS environment variable in solr.bin.sh.
It's a bit different for Docker because you don't directly have access to solr.bin.sh, but it after some trial and error, it was as easy as adding this to my Dockerfile.
RUN echo 'SOLR_OPTS="$SOLR_OPTS -Dsolr.database.ip=$POSTGRESQL_PORT_5432_TCP_ADDR"' >> /opt/solr/bin/solr.in.sh
Then you can use it in the solrconfig.xml file as
${solr.database.ip}
An important thing to note is that you can call the JVM environment variable whatever you want as long as you make sure not to overwrite anything important. I could have called it
-Dsolr.potato
if I wanted to.
For some reason the solr.in.cmd file looks exactly the same as solr.in.sh which confused me on how to set variables there. In windows containers, the command to accomplish the same - from a dockerfile, would be:
RUN Add-Content C:\solr\bin\solr.in.cmd 'set SOLR_OPTS=%SOLR_OPTS% -Dsolr.database.ip=%POSTGRESQL_PORT_5432_TCP_ADDR%'
I'm running docker container in OSX using boot2docker. It is a latest Ubuntu image with mongo installed using official way from package mongodb-org.
I can perfectly run mongod from command line, but can't run it as a service.
When I'm trying to do sudo service mongod start it returns
Rather than invoking init scripts through /etc/init.d, use the service(8)
utility, e.g. service mongod start
Since the script you are attempting to invoke has been converted to an
Upstart job, you may also use the start(8) utility, e.g. start mongod
I have tried to do start mongod which doesn't have any output. I have tried everything I found in Google, but no luck.
Meanwhile, I have tried to install MySQL using apt-get and I can perfectly run it as a service.
Also I have tried to install Mongo from Ubuntu's mongodb package which is a older version. Also no problem to run it as a service.
I suspect that there is something wrong with /etc/init.d/mongod script, but don't know exactly what.
Apprieciate any help.
The init-related commands on the Docker Ubuntu image are dummied out / not working because Upstart (/sbin/init) is not the first process started on the machine.
In general, any service which initializes using Upstart will not run properly in a Docker container unless you start the container with /sbin/init (you probably have to be using the ubuntu-upstart image, and make a bunch of tweaks to it too.)
If you really needed to do it this way, write a traditional init script for mongo and insert it using update-rc.d. Then, starting it with /sbin/service should work.
Why not just have the Dockerimage run mongod instead of init/shell/etc? "One process per container", right?
Use a Dockerfile to create your image, and set the CMD to:
CMD ["/usr/bin/mongod", "-f", "/etc/mongod.conf"]