Running Docker as Non-Root User

When running Neo4j Docker, it will run as neo4j user inside the container. But to run docker as a different user one can specify the --user argument. Documentation has a section for running as non-root user:

but would like to elaborate on the same in this KB article.

When using the --user flag needs to have a valid, non-root user value provided. Our Docker container assumes/requires that the user is a) not root b) has write access to data and logs directories and has read access to conf directory. It is important to note that if you are passing 0:0 or 0 or root etc. as –user, it will still not use root to run neo4j but the container will use its own internal neo4j user and neo4j user group (these happen to currently have uid 101 and gid 101 but that should not be relied upon). The Docker entrypoint is specifically written to avoid running the neo4j docker image as root.

So best approach here is to create a User and group and pass that on to the Docker input –user.

create a user neo4j without a home directory

sudo useradd -M neo4j

prevent neo4j from logging in

sudo usermod -L neo4j

Create data dir.

data_dir="/neo4j/data"
sudo mkdir -p /neo4j/data
sudo chown -R neo4j /neo4j/data
sudo chgrp -R neo4j /neo4j/data

Note we only give group read permissions here

sudo chmod -R u+rwX,g+rX,o-wrx /neo4j/data

We do not recommend any application other than neo4j writing to the data dir. This can corrupt the data store.

sudo mkdir -p /neo4j/conf
sudo chown -R neo4j /neo4j/conf
sudo chgrp -R neo4j /neo4j/conf

Group gets write permissions here

sudo chmod -R u+rX,g+rwX,o-wrx /neo4j/conf

N.b. if you make external changes to the conf dir you must restart the docker image to pickup new configuration (conf is copied from the mounted volume on startup)

sudo mkdir -p /neo4j/plugins
sudo chown -R neo4j /neo4j/plugins
sudo chgrp -R neo4j /neo4j/plugins

Group gets write permissions here

sudo chmod -R u+rwX,g+rwX,o-wrx /neo4j/plugins # N.b. if you make external changes to the plugins dir you must restart neo4j before it will pickup new plugins

Let’s assume that the logs dir is being used by multiple applications n.b. if something interferes with neo4j writing logs it can crash the neo4j process. Create a logs group for all things log related

sudo groupadd logs

Add neo4j to logs group

sudo usermod -a -G logs neo4j
sudo mkdir -p /logs/neo4j
sudo chown -R root /logs/neo4j
sudo chgrp -R logs /logs/neo4j
sudo chmod -R u+rwX,g+rwX,o-wrx /logs/neo4j

If docker does not run as root

docker_user=root
sudo usermod -a -G logs "${docker_user}"
sudo usermod -a -G neo4j "${docker_user}"

Add ourselves to the neo4j group so /neo4j/* dirs created above can be read and editted.

current_user=$(id -un)
sudo usermod -a -G neo4j "${current_user}"

Start a new shell to pick up this group assignment

Note docker doesnt pull in secondary groups automatically so one has to do this explicitly

groups=( $( id --real --groups neo4j ) )
docker run \
    --publish=7474:7474 --publish=7687:7687 \
    --volume=/neo4j/data:/data \
    --volume=/neo4j/plugins:/plugins \
    --volume=/neo4j/conf:/conf \
    --volume=/logs/neo4j:/logs \
    --user="$(id -u neo4j):$(id -g neo4j)" \
    --group-add=$groups \
    neo4j:3.4

  • Last Modified: 2020-09-15 13:07:09 UTC by Rohan Kharwar.
  • Relevant for Neo4j Versions: 3.2,3.3,3.4,3.5,4.0.
  • Relevant keywords startup, permissions, docker.