mjhjmtu

Over my ubuntu GNU/Linux machine I try to build the images from my project

docker-compose build --no-cache --force-rm

And I get the following error:

ERROR: Couldn't connect to Docker daemon at http+docker://localunixsocket - is it running?

If it's at a non-standard location, specify the URL with the DOCKER_HOST environment variable.

But when I try wiuth sudo I can build them:

sudo docker-compose build --no-cache --force-rm

But I find it somewhat mysterious because I can launch them without the need of sudo:

docker-compose up

Can you help me to unsolve the mystery?

The cause of the problem is that you have a volume mount point with root:root owner & group and caused this behavior.

The solution to this problem is to create a file named .dockerignore and put all the folders mounted as volumes.

For example if you have the following docker-compose.yml

version: '2'
services:
 data_map_prod:
 build:
 context: .
 dockerfile: Dockerfile
 image: 'pcmagas/data-map:latest'
 links:
 - 'neo4j'
 - 'mongodb'
 volumes:
 - './docker-volumes/app_dev:/var/log/datamap'
 ports:
 - "9780:9780"
 environment:
 NEO4J_HOST: 'neo4j'
 MONGO_CONNECTION_STRING: 'mongodb://mongodb:map'

 data_map_dev:
 build:
 context: .
 dockerfile: Dockerfile_dev
 image: 'pcmagas/data-map:dev'
 links:
 - 'neo4j_dev'
 - 'mongodb'
 volumes:
 - './src:/opt/map/src'
 - './www:/opt/map/www'
 - './package.json:/opt/map/package.json'
 - './docker-volumes/app_dev:/var/log/datamap'
 ports:
 - "9781:9780"
 environment:
 NEO4J_HOST: 'neo4j_dev'
 NEO4J_USER: 'neo4j'
 NEO4J_PASSWORD: 'neo4j'
 MONGO_CONNECTION_STRING: 'mongodb://mongodb:map_dev'

 neo4j_dev:
 image: 'neo4j'
 ports:
 - '7474:7474'
 volumes:
 - './docker-volumes/neo4j_dev/data:/data'
 environment:
 NEO4J_AUTH: 'neo4j/neo45j'

 neo4j:
 image: 'neo4j'
 volumes:
 - './docker-volumes/neo4j/data:/data'
 environment:
 NEO4J_AUTH: 'neo4j/neo45j'

 mongodb:
 image: 'mongo'
 ports:
 - '27017:27017'
 volumes:
 - './docker-volumes/mongodb/:/data/db'

Then you should create the following .dockerignore:

./docker-volumes

As you can see all the volumes are in ./docker-volumes folder.

Furtermore you can find solutions in: https://stackoverflow.com/questions/29101043/cant-connect-to-docker-from-docker-compose#29111083