VVP
By:
VVP

ERROR: In file './docker-compose.yml', service must be a mapping, not a NoneType

November 21, 2016 141 views
Docker Ubuntu

Hi,
I am trying to use the example provided in the site
https://docs.docker.com/compose/gettingstarted/

Step 3: Define services
Define a set of services using docker-compose.yml:

Create a file called docker-compose.yml in your project directory and add the following:

version: '2'
services:
  web:
    build: .
    ports:
     - "5000:5000"
    volumes:
     - .:/code
    depends_on:
     - redis
  redis:
    image: redis

and when I run the command docker-compose up i got the below error

ERROR: yaml.scanner.ScannerError: while scanning for the next token
found character '\t' that cannot start any token
in "./docker-compose.yml", line 18, column 1
so i removed all spaces and modified it as below

Defines two web services, web and redis

version: '2'
services:
web:
build: .

Build from the dockerfile from current dir

ports:

  • "5000:5000" #Forward the exposed port 5000 on the container to port 5000 on the host machine volumes:
  • .:/code #Mounts the project directory on the host to /code inside the container directory allowing you to modify the code without having to rebuild the image depends_on:
  • redis redis: image: redis #Links the webservice to the redis service

on trying it again i am getting an error now as

docker-compose up
ERROR: In file './docker-compose.yml', service must be a mapping, not a NoneType.

Can I get some help what is wrong here.. I am using MAC.

1 comment
1 Answer

This question was answered by @VVP:

i got the right file

version: '2'
services:
web:
build: .
ports:

  • "5000:5000" volumes:
  • .:/code
  • logvolume01:/var/log links:
  • redis redis: image: redis volumes: logvolume01: {}

This is working .. can refer the following link

https://docs.docker.com/compose/overview/
:)

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