How to escape # in docker file?

Question

I have a docker compose file as follows:

    version: '3'
    services:
    prisma:
        image: prismagraphql/prisma:1.34.10
        restart: always
        ports:
        - '4466:4466'
        environment:
        PRISMA_CONFIG: |
            port: 4466
            databases:
            default:
                connector: mysql
                host: test.mysql.database.azure.com
                database: default@default
                user: rie@dak-prod
                password: ak123#$
                ssl: false
                rawAccess: true
                port: '3306'
                migrations: true

When I try the command docker-compose up -d the command fails with an error :

ERROR: Invalid interpolation format for "environment" option in service "prisma": "port: 4466
databases:
default:
    connector: mysql
    host: est.mysql.database.azure.com
    database: default@default
    user: rie@dak-prod
    password: ak123#$
    ssl: false
    rawAccess: true
    port: '3306'
    migrations: true
"

The reason that I have identified is the # in the password. If # is not there, it does not throw up this error. How can I escape (use) hash the the docker compose file?

score 4 · Answer 1 · answered Aug 18 '20 at 11:36

I think the problem is not with a # but with a $ symbol.

You can use a $$ (double-dollar sign) when your configuration needs a literal dollar sign. This also prevents Compose from interpolating a value, so a $$ allows you to refer to environment variables that you don’t want processed by Compose.

So in your case ak123#$ must be written as ak123#$$

Reference documentation

score 1 · Answer 2 · answered Aug 18 '20 at 11:41

1

Quote your string to include special characters in yaml like the #, and escape the dollar sign using a second dollar sign to prevent docker-compose from expanding it:

password: "ak123#$$"

answered Aug 18 '20 at 11:41

BMitch

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score 0 · Answer 3 · answered Aug 18 '20 at 11:33

0

Best way to use is base64 encode function. convert your password into base64 and try. should work.

Like this

echo "ak123#$" | base64

and whatever the output use as your password and more secure way

answered Aug 18 '20 at 11:33

Dashrath Mundkar

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score 0 · Answer 4 · answered Aug 18 '20 at 12:00

Your docker-compose.yml have two issues:

$ should be escaped with $$ as pointed by @Suhail Gupta's answer and docs:

You can use a $$ (double-dollar sign) when your configuration needs a literal dollar sign

PRISMA_CONFIG indentation under environment: is invalid, as PRISMA_CONFIG should be a subelement of environment

You should use something like:

    environment:
      # proper indentation to have PRISMA_CONFIG part of environment
      PRISMA_CONFIG: |
          port: 4466
          databases:
          default:
              connector: mysql
              host: test.mysql.database.azure.com
              database: default@default
              user: rie@dak-prod
              # double $ to have a literal '$'
              password: ak123#$$
              ssl: false
              rawAccess: true
              port: '3306'
              migrations: true

How to escape # in docker file?

4 Answers4