composeverter - Docker Compose Format Converter

This NPM package provides a simple and convenient way to convert Docker Compose files from one version to another. Docker Compose files allow you to define and run multi-container Docker applications, but the format has evolved over time. With this package, you can easily migrate your Compose files between different versions. It also provides some functions to check YAML and test if a given Docker volume mapping is a named one. It also provides a function to validate a Docker Compose file against Docker Compose Common Specification.

Installation

You can install this package via NPM:

1npm install composeverter

Usage - Conversion

This package provides four main conversion functions, which you can use to convert Docker Compose files from one format to another. Each function takes the Docker Compose file content as input and returns the content in the target format.

Configuration

Each of the following functions can take an additional configuration object, with the following properties:

1. expandVolumes (optional)

• Type: boolean
• Default: false

Set this parameter to true if you want to enable expansion of short volume syntax to long volume syntax.

2. expandPorts (optional)

• Type: boolean
• Default: false

Set this parameter to true if you want to enable expansion of short ports mapping syntax to long ports mapping syntax.

migrateFromV1ToV2x(composeContent: string, configuration: Configuration = null): string

Converts a Docker Compose file from V1 to version 2.x.

1const converter = require('composeverter');
2
3const v1ComposeContent = `
4web:
5  image: nginx:latest
6`;
7const v2ComposeContent = converter.migrateFromV1ToV2x(v1ComposeContent);
8console.log(v2ComposeContent);

migrateFromV2xToV3x(composeContent: string, configuration: Configuration = null): string

Converts a Docker Compose file from version 2.x to version 3.x.

1const converter = require('composeverter');
2
3const v2ComposeContent = `
4version: '2'
5services:
6  web:
7    image: nginx:latest
8`;
9const v3ComposeContent = converter.migrateFromV2xToV3x(v2ComposeContent);
10console.log(v3ComposeContent);

migrateFromV3xToV2x(composeContent: string, configuration: Configuration = null): string

Converts a Docker Compose file from version 3.x to version 2.x.

1const converter = require('composeverter');
2
3const v3ComposeContent = `
4version: '3'
5services:
6  web:
7    image: nginx:latest
8`;
9const v2ComposeContent = converter.migrateFromV3xToV2x(v3ComposeContent);
10console.log(v2ComposeContent);

migrateToCommonSpec(composeContent: string, configuration: Configuration = null): string

Automatically migrates a Docker Compose file to the latest version available : Common Specification.

1const converter = require('composeverter');
2
3const composeContent = `
4web:
5  image: nginx:latest
6`;
7const latestComposeContent = converter.migrateToCommonSpec(composeContent);
8console.log(latestComposeContent);

With configuration:

1const converter = require('composeverter');
2
3const composeContent = `
4web:
5  image: nginx:latest
6`;
7const latestComposeContent = converter.migrateToCommonSpec(composeContent, {expandPorts: true, expandVolumes: true});
8console.log(latestComposeContent);

Usage - others functions

getVolumeNameFromVolumeSpec(volumeSpec: string): string

Get the volume name from a Docker Compose volume mapping.

Parameters:

• volumeSpec: A string representing the Docker Compose volume mapping (e.g., "/data2:/app/data2:ro").

Returns: The extracted volume name as a string.

isNamedVolume(source: string): boolean

Tell if the given source is a named Docker volume.

Parameters:

• source: A string representing the source of the Docker volume (e.g., "data").

Returns: A boolean indicating whether the source is a named Docker volume.

yamlCheck(yaml: string): any

Check YAML validity and return the parsed object if YAML is valid.

Parameters:

• yaml: A string representing the YAML content to be checked.

**Throws: **

Throws YamlSyntaxError if parsing errors occurred. This class has the following members :

• message: concatenated error messages
• lines: line numbers that have errors
• details: array of messages with the following structure:

1{
2  line: number, 
3  message: string, 
4  pos: {
5    start: { line: number, col: number }, 
6    end: { line: number, col: number }
7  }
8}

Returns: The parsed object if the YAML is valid.

validateDockerComposeToCommonSpec(content: string): any

Check Docker Compose validity against Docker Compose Common Specification and returns validation errors.

Parameters:

• content: A string representing the Docker Compose content to be checked.

Returns:

• array of errors (helpLink is a potential link to Docker Compose documentation):

1{
2  line: number,
3  message: string,
4  helpLink: string
5}
6

getDockerComposeSchemaWithoutFormats(): any

Returns the Docker Compose Common Specification schema (with formats replaced with patterns)

License

This package is distributed under the MIT License. See the LICENSE file for details.

Contributing

• Clone a fork of the repo and install the project dependencies by running npm install
• Make your changes, and build the project by running npm run estlin && npm run build
• Test your changes with npm run test

Issues

If you encounter any problems or have suggestions, please open an issue on our GitHub repository.

Credits

This package was created and is maintained by ShareVB.