dfence

dFence (for dependencies fence) helps maintaining dependencies under control by enforcing dependencies policies on your packages.

A dependencies policy defines dependencies constraints among the components of your application. dFence will check that constraints are respected.

Installation

go get github.com/chavacava/dfence

Requirements:

• GO >= 1.11 installed

Building from sources

1. clone the repo: git clone https://github.com/chavacava/dfence.git
2. set GO111MODULE=on
3. make build will generate an executable under ./bin

Describing dependencies policies

dFence will enforce dependencies policies described through a JSON file like the following:

{
    "components":{
        "cli":"dfence/cmd",
        "internal":"dfence/internal"
    },
    "constraints":[
        {
            "scope":"internal",
            "kind":"forbid",
            "deps":"cli",
            "onbreak":"error"
        }
    ]
}

In the components section of the document we define logical names for sets of package name patterns. All packages with names containing one of the given patterns will referred with the corresponding logical name.

The constraints section contains the dependency constraints to enforce. scope lists all the components (thus packages patterns) to which the constraint applies.

A constraint can be of one of two kinds: forbid or allows. Meaning that a a dependency will be forbidden (accepted) if it matches with one of the package patterns in deps. The onbreak field can take one of two values, warn or error; it indicates the error level to produce when the constraint is not respected.

The previous example can be read: Rise an error if a package with a path containing dfence/internal depends on a package with a path containing dfence/cmd.

The JSON Schema for the policy file is available here

Usage

Constraint checking is the main functionality of dFence, its usage is the following:

Usage:
  dfence policy enforce [flags]

Flags:
  -h, --help            help for check
      --policy string   path to dependencies policy file

Global Flags:
      --log string   log level: none, error, warn, info, debug (default "info")

dFence will perform the check on packages defined in the current directory and its subdirectories respectively.

Examples:

dfence policy enforce -log debug -policy policy.revive.json

The above command runs dfence tu enforce constraints described in the file policy.revive.json and over all the packages in the current directory and its subdirectories.

Other functionalities

dFence also provides commands for analyzing dependencies and to facilitate the definition of policies. All these functionalities are accessible through commands under the deps command.

dfence deps --help
Executes dependencies-related commands

Usage:
  dfence deps [command] [flags]
  dfence deps [command]

Available Commands:
  find-cycles Spots dependency cycles
  graph       Outputs a graph of dependencies
  list        List dependencies of the given packages
  who         Shows what packages depend on a given package
  why         Explains why a package depends on the other

Flags:
  -h, --help   help for deps

Global Flags:
      --log string   log level: none, error, warn, info, debug (default "info")