hex_core

Reference implementation of Hex specifications: https://github.com/hexpm/specifications.

Usage

Let's use default config for now. See "Configuration" section below for customization.

Config = hex_core:default_config().

Repository

Get all package names:

> hex_repo:get_names(Config).
{ok, {200, ...,
    #{packages => [
        #{name => <<"package1">>},
        #{name => <<"package2">>},
        ...
    ]}}}

Get all package versions from repository:

> hex_repo:get_versions(Config).
{ok, {200, ...,
    [
        #{name => <<"package1">>, retired => [], versions => [<<"1.0.0">>]},
        #{name => <<"package2">>, retired => [], versions => [<<"0.5.0">>]},
    ]}}

Get package releases from repository:

> hex_repo:get_package(Config, <<"package1">>).
{ok, {200, ...,
    [
        #{checksum => ..., version => <<"0.5.0">>, dependencies => []}],
        #{checksum => ..., version => <<"1.0.0">>, dependencies => []}],
    ]}}

API

For a full list of all parameters and returned objects for the API, check out the API docs: https://github.com/hexpm/specifications/blob/master/http_api.md.

Get package from HTTP API:

> hex_api_package:get(Config, <<"package1">>).
{ok, {200, ...,
    #{
        <<"name">> => <<"package1">>,
        <<"meta">> => #{
           <<"description">> => ...,
           <<"licenses">> => ...,
           <<"links">> => ...,
           <<"maintainers">> => ...,
        },
        ...,
        <<"releases">> => [
            #{<<"url">> => ..., <<"version">> => <<"0.5.0">>}],
            #{<<"url">> => ..., <<"version">> => <<"1.0.0">>}],
            ...
        ]
    }}}

Get package tarball:

{ok, {200, _, Tarball}} = hex_repo:get_tarball(Config, <<"package1">>, <<"1.0.0">>).

Publish package tarball:

{ok, {200, _Headers, _Body} = hex_api_package:publish(Config, Tarball).

Package tarballs

Unpack package tarball:

{ok, #{outer_checksum := Checksum, contents := Contents, metadata := Metadata}} = hex_tarball:unpack(Tarball, memory).

Remember to verify the outer tarball checksum against the registry checksum returned from hex_repo:get_package(Config, Package).

Create package tarball:

{ok, #{tarball := Tarball,
       inner_checksum := InnerChecksum,
       outer_checksum := OuterChecksum}} = hex_tarball:create(Metadata, Contents).

Configuration

The default configuration, provided by hex_core:default_config/0, uses built-in httpc-based adapter and Hex.pm APIs: https://hex.pm/api and https://repo.hex.pm.

HTTP client configuration can be overridden as follows:

Config = maps:merge(hex_core:default_config(), #{
  http_adapter => my_hackney_adapter,
  http_user_agent_fragment => <<"(my_app/0.1.0) (hackney/1.12.1) ">>
}),
hex_repo:get_names(Config).

%% my_hackney_adapter.erl
-module(my_hackney_adapter).
-behaviour(hex_http).
-exports([request/3]).

request(Method, URI, ReqHeaders) ->
    %% ...

See the hex_core module for more information about the configuration.

Wrapper Module

It's recommended to write a wrapper module because a lot of decisions are left to the user, e.g.: where to get configuration from, how to handle caching, failures etc.

For a sample, see: examples/myapp_hex.erl. Here's an excerpt:

-module(myapp_hex).
-export([
    get_api_package/1,
    get_repo_tarball/2,
    get_repo_versions/0
]).

%%====================================================================
%% API functions
%%====================================================================

get_api_package(Name) ->
      case hex_api_package:get(config(), Name) of
          {ok, {200, _Headers, Payload}} ->
              {ok, Payload};

          Other ->
              Other
      end.

get_repo_versions() ->
      case hex_repo:get_versions(config()) of
          {ok, {200, _Headers, Payload}} ->
              {ok, maps:get(packages, Payload)};

          Other ->
              Other
      end.

%%====================================================================
%% Internal functions
%%====================================================================

config() ->
    Config1 = hex_core:default_config(),
    Config2 = put_http_config(Config1),
    Config3 = maybe_put_api_key(Config2),
    Config3.

put_http_config(Config) ->
    maps:put(http_user_agent_fragment, <<"(myapp/1.0.0) (httpc)">>, Config).

maybe_put_api_key(Config) ->
    case os:getenv("HEX_API_KEY") of
        false -> Config;
        Key -> maps:put(api_key, Key, Config)
    end.

Installation

Rebar3

Add to rebar.config:

{deps, [
  {hex_core, "0.6.8"}
]}

Mix

Add to mix.exs:

defp deps() do
  [
    {:hex_core, "~> 0.6.0"}
  ]
end

Development

• Run rebar3 as dev compile to re-generate protobuf files
• Run rebar3 as test proper for property-based tests
• Run rebar3 as docs edoc to generate documentation