Build RPM packages using node modules offline

By default, npm download dependencies from registry.npmjs.org and hides the details in the node_modules subdirectory. Its job is to resolve version dependencies and provide it to Node application in such a way that it satisfied the dependencies and does not conflict with other dependencies. To be able to build and rebuild a package from sources, we will need to be able to install and possibly update these dependencies in a networkless environment like OBS.

When npm installs dependencies, it will create a package-lock.json that will contain the entire list of packages that can possible exist in the node_modules directory structure.

The purpose of this tool is to parse package-lock.json and prepare all externally download sources for use by npm during rpmbuild.

runtime requirements

npm 7+ is required to produce package-lock.json with lockfileVersion:2

As OBS service

Get package-lock.json with localfileVersion: 2. For example,
- npm install --package-lock-only --legacy-peer-deps with npm 7+
- --legacy-peer-deps is required to fetch peer dependencies from remote locally so they are available during peer resolution in the VM. Without this you may get additional warnings during install.
Make sure to put the package-lock.json next to the spec file and remove it from the sources. Sources should only have package.json, even if they ship a compatible package-lock.json

Add the following line to the spec file:

%include  %{_sourcedir}/node_modules.spec.inc

Create file _service with the following content:

<services>
  <service name="node_modules" mode="manual">
    <param name="cpio">node_modules.obscpio</param>
    <param name="output">node_modules.spec.inc</param>
    <param name="source-offset">10000</param>
  </service>
</services>

osc service manualrun
- this generates the NPM dependency archive along with its source URLs
osc add node_modules.obscpio
osc add node_modules.spec.inc
osc commit

Example

Source10:       package-lock.json
Source11:       node_modules.spec.inc
%include        %{_sourcedir}/node_modules.spec.inc
BuildRequires:  local-npm-registry

[...]

%prep
%setup
local-npm-registry %{_sourcedir} install --also=dev

[...]

%build
npm run build

In Practice

https://build.opensuse.org/package/show/openSUSE:Factory/cockpit-podman

External Resources