Package envdef implements a parser for the runtime environment for alternative builds

Builds that are built with the alternative build environment, include runtime.json files that define which environment variables need to be set to install and use the provided artifacts. The schema of this file can be downloaded here

The same parser and interpreter also exists in TheHomeRepot

Changes to the runtime environment definition schema should be synchronized between these two places. For now, this can be most easily accomplished by keeping the description of test cases in the cli repo and TheHomeRepot in sync.

Examples:

Define a PATH and LD_LIBRARY_PATH variable

Assuming the runtime is installed to a directory /home/user/.cache/installdir, the following definition asks to set the PATH variables to/home/user/.cache/installdir/bin:/home/user/.cache/installdir/usr/bin andLD_LIBRARY_PATH to/home/user/.cache/installdir/libThe set inherit flag on the PATH variable ensures that the PATH value is prepended to the existing PATH that is already set in the environment.

{
  "env": [
    {
      "env_name": "PATH",
      "values": [
        "${INSTALLDIR}/bin",
        "${INSTALLDIR}/usr/bin"
      ],
      "join": "prepend",
      "inherit": true,
      "separator": ":"
    },
    {
      "env_name": "LD_LIBRARY_PATH",
      "values": [
        "${INSTALLDIR}/lib"
      ],
      "join": "prepend",
      "inherit": false,
      "separator": ":"
    }
  ],
  "installdir": "installdir"
}

The installdir is used during the unpacking step to identify the directory inside the artifact tarball that needs to be unpacked to /home/user/.cache/installdir

Joining two definitions

Assume we have a second environment definition file exists with the following contents:

{
  "env": [
    {
      "env_name": "PATH",
      "values": [
        "${INSTALLDIR}/bin",
        "${INSTALLDIR}/usr/local/bin"
      ],
      "join": "prepend",
      "inherit": true,
      "separator": ":"
    },
    {
      "env_name": "LD_LIBRARY_PATH",
      "values": [
        "${INSTALLDIR}/lib",
        "${INSTALLDIR}/lib64"
      ],
      "join": "prepend",
      "inherit": false,
      "separator": ":"
    }
  ],
  "installdir": "installdir"
}

Merging this environment definition into the previous one sets the PATH to /home/user/.cache/installdir/bin:/home/user/.cache/installdir/usr/local/bin:/home/user/.cache/installdir/usr/bin. Note, that duplicate values are filtered out. Likewise the LD_LIBRARY_PATH will end up as /home/user/.cache/installdir/lib:/home/user/.cache/installdir/lib64

In this example, the values were joined by prepending the second definition to the first. Other join strategies are append and disallowed.

The disallowed join strategy can be used if a variable should have only ONE value, and this value needs to be the same or undefined between all artifacts that depend on it.

Usage

• Environment definition files can be parsed from a file with the NewEnvironmentDefinition() function.
• Two environment definitions ed1 and ed2 can be merged like so: ed1.Merge(ed2)
• Once the installation directory is specified, the variable values can be expanded: ed.ExpandVariables("/home/user/.cache/installdir")