asteris-llc/converge

// Copyright © 2016 Asteris, LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package apt

import (
    "fmt"
    "strings"

    "github.com/asteris-llc/converge/resource/package"
)

// Outputs from dpkg-query
const (
    // PkgHold means package is installed and held to a version
    PkgHold = "hold ok installed"

    // PkgInstalled means package is installed normally
    PkgInstalled = "install ok installed"

    // PkgRemoved means package has been removed, but not purged (config files still present)
    PkgRemoved = "deinstall ok config-files"

    // PkgUninstalled means package has been uninstalled
    PkgUninstalled = "unknown ok not-installed"
)

// Manager provides a concrete implementation of PackageManager for debian
// packages.
type Manager struct {
    Sys pkg.SysCaller
}

// InstalledVersion gets the installed version of package, if available
func (a *Manager) InstalledVersion(p string) (pkg.PackageVersion, bool) {
    var version string
    var installed bool

    result, err := a.Sys.Run(fmt.Sprintf("dpkg-query -W -f'${Package},${Status},${Version}\n' %s", p))
    exitCode, _ := pkg.GetExitCode(err)
    if exitCode != 0 {
        return "", false
    }
    // Deal with situations where dpkg exits 0 with packages that have been uninstalled
    for _, line := range strings.Split(strings.TrimSpace(string(result)), "\n") {
        l := strings.Split(line, ",")
        if len(l) == 3 {
            name, status, ver := l[0], l[1], l[2]

            if strings.Contains(status, PkgRemoved) || strings.Contains(status, PkgUninstalled) {
                return "", false
            }

            if strings.Contains(status, PkgInstalled) || strings.Contains(status, PkgHold) {
                version = fmt.Sprintf("%s-%s", name, ver)
                installed = true
            }
        }
    }
    return (pkg.PackageVersion)(version), installed
}

// InstallPackage installs a package, returning an error if something went wrong
func (a *Manager) InstallPackage(p string) (string, error) {
    if _, isInstalled := a.InstalledVersion(p); isInstalled {
        return "already installed", nil
    }
    res, err := a.Sys.Run(fmt.Sprintf("apt-get install -y %s", p))
    return string(res), err
}

// RemovePackage removes a package, returning an error if something went wrong
func (a *Manager) RemovePackage(p string) (string, error) {
    switch _, isInstalled := a.InstalledVersion(p); isInstalled {
    case true:
        res, err := a.Sys.Run(fmt.Sprintf("apt-get purge -y %s", p))
        return string(res), err
    default:
        return "package is not installed ", nil
    }

}