🎨 Introduce contextualized logging

This commit is multi-fold as it also refactors internally context and logger
as interfaces so it is easier to plug luet as a library externally.

Introduces a garbage collector (related to #227) but doesn't handle yet
parallelism.

Closes #265

pkg/api/core/context/context.go

@@ -0,0 +1,159 @@
+// Copyright © 2021 Ettore Di Giacinto <mudler@mocaccino.org>
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this program; if not, see <http://www.gnu.org/licenses/>.
+
+package context
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+
+	fileHelper "github.com/mudler/luet/pkg/helpers/file"
+
+	gc "github.com/mudler/luet/pkg/api/core/garbagecollector"
+	"github.com/mudler/luet/pkg/api/core/logger"
+	"github.com/mudler/luet/pkg/api/core/types"
+
+	"github.com/pkg/errors"
+)
+
+type Context struct {
+	*logger.Logger
+	context.Context
+	types.GarbageCollector
+	Config      *types.LuetConfig
+	NoSpinner   bool
+	annotations map[string]interface{}
+}
+
+// SetAnnotation sets generic annotations to hold in a context
+func (c *Context) SetAnnotation(s string, i interface{}) {
+	c.annotations[s] = i
+}
+
+// GetAnnotation gets generic annotations to hold in a context
+func (c *Context) GetAnnotation(s string) interface{} {
+	return c.annotations[s]
+}
+
+type ContextOption func(c *Context) error
+
+// WithLogger sets the logger
+func WithLogger(l *logger.Logger) ContextOption {
+	return func(c *Context) error {
+		c.Logger = l
+		return nil
+	}
+}
+
+// WithConfig sets the luet config
+func WithConfig(cc *types.LuetConfig) ContextOption {
+	return func(c *Context) error {
+		c.Config = cc
+		return nil
+	}
+}
+
+// NOTE: GC needs to be instantiated when a new context is created from system TmpDirBase
+
+// WithGarbageCollector sets the Garbage collector for the given context
+func WithGarbageCollector(l types.GarbageCollector) ContextOption {
+	return func(c *Context) error {
+		if !filepath.IsAbs(l.String()) {
+			abs, err := fileHelper.Rel2Abs(l.String())
+			if err != nil {
+				return errors.Wrap(err, "while converting relative path to absolute path")
+			}
+			l = gc.GarbageCollector(abs)
+		}
+
+		c.GarbageCollector = l
+		return nil
+	}
+}
+
+// NewContext returns a new context.
+// It accepts a Garbage collector, a config and a logger as an option
+func NewContext(opts ...ContextOption) *Context {
+	l, _ := logger.New()
+	d := &Context{
+		annotations:      make(map[string]interface{}),
+		Logger:           l,
+		GarbageCollector: gc.GarbageCollector(filepath.Join(os.TempDir(), "tmpluet")),
+		Config: &types.LuetConfig{
+			ConfigFromHost: true,
+			Logging:        types.LuetLoggingConfig{},
+			General:        types.LuetGeneralConfig{},
+			System: types.LuetSystemConfig{
+				DatabasePath:  filepath.Join("var", "db"),
+				PkgsCachePath: filepath.Join("var", "db", "packages"),
+			},
+			Solver: types.LuetSolverOptions{},
+		},
+	}
+
+	for _, o := range opts {
+		o(d)
+	}
+	return d
+}
+
+// WithLoggingContext returns a copy of the context with a contextualized logger
+func (c *Context) WithLoggingContext(name string) types.Context {
+	configCopy := *c.Config
+	configCopy.System = c.Config.System
+	configCopy.General = c.Config.General
+	configCopy.Logging = c.Config.Logging
+
+	ctx := *c
+	ctxCopy := &ctx
+	ctxCopy.Config = &configCopy
+	ctxCopy.annotations = ctx.annotations
+
+	ctxCopy.Logger, _ = c.Logger.Copy(logger.WithContext(name))
+
+	return ctxCopy
+}
+
+// Copy returns a context copy with a reset logging context
+func (c *Context) Copy() types.Context {
+	return c.WithLoggingContext("")
+}
+
+func (c *Context) Warning(mess ...interface{}) {
+	c.Logger.Warn(mess...)
+	if c.Config.General.FatalWarns {
+		os.Exit(2)
+	}
+}
+
+func (c *Context) Warn(mess ...interface{}) {
+	c.Warning(mess...)
+}
+
+func (c *Context) Warnf(t string, mess ...interface{}) {
+	c.Logger.Warnf(t, mess...)
+	if c.Config.General.FatalWarns {
+		os.Exit(2)
+	}
+}
+
+func (c *Context) Warningf(t string, mess ...interface{}) {
+	c.Warnf(t, mess...)
+}
+
+func (c *Context) GetConfig() types.LuetConfig {
+	return *c.Config
+}