Implemented mixer reset command

It reverts the mix to a good state in case of a build failure or in case
the user wants to roll back to a previous version.
By default, the command will  bring back the mix to the same state
it have when it last build a successful mix.
This value can be overridden if a `--to` flag is provided with a version number.
The command will not be destructive unless a `--clean` flag is provided specified.
If so, mixer will delete all files associated with versions that are bigger than the one provided.
If not, only the values of the state files will change, but the files will be kept.

Signed-off-by: Ashlesha Atrey <[email protected]>

Makefile

@@ -103,7 +103,8 @@ MANPAGES = \
 	docs/mixer.init.1 \
 	docs/mixer.repo.1 \
 	docs/mixer.versions.1 \
-	docs/mixin.1
+	docs/mixin.1 \
+	docs/mixer.reset.1
 
 man: $(MANPAGES)
 

bat/tests/reset-command/Makefile

@@ -0,0 +1,10 @@
+.PHONY: check clean
+
+check:
+	bats ./run.bats
+
+CLEANDIRS = ./update ./test-chroot ./logs ./.repos ./bundles ./update ./mix-bundles ./clr-bundles ./local-yum ./results ./repodata ./local-rpms ./upstream-bundles ./local-bundles
+CLEANFILES = ./*.log ./run.bats.trs ./yum.conf.in ./builder.conf ./mixer.state ./.{c,m}* *.pem .yum-mix.conf mixversion upstreamurl upstreamversion mixbundles
+clean:
+	sudo rm -rf $(CLEANDIRS) $(CLEANFILES)
+

bat/tests/reset-command/description.txt

@@ -0,0 +1,7 @@
+reset
+====================
+This test attempts to create multiple mixes of different versions
+in different format. It then tries to revert the mix to a previous stable
+version. If clean flag is set, mixer will delete all files associated with
+versions that are bigger than the one provided.
+

bat/tests/reset-command/run.bats

@@ -0,0 +1,34 @@
+#!/usr/bin/env bats
+
+# shared test functions
+load ../../lib/mixerlib
+
+setup() {
+  global_setup
+}
+
+@test "reset" {
+  mixer-init-stripped-down latest 10
+  mixer build all --format 1 --native
+  mixer-versions-update 20 latest
+  mixer build all --format 2 --native
+  mixer-versions-update 30 latest
+  mixer build all --format 3 --native
+  #check LAST_VER and PREVIOUS_MIX_VERSION match
+  test $(< update/image/LAST_VER) -eq 30
+  test $(sed -n 's/[ ]*PREVIOUS_MIX_VERSION[ ="]*\([0-9]\+\)[ "]*/\1/p' mixer.state) -eq 20
+  mixer reset --to 20
+  #check LAST_VER and PREVIOUS_MIX_VERSION match
+  test $(< update/image/LAST_VER) -eq 20
+  test $(sed -n 's/[ ]*PREVIOUS_MIX_VERSION[ ="]*\([0-9]\+\)[ "]*/\1/p' mixer.state) -eq 20
+  test -d "./update/www/30"
+  test -d "./update/image/30"
+  mixer reset --to 10 --clean
+  #check LAST_VER and PREVIOUS_MIX_VERSION match
+  test $(< update/image/LAST_VER) -eq 10
+  test $(sed -n 's/[ ]*PREVIOUS_MIX_VERSION[ ="]*\([0-9]\+\)[ "]*/\1/p' mixer.state) -eq 10
+  test ! -d "./update/www/20"
+  test ! -d "./update/image/30"
+  }
+# vi: ft=sh ts=8 sw=2 sts=2 et tw=80
+

docs/mixer.1

@@ -50,7 +50,10 @@ configure remote RPM repositories.
 The output of \fBmixer\fP is a set of manifests readable by \fBswupd\fP as well as
 all the OS content \fBswupd\fP needs to perform its update operations. The OS
 content includes all the files in an update as well as zero\- and delta\-packs for
-improved update performance. See \fBswupd\fP(1) for more details.
+improved update performance. The content that \fBmixer\fP produces is tied to a
+specific format so that \fBswupd\fP is guaranteed to understand it if the client
+is using the right version of \fBswupd\fP\&. See \fBswupd\fP(1) and \fBos\-format\fP(7)
+for more details.
 .SH OPTIONS
 .sp
 The following options are applicable to most subcommands, and can be
@@ -102,9 +105,8 @@ itself. See \fBmixer.build\fP(1) for more details.
 .INDENT 0.0
 .INDENT 3.5
 Perform various configuration actions on local and upstream bundles. The
-user can add or remove bundles from their mix, edit local and upstream
-bundles, create new bundle definitions, or validate local bundle definition
-files. See \fBmixer.bundle\fP(1) for more details.
+user can add or remove bundles from their mix, create new bundle definitions,
+or validate local bundle definition files. See \fBmixer.bundle\fP(1) for more details.
 .UNINDENT
 .UNINDENT
 .sp
@@ -151,6 +153,18 @@ upstream available. Also allows the user to update mix and upstream
 versions. See \fBmixer.versions\fP(1) for more details.
 .UNINDENT
 .UNINDENT
+.sp
+\fBreset\fP
+.INDENT 0.0
+.INDENT 3.5
+Reverts a mix state to the end of the last build or to the end
+of a given version build if one is provided. By default, the value
+of PREVIOUS_MIX_VERSION in mixer.state will be used to define the
+last build. This command can be used to roll back the mixer state
+in case of a build failure or in case the user wants to roll back
+to a previous version. See \fBmixer.reset\fP(1) for more details.
+.UNINDENT
+.UNINDENT
 .SH FILES
 .sp
 \fI<mixer/workspace>/builder.conf\fP
@@ -186,8 +200,12 @@ On success, 0 is returned. A non\-zero return code indicates a failure.
 .IP \(bu 2
 \fBmixer.versions\fP(1)
 .IP \(bu 2
+\fBmixer.reset\fP(1)
+.IP \(bu 2
 \fBswupd\fP(1)
 .IP \(bu 2
+\fBos\-format\fP(7)
+.IP \(bu 2
 \fI\%https://github.com/clearlinux/mixer\-tools\fP
 .IP \(bu 2
 \fI\%https://github.com/clearlinux/swupd\-client\fP

docs/mixer.1.rst

@@ -118,6 +118,15 @@ SUBCOMMANDS
     upstream available. Also allows the user to update mix and upstream
     versions. See ``mixer.versions``\(1) for more details.
 
+``reset``
+
+   Reverts a mix state to the end of the last build or to the end
+   of a given version build if one is provided. By default, the value
+   of PREVIOUS_MIX_VERSION in mixer.state will be used to define the
+   last build. This command can be used to roll back the mixer state
+   in case of a build failure or in case the user wants to roll back
+   to a previous version. See ``mixer.reset``\(1) for more details.
+
 
 FILES
 =====
@@ -146,6 +155,7 @@ SEE ALSO
 * ``mixer.init``\(1)
 * ``mixer.repo``\(1)
 * ``mixer.versions``\(1)
+* ``mixer.reset``\(1)
 * ``swupd``\(1)
 * ``os-format``\(7)
 * https://github.com/clearlinux/mixer-tools

docs/mixer.reset.1

@@ -0,0 +1,73 @@
+.\" Man page generated from reStructuredText.
+.
+.TH MIXER.RESET 1 "" "" ""
+.SH NAME
+mixer.reset \- Reset mixer to a given or stable version
+.
+.nr rst2man-indent-level 0
+.
+.de1 rstReportMargin
+\\$1 \\n[an-margin]
+level \\n[rst2man-indent-level]
+level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
+-
+\\n[rst2man-indent0]
+\\n[rst2man-indent1]
+\\n[rst2man-indent2]
+..
+.de1 INDENT
+.\" .rstReportMargin pre:
+. RS \\$1
+. nr rst2man-indent\\n[rst2man-indent-level] \\n[an-margin]
+. nr rst2man-indent-level +1
+.\" .rstReportMargin post:
+..
+.de UNINDENT
+. RE
+.\" indent \\n[an-margin]
+.\" old: \\n[rst2man-indent\\n[rst2man-indent-level]]
+.nr rst2man-indent-level -1
+.\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
+.in \\n[rst2man-indent\\n[rst2man-indent-level]]u
+..
+.SH SYNOPSIS
+.sp
+\fBmixer reset [flags]\fP
+.SH DESCRIPTION
+.sp
+Reverts a mix state to the end of the last build or to the end
+of a given version build if one is provided. By default, the value
+of PREVIOUS_MIX_VERSION in mixer.state will be used to define the
+last build. This command can be used to roll back the mixer state
+in case of a build failure or in case the user wants to roll back
+to a previous version.
+.SH OPTIONS
+.sp
+In addition to the globally recognized \fBmixer\fP flags (see \fBmixer\fP(1) for
+more details), the following options are recognized.
+.INDENT 0.0
+.IP \(bu 2
+\fB\-\-to\fP
+.sp
+Reverts the mix to the version provided by the flag
+.IP \(bu 2
+\fB\-\-clean\fP
+.sp
+Delete all files associated with versions that are bigger than the one provided.
+.IP \(bu 2
+\fB\-h, \-\-help\fP
+.sp
+Display \fBreset\fP help information and exit.
+.UNINDENT
+.SH EXIT STATUS
+.sp
+On success, 0 is returned. A non\-zero return code indicates a failure.
+.SS SEE ALSO
+.INDENT 0.0
+.IP \(bu 2
+\fBmixer\fP(1)
+.UNINDENT
+.SH COPYRIGHT
+(C) 2019 Intel Corporation, CC-BY-SA-3.0
+.\" Generated by docutils manpage writer.
+.

docs/mixer.reset.1.rst

@@ -0,0 +1,56 @@
+===========
+mixer.reset
+===========
+
+----------------------------------------
+Reset mixer to a given or stable version
+----------------------------------------
+
+:Copyright: \(C) 2019 Intel Corporation, CC-BY-SA-3.0
+:Manual section: 1
+
+
+SYNOPSIS
+========
+
+``mixer reset [flags]``
+
+
+DESCRIPTION
+===========
+
+Reverts a mix state to the end of the last build or to the end
+of a given version build if one is provided. By default, the value
+of PREVIOUS_MIX_VERSION in mixer.state will be used to define the
+last build. This command can be used to roll back the mixer state
+in case of a build failure or in case the user wants to roll back
+to a previous version.
+
+OPTIONS
+=======
+
+In addition to the globally recognized ``mixer`` flags (see ``mixer``\(1) for
+more details), the following options are recognized.
+
+-  ``--to``
+
+   Reverts the mix to the version provided by the flag
+
+-  ``--clean``
+
+   Delete all files associated with versions that are bigger than the one provided.
+
+-  ``-h, --help``
+
+   Display ``reset`` help information and exit.
+
+
+EXIT STATUS
+===========
+
+On success, 0 is returned. A non-zero return code indicates a failure.
+
+SEE ALSO
+--------
+
+* ``mixer``\(1)