oe-setup-build: add a tool for discovering config templates and setting up builds

This is another piece of the puzzle in setting up builds from nothing
without having to write custom scripts or use external tools.

After layers have been fetched and placed into their respective locations by
oe-setup-layers, one would surely want to proceed to the actual build, and here's how:

1. Without arguments the tool reads available layers
from .oe-layers.json file (written out by oe-setup-layers or a fallback under scripts/),
prints what templates it has found, and asks the user to select one, as seen below.
This will land the user in a shell ready to run bitbake:

=============================================
alex@Zen2:/srv/work/alex$ ./setup-build
Available build configurations:

1. alex-configuration-gadget
This configuration will set up a build for the purposes of supporting gadget.

2. alex-configuration-gizmo
This configuration allows building a gizmo.

3. poky-default
This is the default build configuration for the Poky reference distribution.

Re-run with 'list -v' to see additional information.
Please choose a configuration by its number: 1
Running: TEMPLATECONF=/srv/work/alex/meta-alex/conf/templates/configuration-gadget . /srv/work/alex/poky/oe-init-build-env /srv/work/alex/build-alex-configuration-gadget && /bin/bash
You had no conf/local.conf file. This configuration file has therefore been
created for you from /srv/work/alex/meta-alex/conf/templates/configuration-gadget/local.conf.sample
You may wish to edit it to, for example, select a different MACHINE (target
hardware).

You had no conf/bblayers.conf file. This configuration file has therefore been
created for you from /srv/work/alex/meta-alex/conf/templates/configuration-gadget/bblayers.conf.sample
To add additional metadata layers into your configuration please add entries
to conf/bblayers.conf.

The Yocto Project has extensive documentation about OE including a reference
manual which can be found at:
    https://docs.yoctoproject.org

For more information about OpenEmbedded see the website:
    https://www.openembedded.org/

This configuration will set up a build for the purposes of supporting gadget.
Please refer to meta-alex/README for additional details and available bitbake targets.
==============================================

2. It is also possible to list available configurations without selecting one using
'setup-build list' or to select and setup one non-interactively with 'setup-build setup'.

3. The full set of command line options is:

$ ./setup-build --help
usage: setup-build [-h] [--layerlist LAYERLIST] {list,setup} ...

A script that discovers available build configurations and sets up a build environment based on one of them. Run without arguments to choose one interactively.

positional arguments:
  {list,setup}
    list                List available configurations
    setup               Set up a build environment and open a shell session with it, ready to run builds.

optional arguments:
  -h, --help            show this help message and exit
  --layerlist LAYERLIST
                        Where to look for available layers (as written out by setup-layers script) (default is /srv/work/alex/.oe-layers.json).

$ ./setup-build list --help
usage: setup-build list [-h] [-v]

optional arguments:
  -h, --help  show this help message and exit
  -v          Print detailed information and usage notes for each available build configuration.

$ ./setup-build setup --help
usage: setup-build setup [-h] [-c configuration_name] [-b build_path] [--no-shell]

optional arguments:
  -h, --help            show this help message and exit
  -c configuration_name
                        Use a build configuration configuration_name to set up a build environment (run this script with 'list' to see what is available)
  -b build_path         Set up a build directory in build_path (run this script with 'list -v' to see where it would be by default)
  --no-shell            Create a build directory but do not start a shell session with the build environment from it.

4. There's an an added hint in oe-setup-layers about how to proceed (as it is really not user-friendly
to fetch the layer repos successfully and then exit without a word), and a symlink to the script
from the top level layer checkout directory.

5. The selftest to check layer setup has been adjusted to run a basic check for template
discovery and build setup. The revision of poky to be cloned has been bumped to 4.1,
as that's the first version with a default template in a standard location.

Signed-off-by: Alexander Kanavin <alex@linutronix.de>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 24 insertions, 2 deletions

diff --git a/meta/lib/oeqa/selftest/cases/bblayers.py b/meta/lib/oeqa/selftest/cases/bblayers.py
index f2460cb451..e2009496ad 100644
--- a/meta/lib/oeqa/selftest/cases/bblayers.py
+++ b/meta/lib/oeqa/selftest/cases/bblayers.py
@@ -152,12 +152,12 @@ class BitbakeLayers(OESelftestTestCase):
         self.validate_layersjson(jsonfile)
 
         # The revision-under-test may not necessarily be available on the remote server,
-        # so replace it with a revision that has a yocto-4.0 tag.
+        # so replace it with a revision that has a yocto-4.1 tag.
         import json
         with open(jsonfile) as f:
             data = json.load(f)
         for s in data['sources']:
-            data['sources'][s]['git-remote']['rev'] = '00cfdde791a0176c134f31e5a09eff725e75b905'
+            data['sources'][s]['git-remote']['rev'] = '5200799866b92259e855051112520006e1aaaac0'
         with open(jsonfile, 'w') as f:
             json.dump(data, f)
 
@@ -165,3 +165,25 @@ class BitbakeLayers(OESelftestTestCase):
         result = runCmd('{}/setup-layers --destdir {}'.format(self.testlayer_path, testcheckoutdir))
         layers_json = os.path.join(testcheckoutdir, ".oe-layers.json")
         self.assertTrue(os.path.exists(layers_json), "File {} not found in test layer checkout".format(layers_json))
+
+        # As setup-layers checkout out an old revision of poky, there is no setup-build symlink,
+        # and we need to run oe-setup-build directly from the current poky tree under test
+        oe_setup_build = os.path.join(get_bb_var('COREBASE'), 'scripts/oe-setup-build')
+        oe_setup_build_l = os.path.join(testcheckoutdir, 'setup-build')
+        os.symlink(oe_setup_build,oe_setup_build_l)
+
+        cmd = '{} --layerlist {} list -v'.format(oe_setup_build_l, layers_json)
+        result = runCmd(cmd)
+        cond = "conf/templates/default" in result.output
+        self.assertTrue(cond, "Incorrect output from {}: {}".format(cmd, result.output))
+
+        # rather than hardcode the build setup cmdline here, let's actually run what the tool suggests to the user
+        conf = None
+        if 'poky-default' in result.output:
+            conf = 'poky-default'
+        elif 'meta-default' in result.output:
+            conf = 'meta-default'
+        self.assertIsNotNone(conf, "Could not find the configuration to set up a build in the output: {}".format(result.output))
+
+        cmd = '{} --layerlist {} setup -c {} --no-shell'.format(oe_setup_build_l, layers_json, conf)
+        result = runCmd(cmd)