Following is a sentence from Bitbake user's manual:
"BitBake parses each recipe and append file located with BBFILES and stores the values of various variables into the datastore."
What data type is 'datastore' ? Is it list or Tuple or Dictionary ? Or what data type is it?
Bitbake's datastore is complex store of key+value pairs where keys also have flags (also key+value pairs). Its a custom structure written with a copy on write backend. It supports the idea of 'overrides' where one variable with special naming can override another. See https://git.openembedded.org/bitbake/tree/lib/bb/data_smart.py and https://git.openembedded.org/bitbake/tree/lib/bb/data.py within the codebase for the implementation, the Bitbake manual for information about how to use the data store and https://git.openembedded.org/bitbake/tree/lib/bb/tests/data.py for unittests of it.
You can work out the type of an object in python by executing type(foo) in the same environment. As for that specific type (datastore), a quick google indicates that it's neither a tuple or a dictionary, but a custom object with it's API documented here.
Related
We are using the roles pattern in puppet with hiera, meaning we have these lines in hiera.yaml:
- name: "Roles data"
path: "roles/%{::server_role}.yaml"
We have a custom fact that produces the role name when facter runs, but we would like to move this into hiera. Instead of the server_role variable being produced by facter, we want to specify the server_role inside of hiera, and let that variable be referenced elsewhere in hiera. Something like this:
hiera.yaml:
- name: "Per-node data"
path: "nodes/%{trusted.certname}.yaml"
- name: "Roles data"
path: "roles/%{lookup(server_role)}.yaml"
nodes/hostname.yaml:
server_role: foo_bar
I have seen this question, which says to use hiera() or lookup() but when I try to use those, I get this error message:
Interpolation using method syntax is not allowed in this context
So how can I use a hiera variable that's defined elsewhere in hiera?
Edit:
The prototypical code examples for defining roles could use any fact that's known to facter, often giving examples that are based on hostname. When you can't embed server config into hostname, a common(ish) workaround is to write a file such as /etc/server_role, but it seems to defeat the purpose of config management, when you need to ssh into a machine and edit a file. As the other comments & answer here so far mentioned, you could use an ENC, but again, the goal here is not to have config stored outside of version control. In fact, we have foreman as an ENC and we make a practice to never use it that way because then upgrades and other maintenance become unsustainable.
We could write a class which will pick up data from hiera, write it to /etc/server_role, and on the next puppet run, facter will pick that up and send it back to hiera, so then we'll have the server_role fact available to use in hiera.yaml. As gross as this sounds, so far, it's the best known solution. Still looking for better answers to this question.
Thanks.
As #MattSchuchard explained in comments, you cannot interpolate Hiera data into your Hiera config, because the config has to be known before the data can be looked up.
If you need a per-role level in your data hierarchy then an alternative would be to assign roles to machines via an external node classifier. You don't need it to assign any classes, just the server_role top-scope variable and probably also environment.
On the other hand, maybe you don't need a per-role level of your general hierarchy in the first place. Lots of people do roles & profiles without per-role data, but even if you don't want to do altogether without then it may be that module-specific data inside the module providing your role classes could be made to suffice.
part question. First, how do I configure the size of a branch predictor?
I can see that I can set the type using the se.py config script and the --bp-type argument. (In my case I'm setting it to LTAGE), but how do I change the size of the tables? And is there an easy way to see the total size of all tables?
My second part, is looking at the code, I don't understand the LTAGE constructor:
LTAGE::LTAGE(const LTAGEParams *params)
: TAGE(params), loopPredictor(params->loop_predictor)
{
}
The LTAGEParams doesn't appear to be defined anywhere except here:
LTAGE*
LTAGEParams::create()
{
return new LTAGE(this);
}
How can I see what all the members of LTAGEParams are?
About the size, have a look at m5out/config.ini after running a simulation, it contains all SimObject parameters.
In the case of branch predictors, all Python-visible parameters of each implemented predictor will be defined in its respective class declaration at src/cpu/pred/BranchPredictor.py. They also inherit the parameters of their base class. For example, LTAGE has all the parameters of the TAGE class - out of which the tage object is re-assigned to be an instance of LTAGE_TAGE - and a new parameter, loop_predictor, which is a LoopPredictor instance.
You can then just set any of the values in that file from your Python config and they will be used (double check in config.ini after re-running).
The C++ constructor of SimObjects takes a param object like LTAGEParams and that object is autogenerated from the corresponding Python SimObject file, and passes values from Python configs to C++ using pybind11.
gem5 has a lot of code generation, so whenever you can't find a definition, grep inside the build directory. This is also why I recommend setting up Eclipse inside the build directory: How to setup Eclipse IDE for gem5 development?
SimObject autogeneration is described further at: https://cirosantilli.com/linux-kernel-module-cheat/#gem5-python-c-interaction
I have a collection of nodes of concept Command that I'm iterating over with a $LOOP$ macro. Command is an abstract concept. I have defined templates and reduction rules for concrete subconcepts, such as Outline:
template tpl_Outline
input Outline
...
and
reduction rules:
[concept Outline ] --> tpl_Outline
[inheritors false ]
[condition <always>]
Question: How would I invoke the appropriate generator rule for the concrete concept from inside the $LOOP$ macro where the nodes are only known to be of the abstract type Command?
[EDIT] Since the proposed answer is specific to looping over a collection of elements, how would I do the same when there's no looping? That is, how to trigger the configured rule for a given node (e.g. a certain child of the current node).
Note 1: I tried using just $LOOP$[null], hoping for the element nodes to be processed by appropriate rules automatically, but that just produced nulls in the output.
Note 2: I tried $LOOP[$COPY_SRC$[null]], but that produced
textgen error: 'No textgen for Draw.structure.Outline' in [actualArgument] Outline null[847086916111387210] in Draw.sandbox#0
[EDIT 2] This is actually a working solution. What helped was probably invalidating the caches (just Rebuild Project was not working).
Note 3: Previously I used a template switch to call an appropriate template based on concrete concept, but I now want to support custom extensions of Command so I can no longer create an exhaustive template switch.
Try using $COPY_SRCL$ (L stands for Loop here), this macro is designed exactly for your situation.
Also, template switches are extensible
Regarding your Build --> Rebuild Project problem: sometimes File --> Invalidate caches can help to resolve such problems.
I'm new to configuration management, just FYI.
I'm trying to puppetize elasticsearch, and want to have a master list of elasticsearch nodes in a file (which can be used for multiple things, not just this purpose).
I would like to add elasticsearch.yml via an ERB template and expand the list of FDQN's into the discovery.zen.ping.unicast.hosts: [] param.
For example I have an external file called es_hosts in module/files that contains:
host1.domain.com
host2.domain.com
host3.domain.com
host4.domain.com
Then when puppet builds the ERB template have this in the param:
discovery.zen.ping.unicast.hosts: ["host1.domain.com", "host2.domain.com", "host3.domain.com", "host4.domain.com"]
I've tried a few things, but I can't get my head wrapped around it.
I would be using this list for other things like building firewall rules, etc, so I'd like to have one master list for reference that can be updated by my team.
Thanks for any help!
Rather than have a list in a file, it would be better to have it in Hiera, since defining lists and other external data is specifically what Hiera is for.
(If you have not used Hiera yet, you definitely should read up on it.)
So in Hiera you would have:
---
es_hosts:
- host1.domain.com
- host2.domain.com
- host3.domain.com
- host4.domain.com
In your manifest, you would read that in from Hiera using the hiera function:
$es_hosts = hiera('es_hosts')
(Note that instead of the hiera function, we often use Puppet's Automatic Parameter Lookup feature instead to read data into our manifests from Hiera, but your requirement here - a list of ES hosts to be used in multiple contexts - suggests you will want this list not to be bound to a specific class input. If this does not make sense to you right now, you will need to learn about Parameterised Classes and Automatic Parameter Lookup, but it's otherwise not relevant to this answer.)
Finally, in your ERB template you would have:
discovery.zen.ping.unicast.hosts: ["<%= #es_hosts.join('", "') %>"]
Pay attention to the fact that the $es_hosts variable from your manifest is accessed via a Ruby instance variable #es_hosts in your ERB template.
Finally, note that there is an Elasticsearch Puppet module available on the Puppet Forget here. You may find that using that module is better than writing your own.
When you are debugging a program and you hover over a GUID variable, MSVC retrieves both the variable name (e.g. CLSID_FilterGraph) and the human name (e.g. Filter Graph Object).
It does the second by looking at HKCR\CLSID\GUID - but where does it get the variable name from?? It's not in the registry.
Any ideas?
The debugging info in the .pdb, probably. It just needs to iterate the CLSIDs defined in the mumble_i.c file generated by MIDL. No problem matching them, they are after all globally unique :)