Containers | A library of binary tree data structures | Dataset library

Both replica set and deployment have the attribute replica: 3, what's the difference between deployment and replica set? Does deployment work via replica set under the hood?

configuration of deployment

I was able to build a multiarch image successfully from an M1 Macbook which is arm64. Here's my docker file and trying to run from a raspberrypi aarch64/arm64 and I am getting this error when running the image: standard_init_linux.go:228: exec user process caused: exec format error

Editing the post with the python file as well:

I am trying to create an std::set of pointers to data members. However, I can't find a method to sort or hash such pointers.

They can't be compared with operator<, they don't seem to be supported by std::less and there is no standard integer type that is guaranteed to hold their representation (they might not fit in std::uintptr_t).

This is what I tried first (https://godbolt.org/z/K8ajn3rM8) :

I am trying to get to grips with the specifics of the (C++20) standards requirements for container classes with a view to writing some container classes that are compatible with the standard library. To begin looking into this matter I have looked up the references for named requirements, specifically around container requirements, and have only found one general container requirement called Container given by the standard. Reading this requirement has given my two queries that I am unsure about and would like some clarification on:

1. The requirement for the expression a == b for two container type C has as precondition on the element type T that it is equality comparable. However, noted later on the same page under the header 'other requirements' is the explicitly requirement that T be always equality comparable. Thus, on my reading the precondition for the aforementioned requirement is redundant and need not be given. Am I correct in this thinking, or is there something else at play here that I should take into account?

2. I was surprised to see explicit requirements on T at all: notably the equality comparable requirement above and the named requirement destructible. Does this mean it is undefined behaviour to ever construct standard containers of types failing these requirements, or only to perform certain standard library function calls on them?

Apologies if these two questions sound asinine, I am currently trying to transition my C++ knowledge from a place of having a basic understanding of how to use features to a robust understanding so that I may write good generic code. Whilst I am trying to use (a draft of) the standard to look up behaviour where possible, its verbiage is oft too verbose for me to completely understand what is actually being said.

In an attempt to seek the answer I cooked up a a quick test .cpp file to try an compile, given below. All uncommented code compiles with MSVC compiler set to C++20. All commented code will not compile, and visa versa all uncommented code will. It seems that what one naively thinks should work does In particular:

• We cannot construct any object without a destructor, though the objects type is valid and can be used for other things (for example as a template parameter!)
• We cannot create an object of vector, where T has no destructor, even if we don't attempt to create any objects T. Presumably because creating the destructor for vector tries to access a destructor for T.
• We can create an object of type vector, T where T has no operator ==, so long as we do not try to use operator ==, which would require T to have operator ==.

However, just because my compiler lets me make an object of vector where T is not equality-comparable does not mean I have achieved standards compliant behaviour/ all of our behaviour is not undefined - which is what I want I concerned about, especially as at least some of the usual requirements on the container object have been violated.

Code:

I use std::erase_if to erase half the elements from containers using a captured counter as follows. C++20 compiled with gcc10

We've had a working Ansible AWX instance running on v5.0.0 for over a year, and suddenly all jobs stop working -- no output is rendered. They will start "running" but hang indefinitely without printing out any logging.

The AWX instance is running in a docker compose container setup as defined here: https://github.com/ansible/awx/blob/5.0.0/INSTALL.md#docker-compose

Standard troubleshooting such as restarting of containers, host OS, etc. hasn't helped. No configuration changes in either environment.

Upon debugging an actual playbook command, we observe that the command to run a playbook from the UI is like the below:

ssh-agent sh -c ssh-add /tmp/awx_11021_0fmwm5uz/artifacts/11021/ssh_key_data && rm -f /tmp/awx_11021_0fmwm5uz/artifacts/11021/ssh_key_data && ansible-playbook -vvvvv -u ubuntu --become --ask-vault-pass -i /tmp/awx_11021_0fmwm5uz/tmppo7rcdqn -e @/tmp/awx_11021_0fmwm5uz/env/extravars playbook.yml

That's broken down into three commands in sequence:

1. ssh-agent sh -c ssh-add /tmp/awx_11021_0fmwm5uz/artifacts/11021/ssh_key_data
2. rm -f /tmp/awx_11021_0fmwm5uz/artifacts/11021/ssh_key_data
3. ansible-playbook -vvvvv -u ubuntu --become --ask-vault-pass -i /tmp/awx_11021_0fmwm5uz/tmppo7rcdqn -e @/tmp/awx_11021_0fmwm5uz/env/extravars playbook.yml

You can see in part 3, the -vvvvv is the debugging argument -- however, the hang is happening on command #1. Which has nothing to do with ansible or AWX specifically, but it's not going to get us much debugging info.

I tried doing an strace to see what is going on, but for reasons given below, it is pretty difficult to follow what it is actually hanging on. I can provide this output if it might help.

So one natural question with command #1 -- what is 'ssh_key_data'?

Well it's what we set up to be the Machine credential in AWX (an SSH key) -- it hasn't changed in a while and it works just fine when used in a direct SSH command. It's also apparently being set up by AWX as a file pipe:

prw------- 1 root root 0 Dec 10 08:29 ssh_key_data

Which starts to explain why it could be potentially hanging (if nothing is being read in from the other side of the pipe).

Running a normal ansible-playbook from command line (and supplying the SSH key in a more normal way) works just fine, so we can still deploy, but only via CLI right now -- it's just AWX that is broken.

So the question then becomes "why now"? And "how to debug"? I have checked the health of awx_postgres, and verified that indeed the Machine credential is present in an expected format (in the main_credential table). I have also verified that can use ssh-agent on the awx_task container without the use of that pipe keyfile. So it really seems to be this piped file that is the problem -- but I haven't been able to glean from any logs where the other side of the pipe (sender) is supposed to be or why they aren't sending the data.

I always used docker-compose on Ubuntu, in this environment containers are named with underscore:

• __

But now, I switched to Windows 10 (using Docker Desktop) and naming convention has changed:

• --

I don't know if this is OS dependent but it's a problem. My scripts are failing because they rely on containers named with underscores.

Is there a way to customize this and use underscore instead of dashes?

C++20 introduced std::span, which is a view-like object that can take in a continuous sequence, such as a C-style array, std::array, and std::vector. A common problem with a C-style array is it will decay to a pointer when passing to a function. Such a problem can be solved by using std::span:

I want to programmatically detect whenever someone sends Bitcoin to some address. This happens on a local testnet which I start using this docker-compose.yml file.

Once the local testnet runs, I create a new address using