Add Gitpod configuration

[i-ky]

Gitpod provides development environment in your browser.

To simplify integration with Gitpod and improve development experience in general, I've tweaked Makefile a bit to allow builds outside of Zabbix source tree:

$ make ZABBIX_SOURCE=/path/to/zabbix

In this case copying files to src/modules/ of Zabbix is not required. But by default Makefile will behave like before (and Travis CI config didn't change).

[i-ky]

I guess it would be nice to provide some explanations.

.gitpod.Dockerfile describes a container we will use for development. It is based on gitpod/workspace-full which comes with lots of development tools, but we still need few more:

• Autotools to configure Zabbix sources;
• Build EAR to capture compiler invocations into compilation database.

.gitpod.yml describes actions that need to be performed when you start a new workspace or jump into existing one. In our case we check out Zabbix sources and configure them. We do it in /workspace/ folder, because it is persisted between sessions. That way if you jump into existing workspace Zabbix is already configured and everything is ready to go.

Gitpod comes packed with C/C++ development tools, one of which is clangd language server. But for it to work properly, it needs to know how we compile our source files. So another thing we do when initialising workspace is building module using bear. This produces compile_commands.json file.

TODO for the future is to add compile_commands.json and .clangd/ (where clangd stores its stuff) to .gitignore).

Perhaps it also makes sense to install Docker and Zabbix agent into workspace. This will allow testing module without even leaving your browser.

[jangaraj]

Perhaps it also makes sense to install Docker and Zabbix agent into workspace.

Yes, I was trying that, but running Docker in Docker (in the Gitpod container) will be tricky. Maybe some Docker service simulation and hardcoded cgroup structure will help with development/testing.

[i-ky]

running Docker in Docker (in the Gitpod container) will be tricky

Indeed, currently it is not possible. Here is the issue.

Maybe some Docker service simulation and hardcoded cgroup structure will help with development/testing.

This could be the way to go. I can recall using SNMP simulator for testing SNMP monitoring. It can "record" actual devices and then "replay" them. Maybe a similar project exists for Docker.

[i-ky]

@jangaraj, FYI Gitpod now supports root and Docker.

[jangaraj]

Unfortunately, this is still something like Docker in Docker - the same problem for GitHub Action/Gitpod: cgroups are not visible, so only keys which use Docker API can be tested, but metrics from cgroups will fail:

The best way (also from the future point of view, where cgroup v2 will be used) will be to calculate everything from the Docker API container stat response - https://docs.docker.com/engine/api/v1.41/#operation/ContainerStats