compile client under freebsd

[skillcoder]

Describe your changes

Compile netbird client under freebsd and now support netstack and userspace modes.
Refactoring linux specific code to share same code with FreeBSD, move to *_unix.go files.

Not implemented yet:

• Kernel mode not supported
• DNS probably does not work yet
• Routing also probably does not work yet
• SSH support did not tested yet
• Lack of test environment for freebsd (dedicated VM for github runners under FreeBSD required)
• Lack of tests for freebsd specific code
• info reporting need to review and also implement, for example OS reported as GENERIC instead of FreeBSD (lack of FreeBSD icon in management interface)
• Lack of proper client setup under FreeBSD
• Lack of FreeBSD port/package

Issue ticket number and link

#1505

Checklist

• Is it a bug fix
• Is a typo/documentation fix
• Is a feature enhancement
• It is a refactor
• Created tests that fail without the change (if possible)
• Extended the README / documentation, if necessary

[CLAassistant]

All committers have signed the CLA.

[braginini]

Great stuff @skillcoder! Thank you for the contribution.

P.S. Would you like to get a NetBird t-shirt? Ping me on Slack

[skillcoder]

I need help from core team to setup github checks (tests, linters) for freebsd os.
And seems currents test required root to run + do not cleanup all created interfaces
Also need take into account following test warnings and error

time="2024-03-31T16:01:29Z" level=warning msg="the network 192.168.0.0/24 has not been assigned a routing peer as no peers from the list [peer1] are currently connected"
time="2024-03-31T16:01:29Z" level=warning msg="received a route to manage, but agent doesn't support router mode on freebsd OS"
time="2024-03-31T16:01:29Z" level=warning msg="the network 8.8.20.0/24 has not been assigned a routing peer as no peers from the list [remote1 remote1] are currently connected"
time="2024-03-31T16:01:29Z" level=error msg="this agent version: development, doesn't support default routes, received 0.0.0.0/0, skipping this route"
--- FAIL: TestAddRemoveRoutes (0.09s)
    --- FAIL: TestAddRemoveRoutes/Should_Not_Add_Or_Remove_Route_127.0.0.1/32 (0.03s)
        systemops_nonandroid_test.go:58: 
            	Error Trace:	/usr/home/jeff/github/skillcoder/netbird/client/internal/routemanager/systemops_nonandroid_test.go:58
            	Error:      	Received unexpected error:
            	            	exit status 1
            	Test:       	TestAddRemoveRoutes/Should_Not_Add_Or_Remove_Route_127.0.0.1/32
            	Messages:   	addToRouteTableIfNoExists should not return err
--- FAIL: TestAddExistAndRemoveRouteNonAndroid (0.14s)
    systemops_nonandroid_test.go:133: defaultGateway:  192.168.1.1
    --- FAIL: TestAddExistAndRemoveRouteNonAndroid/Should_Add_And_Remove_random_Route (0.02s)
        systemops_nonandroid_test.go:208: 
            	Error Trace:	/usr/home/jeff/github/skillcoder/netbird/client/internal/routemanager/systemops_nonandroid_test.go:208
            	Error:      	Should be true
            	Test:       	TestAddExistAndRemoveRouteNonAndroid/Should_Add_And_Remove_random_Route
            	Messages:   	route should exist
--- FAIL: TestExistsInRouteTable (0.00s)
    systemops_nonandroid_test.go:247: address 127.0.0.0/8 should exist in route table
FAIL
FAIL	github.com/netbirdio/netbird/client/internal/routemanager	0.445s

I did not touch routes on freebsd yet.
And did not check dns management so highly likely it also does not work properly.

[skillcoder]

Actually running tests locally is very risky.
You MUST run them only in isolated VM.
I noticed tests changed system state and keep it inconsistent.
For example /etc/resolv.conf

[lixmal]

manager.go:224 needs another case for freebsd

[pappz]

Hi! I tested the PR on FreeBSD and it works fine. Could you fix the conflict and then we will merge the PR?

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
No data about Duplication

See analysis details on SonarCloud