feat: retry x times if unable to find pom data

[siddarthkay]

As seen here : status-im/status-mobile#18294 and multiple times locally,
sometimes make nix-update-gradle fails to get pom data for this gradle dependency : https://plugins.gradle.org/plugin/com.adarshr.test-logger/2.0.0

Running make nix-update-gradle again fixes it, sometimes it takes more than a single retry to fix.

This PR introduces a minimum of 3 retries if go-maven-resolver fails to get pom data for any gradle dependency due to networking issues that could potentially be caused by concurrent threads.

This is just a suggestion and my not fix the problem for good, but I wanted your opinion on this @jakubgs and hence I opened this PR.

[siddarthkay]

I at first kept retryDelay to 2 seconds and although i didn't get any error but it was taking a lot of time to run make nix-update-gradle , I manually terminated the process after it was > 30 mins.

I then updated retryDelay to half a second and get errors like this :

finder.go:138: error: 'context deadline exceeded (Client.Timeout or context cancellation while 
reading body)' for: <Dep ID=io.netty:netty-parent:4.1.34.Final O=false S= >
finder.go:138: error: 'context deadline exceeded (Client.Timeout or context cancellation while 
reading body)' for: <Dep ID=org.apache.commons:commons-parent:32 O=false S= >
finder.go:138: error: 'context deadline exceeded (Client.Timeout or context cancellation while 
reading body)' for: <Dep ID=com.sun.activation:all:1.2.0 O=false S= >
finder.go:138: error: 'context deadline exceeded (Client.Timeout or context cancellation while 
reading body)' for: <Dep ID=io.netty:netty-parent:4.1.72.Final O=false S= >
finder.go:138: error: 'context deadline exceeded (Client.Timeout or context cancellation while 
reading body)' for: <Dep ID=io.netty:netty-parent:4.1.52.Final O=false S= >
finder.go:138: error: 'context deadline exceeded (Client.Timeout or context cancellation while 
reading body)' for: <Dep ID=com.sun.activation:all:1.2.1 O=false S= >

[siddarthkay]

After keeping delay of 1 second, make nix-upgrade-gradle ran fine but took 40 minutes 🥲🥲🥲
And then later when i added one more gradle dep manually, its been failing with errors like this :

finder.go:138: error: 'context deadline exceeded (Client.Timeout or context cancellation while reading 
body)' for: <Dep ID=org.apache.commons:commons-parent:52 O=false S= >
finder.go:138: error: 'context deadline exceeded (Client.Timeout or context cancellation while reading 
body)' for: <Dep ID=org.apache.commons:commons-parent:33 O=false S= >
finder.go:138: error: 'context deadline exceeded (Client.Timeout or context cancellation while reading 
body)' for: <Dep ID=org.apache.commons:commons-parent:39 O=false S= >
finder.go:138: error: 'context deadline exceeded (Client.Timeout or context cancellation while reading 
body)' for: <Dep ID=org.apache.commons:commons-parent:48 O=false S= >
finder.go:138: error: 'context deadline exceeded (Client.Timeout or context cancellation while reading 
body)' for: <Dep ID=net.sf.proguard:proguard-parent:5.2.1 O=false S= >
finder.go:138: error: 'context deadline exceeded (Client.Timeout or context cancellation while reading 
body)' for: <Dep ID=org.codehaus.mojo:mojo-parent:34 O=false S= >
finder.go:138: error: 'context deadline exceeded (Client.Timeout or context cancellation while reading 
body)' for: <Dep ID=org.codehaus.mojo:mojo-parent:50 O=false S= >

so probably this change is not such a good idea :)

[siddarthkay]

but took 40 minutes

could also be because of hotel wifi,
I'll check on another network and update here.

[siddarthkay]

yeah right the 40mins was due to bad wifi, it takes 9 minutes now

[jakubgs]

You are embedding magic constants into the finder modules. This is not how things should be done. Look at the Options struct that contains things like IgnoreOptional or RecursiveSearch. Clearly these settings should be added there as retryAttempts and retryDelayMsec to allow for configuration at runtime via CLI flags.

Secondly, why are you adding retries here if the fetcher module already has retries implemented?

go-maven-resolver/fetcher/fetcher.go

Lines 70 to 72 in bd9da57

	func (p *Fetcher) retryFetch(url string) (io.ReadCloser, error) {
	var resp http.Response
	for r := 1; r <= p.retries; r++ {