Go: x/pkgsite: local setup - tracking issue

[julieqiu]

Today, users can run pkgsite locally without setting up a local database by running:

go run cmd/frontend/main.go -direct_proxy -proxy_url=<your proxy URL>

See flags in cmd/frontend/main.go, and doc/frontend.md for docs.

Doing so allows users to view the package documentation, overview, imports, and licenses tabs. Search and other tabs on the package page are not supported in direct proxy mode.

However, there are cases when a user might want to run pkgsite on their local machine, and be able to view a private repository that is not available via a proxy.

Issues related to this topic:

• [x] #40159: run locally to view documentation of a pending CL

This is an umbrella issue to discuss what features are needed for this to happen, so please comment on your use cases below. For discussions about hosting a private instance of pkgsite, including your own internal proxy, see #39827.

[achille-roussel]

Hello @julieqiu

If I can add color to the pain points of running locally, having to start a proxy isn't too much trouble, but the constraint of requiring https is a bigger barrier:

$ go run ./cmd/frontend -direct_proxy -proxy_url http://localhost:8888
config: {
    "AuthHeader": "",
    "ProxyURL": "https://proxy.golang.org",
    "IndexURL": "https://index.golang.org/index",
    "Port": "",
    "DebugPort": "",
    "ProjectID": "",
    "ServiceID": "",
    "VersionID": "",
    "ZoneID": "",
    "InstanceID": "",
    "LocationID": "us-central1",
    "QueueService": "",
    "GaeEnv": "",
    "GoogleTagManagerID": "",
    "AppMonitoredResource": {
        "type": "gae_app",
        "labels": {
            "module_id": "",
            "project_id": "",
            "version_id": "",
            "zone": ""
        }
    },
    "FallbackVersionLabel": "20200729t023455",
    "DBSecret": "",
    "DBUser": "postgres",
    "DBHost": "localhost",
    "DBPort": "5432",
    "DBName": "discovery-db",
    "DBSecondaryHost": "",
    "RedisCacheHost": "",
    "RedisCachePort": "6379",
    "RedisHAHost": "",
    "RedisHAPort": "6379",
    "UseProfiler": false,
    "Quota": {
        "QPS": 10,
        "Burst": 20,
        "MaxEntries": 1000,
        "RecordOnly": true,
        "AuthHeader": "",
        "AuthValues": null
    },
    "TeeproxyAuthValue": "",
    "TeeproxyForwardedHosts": null
}
2020/07/29 02:34:55 Error: proxy.New("http://localhost:8888"): scheme must be https (got http)
exit status 1

What do you think about relaxing this constraint?

[gopherbot]

Change https://golang.org/cl/245639 mentions this issue: internal/proxy: remove URL validation in New

[julieqiu]

@achille-roussel - done! Thanks for the feedback.

[MicahParks]

To run pkgsite in a docker container, it'd be good to customize what networking interface the program binds to.

Executables in docker containers can more easily publish their services on the host's networking interface if bound to 0.0.0.0. It would be possible to allow this configuration via a flag by changing these lines:

https://github.com/golang/pkgsite/blob/ef183200d192b20102bb1246a86ae11de2d0738e/cmd/frontend/main.go#L170
https://github.com/golang/pkgsite/blob/ef183200d192b20102bb1246a86ae11de2d0738e/cmd/frontend/main.go#L148

to use a variable that is assigned by a flag instead of the "localhost" string.

[achille-roussel]

We had to solve for this as well in the fork we maintain at https://github.com/segmentio/pkgsite:

diff --git a/cmd/frontend/main.go b/cmd/frontend/main.go
index 5773d8e..e81022b 100644
--- a/cmd/frontend/main.go
+++ b/cmd/frontend/main.go
@@ -42,6 +42,7 @@ var (
                "for direct proxy mode and frontend fetches")
        directProxy = flag.Bool("direct_proxy", false, "if set to true, uses the module proxy referred to by this URL "+
                "as a direct backend, bypassing the database")
+       httpAddr = flag.String("http", "localhost:8080", "address to listen for incoming requests on")
 )

 func main() {
@@ -167,7 +168,7 @@ func main() {
                middleware.Timeout(54*time.Second),
                middleware.Experiment(experimenter),
        )
-       addr := cfg.HostAddr("localhost:8080")
+       addr := cfg.HostAddr(*httpAddr)
        log.Infof(ctx, "Listening on addr %s", addr)
        log.Fatal(ctx, http.ListenAndServe(addr, mw(router)))
 }

Taking a closer look at the way the configuration is setup, it appears that if the PORT environment variable is set the server will be listening on all network interfaces (as the address will be :$PORT), so maybe that change was unnecessary:

// HostAddr returns the network on which to serve the primary HTTP service.
func (c *Config) HostAddr(dflt string) string {
    if c.Port != "" {
        return fmt.Sprintf(":%s", c.Port)
    }
    return dflt
}

[gopherbot]

Change https://golang.org/cl/260779 mentions this issue: cmd/frontend: add -local flag