Replace the use of viper.bind flags with variables binding

[Jack-R-lantern]

That PR is the one that changes viper.BindPFlags.

Fixed #1108

[kkourt]

@mtardy could you please take a look? You created the issue, so I'm guessing you have context.

[mtardy]

Thanks indeed it removes the use of viper.Bind which is cool, thanks. However I have a few comments:

[mtardy]

It looks like some of those vars are unused, could we keep only the var used?

[Jack-R-lantern]

sure i will remove unused variable

[mtardy]

Can you rebase your PR on top of main as well so that the tests on vmtests will pass, I merged a PR to fix this recently :)

[Jack-R-lantern]

@mtardy
While checking the code, I noticed that for ServerAddress, using viper.IsSet.
For this, I changed it from the existing default value localhost:54321 to empty string

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[mtardy]

Thanks it looks good! Thank you for adding the feedback :)

[mtardy]

just as a note we could remove this useless variable but I'm okay to merge this as is! :)

[mtardy]

ah sorry we will need a last fix, I just noticed by reading carefully that the default value localhost:54321 value was removed here, not sure this is intentional?

I'm sorry there is just a little default value removed that might not be intentional!

[mtardy]

aaaah maybe you removed the default value because of this. I think @tixxdz worked on this, what do you think? Should we remove the default value localhost:54321 from the flag, see this https://github.com/cilium/tetragon/pull/1119/files#r1379864446.

[mtardy]

sorry to delay this PR again @Jack-R-lantern, will just need a look from Djalal because he worked on the default gRPC address to put so let him just ack this :)

[mtardy]

as far as I understand it would not be okay to remove the default since for most tetra users, tetragon might not run locally and the file (tetragon-info.json) it's trying to read will not be available. But with the default value, this part of the code will never be triggered. Maybe we could try to read the file containing the server address and fall back to the default localhost:54321 value on file read error?

[mtardy]

I haven't tested it but I think viper.IsSet returned false for the default value. So we would need to test this and to get the same behavior as before we should change some stuff here.

[Jack-R-lantern]

I'll do some more thinking about that code as well

[mtardy]

@tixxdz could you take a look at this one :)?

[Jack-R-lantern]

@mtardy I changed the code flow, what do you think?

[mtardy]

Really sorry for the delays here, Djalal seems busy, so I took a look and I find the code too complicated for what it wants to achieve, not your fault but the old code + this change are hard to read, so I suggest something like that:

diff --git a/cmd/tetra/common/client.go b/cmd/tetra/common/client.go
index 8d6d032e..237734a0 100644
--- a/cmd/tetra/common/client.go
+++ b/cmd/tetra/common/client.go
@@ -24,7 +24,7 @@ type daemonInfo struct {
 	ServerAddr string `json:"server_address"`
 }
 
-func getActiveServAddr(fname string) (string, error) {
+func readActiveServerAddress(fname string) (string, error) {
 	f, err := os.Open(fname)
 	if err != nil {
 		return "", err
@@ -43,42 +43,25 @@ func connect(ctx context.Context) (*grpc.ClientConn, string, error) {
 	connCtx, connCancel := context.WithTimeout(ctx, Timeout)
 	defer connCancel()
 
-	var conn *grpc.ClientConn
-	var serverAddr string
-	var err error
-
-	// The client cli can run remotely so to support most cases transparently
-	// Check if the server address was set
-	//   - If yes: use it directly, users know better
-	//   - If no: then try the default tetragon-info.json file to find the best
-	//       address if possible (could be unix socket). This also covers the
-	//       case that default address is localhost so we are operating in localhost
-	//       context anyway.
-	//       If that address is set try it, if it fails for any reason then retry
-	//       last time with the server address.
-	if ServerAddress != "" {
-		serverAddr = ServerAddress
-		conn, err = grpc.DialContext(connCtx, serverAddr, grpc.WithTransportCredentials(insecure.NewCredentials()), grpc.WithBlock())
-	} else {
-		serverAddr, err = getActiveServAddr(defaults.InitInfoFile)
-		if err == nil {
-			if serverAddr == "" {
-				serverAddr = defaultServerAddress
-			}
-			conn, err = grpc.DialContext(connCtx, serverAddr, grpc.WithTransportCredentials(insecure.NewCredentials()), grpc.WithBlock())
-			if err != nil {
-				logger.GetLogger().WithFields(logrus.Fields{
-					"InitInfoFile":   defaults.InitInfoFile,
-					"server-address": serverAddr,
-				}).WithError(err).Debugf("Failed to connect to server")
-			}
-		}
-		if conn == nil {
-			serverAddr = defaultServerAddress
-			conn, err = grpc.DialContext(connCtx, serverAddr, grpc.WithTransportCredentials(insecure.NewCredentials()), grpc.WithBlock())
+	// resolve ServerAdress: if flag set by user, use it, otherwise try to read
+	// it from tetragon-info.json, if it doesn't exist, just use default value
+	if ServerAddress == "" {
+		var err error
+		ServerAddress, err = readActiveServerAddress(defaults.InitInfoFile)
+		// if address could not be found in tetragon-info.json file, use default
+		if err != nil {
+			ServerAddress = defaultServerAddress
+			logger.GetLogger().WithField("ServerAddress", ServerAddress).Debug("connect to server using default value")
+		} else {
+			logger.GetLogger().WithFields(logrus.Fields{
+				"InitInfoFile":  defaults.InitInfoFile,
+				"ServerAddress": ServerAddress,
+			}).Debug("connect to server using address in info file")
 		}
 	}
-	return conn, serverAddr, err
+
+	conn, err := grpc.DialContext(connCtx, ServerAddress, grpc.WithTransportCredentials(insecure.NewCredentials()), grpc.WithBlock())
+	return conn, ServerAddress, err
 }
 
 func CliRunErr(fn func(ctx context.Context, cli tetragon.FineGuidanceSensorsClient), fnErr func(err error)) {

You can save this into a file and git apply it to your branch, it should work

[Jack-R-lantern]

@mtardy
I'm fine. You don't have to worry about it.
I'll change it
thanks

[mtardy]

Thanks a lot for your patience, let's merge this, Djalal can always revert if anything is not good but I tested it and it's great, thanks!

I would have squashed the commits but it's okay we can go like that :)

[Jack-R-lantern]

When I thought of 'revert', 'squash' seems to be a must.
I'll reflect it in the PR, thanks for the review.

[mtardy]

Thanks again for your patience and work :)