extract ethereum connectors from ethereum upstreams and add ethereum pos config

src/main/kotlin/io/emeraldpay/dshackle/upstream/HttpRpcFactory.kt

@@ -0,0 +1,45 @@
+package io.emeraldpay.dshackle.upstream
+
+import io.emeraldpay.dshackle.config.AuthConfig
+import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcHttpClient
+import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcRequest
+import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcResponse
+import io.emeraldpay.dshackle.upstream.rpcclient.RpcMetrics
+import io.emeraldpay.grpc.Chain
+import io.micrometer.core.instrument.Counter
+import io.micrometer.core.instrument.Metrics
+import io.micrometer.core.instrument.Tag
+import io.micrometer.core.instrument.Timer
+
+open class HttpRpcFactory(
+    private val url: String,
+    private val basicAuth: AuthConfig.ClientBasicAuth?,
+    private val tls: ByteArray?
+) : HttpFactory {
+    override fun create(id: String?, chain: Chain): Reader<JsonRpcRequest, JsonRpcResponse> {
+        val metricsTags = listOf(
+            // "unknown" is not supposed to happen
+            Tag.of("upstream", id ?: "unknown"),
+            // UNSPECIFIED shouldn't happen too
+            Tag.of("chain", chain.chainCode)
+        )
+        val metrics = RpcMetrics(
+            Timer.builder("upstream.rpc.conn")
+                .description("Request time through a HTTP JSON RPC connection")
+                .tags(metricsTags)
+                .publishPercentileHistogram()
+                .register(Metrics.globalRegistry),
+            Counter.builder("upstream.rpc.fail")
+                .description("Number of failures of HTTP JSON RPC requests")
+                .tags(metricsTags)
+                .register(Metrics.globalRegistry)
+        )
+        return JsonRpcHttpClient(
+            url,
+            metrics,
+            basicAuth,
+            tls
+        )
+    }
+}