doPush impl almost done

README.md

@@ -1,2 +1,24 @@
 # prometheus-android-exporter
 Prometheus exporter for android
+
+# Not public
+143.42.59.63:9090 - prometheus
+
+# Client
+Android app written in kotlin using Jetpack Compose.
+
+# Server
+
+## TL;DR
+```
+cd ./server
+
+# edit ansible_inventory
+
+# To apply ansible playbook
+$ ansible-playbook ansible_playbook.yaml
+
+# To only apply changed configuration
+$ ansible-playbook ansible_playbook.yaml --tags config
+``` 
+

client/app/build.gradle

@@ -59,9 +59,8 @@ dependencies {
     implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:1.7.0-RC"
 
     // custom - ktor web client
-    implementation("io.ktor:ktor-server-core:2.2.4")
+    implementation("io.ktor:ktor-client-core:2.3.0")
-    runtimeOnly("io.ktor:ktor-client-core:2.2.4")
+    implementation("io.ktor:ktor-client-cio:2.3.0")
-    implementation("io.ktor:ktor-client-cio:2.2.4")
 
 
     implementation 'androidx.core:core-ktx:1.7.0'

client/app/src/main/java/com/birdthedeveloper/prometheus/android/prometheus/android/exporter/MainActivity.kt

@@ -18,6 +18,7 @@ import com.birdthedeveloper.prometheus.android.prometheus.android.exporter.ui.th
 import io.prometheus.client.Collector
 import io.prometheus.client.CollectorRegistry
 import io.prometheus.client.exporter.common.TextFormat
+import kotlinx.coroutines.delay
 import kotlinx.coroutines.launch
 import java.io.StringWriter
 
@@ -27,6 +28,7 @@ class MainActivity : ComponentActivity() {
     private lateinit var metricsEngine: MetricsEngine
     private lateinit var customExporter: AndroidCustomExporter
 
+    private var pushProxStarted : Boolean = false
     private lateinit var pushProxClient : PushProxClient
 
     override fun onCreate(savedInstanceState: Bundle?) {
@@ -51,22 +53,32 @@ class MainActivity : ComponentActivity() {
         customExporter = AndroidCustomExporter(metricsEngine).register(collectorRegistry)
     }
 
-    fun CollectMetrics(): String{
+    private suspend fun reallyCollectMetrics() : String {
+        delay(500)
+        val writer = StringWriter()
+        TextFormat.write004(writer, collectorRegistry.metricFamilySamples())
+        return writer.toString()
+    }
+
+    private fun CollectMetrics(): String{
         val writer = StringWriter()
         TextFormat.write004(writer, collectorRegistry.metricFamilySamples())
 
         // initialize PushProx
-        pushProxClient = PushProxClient(
+        if (!pushProxStarted) {
-            config = PushProxConfig(
+            pushProxClient = PushProxClient(
-                "test.example.com",
+                config = PushProxConfig(
-                "143.42.59.63",
+                    "test.example.com",
-                1,
+                    "http://143.42.59.63:8080",
-                5,
+                    1,
-                true
+                    5,
-
+                    collectorRegistry,
+                    ::reallyCollectMetrics,
+                )
             )
-        )
+            pushProxClient.startBackground()
-        pushProxClient.startBackground()
+            pushProxStarted = true
+        }
 
         return writer.toString()
     }

client/app/src/main/java/com/birdthedeveloper/prometheus/android/prometheus/android/exporter/PushProxClient.kt

@@ -1,5 +1,6 @@
 package com.birdthedeveloper.prometheus.android.prometheus.android.exporter
 
+import android.preference.PreferenceActivity.Header
 import android.util.Log
 import io.github.reugn.kotlin.backoff.StrategyBackoff
 import io.github.reugn.kotlin.backoff.strategy.ExponentialStrategy
@@ -8,14 +9,17 @@ import io.ktor.client.call.body
 import io.ktor.client.engine.cio.CIO
 import io.ktor.client.request.HttpRequestBuilder
 import io.ktor.client.request.get
+import io.ktor.client.request.header
 import io.ktor.client.request.post
 import io.ktor.client.request.request
 import io.ktor.client.request.setBody
 import io.ktor.client.statement.HttpResponse
+import io.ktor.http.HttpHeaders
 import io.ktor.http.HttpMethod
 import io.ktor.http.URLBuilder
 import io.ktor.http.Url
 import io.ktor.http.maxAge
+import io.prometheus.client.CollectorRegistry
 import io.prometheus.client.Counter
 import kotlinx.coroutines.Deferred
 import kotlinx.coroutines.GlobalScope
@@ -26,35 +30,38 @@ import kotlinx.coroutines.runBlocking
 import kotlin.time.Duration
 
 // Counters for monitoring the pushprox itself, compatible with the reference implementation in go.
-private class Counters(enabled: Boolean) {
+private class Counters(collectorRegistry: CollectorRegistry?) {
-    private val enabled : Boolean
+    private val collectorRegistry : CollectorRegistry?
     private lateinit var scrapeErrorCounter : Counter
     private lateinit var pushErrorCounter : Counter
     private lateinit var pollErrorCounter : Counter
     private lateinit var pollSuccessCounter : Counter
+    private var enabled : Boolean = false
 
     init {
-        this.enabled = enabled
+        this.collectorRegistry = collectorRegistry
-        if (enabled){
+        if (collectorRegistry != null){
+            this.enabled = true
+
             // following 3 counters are compatible with reference implementation
             scrapeErrorCounter = Counter.build()
                 .name("pushprox_client_scrape_errors_total")
                 .help("Number of scrape errors")
-                .register()
+                .register(collectorRegistry)
             pushErrorCounter = Counter.build()
                 .name("pushprox_client_push_errors_total")
                 .help("Number of push errors")
-                .register()
+                .register(collectorRegistry)
             pollErrorCounter = Counter.build()
                 .name("pushprox_client_poll_errors_total")
                 .help("Number of poll errors")
-                .register()
+                .register(collectorRegistry)
 
             // custom
             pollSuccessCounter = Counter.build()
                 .name("pushprox_client_poll_total")
                 .help("Number of succesfull polls")
-                .register()
+                .register(collectorRegistry)
         }
     }
 
@@ -73,11 +80,13 @@ data class PushProxConfig(
     val proxyURL: String,
     val retryInitialWaitSeconds: Int = 1, //TODO will this be even used?
     val retryMaxWaitSeconds: Int = 5, //TODO will this be even used?
-    val enablePushProxClientMonitoring: Boolean = true,
+    val collectorRegistry: CollectorRegistry? = null,
+    val performScrape: suspend () -> String,
 )
 
 // This is a stripped down kotlin implementation of github.com/prometheus-community/PushProx client
 class PushProxClient(config: PushProxConfig) {
+    //TODO dispose this thing - delete http client
     private val config: PushProxConfig
     private val pollURL: String
     private val pushURL: String
@@ -88,8 +97,8 @@ class PushProxClient(config: PushProxConfig) {
     init {
         this.config = config
 
-        // make sure proxyURL ends with a single '/'
+        // make sure proxyURL ends without '/'
-        val modifiedProxyURL = config.proxyURL.trim('/') + '/'
+        val modifiedProxyURL = config.proxyURL.trim('/')
         log("ModifiedUrl", modifiedProxyURL)
 
         pollURL = "$modifiedProxyURL/poll"
@@ -99,7 +108,7 @@ class PushProxClient(config: PushProxConfig) {
     // initialize resource - heavier objects
     private fun setup(){
         // init counters if they are enabled
-        counters = Counters(config.enablePushProxClientMonitoring)
+        counters = Counters(config.collectorRegistry)
         client = HttpClient(CIO)
     }
 
@@ -110,10 +119,15 @@ class PushProxClient(config: PushProxConfig) {
     }
 
     private suspend fun doPoll(){
+        log("poll", "polling now")
+        log(pollURL, pollURL)
         val response : HttpResponse = client.post(pollURL){
             setBody(config.myFqdn)
         }
+        log("here", "here")
         val responseBody: String = response.body<String>()
+        doPush(responseBody)
+        // response body is not needed
         log("responseBody in poll", responseBody)
         log("got scrape request", responseBody)
 
@@ -121,16 +135,43 @@ class PushProxClient(config: PushProxConfig) {
 
     }
 
-    private fun parseRequest(request : String) : HttpRequestBuilder {
+    private fun getIdFromResponseBody(responseBody: String) : String {
-        var result : HttpRequestBuilder = HttpRequestBuilder()
-
         //TODO implement this
-
+        return "5"
-        return result
+        //TODO throw custom exception if this is wrong
     }
 
-    private fun doPush() {
+    // responseBody: response body of /poll request
+    private suspend fun doPush(responseBody : String) {
         //TODO implement
+
+        // perform scrape
+        lateinit var scrapedMetrics : String
+        try {
+            scrapedMetrics = config.performScrape()
+        }catch(e : Exception){
+            counters.scrapeError()
+            log("scrape exception", e.toString())
+            return
+        }
+
+        try{
+            log("scraped metrics in doPush", scrapedMetrics)
+            val scrapeId : String = getIdFromResponseBody(responseBody)
+            val response : HttpResponse = client.request(pushURL) {
+                header("id", scrapeId)
+                header("X-prometheus-scrape-timeout", "4") //TODO this is dummy for now
+                method = HttpMethod.Post
+
+                setBody(scrapedMetrics)
+            }
+
+        }catch(e : Exception){
+            counters.pushError()
+            log("push exception", e.toString())
+            return
+        }
+
     }
 
     private fun handleErr(){
@@ -151,10 +192,7 @@ class PushProxClient(config: PushProxConfig) {
         )
     }
 
-    private suspend fun exceptionTest(){
+
-        delay(1000L)
-        throw IllegalArgumentException()
-    }
 
     private fun loop(backoff: StrategyBackoff<Unit>) {
         // fire and forget a new coroutine
@@ -162,26 +200,18 @@ class PushProxClient(config: PushProxConfig) {
             launch {
                 while (true) {
                     val job = launch {
-                        log("pushprox loop now", "-")
+                        log("pushprox main loop", "loop start")
                         var result = backoff.withRetries {
-                            val result: Deferred<Unit> = async {
+                            // register poll error using try-catch block
-                                delay(1000L)
-                            }
-
-                            log("progress", "after poll")
-
-                            // register poll error
                             try {
-                                result.await()
+                                doPoll()
                             } catch (e: Exception) {
-                                log("progress", "catched")
+                                log("exception encountered!", e.toString())
-                                log("exception", e.toString())
                                 counters.pollError()
                                 throw e
                             }
                         }
-
+                        log("pushprox main loop", "loop end")
-                        log("pushprox loop end", "end")
                     }
                     job.join()
                 }

server/README.md

@@ -1,2 +0,0 @@
-# Server configuration, intended use of this demo
-#TODO demo , describe all files

server/ansible_playbook.yaml

@@ -105,6 +105,7 @@
             mode: 0644
             force: true
           register: config_files
+          tags: config
 
         - name: Copy docker-compose.yaml
           ansible.builtin.copy:
@@ -115,19 +116,22 @@
             mode: 0644
             force: true
           register: compose_file
+          tags: config
 
         - name: Pull images
           community.docker.docker_compose:
             pull: true
             project_src: "{{ '/home/' + new_user_name }}"
+          tags: config
 
         - name: Start docker compose
           community.docker.docker_compose:
             state: present
             project_src: "{{ '/home/' + new_user_name }}"
             restarted: "{{ (config_files.changed | bool) or (compose_file.changed | bool) }}"
+          tags: config
 
-    - name: Create docker compose systemd service
+    - name: Create docker compose systemd service to start docker compose on boot
       block:
         - name: Copy docker compose unit file
           ansible.builtin.template:

server/configuration/nginx.conf

@@ -13,7 +13,7 @@ http{
     }
 
     upstream pushprox{
-        server pushprox:8080;    
+        server pushprox:8080;
     }
 
     upstream grafana{
@@ -46,9 +46,14 @@ http{
     server {
         listen 8080;
 
+        proxy_read_timeout 3600;
+        proxy_connect_timeout 3600;
+        proxy_send_timeout 3600; 
+
         location / {
             proxy_pass http://pushprox;
         }
+
     }
 
     # Prometheus UI server configuration

server/configuration/prometheus.yaml

@@ -10,4 +10,8 @@ scrape_configs:
   
   - job_name: "android phones"
     proxy_url: "http://pushprox:8080" #TODO add mobile phones here
+    static_configs:
+      - targets: [
+          "test.example.com"
+        ]