feat: add preprod observability foundation

deploy/observability/alloy/config.alloy

@@ -0,0 +1,95 @@
+logging {
+  level  = "info"
+  format = "logfmt"
+}
+
+otelcol.receiver.otlp "api" {
+  grpc {
+    endpoint = "0.0.0.0:4317"
+  }
+
+  http {
+    endpoint = "0.0.0.0:4318"
+  }
+
+  output {
+    metrics = [otelcol.processor.transform.metric_labels.input]
+    traces  = [otelcol.processor.batch.default.input]
+  }
+}
+
+otelcol.processor.transform "metric_labels" {
+  error_mode = "ignore"
+
+  metric_statements {
+    context = "datapoint"
+    statements = [
+      `set(attributes["service.name"], resource.attributes["service.name"])`,
+      `set(attributes["deployment.environment"], resource.attributes["deployment.environment"])`,
+    ]
+  }
+
+  output {
+    metrics = [otelcol.processor.batch.default.input]
+  }
+}
+
+otelcol.processor.batch "default" {
+  output {
+    metrics = [otelcol.exporter.prometheus.local.input]
+    traces  = [otelcol.exporter.otlp.tempo.input]
+  }
+}
+
+otelcol.exporter.prometheus "local" {
+  forward_to = [prometheus.remote_write.local.receiver]
+}
+
+prometheus.remote_write "local" {
+  endpoint {
+    url = "http://prometheus:9090/api/v1/write"
+  }
+}
+
+otelcol.exporter.otlp "tempo" {
+  client {
+    endpoint = "tempo:4317"
+
+    tls {
+      insecure = true
+    }
+  }
+}
+
+discovery.docker "linux" {
+  host = "unix:///var/run/docker.sock"
+}
+
+discovery.relabel "docker_logs" {
+  targets = []
+
+  rule {
+    source_labels = ["__meta_docker_container_name"]
+    regex         = "/(.*)"
+    target_label  = "service_name"
+  }
+
+  rule {
+    source_labels = ["__meta_docker_container_label_com_docker_compose_service"]
+    target_label  = "compose_service"
+  }
+}
+
+loki.source.docker "default" {
+  host          = "unix:///var/run/docker.sock"
+  targets       = discovery.docker.linux.targets
+  labels        = {"platform" = "docker"}
+  relabel_rules = discovery.relabel.docker_logs.rules
+  forward_to    = [loki.write.local.receiver]
+}
+
+loki.write "local" {
+  endpoint {
+    url = "http://loki:3100/loki/api/v1/push"
+  }
+}