1 /* 2 * Copyright 2018, OpenCensus Authors 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 /** 18 * API for resource information population. 19 * 20 * <p>The resource library primarily defines a type "Resource" that captures information about the 21 * entity for which stats or traces are recorded. For example, metrics exposed by a Kubernetes 22 * container can be linked to a resource that specifies the cluster, namespace, pod, and container 23 * name. 24 * 25 * <p>Two environment variables are used to populate resource information: 26 * 27 * <ul> 28 * <li>OC_RESOURCE_TYPE: A string that describes the type of the resource prefixed by a domain 29 * namespace. Leading and trailing whitespaces are trimmed. e.g. “kubernetes.io/container”. 30 * <li>OC_RESOURCE_LABELS: A comma-separated list of labels describing the source in more detail, 31 * e.g. “key1=val1,key2=val2”. The allowed character set is appropriately constrained. 32 * </ul> 33 * 34 * <p>Type, label keys, and label values MUST contain only printable ASCII (codes between 32 and 35 * 126, inclusive) and less than 256 characters. Type and label keys MUST have a length greater than 36 * zero. They SHOULD start with a domain name and separate hierarchies with / characters, e.g. 37 * k8s.io/namespace/name. 38 * 39 * <p>WARNING: Currently all the public classes under this package are marked as {@link 40 * io.opencensus.common.ExperimentalApi}. DO NOT USE except for experimental purposes. 41 * 42 * <p>Please see 43 * https://github.com/census-instrumentation/opencensus-specs/blob/master/resource/Resource.md for 44 * more details. 45 */ 46 @io.opencensus.common.ExperimentalApi 47 package io.opencensus.resource; 48