org.apache.kafka.common.config.AbstractConfig Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.kafka.common.config;
import org.apache.kafka.common.Configurable;
import org.apache.kafka.common.KafkaException;
import org.apache.kafka.common.config.types.Password;
import org.apache.kafka.common.utils.Utils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.kafka.common.config.provider.ConfigProvider;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;
/**
* A convenient base class for configurations to extend.
*
* This class holds both the original configuration that was provided as well as the parsed
*/
public class AbstractConfig {
private final Logger log = LoggerFactory.getLogger(getClass());
/* configs for which values have been requested, used to detect unused configs */
private final Set used;
/* the original values passed in by the user */
private final Map originals;
/* the parsed values */
private final Map values;
private final ConfigDef definition;
public static final String CONFIG_PROVIDERS_CONFIG = "config.providers";
private static final String CONFIG_PROVIDERS_PARAM = ".param.";
/**
* Construct a configuration with a ConfigDef and the configuration properties, which can include properties
* for zero or more {@link ConfigProvider} that will be used to resolve variables in configuration property
* values.
*
* The originals is a name-value pair configuration properties and optional config provider configs. The
* value of the configuration can be a variable as defined below or the actual value. This constructor will
* first instantiate the ConfigProviders using the config provider configs, then it will find all the
* variables in the values of the originals configurations, attempt to resolve the variables using the named
* ConfigProviders, and then parse and validate the configurations.
*
* ConfigProvider configs can be passed either as configs in the originals map or in the separate
* configProviderProps map. If config providers properties are passed in the configProviderProps any config
* provider properties in originals map will be ignored. If ConfigProvider properties are not provided, the
* constructor will skip the variable substitution step and will simply validate and parse the supplied
* configuration.
*
* The "{@code config.providers}" configuration property and all configuration properties that begin with the
* "{@code config.providers.}" prefix are reserved. The "{@code config.providers}" configuration property
* specifies the names of the config providers, and properties that begin with the "{@code config.providers..}"
* prefix correspond to the properties for that named provider. For example, the "{@code config.providers..class}"
* property specifies the name of the {@link ConfigProvider} implementation class that should be used for
* the provider.
*
* The keys for ConfigProvider configs in both originals and configProviderProps will start with the above
* mentioned "{@code config.providers.}" prefix.
*
* Variables have the form "${providerName:[path:]key}", where "providerName" is the name of a ConfigProvider,
* "path" is an optional string, and "key" is a required string. This variable is resolved by passing the "key"
* and optional "path" to a ConfigProvider with the specified name, and the result from the ConfigProvider is
* then used in place of the variable. Variables that cannot be resolved by the AbstractConfig constructor will
* be left unchanged in the configuration.
*
*
* @param definition the definition of the configurations; may not be null
* @param originals the configuration properties plus any optional config provider properties;
* @param configProviderProps the map of properties of config providers which will be instantiated by
* the constructor to resolve any variables in {@code originals}; may be null or empty
* @param doLog whether the configurations should be logged
*/
@SuppressWarnings("unchecked")
public AbstractConfig(ConfigDef definition, Map originals, Map configProviderProps, boolean doLog) {
/* check that all the keys are really strings */
for (Map.Entry entry : originals.entrySet())
if (!(entry.getKey() instanceof String))
throw new ConfigException(entry.getKey().toString(), entry.getValue(), "Key must be a string.");
this.originals = resolveConfigVariables(configProviderProps, (Map) originals);
this.values = definition.parse(this.originals);
this.used = Collections.synchronizedSet(new HashSet<>());
Map configUpdates = postProcessParsedConfig(Collections.unmodifiableMap(this.values));
for (Map.Entry update : configUpdates.entrySet()) {
this.values.put(update.getKey(), update.getValue());
}
definition.parse(this.values);
this.definition = definition;
if (doLog)
logAll();
}
/**
* Construct a configuration with a ConfigDef and the configuration properties,
* which can include properties for zero or more {@link ConfigProvider}
* that will be used to resolve variables in configuration property values.
*
* @param definition the definition of the configurations; may not be null
* @param originals the configuration properties plus any optional config provider properties; may not be null
*/
public AbstractConfig(ConfigDef definition, Map originals) {
this(definition, originals, Collections.emptyMap(), true);
}
/**
* Construct a configuration with a ConfigDef and the configuration properties,
* which can include properties for zero or more {@link ConfigProvider}
* that will be used to resolve variables in configuration property values.
*
* @param definition the definition of the configurations; may not be null
* @param originals the configuration properties plus any optional config provider properties; may not be null
* @param doLog whether the configurations should be logged
*/
public AbstractConfig(ConfigDef definition, Map originals, boolean doLog) {
this(definition, originals, Collections.emptyMap(), doLog);
}
/**
* Called directly after user configs got parsed (and thus default values got set).
* This allows to change default values for "secondary defaults" if required.
*
* @param parsedValues unmodifiable map of current configuration
* @return a map of updates that should be applied to the configuration (will be validated to prevent bad updates)
*/
protected Map postProcessParsedConfig(Map parsedValues) {
return Collections.emptyMap();
}
protected Object get(String key) {
if (!values.containsKey(key))
throw new ConfigException(String.format("Unknown configuration '%s'", key));
used.add(key);
return values.get(key);
}
public void ignore(String key) {
used.add(key);
}
public Short getShort(String key) {
return (Short) get(key);
}
public Integer getInt(String key) {
return (Integer) get(key);
}
public Long getLong(String key) {
return (Long) get(key);
}
public Double getDouble(String key) {
return (Double) get(key);
}
@SuppressWarnings("unchecked")
public List getList(String key) {
return (List) get(key);
}
public Boolean getBoolean(String key) {
return (Boolean) get(key);
}
public String getString(String key) {
return (String) get(key);
}
public ConfigDef.Type typeOf(String key) {
ConfigDef.ConfigKey configKey = definition.configKeys().get(key);
if (configKey == null)
return null;
return configKey.type;
}
public String documentationOf(String key) {
ConfigDef.ConfigKey configKey = definition.configKeys().get(key);
if (configKey == null)
return null;
return configKey.documentation;
}
public Password getPassword(String key) {
return (Password) get(key);
}
public Class getClass(String key) {
return (Class) get(key);
}
public Set unused() {
Set keys = new HashSet<>(originals.keySet());
keys.removeAll(used);
return keys;
}
public Map originals() {
Map copy = new RecordingMap<>();
copy.putAll(originals);
return copy;
}
/**
* Get all the original settings, ensuring that all values are of type String.
* @return the original settings
* @throws ClassCastException if any of the values are not strings
*/
public Map originalsStrings() {
Map copy = new RecordingMap<>();
for (Map.Entry entry : originals.entrySet()) {
if (!(entry.getValue() instanceof String))
throw new ClassCastException("Non-string value found in original settings for key " + entry.getKey() +
": " + (entry.getValue() == null ? null : entry.getValue().getClass().getName()));
copy.put(entry.getKey(), (String) entry.getValue());
}
return copy;
}
/**
* Gets all original settings with the given prefix, stripping the prefix before adding it to the output.
*
* @param prefix the prefix to use as a filter
* @return a Map containing the settings with the prefix
*/
public Map originalsWithPrefix(String prefix) {
return originalsWithPrefix(prefix, true);
}
/**
* Gets all original settings with the given prefix.
*
* @param prefix the prefix to use as a filter
* @param strip strip the prefix before adding to the output if set true
* @return a Map containing the settings with the prefix
*/
public Map originalsWithPrefix(String prefix, boolean strip) {
Map result = new RecordingMap<>(prefix, false);
for (Map.Entry entry : originals.entrySet()) {
if (entry.getKey().startsWith(prefix) && entry.getKey().length() > prefix.length()) {
if (strip)
result.put(entry.getKey().substring(prefix.length()), entry.getValue());
else
result.put(entry.getKey(), entry.getValue());
}
}
return result;
}
/**
* Put all keys that do not start with {@code prefix} and their parsed values in the result map and then
* put all the remaining keys with the prefix stripped and their parsed values in the result map.
*
* This is useful if one wants to allow prefixed configs to override default ones.
*
* Two forms of prefixes are supported:
*
* - listener.name.{listenerName}.some.prop: If the provided prefix is `listener.name.{listenerName}.`,
* the key `some.prop` with the value parsed using the definition of `some.prop` is returned.
* - listener.name.{listenerName}.{mechanism}.some.prop: If the provided prefix is `listener.name.{listenerName}.`,
* the key `{mechanism}.some.prop` with the value parsed using the definition of `some.prop` is returned.
* This is used to provide per-mechanism configs for a broker listener (e.g sasl.jaas.config)
*
*
*/
public Map valuesWithPrefixOverride(String prefix) {
Map result = new RecordingMap<>(values(), prefix, true);
for (Map.Entry entry : originals.entrySet()) {
if (entry.getKey().startsWith(prefix) && entry.getKey().length() > prefix.length()) {
String keyWithNoPrefix = entry.getKey().substring(prefix.length());
ConfigDef.ConfigKey configKey = definition.configKeys().get(keyWithNoPrefix);
if (configKey != null)
result.put(keyWithNoPrefix, definition.parseValue(configKey, entry.getValue(), true));
else {
String keyWithNoSecondaryPrefix = keyWithNoPrefix.substring(keyWithNoPrefix.indexOf('.') + 1);
configKey = definition.configKeys().get(keyWithNoSecondaryPrefix);
if (configKey != null)
result.put(keyWithNoPrefix, definition.parseValue(configKey, entry.getValue(), true));
}
}
}
return result;
}
/**
* If at least one key with {@code prefix} exists, all prefixed values will be parsed and put into map.
* If no value with {@code prefix} exists all unprefixed values will be returned.
*
* This is useful if one wants to allow prefixed configs to override default ones, but wants to use either
* only prefixed configs or only regular configs, but not mix them.
*/
public Map valuesWithPrefixAllOrNothing(String prefix) {
Map withPrefix = originalsWithPrefix(prefix, true);
if (withPrefix.isEmpty()) {
return new RecordingMap<>(values(), "", true);
} else {
Map result = new RecordingMap<>(prefix, true);
for (Map.Entry entry : withPrefix.entrySet()) {
ConfigDef.ConfigKey configKey = definition.configKeys().get(entry.getKey());
if (configKey != null)
result.put(entry.getKey(), definition.parseValue(configKey, entry.getValue(), true));
}
return result;
}
}
public Map values() {
return new RecordingMap<>(values);
}
private void logAll() {
StringBuilder b = new StringBuilder();
b.append(getClass().getSimpleName());
b.append(" values: ");
b.append(Utils.NL);
for (Map.Entry entry : new TreeMap<>(this.values).entrySet()) {
b.append('\t');
b.append(entry.getKey());
b.append(" = ");
b.append(entry.getValue());
b.append(Utils.NL);
}
log.info(b.toString());
}
/**
* Log warnings for any unused configurations
*/
public void logUnused() {
for (String key : unused())
log.warn("The configuration '{}' was supplied but isn't a known config.", key);
}
private T getConfiguredInstance(Object klass, Class t, Map configPairs) {
if (klass == null)
return null;
Object o;
if (klass instanceof String) {
try {
o = Utils.newInstance((String) klass, t);
} catch (ClassNotFoundException e) {
throw new KafkaException("Class " + klass + " cannot be found", e);
}
} else if (klass instanceof Class) {
o = Utils.newInstance((Class) klass);
} else
throw new KafkaException("Unexpected element of type " + klass.getClass().getName() + ", expected String or Class");
if (!t.isInstance(o))
throw new KafkaException(klass + " is not an instance of " + t.getName());
if (o instanceof Configurable)
((Configurable) o).configure(configPairs);
return t.cast(o);
}
/**
* Get a configured instance of the give class specified by the given configuration key. If the object implements
* Configurable configure it using the configuration.
*
* @param key The configuration key for the class
* @param t The interface the class should implement
* @return A configured instance of the class
*/
public T getConfiguredInstance(String key, Class t) {
Class c = getClass(key);
return getConfiguredInstance(c, t, originals());
}
/**
* Get a list of configured instances of the given class specified by the given configuration key. The configuration
* may specify either null or an empty string to indicate no configured instances. In both cases, this method
* returns an empty list to indicate no configured instances.
* @param key The configuration key for the class
* @param t The interface the class should implement
* @return The list of configured instances
*/
public List getConfiguredInstances(String key, Class t) {
return getConfiguredInstances(key, t, Collections.emptyMap());
}
/**
* Get a list of configured instances of the given class specified by the given configuration key. The configuration
* may specify either null or an empty string to indicate no configured instances. In both cases, this method
* returns an empty list to indicate no configured instances.
* @param key The configuration key for the class
* @param t The interface the class should implement
* @param configOverrides Configuration overrides to use.
* @return The list of configured instances
*/
public List getConfiguredInstances(String key, Class t, Map configOverrides) {
return getConfiguredInstances(getList(key), t, configOverrides);
}
/**
* Get a list of configured instances of the given class specified by the given configuration key. The configuration
* may specify either null or an empty string to indicate no configured instances. In both cases, this method
* returns an empty list to indicate no configured instances.
* @param classNames The list of class names of the instances to create
* @param t The interface the class should implement
* @param configOverrides Configuration overrides to use.
* @return The list of configured instances
*/
public List getConfiguredInstances(List classNames, Class t, Map configOverrides) {
List objects = new ArrayList<>();
if (classNames == null)
return objects;
Map configPairs = originals();
configPairs.putAll(configOverrides);
for (Object klass : classNames) {
Object o = getConfiguredInstance(klass, t, configPairs);
objects.add(t.cast(o));
}
return objects;
}
private Map extractPotentialVariables(Map configMap) {
// Variables are tuples of the form "${providerName:[path:]key}". From the configMap we extract the subset of configs with string
// values as potential variables.
Map configMapAsString = new HashMap<>();
for (Map.Entry entry : configMap.entrySet()) {
if (entry.getValue() instanceof String)
configMapAsString.put((String) entry.getKey(), (String) entry.getValue());
}
return configMapAsString;
}
/**
* Instantiates given list of config providers and fetches the actual values of config variables from the config providers.
* returns a map of config key and resolved values.
* @param configProviderProps The map of config provider configs
* @param originals The map of raw configs.
* @return map of resolved config variable.
*/
@SuppressWarnings("unchecked")
private Map resolveConfigVariables(Map configProviderProps, Map originals) {
Map providerConfigString;
Map configProperties;
Map resolvedOriginals = new HashMap<>();
// As variable configs are strings, parse the originals and obtain the potential variable configs.
Map indirectVariables = extractPotentialVariables(originals);
resolvedOriginals.putAll(originals);
if (configProviderProps == null || configProviderProps.isEmpty()) {
providerConfigString = indirectVariables;
configProperties = originals;
} else {
providerConfigString = extractPotentialVariables(configProviderProps);
configProperties = configProviderProps;
}
Map providers = instantiateConfigProviders(providerConfigString, configProperties);
if (!providers.isEmpty()) {
ConfigTransformer configTransformer = new ConfigTransformer(providers);
ConfigTransformerResult result = configTransformer.transform(indirectVariables);
if (!result.data().isEmpty()) {
resolvedOriginals.putAll(result.data());
}
}
providers.values().forEach(x -> Utils.closeQuietly(x, "config provider"));
return new ResolvingMap<>(resolvedOriginals, originals);
}
private Map configProviderProperties(String configProviderPrefix, Map providerConfigProperties) {
Map result = new HashMap<>();
for (Map.Entry entry : providerConfigProperties.entrySet()) {
String key = entry.getKey();
if (key.startsWith(configProviderPrefix) && key.length() > configProviderPrefix.length()) {
result.put(key.substring(configProviderPrefix.length()), entry.getValue());
}
}
return result;
}
/**
* Instantiates and configures the ConfigProviders. The config providers configs are defined as follows:
* config.providers : A comma-separated list of names for providers.
* config.providers.{name}.class : The Java class name for a provider.
* config.providers.{name}.param.{param-name} : A parameter to be passed to the above Java class on initialization.
* returns a map of config provider name and its instance.
* @param indirectConfigs The map of potential variable configs
* @param providerConfigProperties The map of config provider configs
* @return map map of config provider name and its instance.
*/
private Map instantiateConfigProviders(Map indirectConfigs, Map providerConfigProperties) {
final String configProviders = indirectConfigs.get(CONFIG_PROVIDERS_CONFIG);
if (configProviders == null || configProviders.isEmpty()) {
return Collections.emptyMap();
}
Map providerMap = new HashMap<>();
for (String provider: configProviders.split(",")) {
String providerClass = CONFIG_PROVIDERS_CONFIG + "." + provider + ".class";
if (indirectConfigs.containsKey(providerClass))
providerMap.put(provider, indirectConfigs.get(providerClass));
}
// Instantiate Config Providers
Map configProviderInstances = new HashMap<>();
for (Map.Entry entry : providerMap.entrySet()) {
try {
String prefix = CONFIG_PROVIDERS_CONFIG + "." + entry.getKey() + CONFIG_PROVIDERS_PARAM;
Map configProperties = configProviderProperties(prefix, providerConfigProperties);
ConfigProvider provider = Utils.newInstance(entry.getValue(), ConfigProvider.class);
provider.configure(configProperties);
configProviderInstances.put(entry.getKey(), provider);
} catch (ClassNotFoundException e) {
log.error("ClassNotFoundException exception occurred: " + entry.getValue());
throw new ConfigException("Invalid config:" + entry.getValue() + " ClassNotFoundException exception occurred", e);
}
}
return configProviderInstances;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
AbstractConfig that = (AbstractConfig) o;
return originals.equals(that.originals);
}
@Override
public int hashCode() {
return originals.hashCode();
}
/**
* Marks keys retrieved via `get` as used. This is needed because `Configurable.configure` takes a `Map` instead
* of an `AbstractConfig` and we can't change that without breaking public API like `Partitioner`.
*/
private class RecordingMap extends HashMap {
private final String prefix;
private final boolean withIgnoreFallback;
RecordingMap() {
this("", false);
}
RecordingMap(String prefix, boolean withIgnoreFallback) {
this.prefix = prefix;
this.withIgnoreFallback = withIgnoreFallback;
}
RecordingMap(Map m) {
this(m, "", false);
}
RecordingMap(Map m, String prefix, boolean withIgnoreFallback) {
super(m);
this.prefix = prefix;
this.withIgnoreFallback = withIgnoreFallback;
}
@Override
public V get(Object key) {
if (key instanceof String) {
String stringKey = (String) key;
String keyWithPrefix;
if (prefix.isEmpty()) {
keyWithPrefix = stringKey;
} else {
keyWithPrefix = prefix + stringKey;
}
ignore(keyWithPrefix);
if (withIgnoreFallback)
ignore(stringKey);
}
return super.get(key);
}
}
/**
* ResolvingMap keeps a track of the original map instance and the resolved configs.
* The originals are tracked in a separate nested map and may be a `RecordingMap`; thus
* any access to a value for a key needs to be recorded on the originals map.
* The resolved configs are kept in the inherited map and are therefore mutable, though any
* mutations are not applied to the originals.
*/
private static class ResolvingMap extends HashMap {
private final Map originals;
ResolvingMap(Map resolved, Map originals) {
super(resolved);
this.originals = Collections.unmodifiableMap(originals);
}
@Override
public V get(Object key) {
if (key instanceof String && originals.containsKey(key)) {
// Intentionally ignore the result; call just to mark the original entry as used
originals.get(key);
}
// But always use the resolved entry
return super.get(key);
}
}
}