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/*
*
* Copyright 2018 gRPC authors.
*
* Licensed 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 envconfig contains grpc settings configured by environment variables.
package envconfig
import (
"os"
"strconv"
"strings"
)
var (
// EnableTXTServiceConfig is set if the DNS resolver should perform TXT
// lookups for service config ("GRPC_ENABLE_TXT_SERVICE_CONFIG" is not
// "false").
EnableTXTServiceConfig = boolFromEnv("GRPC_ENABLE_TXT_SERVICE_CONFIG", true)
// TXTErrIgnore is set if TXT errors should be ignored
// ("GRPC_GO_IGNORE_TXT_ERRORS" is not "false").
TXTErrIgnore = boolFromEnv("GRPC_GO_IGNORE_TXT_ERRORS", true)
// RingHashCap indicates the maximum ring size which defaults to 4096
// entries but may be overridden by setting the environment variable
// "GRPC_RING_HASH_CAP". This does not override the default bounds
// checking which NACKs configs specifying ring sizes > 8*1024*1024 (~8M).
RingHashCap = uint64FromEnv("GRPC_RING_HASH_CAP", 4096, 1, 8*1024*1024)
// ALTSMaxConcurrentHandshakes is the maximum number of concurrent ALTS
// handshakes that can be performed.
ALTSMaxConcurrentHandshakes = uint64FromEnv("GRPC_ALTS_MAX_CONCURRENT_HANDSHAKES", 100, 1, 100)
// EnforceALPNEnabled is set if TLS connections to servers with ALPN disabled
// should be rejected. The HTTP/2 protocol requires ALPN to be enabled, this
// option is present for backward compatibility. This option may be overridden
// by setting the environment variable "GRPC_ENFORCE_ALPN_ENABLED" to "true"
// or "false".
EnforceALPNEnabled = boolFromEnv("GRPC_ENFORCE_ALPN_ENABLED", true)
// NewPickFirstEnabled is set if the new pickfirst leaf policy is to be used
// instead of the exiting pickfirst implementation. This can be disabled by
// setting the environment variable "GRPC_EXPERIMENTAL_ENABLE_NEW_PICK_FIRST"
// to "false".
NewPickFirstEnabled = boolFromEnv("GRPC_EXPERIMENTAL_ENABLE_NEW_PICK_FIRST", true)
// XDSEndpointHashKeyBackwardCompat controls the parsing of the endpoint hash
// key from EDS LbEndpoint metadata. Endpoint hash keys can be disabled by
// setting "GRPC_XDS_ENDPOINT_HASH_KEY_BACKWARD_COMPAT" to "true". When the
// implementation of A76 is stable, we will flip the default value to false
// in a subsequent release. A final release will remove this environment
// variable, enabling the new behavior unconditionally.
XDSEndpointHashKeyBackwardCompat = boolFromEnv("GRPC_XDS_ENDPOINT_HASH_KEY_BACKWARD_COMPAT", true)
// RingHashSetRequestHashKey is set if the ring hash balancer can get the
// request hash header by setting the "requestHashHeader" field, according
// to gRFC A76. It can be enabled by setting the environment variable
// "GRPC_EXPERIMENTAL_RING_HASH_SET_REQUEST_HASH_KEY" to "true".
RingHashSetRequestHashKey = boolFromEnv("GRPC_EXPERIMENTAL_RING_HASH_SET_REQUEST_HASH_KEY", false)
// ALTSHandshakerKeepaliveParams is set if we should add the
// KeepaliveParams when dial the ALTS handshaker service.
ALTSHandshakerKeepaliveParams = boolFromEnv("GRPC_EXPERIMENTAL_ALTS_HANDSHAKER_KEEPALIVE_PARAMS", false)
)
func boolFromEnv(envVar string, def bool) bool {
if def {
// The default is true; return true unless the variable is "false".
return !strings.EqualFold(os.Getenv(envVar), "false")
}
// The default is false; return false unless the variable is "true".
return strings.EqualFold(os.Getenv(envVar), "true")
}
func uint64FromEnv(envVar string, def, min, max uint64) uint64 {
v, err := strconv.ParseUint(os.Getenv(envVar), 10, 64)
if err != nil {
return def
}
if v < min {
return min
}
if v > max {
return max
}
return v
}
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