examples/

README

Examples

Prerequisites

For examples 02_consul and 03_consul_monitor we need Consul obviously. A fast way to get consul is the following:

wget https://releases.hashicorp.com/consul/1.4.3/consul_1.4.3_linux_amd64.zip  
unzip "consul_1.4.3_linux_amd64.zip"
./consul agent -server -bootstrap-expect 1 -data-dir /tmp/consul -dev -bind=$(hostname -I | awk '{print $1}' | xargs) -http-port 8500

01 Basic usage with env vars

go run examples/01_basic/main.go

2019/09/19 11:18:36 INFO: field IndexName updated with value customers-v1, version: 0
2019/09/19 11:18:36 INFO: seed value customers-v1 applied on field IndexName
2019/09/19 11:18:36 INFO: field CacheRetention updated with value 43200, version: 0
2019/09/19 11:18:36 INFO: seed value 43200 applied on field CacheRetention
2019/09/19 11:18:36 INFO: field CacheRetention updated with value 86400, version: 0
2019/09/19 11:18:36 INFO: env var value 86400 applied on field CacheRetention
2019/09/19 11:18:36 INFO: field LogLevel updated with value DEBUG, version: 0
2019/09/19 11:18:36 INFO: seed value DEBUG applied on field LogLevel
2019/09/19 11:18:36 WARN: flag var loglevel did not exist for field LogLevel
2019/09/19 11:18:36 Config : IndexName: customers-v1, CacheRetention: 86400, LogLevel: DEBUG

02 Seed values from Consul

go run examples/02_consul/main.go

2019/09/19 11:27:29 INFO: field IndexName updated with value customers-v1, version: 0
2019/09/19 11:27:29 INFO: seed value customers-v1 applied on field IndexName
2019/09/19 11:27:29 INFO: field CacheRetention updated with value 43200, version: 0
2019/09/19 11:27:29 INFO: seed value 43200 applied on field CacheRetention
2019/09/19 11:27:29 INFO: field CacheRetention updated with value 86400, version: 0
2019/09/19 11:27:29 INFO: env var value 86400 applied on field CacheRetention
2019/09/19 11:27:29 INFO: field LogLevel updated with value DEBUG, version: 0
2019/09/19 11:27:29 INFO: seed value DEBUG applied on field LogLevel
2019/09/19 11:27:29 INFO: field OpeningBalance updated with value 0.0, version: 0
2019/09/19 11:27:29 INFO: seed value 0.0 applied on field OpeningBalance
2019/09/19 11:27:29 WARN: env var ENV_CONSUL_VAR did not exist for field OpeningBalance
2019/09/19 11:27:29 INFO: field OpeningBalance updated with value 100.0, version: 12
2019/09/19 11:27:29 INFO: consul value 100.0 applied on field OpeningBalance
2019/09/19 11:27:29 WARN: flag var loglevel did not exist for field LogLevel
2019/09/19 11:27:29 Config: IndexName: customers-v1, CacheRetention: 86400, LogLevel: DEBUG, OpeningBalance: 100.000000

03 Monitor Consul for live changes

go run examples/03_consul_monitor/main.go

2019/09/19 11:31:13 INFO: field IndexName updated with value customers-v1, version: 0
2019/09/19 11:31:13 INFO: seed value customers-v1 applied on field IndexName
2019/09/19 11:31:13 INFO: field CacheRetention updated with value 43200, version: 0
2019/09/19 11:31:13 INFO: seed value 43200 applied on field CacheRetention
2019/09/19 11:31:13 INFO: field CacheRetention updated with value 86400, version: 0
2019/09/19 11:31:13 INFO: env var value 86400 applied on field CacheRetention
2019/09/19 11:31:13 INFO: field LogLevel updated with value DEBUG, version: 0
2019/09/19 11:31:13 INFO: seed value DEBUG applied on field LogLevel
2019/09/19 11:31:13 INFO: field OpeningBalance updated with value 0.0, version: 0
2019/09/19 11:31:13 INFO: seed value 0.0 applied on field OpeningBalance
2019/09/19 11:31:13 WARN: env var ENV_CONSUL_VAR did not exist for field OpeningBalance
2019/09/19 11:31:13 INFO: field OpeningBalance updated with value 100.0, version: 31
2019/09/19 11:31:13 INFO: consul value 100.0 applied on field OpeningBalance
2019/09/19 11:31:13 WARN: flag var loglevel did not exist for field LogLevel
2019/09/19 11:31:13 INFO: plan for key harvester/example_03/openingbalance created
2019/09/19 11:31:13 Config: IndexName: customers-v1, CacheRetention: 86400, LogLevel: DEBUG, OpeningBalance: 100.000000
2019/09/19 11:31:13 WARN: version 31 is older or same as the field's OpeningBalance
2019/09/19 11:31:14 INFO: field OpeningBalance updated with value 999.99, version: 33
2019/09/19 11:31:15 Config: IndexName: customers-v1, CacheRetention: 86400, LogLevel: DEBUG, OpeningBalance: 999.990000

04 Monitor Consul for live changes with secrets

2019/09/24 16:40:14 INFO: field IndexName updated with value customers-v1, version: 0
2019/09/24 16:40:14 INFO: seed value customers-v1 applied on field IndexName
2019/09/24 16:40:14 INFO: field CacheRetention updated with value 43200, version: 0
2019/09/24 16:40:14 INFO: seed value 43200 applied on field CacheRetention
2019/09/24 16:40:14 INFO: field CacheRetention updated with value 86400, version: 0
2019/09/24 16:40:14 INFO: env var value 86400 applied on field CacheRetention
2019/09/24 16:40:14 INFO: field LogLevel updated with value DEBUG, version: 0
2019/09/24 16:40:14 INFO: seed value DEBUG applied on field LogLevel
2019/09/24 16:40:14 INFO: field AccessToken updated with value ***, version: 0
2019/09/24 16:40:14 INFO: seed value *** applied on field AccessToken
2019/09/24 16:40:14 INFO: field AccessToken updated with value ***, version: 135
2019/09/24 16:40:14 INFO: consul value *** applied on field AccessToken
2019/09/24 16:40:14 WARN: flag var loglevel did not exist for field LogLevel
2019/09/24 16:40:14 INFO: plan for key harvester/example_04/accesstoken created
2019/09/24 16:40:14 Config: IndexName: customers-v1, CacheRetention: 86400, LogLevel: DEBUG, AccessToken: currentaccesstoken
2019/09/24 16:40:14 WARN: version 135 is older or same as the field's AccessToken
2019/09/24 16:40:15 INFO: field AccessToken updated with value ***, version: 136
2019/09/24 16:40:16 Config: IndexName: customers-v1, CacheRetention: 86400, LogLevel: DEBUG, AccessToken: newaccesstoken

05 Custom config types with complex structure and validation

go run examples/05_custom_types/main.go

2020/01/21 13:39:34 INFO: field IndexName updated with value customers-v1, version: 0
2020/01/21 13:39:34 INFO: seed value customers-v1 applied on field IndexName
2020/01/21 13:39:34 INFO: field EMail updated with value foo@example.com, version: 0
2020/01/21 13:39:34 INFO: seed value foo@example.com applied on field EMail
2020/01/21 13:39:34 INFO: field EMail updated with value bar@example.com, version: 0
2020/01/21 13:39:34 INFO: env var value bar@example.com applied on field EMail
2020/01/21 13:39:34 Config : IndexName: customers-v1, EMail: bar@example.com, EMail.Name: bar, EMail.Domain: example.com