Clean up dependencies

This commit was created by manually removing github.com/ugorji/go/codec from
the go.mod (which now does not exist - see https://github.com/ugorji/go/issues/299)
and running `go mod tidy`.

Closes #658

.gitignore

@@ -21,4 +21,9 @@ _testmain.go
 
 *.exe
 *.test
-*.bench
+*.bench
+
+.vscode
+
+# exclude dependencies in the `/vendor` folder
+vendor

.travis.yml

@@ -1,8 +1,12 @@
 go_import_path: github.com/spf13/viper
 
 language: go
+
+env:
+  global:
+  - GO111MODULE="on"
+
 go:
-  - 1.10.x
   - 1.11.x
   - tip
 

README.md

@@ -179,13 +179,14 @@ viper.GetBool("verbose") // true
 ### Working with Environment Variables
 
 Viper has full support for environment variables. This enables 12 factor
-applications out of the box. There are four methods that exist to aid working
+applications out of the box. There are five methods that exist to aid working
 with ENV:
 
  * `AutomaticEnv()`
  * `BindEnv(string...) : error`
  * `SetEnvPrefix(string)`
  * `SetEnvKeyReplacer(string...) *strings.Replacer`
+  * `AllowEmptyEnvVar(bool)`
 
 _When working with ENV variables, it’s important to recognize that Viper
 treats ENV variables as case sensitive._
@@ -217,6 +218,10 @@ keys to an extent. This is useful if you want to use `-` or something in your
 `Get()` calls, but want your environmental variables to use `_` delimiters. An
 example of using it can be found in `viper_test.go`.
 
+By default empty environment variables are considered unset and will fall back to
+the next configuration source. To treat empty environment variables as set, use
+the `AllowEmptyEnv` method.
+
 #### Env example
 
 ```go

go.mod

@@ -1,16 +1,43 @@
 module github.com/spf13/viper
 
 require (
+	github.com/armon/consul-api v0.0.0-20180202201655-eb2c6b5be1b6 // indirect
+	github.com/coreos/bbolt v1.3.2 // indirect
+	github.com/coreos/etcd v3.3.10+incompatible // indirect
+	github.com/coreos/go-semver v0.2.0 // indirect
+	github.com/coreos/go-systemd v0.0.0-20190321100706-95778dfbb74e // indirect
+	github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f // indirect
+	github.com/dgrijalva/jwt-go v3.2.0+incompatible // indirect
 	github.com/fsnotify/fsnotify v1.4.7
+	github.com/gogo/protobuf v1.2.1 // indirect
+	github.com/golang/groupcache v0.0.0-20190129154638-5b532d6fd5ef // indirect
+	github.com/google/btree v1.0.0 // indirect
+	github.com/gorilla/websocket v1.4.0 // indirect
+	github.com/grpc-ecosystem/go-grpc-middleware v1.0.0 // indirect
+	github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0 // indirect
+	github.com/grpc-ecosystem/grpc-gateway v1.9.0 // indirect
 	github.com/hashicorp/hcl v1.0.0
+	github.com/jonboulle/clockwork v0.1.0 // indirect
 	github.com/magiconair/properties v1.8.0
-	github.com/mitchellh/mapstructure v1.0.0
+	github.com/mitchellh/mapstructure v1.1.2
 	github.com/pelletier/go-toml v1.2.0
+	github.com/prometheus/client_golang v0.9.3 // indirect
+	github.com/soheilhy/cmux v0.1.4 // indirect
 	github.com/spf13/afero v1.1.2
-	github.com/spf13/cast v1.2.0
+	github.com/spf13/cast v1.3.0
 	github.com/spf13/jwalterweatherman v1.0.0
-	github.com/spf13/pflag v1.0.2
-	golang.org/x/sys v0.0.0-20180906133057-8cf3aee42992 // indirect
-	golang.org/x/text v0.3.0 // indirect
-	gopkg.in/yaml.v2 v2.2.1
+	github.com/spf13/pflag v1.0.3
+	github.com/stretchr/testify v1.2.2
+	github.com/tmc/grpc-websocket-proxy v0.0.0-20190109142713-0ad062ec5ee5 // indirect
+	github.com/ugorji/go v1.1.4 // indirect
+	github.com/xiang90/probing v0.0.0-20190116061207-43a291ad63a2 // indirect
+	github.com/xordataexchange/crypt v0.0.3-0.20170626215501-b2862e3d0a77
+	go.etcd.io/bbolt v1.3.2 // indirect
+	go.uber.org/atomic v1.4.0 // indirect
+	go.uber.org/multierr v1.1.0 // indirect
+	go.uber.org/zap v1.10.0 // indirect
+	golang.org/x/net v0.0.0-20190522155817-f3200d17e092 // indirect
+	golang.org/x/time v0.0.0-20190308202827-9d24e82272b4 // indirect
+	google.golang.org/grpc v1.21.0 // indirect
+	gopkg.in/yaml.v2 v2.2.2
 )

go.sum

@@ -1,26 +1,178 @@
+cloud.google.com/go v0.26.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
+github.com/BurntSushi/toml v0.3.1 h1:WXkYYl6Yr3qBf1K79EBnL4mak0OimBfB0XUf9Vl28OQ=
+github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
+github.com/OneOfOne/xxhash v1.2.2/go.mod h1:HSdplMjZKSmBqAxg5vPj2TmRDmfkzw+cTzAElWljhcU=
+github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
+github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
+github.com/armon/consul-api v0.0.0-20180202201655-eb2c6b5be1b6 h1:G1bPvciwNyF7IUmKXNt9Ak3m6u9DE1rF+RmtIkBpVdA=
+github.com/armon/consul-api v0.0.0-20180202201655-eb2c6b5be1b6/go.mod h1:grANhF5doyWs3UAsr3K4I6qtAmlQcZDesFNEHPZAzj8=
+github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
+github.com/beorn7/perks v1.0.0 h1:HWo1m869IqiPhD389kmkxeTalrjNbbJTC8LXupb+sl0=
+github.com/beorn7/perks v1.0.0/go.mod h1:KWe93zE9D1o94FZ5RNwFwVgaQK1VOXiVxmqh+CedLV8=
+github.com/cespare/xxhash v1.1.0/go.mod h1:XrSqR1VqqWfGrhpAt58auRo0WTKS1nRRg3ghfAqPWnc=
+github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
+github.com/coreos/bbolt v1.3.2 h1:wZwiHHUieZCquLkDL0B8UhzreNWsPHooDAG3q34zk0s=
+github.com/coreos/bbolt v1.3.2/go.mod h1:iRUV2dpdMOn7Bo10OQBFzIJO9kkE559Wcmn+qkEiiKk=
+github.com/coreos/etcd v3.3.10+incompatible h1:jFneRYjIvLMLhDLCzuTuU4rSJUjRplcJQ7pD7MnhC04=
+github.com/coreos/etcd v3.3.10+incompatible/go.mod h1:uF7uidLiAD3TWHmW31ZFd/JWoc32PjwdhPthX9715RE=
+github.com/coreos/go-semver v0.2.0 h1:3Jm3tLmsgAYcjC+4Up7hJrFBPr+n7rAqYeSw/SZazuY=
+github.com/coreos/go-semver v0.2.0/go.mod h1:nnelYz7RCh+5ahJtPPxZlU+153eP4D4r3EedlOD2RNk=
+github.com/coreos/go-systemd v0.0.0-20190321100706-95778dfbb74e h1:Wf6HqHfScWJN9/ZjdUKyjop4mf3Qdd+1TvvltAvM3m8=
+github.com/coreos/go-systemd v0.0.0-20190321100706-95778dfbb74e/go.mod h1:F5haX7vjVVG0kc13fIWeqUViNPyEJxv/OmvnBo0Yme4=
+github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f h1:lBNOc5arjvs8E5mO2tbpBpLoyyu8B6e44T7hJy6potg=
+github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f/go.mod h1:E3G3o1h8I7cfcXa63jLwjI0eiQQMgzzUDFVpN/nH/eA=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/dgrijalva/jwt-go v3.2.0+incompatible h1:7qlOGliEKZXTDg6OTjfoBKDXWrumCAMpl/TFQ4/5kLM=
+github.com/dgrijalva/jwt-go v3.2.0+incompatible/go.mod h1:E3ru+11k8xSBh+hMPgOLZmtrrCbhqsmaPHjLKYnJCaQ=
+github.com/dgryski/go-sip13 v0.0.0-20181026042036-e10d5fee7954/go.mod h1:vAd38F8PWV+bWy6jNmig1y/TA+kYO4g3RSRF0IAv0no=
 github.com/fsnotify/fsnotify v1.4.7 h1:IXs+QLmnXW2CcXuY+8Mzv/fWEsPGWxqefPtCP5CnV9I=
 github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
+github.com/ghodss/yaml v1.0.0 h1:wQHKEahhL6wmXdzwWG11gIVCkOv05bNOh+Rxn0yngAk=
+github.com/ghodss/yaml v1.0.0/go.mod h1:4dBDuWmgqj2HViK6kFavaiC9ZROes6MMH2rRYeMEF04=
+github.com/go-kit/kit v0.8.0/go.mod h1:xBxKIO96dXMWWy0MnWVtmwkA9/13aqxPnvrjFYMA2as=
+github.com/go-logfmt/logfmt v0.3.0/go.mod h1:Qt1PoO58o5twSAckw1HlFXLmHsOX5/0LbT9GBnD5lWE=
+github.com/go-logfmt/logfmt v0.4.0/go.mod h1:3RMwSq7FuexP4Kalkev3ejPJsZTpXXBr9+V4qmtdjCk=
+github.com/go-stack/stack v1.8.0/go.mod h1:v0f6uXyyMGvRgIKkXu+yp6POWl0qKG85gN/melR3HDY=
+github.com/gogo/protobuf v1.1.1/go.mod h1:r8qH/GZQm5c6nD/R0oafs1akxWv10x8SbQlK7atdtwQ=
+github.com/gogo/protobuf v1.2.1 h1:/s5zKNz0uPFCZ5hddgPdo2TK2TVrUNMn0OOX8/aZMTE=
+github.com/gogo/protobuf v1.2.1/go.mod h1:hp+jE20tsWTFYpLwKvXlhS1hjn+gTNwPg2I6zVXpSg4=
+github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b h1:VKtxabqXZkF25pY9ekfRL6a582T4P37/31XEstQ5p58=
+github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b/go.mod h1:SBH7ygxi8pfUlaOkMMuAQtPIUF8ecWP5IEl/CR7VP2Q=
+github.com/golang/groupcache v0.0.0-20190129154638-5b532d6fd5ef h1:veQD95Isof8w9/WXiA+pa3tz3fJXkt5B7QaRBrM62gk=
+github.com/golang/groupcache v0.0.0-20190129154638-5b532d6fd5ef/go.mod h1:cIg4eruTrX1D+g88fzRXU5OdNfaM+9IcxsU14FzY7Hc=
+github.com/golang/mock v1.1.1/go.mod h1:oTYuIxOrZwtPieC+H1uAHpcLFnEyAGVDL/k47Jfbm0A=
+github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/golang/protobuf v1.3.1 h1:YF8+flBXS5eO826T4nzqPrxfhQThhXl0YzfuUPu4SBg=
+github.com/golang/protobuf v1.3.1/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/google/btree v1.0.0 h1:0udJVsspx3VBr5FwtLhQQtuAsVc79tTq0ocGIPAU6qo=
+github.com/google/btree v1.0.0/go.mod h1:lNA+9X1NB3Zf8V7Ke586lFgjr2dZNuvo3lPJSGZ5JPQ=
+github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
+github.com/gorilla/websocket v1.4.0 h1:WDFjx/TMzVgy9VdMMQi2K2Emtwi2QcUQsztZ/zLaH/Q=
+github.com/gorilla/websocket v1.4.0/go.mod h1:E7qHFY5m1UJ88s3WnNqhKjPHQ0heANvMoAMk2YaljkQ=
+github.com/grpc-ecosystem/go-grpc-middleware v1.0.0 h1:Iju5GlWwrvL6UBg4zJJt3btmonfrMlCDdsejg4CZE7c=
+github.com/grpc-ecosystem/go-grpc-middleware v1.0.0/go.mod h1:FiyG127CGDf3tlThmgyCl78X/SZQqEOJBCDaAfeWzPs=
+github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0 h1:Ovs26xHkKqVztRpIrF/92BcuyuQ/YW4NSIpoGtfXNho=
+github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0/go.mod h1:8NvIoxWQoOIhqOTXgfV/d3M/q6VIi02HzZEHgUlZvzk=
+github.com/grpc-ecosystem/grpc-gateway v1.9.0 h1:bM6ZAFZmc/wPFaRDi0d5L7hGEZEx/2u+Tmr2evNHDiI=
+github.com/grpc-ecosystem/grpc-gateway v1.9.0/go.mod h1:vNeuVxBJEsws4ogUvrchl83t/GYV9WGTSLVdBhOQFDY=
 github.com/hashicorp/hcl v1.0.0 h1:0Anlzjpi4vEasTeNFn2mLJgTSwt0+6sfsiTG8qcWGx4=
 github.com/hashicorp/hcl v1.0.0/go.mod h1:E5yfLk+7swimpb2L/Alb/PJmXilQ/rhwaUYs4T20WEQ=
+github.com/jonboulle/clockwork v0.1.0 h1:VKV+ZcuP6l3yW9doeqz6ziZGgcynBVQO+obU0+0hcPo=
+github.com/jonboulle/clockwork v0.1.0/go.mod h1:Ii8DK3G1RaLaWxj9trq07+26W01tbo22gdxWY5EU2bo=
+github.com/julienschmidt/httprouter v1.2.0/go.mod h1:SYymIcj16QtmaHHD7aYtjjsJG7VTCxuUUipMqKk8s4w=
+github.com/kisielk/errcheck v1.1.0/go.mod h1:EZBBE59ingxPouuu3KfxchcWSUPOHkagtvWXihfKN4Q=
+github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
+github.com/konsorten/go-windows-terminal-sequences v1.0.1 h1:mweAR1A6xJ3oS2pRaGiHgQ4OO8tzTaLawm8vnODuwDk=
+github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
+github.com/kr/logfmt v0.0.0-20140226030751-b84e30acd515/go.mod h1:+0opPa2QZZtGFBFZlji/RkVcI2GknAs/DXo4wKdlNEc=
+github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
+github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
+github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
+github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/magiconair/properties v1.8.0 h1:LLgXmsheXeRoUOBOjtwPQCWIYqM/LU1ayDtDePerRcY=
 github.com/magiconair/properties v1.8.0/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=
-github.com/mitchellh/mapstructure v1.0.0 h1:vVpGvMXJPqSDh2VYHF7gsfQj8Ncx+Xw5Y1KHeTRY+7I=
-github.com/mitchellh/mapstructure v1.0.0/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
+github.com/matttproud/golang_protobuf_extensions v1.0.1 h1:4hp9jkHxhMHkqkrB3Ix0jegS5sx/RkqARlsWZ6pIwiU=
+github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
+github.com/mitchellh/mapstructure v1.1.2 h1:fmNYVwqnSfB9mZU6OS2O6GsXM+wcskZDuKQzvN1EDeE=
+github.com/mitchellh/mapstructure v1.1.2/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
+github.com/mwitkow/go-conntrack v0.0.0-20161129095857-cc309e4a2223/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
+github.com/oklog/ulid v1.3.1/go.mod h1:CirwcVhetQ6Lv90oh/F+FBtV6XMibvdAFo93nm5qn4U=
 github.com/pelletier/go-toml v1.2.0 h1:T5zMGML61Wp+FlcbWjRDT7yAxhJNAiPPLOFECq181zc=
 github.com/pelletier/go-toml v1.2.0/go.mod h1:5z9KED0ma1S8pY6P1sdut58dfprrGBbd/94hg7ilaic=
+github.com/pkg/errors v0.8.0 h1:WdK/asTD0HN+q6hsWO3/vpuAkAr+tw6aNJNDFFf0+qw=
+github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/prometheus/client_golang v0.9.1/go.mod h1:7SWBe2y4D6OKWSNQJUaRYU/AaXPKyh/dDVn+NZz0KFw=
+github.com/prometheus/client_golang v0.9.3 h1:9iH4JKXLzFbOAdtqv/a+j8aewx2Y8lAjAydhbaScPF8=
+github.com/prometheus/client_golang v0.9.3/go.mod h1:/TN21ttK/J9q6uSwhBd54HahCDft0ttaMvbicHlPoso=
+github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910/go.mod h1:MbSGuTsp3dbXC40dX6PRTWyKYBIrTGTE9sqQNg2J8bo=
+github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90 h1:S/YWwWx/RA8rT8tKFRuGUZhuA90OyIBpPCXkcbwU8DE=
+github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
+github.com/prometheus/common v0.0.0-20181113130724-41aa239b4cce/go.mod h1:daVV7qP5qjZbuso7PdcryaAu0sAZbrN9i7WWcTMWvro=
+github.com/prometheus/common v0.4.0 h1:7etb9YClo3a6HjLzfl6rIQaU+FDfi0VSX39io3aQ+DM=
+github.com/prometheus/common v0.4.0/go.mod h1:TNfzLD0ON7rHzMJeJkieUDPYmFC7Snx/y86RQel1bk4=
+github.com/prometheus/procfs v0.0.0-20181005140218-185b4288413d/go.mod h1:c3At6R/oaqEKCNdg8wHV1ftS6bRYblBhIjjI8uT2IGk=
+github.com/prometheus/procfs v0.0.0-20190507164030-5867b95ac084 h1:sofwID9zm4tzrgykg80hfFph1mryUeLRsUfoocVVmRY=
+github.com/prometheus/procfs v0.0.0-20190507164030-5867b95ac084/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsTZCD3I8kEA=
+github.com/prometheus/tsdb v0.7.1/go.mod h1:qhTCs0VvXwvX/y3TZrWD7rabWM+ijKTux40TwIPHuXU=
+github.com/rogpeppe/fastuuid v0.0.0-20150106093220-6724a57986af/go.mod h1:XWv6SoW27p1b0cqNHllgS5HIMJraePCO15w5zCzIWYg=
+github.com/sirupsen/logrus v1.2.0 h1:juTguoYk5qI21pwyTXY3B3Y5cOTH3ZUyZCg1v/mihuo=
+github.com/sirupsen/logrus v1.2.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPxbbu5VWo=
+github.com/soheilhy/cmux v0.1.4 h1:0HKaf1o97UwFjHH9o5XsHUOF+tqmdA7KEzXLpiyaw0E=
+github.com/soheilhy/cmux v0.1.4/go.mod h1:IM3LyeVVIOuxMH7sFAkER9+bJ4dT7Ms6E4xg4kGIyLM=
+github.com/spaolacci/murmur3 v0.0.0-20180118202830-f09979ecbc72/go.mod h1:JwIasOWyU6f++ZhiEuf87xNszmSA2myDM2Kzu9HwQUA=
 github.com/spf13/afero v1.1.2 h1:m8/z1t7/fwjysjQRYbP0RD+bUIF/8tJwPdEZsI83ACI=
 github.com/spf13/afero v1.1.2/go.mod h1:j4pytiNVoe2o6bmDsKpLACNPDBIoEAkihy7loJ1B0CQ=
-github.com/spf13/cast v1.2.0 h1:HHl1DSRbEQN2i8tJmtS6ViPyHx35+p51amrdsiTCrkg=
-github.com/spf13/cast v1.2.0/go.mod h1:r2rcYCSwa1IExKTDiTfzaxqT2FNHs8hODu4LnUfgKEg=
+github.com/spf13/cast v1.3.0 h1:oget//CVOEoFewqQxwr0Ej5yjygnqGkvggSE/gB35Q8=
+github.com/spf13/cast v1.3.0/go.mod h1:Qx5cxh0v+4UWYiBimWS+eyWzqEqokIECu5etghLkUJE=
 github.com/spf13/jwalterweatherman v1.0.0 h1:XHEdyB+EcvlqZamSM4ZOMGlc93t6AcsBEu9Gc1vn7yk=
 github.com/spf13/jwalterweatherman v1.0.0/go.mod h1:cQK4TGJAtQXfYWX+Ddv3mKDzgVb68N+wFjFa4jdeBTo=
-github.com/spf13/pflag v1.0.2 h1:Fy0orTDgHdbnzHcsOgfCN4LtHf0ec3wwtiwJqwvf3Gc=
-github.com/spf13/pflag v1.0.2/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
-golang.org/x/sys v0.0.0-20180906133057-8cf3aee42992 h1:BH3eQWeGbwRU2+wxxuuPOdFBmaiBH81O8BugSjHeTFg=
-golang.org/x/sys v0.0.0-20180906133057-8cf3aee42992/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+github.com/spf13/pflag v1.0.3 h1:zPAT6CGy6wXeQ7NtTnaTerfKOsV6V6F8agHXFiazDkg=
+github.com/spf13/pflag v1.0.3/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
+github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.2.2 h1:bSDNvY7ZPG5RlJ8otE/7V6gMiyenm9RtJ7IUVIAoJ1w=
+github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+github.com/tmc/grpc-websocket-proxy v0.0.0-20190109142713-0ad062ec5ee5 h1:LnC5Kc/wtumK+WB441p7ynQJzVuNRJiqddSIE3IlSEQ=
+github.com/tmc/grpc-websocket-proxy v0.0.0-20190109142713-0ad062ec5ee5/go.mod h1:ncp9v5uamzpCO7NfCPTXjqaC+bZgJeR0sMTm6dMHP7U=
+github.com/ugorji/go v1.1.4 h1:j4s+tAvLfL3bZyefP2SEWmhBzmuIlH/eqNuPdFPgngw=
+github.com/ugorji/go v1.1.4/go.mod h1:uQMGLiO92mf5W77hV/PUCpI3pbzQx3CRekS0kk+RGrc=
+github.com/xiang90/probing v0.0.0-20190116061207-43a291ad63a2 h1:eY9dn8+vbi4tKz5Qo6v2eYzo7kUS51QINcR5jNpbZS8=
+github.com/xiang90/probing v0.0.0-20190116061207-43a291ad63a2/go.mod h1:UETIi67q53MR2AWcXfiuqkDkRtnGDLqkBTpCHuJHxtU=
+github.com/xordataexchange/crypt v0.0.3-0.20170626215501-b2862e3d0a77 h1:ESFSdwYZvkeru3RtdrYueztKhOBCSAAzS4Gf+k0tEow=
+github.com/xordataexchange/crypt v0.0.3-0.20170626215501-b2862e3d0a77/go.mod h1:aYKd//L2LvnjZzWKhF00oedf4jCCReLcmhLdhm1A27Q=
+go.etcd.io/bbolt v1.3.2 h1:Z/90sZLPOeCy2PwprqkFa25PdkusRzaj9P8zm/KNyvk=
+go.etcd.io/bbolt v1.3.2/go.mod h1:IbVyRI1SCnLcuJnV2u8VeU0CEYM7e686BmAb1XKL+uU=
+go.uber.org/atomic v1.4.0 h1:cxzIVoETapQEqDhQu3QfnvXAV4AlzcvUCxkVUFw3+EU=
+go.uber.org/atomic v1.4.0/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
+go.uber.org/multierr v1.1.0 h1:HoEmRHQPVSqub6w2z2d2EOVs2fjyFRGyofhKuyDq0QI=
+go.uber.org/multierr v1.1.0/go.mod h1:wR5kodmAFQ0UK8QlbwjlSNy0Z68gJhDJUG5sjR94q/0=
+go.uber.org/zap v1.10.0 h1:ORx85nbTijNz8ljznvCMR1ZBIPKFn3jQrag10X2AsuM=
+go.uber.org/zap v1.10.0/go.mod h1:vwi/ZaCAaUcBkycHslxD9B2zi4UTXhF60s6SWpuDF0Q=
+golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2 h1:VklqNMn3ovrHsnt90PveolxSbWFaJdECFbxSq0Mqo2M=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
+golang.org/x/lint v0.0.0-20190313153728-d0100b6bd8b3/go.mod h1:6SW0HCj/g11FgYtHlgUYUwCkIfeOF89ocIRzGO/8vkc=
+golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20181114220301-adae6a3d119a/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20181220203305-927f97764cc3/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20190522155817-f3200d17e092 h1:4QSRKanuywn15aTZvI/mIDEgPQpswuFndXpOj3rKEco=
+golang.org/x/net v0.0.0-20190522155817-f3200d17e092/go.mod h1:HSz+uSET+XFnRR8LxR5pz3Of3rY3CfYBVs4xY44aLks=
+golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
+golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20181107165924-66b7b1311ac8/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20181116152217-5ac8a444bdc5/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a h1:1BGLXjeY4akVXGgbC9HugT3Jv3hCI0z56oJR5vAMgBU=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/time v0.0.0-20190308202827-9d24e82272b4 h1:SvFZT6jyqRaOeXpc5h/JSfZenJ2O330aBsf7JfSUXmQ=
+golang.org/x/time v0.0.0-20190308202827-9d24e82272b4/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
+golang.org/x/tools v0.0.0-20180221164845-07fd8470d635/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20190114222345-bf090417da8b/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20190311212946-11955173bddd/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
+google.golang.org/appengine v1.1.0/go.mod h1:EbEs0AVv82hx2wNQdGPgUI5lhzA/G0D9YwlJXL52JkM=
+google.golang.org/genproto v0.0.0-20180817151627-c66870c02cf8 h1:Nw54tB0rB7hY/N0NQvRW8DG4Yk3Q6T9cu9RcFQDu1tc=
+google.golang.org/genproto v0.0.0-20180817151627-c66870c02cf8/go.mod h1:JiN7NxoALGmiZfu7CAH4rXhgtRTLTxftemlI0sWmxmc=
+google.golang.org/grpc v1.19.0/go.mod h1:mqu4LbDTu4XGKhr4mRzUsmM4RtVoemTSY81AxZiDr8c=
+google.golang.org/grpc v1.21.0 h1:G+97AoqBnmZIT91cLG/EkCoK9NSelj64P8bOHHNmGn0=
+google.golang.org/grpc v1.21.0/go.mod h1:oYelfM1adQP15Ek0mdvEgi9Df8B9CZIaU1084ijfRaM=
+gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/yaml.v2 v2.2.1 h1:mUhvW9EsL+naU5Q3cakzfE91YhliOondGd6ZrsDBHQE=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/resty.v1 v1.12.0/go.mod h1:mDo4pnntr5jdWRML875a/NmxYqAlA73dVijT2AXvQQo=
+gopkg.in/yaml.v2 v2.0.0-20170812160011-eb3733d160e7/go.mod h1:JAlM8MvJe8wmxCU4Bli9HhUf9+ttbYbLASfIpnQbh74=
 gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
+gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=

viper.go

@@ -30,6 +30,7 @@ import (
 	"path/filepath"
 	"reflect"
 	"strings"
+	"sync"
 	"time"
 
 	yaml "gopkg.in/yaml.v2"
@@ -179,13 +180,15 @@ type Viper struct {
 	remoteProviders []*defaultRemoteProvider
 
 	// Name of file to look for inside the path
-	configName string
-	configFile string
-	configType string
-	envPrefix  string
+	configName        string
+	configFile        string
+	configType        string
+	configPermissions os.FileMode
+	envPrefix         string
 
 	automaticEnvApplied bool
 	envKeyReplacer      *strings.Replacer
+	allowEmptyEnv       bool
 
 	config         map[string]interface{}
 	override       map[string]interface{}
@@ -208,6 +211,7 @@ func New() *Viper {
 	v := new(Viper)
 	v.keyDelim = "."
 	v.configName = "config"
+	v.configPermissions = os.FileMode(0644)
 	v.fs = afero.NewOsFs()
 	v.config = make(map[string]interface{})
 	v.override = make(map[string]interface{})
@@ -276,48 +280,73 @@ func (v *Viper) OnConfigChange(run func(in fsnotify.Event)) {
 }
 
 func WatchConfig() { v.WatchConfig() }
+
 func (v *Viper) WatchConfig() {
+	initWG := sync.WaitGroup{}
+	initWG.Add(1)
 	go func() {
 		watcher, err := fsnotify.NewWatcher()
 		if err != nil {
 			log.Fatal(err)
 		}
 		defer watcher.Close()
-
 		// we have to watch the entire directory to pick up renames/atomic saves in a cross-platform way
 		filename, err := v.getConfigFile()
 		if err != nil {
-			log.Println("error:", err)
+			log.Printf("error: %v\n", err)
 			return
 		}
 
 		configFile := filepath.Clean(filename)
 		configDir, _ := filepath.Split(configFile)
+		realConfigFile, _ := filepath.EvalSymlinks(filename)
 
-		done := make(chan bool)
+		eventsWG := sync.WaitGroup{}
+		eventsWG.Add(1)
 		go func() {
 			for {
 				select {
-				case event := <-watcher.Events:
-					// we only care about the config file
-					if filepath.Clean(event.Name) == configFile {
-						if event.Op&fsnotify.Write == fsnotify.Write || event.Op&fsnotify.Create == fsnotify.Create {
-							err := v.ReadInConfig()
-							if err != nil {
-								log.Println("error:", err)
-							}
+				case event, ok := <-watcher.Events:
+					if !ok { // 'Events' channel is closed
+						eventsWG.Done()
+						return
+					}
+					currentConfigFile, _ := filepath.EvalSymlinks(filename)
+					// we only care about the config file with the following cases:
+					// 1 - if the config file was modified or created
+					// 2 - if the real path to the config file changed (eg: k8s ConfigMap replacement)
+					const writeOrCreateMask = fsnotify.Write | fsnotify.Create
+					if (filepath.Clean(event.Name) == configFile &&
+						event.Op&writeOrCreateMask != 0) ||
+						(currentConfigFile != "" && currentConfigFile != realConfigFile) {
+						realConfigFile = currentConfigFile
+						err := v.ReadInConfig()
+						if err != nil {
+							log.Printf("error reading config file: %v\n", err)
+						}
+						if v.onConfigChange != nil {
 							v.onConfigChange(event)
 						}
+					} else if filepath.Clean(event.Name) == configFile &&
+						event.Op&fsnotify.Remove&fsnotify.Remove != 0 {
+						eventsWG.Done()
+						return
 					}
-				case err := <-watcher.Errors:
-					log.Println("error:", err)
+
+				case err, ok := <-watcher.Errors:
+					if ok { // 'Errors' channel is not closed
+						log.Printf("watcher error: %v\n", err)
+					}
+					eventsWG.Done()
+					return
 				}
 			}
 		}()
-
 		watcher.Add(configDir)
-		<-done
+		initWG.Done()   // done initalizing the watch in this go routine, so the parent routine can move on...
+		eventsWG.Wait() // now, wait for event loop to end in this go-routine...
 	}()
+	initWG.Wait() // make sure that the go routine above fully ended before returning
 }
 
 // SetConfigFile explicitly defines the path, name and extension of the config file.
@@ -347,6 +376,14 @@ func (v *Viper) mergeWithEnvPrefix(in string) string {
 	return strings.ToUpper(in)
 }
 
+// AllowEmptyEnv tells Viper to consider set,
+// but empty environment variables as valid values instead of falling back.
+// For backward compatibility reasons this is false by default.
+func AllowEmptyEnv(allowEmptyEnv bool) { v.AllowEmptyEnv(allowEmptyEnv) }
+func (v *Viper) AllowEmptyEnv(allowEmptyEnv bool) {
+	v.allowEmptyEnv = allowEmptyEnv
+}
+
 // TODO: should getEnv logic be moved into find(). Can generalize the use of
 // rewriting keys many things, Ex: Get('someKey') -> some_key
 // (camel case to snake case for JSON keys perhaps)
@@ -354,11 +391,14 @@ func (v *Viper) mergeWithEnvPrefix(in string) string {
 // getEnv is a wrapper around os.Getenv which replaces characters in the original
 // key. This allows env vars which have different keys than the config object
 // keys.
-func (v *Viper) getEnv(key string) string {
+func (v *Viper) getEnv(key string) (string, bool) {
 	if v.envKeyReplacer != nil {
 		key = v.envKeyReplacer.Replace(key)
 	}
-	return os.Getenv(key)
+
+	val, ok := os.LookupEnv(key)
+
+	return val, ok && (v.allowEmptyEnv || val != "")
 }
 
 // ConfigFileUsed returns the file used to populate the config registry.
@@ -585,10 +625,9 @@ func (v *Viper) isPathShadowedInFlatMap(path []string, mi interface{}) string {
 //       "foo.bar.baz" in a lower-priority map
 func (v *Viper) isPathShadowedInAutoEnv(path []string) string {
 	var parentKey string
-	var val string
 	for i := 1; i < len(path); i++ {
 		parentKey = strings.Join(path[0:i], v.keyDelim)
-		if val = v.getEnv(v.mergeWithEnvPrefix(parentKey)); val != "" {
+		if _, ok := v.getEnv(v.mergeWithEnvPrefix(parentKey)); ok {
 			return parentKey
 		}
 	}
@@ -650,6 +689,12 @@ func (v *Viper) Get(key string) interface{} {
 			return cast.ToString(val)
 		case int32, int16, int8, int:
 			return cast.ToInt(val)
+		case uint:
+			return cast.ToUint(val)
+		case uint32:
+			return cast.ToUint32(val)
+		case uint64:
+			return cast.ToUint64(val)
 		case int64:
 			return cast.ToInt64(val)
 		case float64, float32:
@@ -713,6 +758,24 @@ func (v *Viper) GetInt64(key string) int64 {
 	return cast.ToInt64(v.Get(key))
 }
 
+// GetUint returns the value associated with the key as an unsigned integer.
+func GetUint(key string) uint { return v.GetUint(key) }
+func (v *Viper) GetUint(key string) uint {
+	return cast.ToUint(v.Get(key))
+}
+
+// GetUint32 returns the value associated with the key as an unsigned integer.
+func GetUint32(key string) uint32 { return v.GetUint32(key) }
+func (v *Viper) GetUint32(key string) uint32 {
+	return cast.ToUint32(v.Get(key))
+}
+
+// GetUint64 returns the value associated with the key as an unsigned integer.
+func GetUint64(key string) uint64 { return v.GetUint64(key) }
+func (v *Viper) GetUint64(key string) uint64 {
+	return cast.ToUint64(v.Get(key))
+}
+
 // GetFloat64 returns the value associated with the key as a float64.
 func GetFloat64(key string) float64 { return v.GetFloat64(key) }
 func (v *Viper) GetFloat64(key string) float64 {
@@ -774,8 +837,6 @@ func (v *Viper) UnmarshalKey(key string, rawVal interface{}, opts ...DecoderConf
 		return err
 	}
 
-	v.insensitiviseMaps()
-
 	return nil
 }
 
@@ -791,8 +852,6 @@ func (v *Viper) Unmarshal(rawVal interface{}, opts ...DecoderConfigOption) error
 		return err
 	}
 
-	v.insensitiviseMaps()
-
 	return nil
 }
 
@@ -835,8 +894,6 @@ func (v *Viper) UnmarshalExact(rawVal interface{}) error {
 		return err
 	}
 
-	v.insensitiviseMaps()
-
 	return nil
 }
 
@@ -967,7 +1024,7 @@ func (v *Viper) find(lcaseKey string) interface{} {
 	if v.automaticEnvApplied {
 		// even if it hasn't been registered, if automaticEnv is used,
 		// check any Get request
-		if val = v.getEnv(v.mergeWithEnvPrefix(lcaseKey)); val != "" {
+		if val, ok := v.getEnv(v.mergeWithEnvPrefix(lcaseKey)); ok {
 			return val
 		}
 		if nested && v.isPathShadowedInAutoEnv(path) != "" {
@@ -976,7 +1033,7 @@ func (v *Viper) find(lcaseKey string) interface{} {
 	}
 	envkey, exists := v.env[lcaseKey]
 	if exists {
-		if val = v.getEnv(envkey); val != "" {
+		if val, ok := v.getEnv(envkey); ok {
 			return val
 		}
 	}
@@ -1222,13 +1279,21 @@ func (v *Viper) ReadConfig(in io.Reader) error {
 // MergeConfig merges a new configuration with an existing config.
 func MergeConfig(in io.Reader) error { return v.MergeConfig(in) }
 func (v *Viper) MergeConfig(in io.Reader) error {
-	if v.config == nil {
-		v.config = make(map[string]interface{})
-	}
 	cfg := make(map[string]interface{})
 	if err := v.unmarshalReader(in, cfg); err != nil {
 		return err
 	}
+	return v.MergeConfigMap(cfg)
+}
+
+// MergeConfigMap merges the configuration from the map given with an existing config.
+// Note that the map given may be modified.
+func MergeConfigMap(cfg map[string]interface{}) error { return v.MergeConfigMap(cfg) }
+func (v *Viper) MergeConfigMap(cfg map[string]interface{}) error {
+	if v.config == nil {
+		v.config = make(map[string]interface{})
+	}
+	insensitiviseMap(cfg)
 	mergeMaps(cfg, v.config, nil)
 	return nil
 }
@@ -1289,7 +1354,7 @@ func (v *Viper) writeConfig(filename string, force bool) error {
 			return fmt.Errorf("File: %s exists. Use WriteConfig to overwrite.", filename)
 		}
 	}
-	f, err := v.fs.OpenFile(filename, flags, os.FileMode(0644))
+	f, err := v.fs.OpenFile(filename, flags, v.configPermissions)
 	if err != nil {
 		return err
 	}
@@ -1534,13 +1599,6 @@ func (v *Viper) WatchRemoteConfigOnChannel() error {
 	return v.watchKeyValueConfigOnChannel()
 }
 
-func (v *Viper) insensitiviseMaps() {
-	insensitiviseMap(v.config)
-	insensitiviseMap(v.defaults)
-	insensitiviseMap(v.override)
-	insensitiviseMap(v.kvstore)
-}
-
 // Retrieve the first found remote configuration.
 func (v *Viper) getKeyValueConfig() error {
 	if RemoteConfig == nil {
@@ -1733,6 +1791,12 @@ func (v *Viper) SetConfigType(in string) {
 	}
 }
 
+// SetConfigPermissions sets the permissions for the config file.
+func SetConfigPermissions(perm os.FileMode) { v.SetConfigPermissions(perm) }
+func (v *Viper) SetConfigPermissions(perm os.FileMode) {
+	v.configPermissions = perm.Perm()
+}
+
 func (v *Viper) getConfigType() string {
 	if v.configType != "" {
 		return v.configType

viper_test.go

@@ -12,19 +12,24 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
+	"os/exec"
 	"path"
 	"reflect"
+	"runtime"
 	"sort"
 	"strings"
+	"sync"
 	"testing"
 	"time"
 
+	"github.com/fsnotify/fsnotify"
 	"github.com/mitchellh/mapstructure"
 	"github.com/spf13/afero"
 	"github.com/spf13/cast"
 
 	"github.com/spf13/pflag"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 var yamlExample = []byte(`Hacker: true
@@ -383,6 +388,36 @@ func TestEnv(t *testing.T) {
 
 }
 
+func TestEmptyEnv(t *testing.T) {
+	initJSON()
+
+	BindEnv("type") // Empty environment variable
+	BindEnv("name") // Bound, but not set environment variable
+
+	os.Clearenv()
+
+	os.Setenv("TYPE", "")
+
+	assert.Equal(t, "donut", Get("type"))
+	assert.Equal(t, "Cake", Get("name"))
+}
+
+func TestEmptyEnv_Allowed(t *testing.T) {
+	initJSON()
+
+	AllowEmptyEnv(true)
+
+	BindEnv("type") // Empty environment variable
+	BindEnv("name") // Bound, but not set environment variable
+
+	os.Clearenv()
+
+	os.Setenv("TYPE", "")
+
+	assert.Equal(t, "", Get("type"))
+	assert.Equal(t, "Cake", Get("name"))
+}
+
 func TestEnvPrefix(t *testing.T) {
 	initJSON()
 
@@ -578,24 +613,28 @@ func TestBindPFlags(t *testing.T) {
 }
 
 func TestBindPFlagsStringSlice(t *testing.T) {
-	for _, testValue := range []struct {
+	tests := []struct {
 		Expected []string
 		Value    string
 	}{
-		{[]string{}, ""},
+		{nil, ""},
 		{[]string{"jeden"}, "jeden"},
 		{[]string{"dwa", "trzy"}, "dwa,trzy"},
-		{[]string{"cztery", "piec , szesc"}, "cztery,\"piec , szesc\""}} {
+		{[]string{"cztery", "piec , szesc"}, "cztery,\"piec , szesc\""},
+	}
+
+	v := New() // create independent Viper object
+	defaultVal := []string{"default"}
+	v.SetDefault("stringslice", defaultVal)
+
+	for _, testValue := range tests {
+		flagSet := pflag.NewFlagSet("test", pflag.ContinueOnError)
+		flagSet.StringSlice("stringslice", testValue.Expected, "test")
 
 		for _, changed := range []bool{true, false} {
-			v := New() // create independent Viper object
-			flagSet := pflag.NewFlagSet("test", pflag.ContinueOnError)
-			flagSet.StringSlice("stringslice", testValue.Expected, "test")
-			flagSet.Visit(func(f *pflag.Flag) {
-				if len(testValue.Value) > 0 {
-					f.Value.Set(testValue.Value)
-					f.Changed = changed
-				}
+			flagSet.VisitAll(func(f *pflag.Flag) {
+				f.Value.Set(testValue.Value)
+				f.Changed = changed
 			})
 
 			err := v.BindPFlags(flagSet)
@@ -610,7 +649,11 @@ func TestBindPFlagsStringSlice(t *testing.T) {
 			if err := v.Unmarshal(val); err != nil {
 				t.Fatalf("%+#v cannot unmarshal: %s", testValue.Value, err)
 			}
-			assert.Equal(t, testValue.Expected, val.StringSlice)
+			if changed {
+				assert.Equal(t, testValue.Expected, val.StringSlice)
+			} else {
+				assert.Equal(t, defaultVal, val.StringSlice)
+			}
 		}
 	}
 }
@@ -1073,7 +1116,8 @@ func TestWriteConfigYAML(t *testing.T) {
 var yamlMergeExampleTgt = []byte(`
 hello:
     pop: 37890
-    lagrenum: 765432101234567
+    largenum: 765432101234567
+    num2pow63: 9223372036854775808
     world:
     - us
     - uk
@@ -1084,7 +1128,7 @@ hello:
 var yamlMergeExampleSrc = []byte(`
 hello:
     pop: 45000
-    lagrenum: 7654321001234567
+    largenum: 7654321001234567
     universe:
     - mw
     - ad
@@ -1106,8 +1150,20 @@ func TestMergeConfig(t *testing.T) {
 		t.Fatalf("pop != 37890, = %d", pop)
 	}
 
-	if pop := v.GetInt64("hello.lagrenum"); pop != int64(765432101234567) {
-		t.Fatalf("int64 lagrenum != 765432101234567, = %d", pop)
+	if pop := v.GetInt64("hello.largenum"); pop != int64(765432101234567) {
+		t.Fatalf("int64 largenum != 765432101234567, = %d", pop)
+	}
+
+	if pop := v.GetUint("hello.pop"); pop != 37890 {
+		t.Fatalf("uint pop != 37890, = %d", pop)
+	}
+
+	if pop := v.GetUint32("hello.pop"); pop != 37890 {
+		t.Fatalf("uint32 pop != 37890, = %d", pop)
+	}
+
+	if pop := v.GetUint64("hello.num2pow63"); pop != 9223372036854775808 {
+		t.Fatalf("uint64 num2pow63 != 9223372036854775808, = %d", pop)
 	}
 
 	if world := v.GetStringSlice("hello.world"); len(world) != 4 {
@@ -1130,8 +1186,8 @@ func TestMergeConfig(t *testing.T) {
 		t.Fatalf("pop != 45000, = %d", pop)
 	}
 
-	if pop := v.GetInt64("hello.lagrenum"); pop != int64(7654321001234567) {
-		t.Fatalf("int64 lagrenum != 7654321001234567, = %d", pop)
+	if pop := v.GetInt64("hello.largenum"); pop != int64(7654321001234567) {
+		t.Fatalf("int64 largenum != 7654321001234567, = %d", pop)
 	}
 
 	if world := v.GetStringSlice("hello.world"); len(world) != 4 {
@@ -1187,6 +1243,48 @@ func TestMergeConfigNoMerge(t *testing.T) {
 	}
 }
 
+func TestMergeConfigMap(t *testing.T) {
+	v := New()
+	v.SetConfigType("yml")
+	if err := v.ReadConfig(bytes.NewBuffer(yamlMergeExampleTgt)); err != nil {
+		t.Fatal(err)
+	}
+
+	assert := func(i int) {
+		large := v.GetInt64("hello.largenum")
+		pop := v.GetInt("hello.pop")
+		if large != 765432101234567 {
+			t.Fatal("Got large num:", large)
+		}
+
+		if pop != i {
+			t.Fatal("Got pop:", pop)
+		}
+	}
+
+	assert(37890)
+
+	update := map[string]interface{}{
+		"Hello": map[string]interface{}{
+			"Pop": 1234,
+		},
+		"World": map[interface{}]interface{}{
+			"Rock": 345,
+		},
+	}
+
+	if err := v.MergeConfigMap(update); err != nil {
+		t.Fatal(err)
+	}
+
+	if rock := v.GetInt("world.rock"); rock != 345 {
+		t.Fatal("Got rock:", rock)
+	}
+
+	assert(1234)
+
+}
+
 func TestUnmarshalingWithAliases(t *testing.T) {
 	v := New()
 	v.SetDefault("ID", 1)
@@ -1406,6 +1504,111 @@ func doTestCaseInsensitive(t *testing.T, typ, config string) {
 
 }
 
+func newViperWithConfigFile(t *testing.T) (*Viper, string, func()) {
+	watchDir, err := ioutil.TempDir("", "")
+	require.Nil(t, err)
+	configFile := path.Join(watchDir, "config.yaml")
+	err = ioutil.WriteFile(configFile, []byte("foo: bar\n"), 0640)
+	require.Nil(t, err)
+	cleanup := func() {
+		os.RemoveAll(watchDir)
+	}
+	v := New()
+	v.SetConfigFile(configFile)
+	err = v.ReadInConfig()
+	require.Nil(t, err)
+	require.Equal(t, "bar", v.Get("foo"))
+	return v, configFile, cleanup
+}
+
+func newViperWithSymlinkedConfigFile(t *testing.T) (*Viper, string, string, func()) {
+	watchDir, err := ioutil.TempDir("", "")
+	require.Nil(t, err)
+	dataDir1 := path.Join(watchDir, "data1")
+	err = os.Mkdir(dataDir1, 0777)
+	require.Nil(t, err)
+	realConfigFile := path.Join(dataDir1, "config.yaml")
+	t.Logf("Real config file location: %s\n", realConfigFile)
+	err = ioutil.WriteFile(realConfigFile, []byte("foo: bar\n"), 0640)
+	require.Nil(t, err)
+	cleanup := func() {
+		os.RemoveAll(watchDir)
+	}
+	// now, symlink the tm `data1` dir to `data` in the baseDir
+	os.Symlink(dataDir1, path.Join(watchDir, "data"))
+	// and link the `<watchdir>/datadir1/config.yaml` to `<watchdir>/config.yaml`
+	configFile := path.Join(watchDir, "config.yaml")
+	os.Symlink(path.Join(watchDir, "data", "config.yaml"), configFile)
+	t.Logf("Config file location: %s\n", path.Join(watchDir, "config.yaml"))
+	// init Viper
+	v := New()
+	v.SetConfigFile(configFile)
+	err = v.ReadInConfig()
+	require.Nil(t, err)
+	require.Equal(t, "bar", v.Get("foo"))
+	return v, watchDir, configFile, cleanup
+}
+
+func TestWatchFile(t *testing.T) {
+	if runtime.GOOS == "linux" {
+		// TODO(bep) FIX ME
+		t.Skip("Skip test on Linux ...")
+	}
+
+	t.Run("file content changed", func(t *testing.T) {
+		// given a `config.yaml` file being watched
+		v, configFile, cleanup := newViperWithConfigFile(t)
+		defer cleanup()
+		_, err := os.Stat(configFile)
+		require.NoError(t, err)
+		t.Logf("test config file: %s\n", configFile)
+		wg := sync.WaitGroup{}
+		wg.Add(1)
+		v.OnConfigChange(func(in fsnotify.Event) {
+			t.Logf("config file changed")
+			wg.Done()
+		})
+		v.WatchConfig()
+		// when overwriting the file and waiting for the custom change notification handler to be triggered
+		err = ioutil.WriteFile(configFile, []byte("foo: baz\n"), 0640)
+		wg.Wait()
+		// then the config value should have changed
+		require.Nil(t, err)
+		assert.Equal(t, "baz", v.Get("foo"))
+	})
+
+	t.Run("link to real file changed (à la Kubernetes)", func(t *testing.T) {
+		// skip if not executed on Linux
+		if runtime.GOOS != "linux" {
+			t.Skipf("Skipping test as symlink replacements don't work on non-linux environment...")
+		}
+		v, watchDir, _, _ := newViperWithSymlinkedConfigFile(t)
+		// defer cleanup()
+		wg := sync.WaitGroup{}
+		v.WatchConfig()
+		v.OnConfigChange(func(in fsnotify.Event) {
+			t.Logf("config file changed")
+			wg.Done()
+		})
+		wg.Add(1)
+		// when link to another `config.yaml` file
+		dataDir2 := path.Join(watchDir, "data2")
+		err := os.Mkdir(dataDir2, 0777)
+		require.Nil(t, err)
+		configFile2 := path.Join(dataDir2, "config.yaml")
+		err = ioutil.WriteFile(configFile2, []byte("foo: baz\n"), 0640)
+		require.Nil(t, err)
+		// change the symlink using the `ln -sfn` command
+		err = exec.Command("ln", "-sfn", dataDir2, path.Join(watchDir, "data")).Run()
+		require.Nil(t, err)
+		wg.Wait()
+		// then
+		require.Nil(t, err)
+		assert.Equal(t, "baz", v.Get("foo"))
+	})
+
+}
+
 func BenchmarkGetBool(b *testing.B) {
 	key := "BenchmarkGetBool"
 	v = New()