273 lines
5.5 KiB
Markdown
273 lines
5.5 KiB
Markdown
etcdctl
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========
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`etcdctl` is a command line client for [etcd][etcd].
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It can be used in scripts or for administrators to explore an etcd cluster.
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[etcd]: https://github.com/coreos/etcd
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## Getting etcdctl
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The latest release is available as a binary at [Github][github-release] along with etcd.
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[github-release]: https://github.com/coreos/etcd/releases/
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You can also build etcdctl from source using the build script found in the parent directory.
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## Usage
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### Setting Key Values
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Set a value on the `/foo/bar` key:
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```
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$ etcdctl set /foo/bar "Hello world"
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Hello world
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```
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Set a value on the `/foo/bar` key with a value that expires in 60 seconds:
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```
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$ etcdctl set /foo/bar "Hello world" --ttl 60
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Hello world
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```
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Conditionally set a value on `/foo/bar` if the previous value was "Hello world":
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```
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$ etcdctl set /foo/bar "Goodbye world" --swap-with-value "Hello world"
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Goodbye world
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```
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Conditionally set a value on `/foo/bar` if the previous etcd index was 12:
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```
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$ etcdctl set /foo/bar "Goodbye world" --swap-with-index 12
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Goodbye world
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```
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Create a new key `/foo/bar`, only if the key did not previously exist:
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```
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$ etcdctl mk /foo/new_bar "Hello world"
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Hello world
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```
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Create a new dir `/fooDir`, only if the key did not previously exist:
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```
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$ etcdctl mkdir /fooDir
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```
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Update an existing key `/foo/bar`, only if the key already existed:
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```
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$ etcdctl update /foo/bar "Hola mundo"
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Hola mundo
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```
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Create or update a directory called `/mydir`:
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```
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$ etcdctl setdir /mydir
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```
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### Retrieving a key value
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Get the current value for a single key in the local etcd node:
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```
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$ etcdctl get /foo/bar
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Hello world
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```
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Get the value of a key with additional metadata in a parseable format:
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```
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$ etcdctl -o extended get /foo/bar
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Key: /foo/bar
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Modified-Index: 72
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TTL: 0
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Etcd-Index: 72
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Raft-Index: 5611
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Raft-Term: 1
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Hello World
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```
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### Listing a directory
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Explore the keyspace using the `ls` command
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```
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$ etcdctl ls
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/akey
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/adir
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$ etcdctl ls /adir
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/adir/key1
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/adir/key2
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```
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Add `--recursive` to recursively list subdirectories encountered.
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```
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$ etcdctl ls --recursive
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/akey
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/adir
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/adir/key1
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/adir/key2
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```
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Directories can also have a trailing `/` added to output using `-p`.
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```
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$ etcdctl ls -p
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/akey
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/adir/
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```
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### Deleting a key
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Delete a key:
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```
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$ etcdctl rm /foo/bar
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```
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Delete an empty directory or a key-value pair
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```
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$ etcdctl rmdir /path/to/dir
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```
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or
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```
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$ etcdctl rm /path/to/dir --dir
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```
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Recursively delete a key and all child keys:
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```
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$ etcdctl rm /path/to/dir --recursive
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```
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Conditionally delete `/foo/bar` if the previous value was "Hello world":
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```
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$ etcdctl rm /foo/bar --with-value "Hello world"
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```
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Conditionally delete `/foo/bar` if the previous etcd index was 12:
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```
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$ etcdctl rm /foo/bar --with-index 12
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```
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### Watching for changes
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Watch for only the next change on a key:
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```
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$ etcdctl watch /foo/bar
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Hello world
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```
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Continuously watch a key:
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```
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$ etcdctl watch /foo/bar --forever
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Hello world
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.... client hangs forever until ctrl+C printing values as key change
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```
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Continuously watch a key, starting with a given etcd index:
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```
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$ etcdctl watch /foo/bar --forever --index 12
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Hello world
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.... client hangs forever until ctrl+C printing values as key change
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```
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Continuously watch a key and exec a program:
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```
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$ etcdctl exec-watch /foo/bar -- sh -c "env | grep ETCD"
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ETCD_WATCH_ACTION=set
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ETCD_WATCH_VALUE=My configuration stuff
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ETCD_WATCH_MODIFIED_INDEX=1999
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ETCD_WATCH_KEY=/foo/bar
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ETCD_WATCH_ACTION=set
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ETCD_WATCH_VALUE=My new configuration stuff
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ETCD_WATCH_MODIFIED_INDEX=2000
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ETCD_WATCH_KEY=/foo/bar
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```
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Continuously and recursively watch a key and exec a program:
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```
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$ etcdctl exec-watch --recursive /foo -- sh -c "env | grep ETCD"
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ETCD_WATCH_ACTION=set
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ETCD_WATCH_VALUE=My configuration stuff
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ETCD_WATCH_MODIFIED_INDEX=1999
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ETCD_WATCH_KEY=/foo/bar
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ETCD_WATCH_ACTION=set
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ETCD_WATCH_VALUE=My new configuration stuff
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ETCD_WATCH_MODIFIED_INDEX=2000
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ETCD_WATCH_KEY=/foo/barbar
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```
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## Return Codes
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The following exit codes can be returned from etcdctl:
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```
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0 Success
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1 Malformed etcdctl arguments
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2 Failed to connect to host
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3 Failed to auth (client cert rejected, ca validation failure, etc)
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4 400 error from etcd
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5 500 error from etcd
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```
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## Endpoint
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If your etcd cluster isn't available on `http://127.0.0.1:2379` you can specify
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a `--endpoint` flag or `ETCDCTL_ENDPOINT` environment variable. You can list one endpoint,
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or a comma-separated list of endpoints. This option is ignored if the `--discovery-srv`
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option is provided.
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```
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ETCDCTL_ENDPOINT="http://10.0.28.1:4002" etcdctl set my-key to-a-value
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ETCDCTL_ENDPOINT="http://10.0.28.1:4002,http://10.0.28.2:4002,http://10.0.28.3:4002" etcdctl set my-key to-a-value
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etcdctl --endpoint http://10.0.28.1:4002 my-key to-a-value
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etcdctl --endpoint http://10.0.28.1:4002,http://10.0.28.2:4002,http://10.0.28.3:4002 etcdctl set my-key to-a-value
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```
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## DNS Discovery
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If you want to discover your etcd cluster through domain SRV records you can specify
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a `--discovery-srv` flag or `ETCDCTL_DISCOVERY_SRV` environment variable. This option takes
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precedence over the `--endpoint` flag.
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```
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ETCDCTL_DISCOVERY_SRV="some-domain" etcdctl set my-key to-a-value
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etcdctl --discovery-srv some-domain set my-key to-a-value
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```
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## Project Details
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### Versioning
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etcdctl uses [semantic versioning][semver].
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Releases will follow lockstep with the etcd release cycle.
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[semver]: http://semver.org/
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### License
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etcdctl is under the Apache 2.0 license. See the [LICENSE][license] file for details.
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[license]: https://github.com/coreos/etcdctl/blob/master/LICENSE
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