mirror of https://github.com/hashicorp/consul
146 lines
4.5 KiB
Markdown
146 lines
4.5 KiB
Markdown
---
|
|
layout: commands
|
|
page_title: 'Commands: KV Put'
|
|
sidebar_title: put
|
|
---
|
|
|
|
# Consul KV Put
|
|
|
|
Command: `consul kv put`
|
|
|
|
The `kv put` command writes the data to the given path in the KV store.
|
|
|
|
## Usage
|
|
|
|
Usage: `consul kv put [options] KEY [DATA]`
|
|
|
|
#### API Options
|
|
|
|
@include 'http_api_options_client.mdx'
|
|
|
|
@include 'http_api_options_server.mdx'
|
|
|
|
#### Enterprise Options
|
|
|
|
@include 'http_api_namespace_options.mdx'
|
|
|
|
#### KV Put Options
|
|
|
|
- `-acquire` - Obtain a lock on the key. If the key does not exist, this
|
|
operation will create the key and obtain the lock. The session must already
|
|
exist and be specified via the -session flag. The default value is false.
|
|
|
|
- `-base64` - Treat the data as base 64 encoded. The default value is false.
|
|
|
|
- `-cas` - Perform a Check-And-Set operation. Specifying this value also
|
|
requires the -modify-index flag to be set. The default value is false.
|
|
|
|
- `-flags=<int>` - Unsigned integer value to assign to this KV pair. This
|
|
value is not read by Consul, so clients can use this value however makes sense
|
|
for their use case. The default value is 0 (no flags).
|
|
|
|
- `-modify-index=<int>` - Unsigned integer representing the ModifyIndex of the
|
|
key. This is used in combination with the -cas flag.
|
|
|
|
- `-release` - Forfeit the lock on the key at the given path. This requires the
|
|
-session flag to be set. The key must be held by the session in order to be
|
|
unlocked. The default value is false.
|
|
|
|
- `-session=<string>` - User-defined identifier for this session as a string.
|
|
This is commonly used with the -acquire and -release operations to build
|
|
robust locking, but it can be set on any key. The default value is empty (no
|
|
session).
|
|
|
|
## Examples
|
|
|
|
To insert a value of "5" for the key named "redis/config/connections" in the
|
|
KV store:
|
|
|
|
```shell-session
|
|
$ consul kv put redis/config/connections 5
|
|
Success! Data written to: redis/config/connections
|
|
```
|
|
|
|
If no data is specified, the key will be created with empty data:
|
|
|
|
```shell-session
|
|
$ consul kv put redis/config/connections
|
|
Success! Data written to: redis/config/connections
|
|
```
|
|
|
|
If the `-base64` flag is set, the data will be decoded before writing:
|
|
|
|
```shell-session
|
|
$ consul kv put -base64 foo/encoded aGVsbG8gd29ybGQK
|
|
Success! Data written to: foo/encoded
|
|
```
|
|
|
|
!> **Be careful when overwriting data!** The above operation would overwrite
|
|
the value at the key to the empty value.
|
|
|
|
For longer or sensitive values, it is possible to read from a file by prefixing
|
|
with the `@` symbol:
|
|
|
|
```shell-session
|
|
$ consul kv put redis/config/password @password.txt
|
|
Success! Data written to: redis/config/connections
|
|
```
|
|
|
|
Or read values from stdin by specifying the `-` symbol:
|
|
|
|
```shell-session
|
|
$ echo "5" | consul kv put redis/config/password -
|
|
Success! Data written to: redis/config/connections
|
|
|
|
$ consul kv put redis/config/password -
|
|
5
|
|
<CTRL+D>
|
|
Success! Data written to: redis/config/connections
|
|
```
|
|
|
|
~> For secret and sensitive values, you should consider using a secret
|
|
management solution like **[HashiCorp's Vault](https://www.vaultproject.io/)**.
|
|
While it is possible to secure values in Consul's KV store, Vault provides a
|
|
more robust interface for secret management.
|
|
|
|
To only update a key if it has not been modified since a given index, specify
|
|
the `-cas` and `-modify-index` flags:
|
|
|
|
```shell-session
|
|
$ consul kv get -detailed redis/config/connections | grep ModifyIndex
|
|
ModifyIndex 456
|
|
|
|
$ consul kv put -cas -modify-index=123 redis/config/connections 10
|
|
Error! Did not write to redis/config/connections: CAS failed
|
|
|
|
$ consul kv put -cas -modify-index=456 redis/config/connections 10
|
|
Success! Data written to: redis/config/connections
|
|
```
|
|
|
|
To specify flags on the key, use the `-flags` option. These flags are completely
|
|
controlled by the user:
|
|
|
|
```shell-session
|
|
$ consul kv put -flags=42 redis/config/password s3cr3t
|
|
Success! Data written to: redis/config/password
|
|
```
|
|
|
|
To create or tune a lock, use the `-acquire` and `-session` flags. The session must already exist (this command will not create it or manage it):
|
|
|
|
```shell-session
|
|
$ consul kv put -acquire -session=abc123 redis/lock/update
|
|
Success! Lock acquired on: redis/lock/update
|
|
```
|
|
|
|
When you are finished, release the lock:
|
|
|
|
```shell-session
|
|
$ consul kv put -release -session=acb123 redis/lock/update
|
|
Success! Lock released on: redis/lock/update
|
|
```
|
|
|
|
~> **Warning!** If you are trying to build a locking mechanism with these
|
|
low-level primitives, you may want to look at the [<tt>consul
|
|
lock</tt>](/commands/lock) command. It provides higher-level
|
|
functionality without exposing the internal APIs of Consul.
|