esctl

esctl

esctl is a command-line tool for managing and interacting with Elasticsearch clusters. It provides a convenient interface to perform various operations, such as querying cluster information, managing indices, retrieving shard details, and monitoring tasks.

Features:

• Retrieve information about nodes, indices, shards, aliases, and tasks in an Elasticsearch cluster
• Describe cluster health and stats
• Describe index settings and mappings
• Simple and intuitive command-line interface

Contributing

Please see the CONTRIBUTING.md file.

Table of Contents

• Installation
• Examples
• Configuration
• Usage
  • Get
  • Describe
  • Count
  • Count with Grouping
  • Query
• License

Installation

To install esctl, ensure that you have Go installed and set up in your development environment. Then, follow the steps below:

1. Open a terminal or command prompt.

2. Run the following command to install esctl:

   go install github.com/fehmicansaglam/esctl@latest
   

   This command will fetch the source code from the GitHub repository, compile it, and install the esctl binary in your Go workspace's bin directory.

3. Make sure that your Go workspace's bin directory is added to your system's PATH environment variable. This step will allow you to run esctl from any directory in the terminal or command prompt.

Once installed, you can run esctl by simply typing esctl in the terminal or command prompt.

Examples

> esctl get shards --index=articles --primary
INDEX     ID                      SHARD  PRI-REP  STATE    DOCS  STORE  IP         NODE               SEGMENTS-COUNT
articles  jxn-Oa3XSPigaCBYt9fKiw  0      primary  STARTED  0     225b   127.0.0.1  es-data-0          0
articles  jxn-Oa3XSPigaCBYt9fKiw  1      primary  STARTED  0     225b   127.0.0.1  es-data-0          0
articles  jxn-Oa3XSPigaCBYt9fKiw  2      primary  STARTED  0     225b   127.0.0.1  es-data-0          0

> esctl get shards --index=articles --shard 0 --unassigned --sort-by=unassigned-at
INDEX     SHARD  PRI-REP  STATE       UNASSIGNED-REASON  UNASSIGNED-AT
articles  0      replica  UNASSIGNED  CLUSTER_RECOVERED  2023-05-07T20:37:07.520Z
articles  0      replica  UNASSIGNED  CLUSTER_RECOVERED  2023-05-07T20:37:07.520Z

> esctl get indices
HEALTH  STATUS  INDEX     UUID                    PRI  REP  DOCS-COUNT  DOCS-DELETED  CREATION-DATE             STORE-SIZE  PRI-STORE-SIZE
yellow  open    articles  8vCars4rQquYHNhpKV2fow  3    2    0           0             2023-05-07T19:17:52.259Z  675b        675b

> esctl get nodes --sort-by=cpu
NAME               IP         NODE-ROLE    MASTER  HEAP-MAX  HEAP-CURRENT  HEAP-PERCENT  CPU  LOAD-1M  DISK-TOTAL  DISK-USED  DISK-AVAILABLE
es-data-0          127.0.0.1  cdfhilmrstw  *       4gb       1.6gb         41%           10%  2.02     232.9gb     199.2gb    33.6gb

> esctl get aliases --index=articles
ALIAS           INDEX
articles_alias  articles

Configuration

esctl supports reading context configurations from a YAML file, enabling you to easily switch between different Elasticsearch contexts.

Create a configuration file named esctl.yml in your $HOME/.config directory. This file will contain the details of the Elasticsearch contexts you want to connect to.

Here is an example configuration:

current-context: "local"
contexts:
  - name: "local"
    protocol: "http"
    host: "localhost"
    port: 9200
  - name: "production"
    protocol: "https"
    host: "prod.es.example.com"
    port: 443
    username: "prod_username"
    password: "prod_password"

In the configuration file:

• current-context is the name of the context that esctl will connect to by default.
• contexts is an array of your Elasticsearch contexts.
  • name is the name you assign to the context.
  • protocol, host, port, username, and password are the connection details for each context.
  • protocol and port are optional and default to http and 9200 respectively.

Note
esctl will use the current-context defined in the configuration file unless another cluster is specified via command-line flag or environment variable.

esctl config use-context

Sets the current context in the configuration file.

esctl config use-context CONTEXT

• CONTEXT: The name of the context to set as the current context.

This command updates the current-context in the configuration file (esctl.yml) with the specified context name. The updated configuration will be used for subsequent operations performed by esctl.

Note
The specified context name must already be defined in the configuration file.

esctl config get-contexts

Displays the contexts defined in the esctl.yml file.

esctl config get-contexts

Example output:

- name: local(*)
  protocol: https
  host: localhost
  port: 9200
  username: myuser
  password: ********
- name: production
  protocol: http
  host: example.com
  port: 9200
  username: anotheruser
  password: ********

In the example output, the current context is marked with an asterisk (*).

esctl config current-context

Displays the current context that esctl is configured to use.

esctl config current-context

Example output:

local

Displaying Current Context with Starship Prompt

If you're using Starship for your prompt, you can display the current esctl context directly in your shell prompt. This can be done by adding a custom module to your Starship configuration. Here's an example:

[custom.esctl]
command = "esctl config current-context 2>/dev/null || echo 'none'"
description = "Displays the current esctl context"
when = "command -v esctl"
symbol = "🄴 "

This configuration adds a new custom module that executes esctl config current-context and displays the current context in your prompt. The module will only appear if esctl is installed (when = "command -v esctl"). The symbol option is used to provide a visual indicator for the esctl context information. The 🄴 symbol is used to represent Elasticsearch.

Elasticsearch Host Configuration

Additionally, esctl allows you to configure the Elasticsearch host, port, protocol, username, and password using command-line flags or environment variables. By default, the port is set to 9200, and the protocol to http.

To specify a custom host, you can use the --host flag followed by the desired host value. For example:

esctl --host=HOST COMMAND

Similarly, to specify a custom port, you can use the --port flag followed by the desired port value. For example:

esctl --port=PORT COMMAND

To specify a custom protocol, you can use the --protocol flag followed by either http or https. For example:

esctl --protocol=https COMMAND

To provide basic authentication credentials, you can use the --username and --password flags followed by the corresponding values. For example:

esctl --username=USERNAME --password=PASSWORD COMMAND

Alternatively, you can set the ESCTL_HOST, ESCTL_PORT, ESCTL_PROTOCOL, ESCTL_USERNAME, and ESCTL_PASSWORD environment variables to your desired Elasticsearch configuration.

If the corresponding command-line flags and environment variables are not provided, esctl will use the default values (9200, http, no username, and no password) for the Elasticsearch connection.

Warning
Since host is mandatory, if host is not provided via a flag, environment variable or esctl.yml, esctl will exit with an error.

Customizing Columns

You can customize the columns displayed when running esctl get ENTITY using the esctl.yml configuration file.

To customize the columns, add an optional entities field to the esctl.yml file. Under entities, specify the desired entities (node, index, shard, alias, task) and their corresponding columns. Here is an example:

contexts:
  - host: localhost
    name: cluster1
    port: 9200
    protocol: http
  - host: 127.0.0.1
    name: cluster2
current-context: cluster2
entities:
  node:
    columns:
      - "NAME"
      - "IP"
      - "NODE-ROLE"
      - "MASTER"
      - "HEAP-MAX"
      - "HEAP-CURRENT"
      - "CPU"
      - "LOAD-1M"
  index:
    columns: []
  task:
    columns: []

In the columns field of each entity, specify the desired columns in the order you want them to appear.

Note
If you do not provide a columns field for an entity, it will use the default columns.

Usage

Get

The get command allows you to retrieve information about Elasticsearch entities. Supported entities include nodes, indices, shards, aliases, and tasks. This command provides a read-only view of the cluster and does not support data querying.

esctl get ENTITY [flags]

Available Entities

• nodes: List all nodes in the Elasticsearch cluster.
• indices: List all indices in the Elasticsearch cluster.
• shards: List detailed information about shards, including their sizes and placement.
• aliases: List all aliases in the Elasticsearch cluster.
• tasks: List all tasks in the Elasticsearch cluster.

Flags

• --index: Specifies the name of the index (applies to indices, shards, and aliases entities).
• --node: Specified the name of the node (applies to nodes and shards entities).
• --shard: Filters shards by shard number.
• --primary: Filters primary shards.
• --replica: Filters replica shards.
• --started: Filters shards in STARTED state.
• --relocating: Filters shards in RELOCATING state.
• --initializing: Filters shards in INITIALIZING state.
• --unassigned: Filters shards in UNASSIGNED state.
• --actions: Filters tasks by actions.
• --sort-by: Specifies the columns to sort by, separated by commas (applies to all entities). The column names are case insensitive.
• --columns: Specifies the columns to display, separated by commas (applies to all entities). To display all columns, use all. The column names are case insensitive.

Get Nodes

Retrieves a list of all nodes in the Elasticsearch cluster.

esctl get nodes

Get Indices

Retrieves a list of all indices in the Elasticsearch cluster.

esctl get indices

Get Shards

To retrieve shards from Elasticsearch, you can use the following command:

esctl get shards [--index index] [--node node] [--shard shard] [--primary] [--replica] [--started] [--relocating] [--initializing] [--unassigned]

• --index: Specifies the name of the index to retrieve shards from.
• --node: Filters shards by node name.
• --shard: Filters shards by shard number.
• --primary: Filters primary shards.
• --replica: Filters replica shards.
• --started: Filters shards in the STARTED state.
• --relocating: Filters shards in the RELOCATING state.
• --initializing: Filters shards in the INITIALIZING state.
• --unassigned: Filters shards in the UNASSIGNED state.

If none of the flags are provided, all shards will be returned.

Example usage:

esctl get shards --index my_index --relocating

This will retrieve only the shards that are currently relocating for the specified index.

Get Aliases

Retrieves the list of aliases defined in Elasticsearch, including the index names they are associated with.

Usage:

esctl get aliases [--index INDEX]

--index: Filter the aliases by a specific index. If not provided, aliases to all indices will be returned.

Get Tasks

The get tasks command retrieves information about tasks in the Elasticsearch cluster.

Usage:

esctl get tasks [--actions ACTIONS]

Example:

esctl get tasks --actions 'index*' --actions '*search*'

Describe

The esctl describe command allows you to retrieve detailed information about various entities in the Elasticsearch cluster. The output is in JSON or YAML format, making it easy to read and understand. You can select your preferred output format using the --output or -o flag, with json and yaml being the available options.

Describe Cluster

This command outputs the cluster information in YAML format, providing a comprehensive overview of the cluster's current state.

esctl describe cluster

Describe Index

This command outputs the mappings and settings of a specified index in JSON format.

esctl describe index INDEX

This command also supports the --mappings and --settings flags, which can be used to get only the mappings or settings respectively.

# To get only mappings
esctl describe index INDEX --mappings

# To get only settings
esctl describe index INDEX --settings

Note
Consider piping the output of describe index to fx, a command-line JSON processing tool, for a more convenient experience.

esctl describe index INDEX | fx

Count

The esctl count command allows you to retrieve the count of documents in one or more Elasticsearch indices. You can specify filters to apply using the --term and --exists flags.

Count All Documents

To count all documents across all indices, use the following command:

esctl count

Count Documents in Specific Index

To count all documents in a specific index, use the following command:

esctl count --index index

Count Documents with Term Filters

You can apply term filters to count documents that match specific field-value combinations. Use the --term flag followed by the field-value pairs separated by a colon (:). For example, to count documents with the field price equal to 12 and category equal to electronics, use the following command:

esctl count --term "price:12" --term "category:electronics"

Count Documents with Existence Filters

To count documents based on the existence of a field, use the --exists flag followed by the field name. For example, to count documents where the field category exists, use the following command:

esctl count --exists "category"

Note
You can combine both term and existence filters in a single command to further refine the count.

Count with Grouping

The esctl count command also supports grouping the documents by a specific field and displaying the respective counts. You can use the --group-by flag to specify the field to group by.

Group Documents by Field

To count and group documents by a specific field, use the --group-by flag followed by the field name. For example, to count documents in the index articles and group them by the category field, use the following command:

esctl count --index articles --group-by category

This command will retrieve the count of documents in the articles index and group them based on the values of the category field.

Grouping with Filters

You can combine the grouping functionality with term and existence filters to further refine the count and group the documents accordingly. For example, to count and group documents in the index articles with the field price equal to 12, use the following command:

esctl count --index articles --term "price:12" --group-by category

This command will count the documents in the articles index that satisfy the term filter (price:12) and group them by the values of the category field.

Note
If an index name is not provided to the count command with --group-by, all the indices will be grouped individually.

Query

The query command allows you to execute queries against Elasticsearch.

esctl query INDEX

Flags

• --id: Specify document IDs to fetch. Can be specified multiple times.

  Example: --id 61 --id 62

• --term (-t): Term filters to apply. The format should be field:value. Can be specified multiple times.

  Example: --term "price:10" --term "category:electronics"

• --size: Specify the number of hits to return. Defaults to 1.

  Example: --size 5

Examples

esctl query articles
esctl query articles --id 61
esctl query articles --term "price:10" --size 2

This would respectively:

• Query all documents in the articles index.
• Query the articles index and get the document with ID 61.
• Query the articles index filtering by the term price:10 and return 2 hits.

License

This project is licensed under the MIT License. See the LICENSE file for more details.