Writing Plugins

The Steampipe Plugin SDK makes writing tables fast, easy, and fun! Most of the heavy lifting is taken care of for you - just define your tables and columns, wire up a few API calls, and you can start to query your service with standard SQL!

While this document will provide an introduction and some examples, note that Steampipe is an evolving, open source project - refer to the code as the authoritative source, as well as for real-world examples.

Also, please try to be a good community citizen - following the standards makes for a better, more consistent experience for end-users and developers alike.

Let's get started!

• main.go
• plugin.go
• Implementing Tables
• Logging
• Installing and Testing Your Plugin

main.go

The main function in then main.go is the entry point for your plugin. This function must call plugin.Serve from the plugin sdk to instantiate your plugin gRPC server. You will pass the plugin function that you will create in the plugin.go file:

Example: main.go

package main

import (
    "github.com/turbot/steampipe-plugin-sdk/v5/plugin"
    "github.com/turbot/steampipe-plugin-zendesk/zendesk"
)

func main() {
    plugin.Serve(&plugin.ServeOpts{PluginFunc: zendesk.Plugin})
}

plugin.go

The plugin.go file should implement a single Plugin Definition (Plugin() function) that returns a pointer to a Plugin to be loaded by the gRPC server.

By convention, the package name for your plugin should be the same name as your plugin, and go files for your plugin (except main.go) should reside in a folder with the same name.

Example: plugin.go

package zendesk

import (
    "context"

    "github.com/turbot/steampipe-plugin-sdk/plugin"
    "github.com/turbot/steampipe-plugin-sdk/plugin/transform"
)

func Plugin(ctx context.Context) *plugin.Plugin {
    p := &plugin.Plugin{
        Name:             "steampipe-plugin-zendesk",
        DefaultTransform: transform.FromGo().NullIfZero(),
        TableMap: map[string]*plugin.Table{
            "zendesk_brand":        tableZendeskBrand(),
            "zendesk_group":        tableZendeskGroup(),
            "zendesk_organization": tableZendeskOrganization(),
            "zendesk_search":       tableZendeskSearch(),
            "zendesk_ticket":       tableZendeskTicket(),
            "zendesk_ticket_audit": tableZendeskTicketAudit(),
            "zendesk_trigger":      tableZendeskTrigger(),
            "zendesk_user":         tableZendeskUser(),
        },
    }
    return p
}

Plugin Definition

Implementing Tables

By convention, each table should be implemented in a separate file named table_{table name}.go. Each table will have a single table definition function that returns a pointer to a plugin.Table (this is the function specified in the TableMap of the plugin definition). The function name is typically the table name in camel case (per golang standards) prefixed by table.

The table definition specifies the name and description of the table, a list of column definitions, and the functions to call in order to list the data for all the rows, or to get data for a single row.

When a connection is created, Steampipe uses the table and column definitions to create the Postgres foreign tables, however the tables don't store the data - the data is populated (hydrated) when a query is run.

The basic flow is:

1. A user runs a steampipe query against the database
2. Postgres parses the query and sends the parsed request to the Steampipe FDW.
3. The Steampipe Foreign Data Wrapper (Steampipe FDW) determines what tables and columns are required.
4. The FDW calls the appropriate Hydrate Functions in the plugin, which fetch the appropriate data from the API, cloud provider, etc.
   • Each table defines two special hydrate functions, List and Get. The List or Get will always be called before any other hydrate function in the table, as the other functions typically depend on the result of the Get or List call.
   • Whether List or Get is called depends upon whether the qualifiers (in where clauses and join...on) match the KeyColumns. This allows Steampipe to fetch only the "row" data that it needs. Qualifiers (aka quals) enable Steampipe to map a Postgres constraint (e.g. where created_at > date('2023-01-01')) to the API parameter (e.g. since=1673992596000) that the plugin's supporting SDK uses to fetch results matching the Postgres constraint. See How To enhance a plugin with a new table that supports 'quals' for a complete example.
   • Multiple columns may (and usually do) get built from the same hydrate function, but steampipe only calls the hydrate functions for the columns requested (specified in the select, join, or where). This allows steampipe to call only those APIs for the "column" data requested in the query.
5. The Transform Functions are called for each column. The transform functions extract and/or reformat data returned by the hydrate functions into the format to be returned in the column.
6. The plugin returns the transformed data to the Steampipe FDW
7. Steampipe FDW returns the results to the database

Hydrate Functions

The purpose of a hydrate function is to connect to an external system or service and gather data for the table.

Get and List are special hydrate functions defined in the the Table Definition that have some specific considerations:

• Every table must define a List and/or Get function.
• The List or Get will always be called before any other hydrate function in the table, as the other functions typically depend on the result of the Get of List call.
• Whether List or Get is called depends upon whether the qualifiers (in where clauses and join...on) match the KeyColumns defined in the Get Config. This allows steampipe to fetch only the "row" data that it needs.
• Typically, hydrate functions return a single data item (data for a single row). List functions are an exception - they stream data for multiple rows using the QueryData object, and return nil.
• The Get function will usually get the key column data from the QueryData.KeyColumnQuals so that it can get the appropriate item as based on the qualifiers (where clause, join...on). If the Get hydrate function is used as both a Get function AND a normal hydrate function, you should get the key column data from the HydrateData.Item if it is not nil, and use the QueryData.KeyColumnQuals otherwise.

Hydrate Dependencies

Steampipe attempts to parallelize the hydrate functions as much as possible. Sometimes, however, one hydrate function requires the output from another. You can define HydrateDependencies for this case:

return &plugin.Table{
        Name: "hydrate_columns_dependency",
        List: &plugin.ListConfig{
            Hydrate: hydrateList,
        },
        HydrateDependencies: []plugin.HydrateDependencies{
            {
                Func:    hydrate2,
                Depends: []plugin.HydrateFunc{hydrate1},
            },
        },
        Columns: []*plugin.Column{
            {Name: "id", Type: proto.ColumnType_INT},
            {Name: "hydrate_column_1", Type: proto.ColumnType_STRING, Hydrate: hydrate1},
            {Name: "hydrate_column_2", Type: proto.ColumnType_STRING, Hydrate: hydrate2},
        },
    }

Here, hydrate function hydrate2 is dependent on hydrate1. This means hydrate2 will not execute until hydrate1 has completed and the results are available. hydrate2 can refer to the results from hydrate1 as follows:

func hydrate2(ctx context.Context, d *plugin.QueryData, h *plugin.HydrateData) (interface{}, error) {
        // NOTE: in this case we know the output of hydrate1 is map[string]interface{} so we cast it accordingly.
        // the data should be cast to th appropriate type
    hydrate1Results := h.HydrateResults["hydrate1"].(map[string]interface{})
.....
}

Note that:

• Multiple dependencies are supported.
• Circular dependencies will be detected and cause a validation failure.
• The Get and List hydrate functions CANNOT have dependencies.

Transform Functions

Transform functions are used to extract and/or reformat data returned by a hydrate function into the desired type/format for a column. You can call your own transform function with From, but you probably don't need to write one -- The SDK provides many that cover the most common cases. You can chain transforms together, but the transform chain must be started with a From function:

Additional functions can be chained after a From function to transform the data:

Example: Table Definition File

package zendesk

import (
    "context"

    "github.com/nukosuke/go-zendesk/zendesk"

    "github.com/turbot/steampipe-plugin-sdk/grpc/proto"
    "github.com/turbot/steampipe-plugin-sdk/plugin"
)

func tableZendeskUser() *plugin.Table {
    return &plugin.Table{
        Name:        "zendesk_user",
        Description: "Zendesk Support has three types of users: end users (your customers), agents, and administrators.",
        List: &plugin.ListConfig{
            Hydrate: listUser,
        },
        Get: &plugin.GetConfig{
            KeyColumns: plugin.SingleColumn("id"),
            Hydrate:    getUser,
        },
        Columns: []*plugin.Column{
            {Name: "active", Type: proto.ColumnType_BOOL, Description: "False if the user has been deleted"},
            {Name: "alias", Type: proto.ColumnType_STRING, Description: "An alias displayed to end users"},
            {Name: "chat_only", Type: proto.ColumnType_BOOL, Description: "Whether or not the user is a chat-only agent"},
            {Name: "created_at", Type: proto.ColumnType_TIMESTAMP, Description: "The time the user was created"},
            {Name: "custom_role_id", Type: proto.ColumnType_INT, Description: "A custom role if the user is an agent on the Enterprise plan"},
            {Name: "default_group_id", Type: proto.ColumnType_INT, Description: "The id of the user's default group"},
            {Name: "details", Type: proto.ColumnType_STRING, Description: "Any details you want to store about the user, such as an address"},
            {Name: "email", Type: proto.ColumnType_STRING, Description: "The user's primary email address. *Writeable on create only. On update, a secondary email is added."},
            {Name: "external_id", Type: proto.ColumnType_STRING, Description: "A unique identifier from another system. The API treats the id as case insensitive. Example: \"ian1\" and \"Ian1\" are the same user"},
            {Name: "id", Type: proto.ColumnType_INT, Description: "Automatically assigned when the user is created"},
            {Name: "last_login_at", Type: proto.ColumnType_TIMESTAMP, Description: "The last time the user signed in to Zendesk Support"},
            {Name: "locale", Type: proto.ColumnType_STRING, Description: "The user's locale. A BCP-47 compliant tag for the locale. If both \"locale\" and \"locale_id\" are present on create or update, \"locale_id\" is ignored and only \"locale\" is used."},
            {Name: "locale_id", Type: proto.ColumnType_INT, Description: "The user's language identifier"},
            {Name: "moderator", Type: proto.ColumnType_BOOL, Description: "Designates whether the user has forum moderation capabilities"},
            {Name: "name", Type: proto.ColumnType_STRING, Description: "The user's name"},
            {Name: "notes", Type: proto.ColumnType_STRING, Description: "Any notes you want to store about the user"},
            {Name: "only_private_comments", Type: proto.ColumnType_BOOL, Description: "true if the user can only create private comments"},
            {Name: "organization_id", Type: proto.ColumnType_INT, Description: "The id of the user's organization. If the user has more than one organization memberships, the id of the user's default organization"},
            {Name: "phone", Type: proto.ColumnType_STRING, Description: "The user's primary phone number."},
            {Name: "photo_content_type", Type: proto.ColumnType_STRING, Description: "The content type of the image. Example value: \"image/png\""},
            {Name: "photo_content_url", Type: proto.ColumnType_STRING, Description: "A full URL where the attachment image file can be downloaded"},
            {Name: "photo_deleted", Type: proto.ColumnType_STRING, Description: "If true, the attachment has been deleted"},
            {Name: "photo_file_name", Type: proto.ColumnType_STRING, Description: "The name of the image file"},
            {Name: "photo_id", Type: proto.ColumnType_INT, Description: "Automatically assigned when created"},
            {Name: "photo_inline", Type: proto.ColumnType_BOOL, Description: "If true, the attachment is excluded from the attachment list and the attachment's URL can be referenced within the comment of a ticket. Default is false"},
            {Name: "photo_size", Type: proto.ColumnType_INT, Description: "The size of the image file in bytes"},
            {Name: "photo_thumbnails", Type: proto.ColumnType_JSON, Description: "An array of attachment objects. Note that photo thumbnails do not have thumbnails"},
            {Name: "report_csv", Type: proto.ColumnType_BOOL, Description: "Whether or not the user can access the CSV report on the Search tab of the Reporting page in the Support admin interface."},
            {Name: "restricted_agent", Type: proto.ColumnType_BOOL, Description: "If the agent has any restrictions; false for admins and unrestricted agents, true for other agents"},
            {Name: "role", Type: proto.ColumnType_STRING, Description: "The user's role. Possible values are \"end-user\", \"agent\", or \"admin\""},
            {Name: "role_type", Type: proto.ColumnType_INT, Description: "The user's role id. 0 for custom agents, 1 for light agent, 2 for chat agent, and 3 for chat agent added to the Support account as a contributor (Chat Phase 4)"},
            {Name: "shared", Type: proto.ColumnType_BOOL, Description: "If the user is shared from a different Zendesk Support instance. Ticket sharing accounts only"},
            {Name: "shared_agent", Type: proto.ColumnType_BOOL, Description: "If the user is a shared agent from a different Zendesk Support instance. Ticket sharing accounts only"},
            {Name: "shared_phone_number", Type: proto.ColumnType_BOOL, Description: "Whether the phone number is shared or not."},
            {Name: "signature", Type: proto.ColumnType_STRING, Description: "The user's signature. Only agents and admins can have signatures"},
            {Name: "suspended", Type: proto.ColumnType_BOOL, Description: "If the agent is suspended. Tickets from suspended users are also suspended, and these users cannot sign in to the end user portal"},
            {Name: "tags", Type: proto.ColumnType_JSON, Description: "The user's tags. Only present if your account has user tagging enabled"},
            {Name: "ticket_restriction", Type: proto.ColumnType_STRING, Description: "Specifies which tickets the user has access to. Possible values are: \"organization\", \"groups\", \"assigned\", \"requested\", null"},
            {Name: "timezone", Type: proto.ColumnType_STRING, Description: "The user's time zone."},
            {Name: "two_factor_auth_enabled", Type: proto.ColumnType_BOOL, Description: "If two factor authentication is enabled"},
            {Name: "updated_at", Type: proto.ColumnType_TIMESTAMP, Description: "The time the user was last updated"},
            {Name: "url", Type: proto.ColumnType_STRING, Description: "The user's API url"},
            {Name: "user_fields", Type: proto.ColumnType_JSON, Description: "Values of custom fields in the user's profile."},
            {Name: "verified", Type: proto.ColumnType_BOOL, Description: "Any of the user's identities is verified."},
        },
    }
}

func listUser(ctx context.Context, d *plugin.QueryData, _ *plugin.HydrateData) (interface{}, error) {
    conn, err := connect(ctx)
    if err != nil {
        return nil, err
    }
    opts := &zendesk.UserListOptions{
        PageOptions: zendesk.PageOptions{
            Page:    1,
            PerPage: 100,
        },
    }
    for true {
        users, page, err := conn.GetUsers(ctx, opts)
        if err != nil {
            return nil, err
        }
        for _, t := range users {
            d.StreamListItem(ctx, t)
        }
        if !page.HasNext() {
            break
        }
        opts.Page++
    }
    return nil, nil
}

func getUser(ctx context.Context, d *plugin.QueryData, h *plugin.HydrateData) (interface{}, error) {
    conn, err := connect(ctx)
    if err != nil {
        return nil, err
    }
    quals := d.KeyColumnQuals
    plugin.Logger(ctx).Warn("getUser", "quals", quals)
    id := quals["id"].GetInt64Value()
    plugin.Logger(ctx).Warn("getUser", "id", id)
    result, err := conn.GetUser(ctx, id)
    if err != nil {
        return nil, err
    }
    return result, nil
}

Dynamic Tables

In the plugin definition, if SchemaMode is set to dynamic, every time Steampipe starts, the plugin's schema will be checked for any changes since the last time it loaded, and re-import the schema if it detects any.

Dynamic tables are useful when you are building a plugin whose schema is not known at compile time; instead, its schema will be generated at runtime. For instance, a plugin with dynamic tables is useful if you want to load CSV files as tables from one or more directories. Each of these CSV files may have different column structures, resulting in a different structure for each table.

In order to create a dynamic table, in the plugin definition, TableMapFunc should call a function that returns map[string]*plugin.Table.

For instance, in the CSV plugin:

func Plugin(ctx context.Context) *plugin.Plugin {
    p := &plugin.Plugin{
        Name: "steampipe-plugin-csv",
        ConnectionConfigSchema: &plugin.ConnectionConfigSchema{
            NewInstance: ConfigInstance,
            Schema:      ConfigSchema,
        },
        DefaultTransform: transform.FromGo().NullIfZero(),
        SchemaMode:       plugin.SchemaModeDynamic,
        TableMapFunc:     PluginTables,
    }
    return p
}

func PluginTables(ctx context.Context, p *plugin.Plugin) (map[string]*plugin.Table, error) {
    // Initialize tables
    tables := map[string]*plugin.Table{}

    // Search for CSV files to create as tables
    paths, err := csvList(ctx, p)
    if err != nil {
        return nil, err
    }
    for _, i := range paths {
        tableCtx := context.WithValue(ctx, "path", i)
        base := filepath.Base(i)
    // tableCSV returns a *plugin.Table type
        tables[base[0:len(base)-len(filepath.Ext(base))]] = tableCSV(tableCtx, p)
    }

    return tables, nil
}

The tableCSV function mentioned in the example above looks for all CSV files in the configured paths, and for each one, builds a *plugin.Table type:

func tableCSV(ctx context.Context, p *plugin.Plugin) *plugin.Table {

    path := ctx.Value("path").(string)
    csvFile, err := os.Open(path)
    if err != nil {
        plugin.Logger(ctx).Error("Could not open CSV file", "path", path)
        panic(err)
    }

    r := csv.NewReader(csvFile)

    csvConfig := GetConfig(p.Connection)
    if csvConfig.Separator != nil && *csvConfig.Separator != "" {
        r.Comma = rune((*csvConfig.Separator)[0])
    }
    if csvConfig.Comment != nil {
        if *csvConfig.Comment == "" {
            // Disable comments
            r.Comment = 0
        } else {
            // Set the comment character
            r.Comment = rune((*csvConfig.Comment)[0])
        }
    }

    // Read the header to peak at the column names
    header, err := r.Read()
    if err != nil {
        plugin.Logger(ctx).Error("Error parsing CSV header:", "path", path, "header", header, "err", err)
        panic(err)
    }
    cols := []*plugin.Column{}
    for idx, i := range header {
        cols = append(cols, &plugin.Column{Name: i, Type: proto.ColumnType_STRING, Transform: transform.FromField(i), Description: fmt.Sprintf("Field %d.", idx)})
    }

    return &plugin.Table{
        Name:        path,
        Description: fmt.Sprintf("CSV file at %s", path),
        List: &plugin.ListConfig{
            Hydrate: listCSVWithPath(path),
        },
        Columns: cols,
    }
}

The end result is when using the CSV plugin, whenever Steampipe starts, it will check for any new, deleted, and modified CSV files in the configured paths and create any discovered CSVs as tables. The CSV filenames are turned directly into table names.

For more information on how the CSV plugin can be queried as a result of being a dynamic table, please see the {csv_filename} table document.

Table Definition

The plugin.Table may specify:

List Config

A ListConfig definition defines how to list all rows of a table.

Get Config

A GetConfig definition defines how to get a single row of a table.

Column Definition

A column definition definition specifies the name and description of the column, its data type, and the functions to call to hydrate the column (if the list call does not) and transform it (if the default transformation is not sufficient).

Column Data Types

Currently supported data types are:

Logging

A logger is passed to the plugin via the context. You can use the logger to write messages to the log at standard log levels:

logger := plugin.Logger(ctx)
logger.Info("Log message and a variable", myVariable)

The plugin logs do not currently get written to the console, but are written to the plugin logs at ~/.steampipe/logs/plugin-YYYY-MM-DD.log, e.g., ~/.steampipe/logs/plugin-2022-01-01.log.

Steampipe uses the hclog package, which uses standard log levels (TRACE, DEBUG, INFO, WARN, ERROR). By default, the log level is WARN. You set it using the STEAMPIPE_LOG_LEVEL environment variable:

export STEAMPIPE_LOG_LEVEL=TRACE

Installing and Testing Your Plugin

A plugin binary can be installed manually, and this is often convenient when developing the plugin. Steampipe will attempt to load any plugin that is referred to in a connection configuration:

• The plugin binary file must have a .plugin extension
• The plugin binary must reside in a subdirectory of the ~/.steampipe/plugins/ directory and must be the ONLY .plugin file in that subdirectory
• The connection must specify the path (relative to ~/.steampipe/plugins/) to the plugin in the plugin argument

For example, consider a myplugin plugin that you have developed. To install it:

• Create a subdirectory .steampipe/plugins/local/myplugin
• Name your plugin binary myplugin.plugin, and copy it to .steampipe/plugins/local/myplugin/myplugin.plugin
• Create a ~/.steampipe/config/myplugin.spc config file containing a connection definition that points to your plugin:

  connection "myplugin" {
      plugin    = "local/myplugin"
  }

• Your connection will be loaded the next time Steampipe runs. If Steampipe is running service mode, you must restart it to load the connection.