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Looker Server - Beta - Import

Availability-note AWS

Bridge Requirements

This bridge:
  • requires Internet access to https://repo.maven.apache.org/maven2/ and/or other tool sites to download drivers into <TDC_HOME>/data/download/MIMB/.

Bridge Specifications

Vendor Looker
Tool Name Looker
Tool Version 7.2
Tool Web Site https://www.looker.com/
Supported Methodology [Business Intelligence] Multi-Model, BI Design (RDBMS Source, Dimensional Target, Transformation Lineage, Expression Parsing), BI Report (Relational Source, Dimensional Source, Report Structure) via REST API
Data Profiling
Incremental Harvesting
Multi-Model Harvesting
Remote Repository Browsing for Model Selection

SPECIFICATIONS
Tool: Looker / Looker version 7.2 via REST API
See https://www.looker.com/
Metadata: [Business Intelligence] Multi-Model, BI Design (RDBMS Source, Dimensional Target, Transformation Lineage, Expression Parsing), BI Report (Relational Source, Dimensional Source, Report Structure)
Component: Looker version 11.2.0

DISCLAIMER
This import bridge requires internet access to download third-party libraries:
- such as https://repo.maven.apache.org/maven2/ to download open source third-party libraries,
- and more sites for other third-party software such as database specific JDBC drivers.

The downloaded third-party libraries are stored into $HOME/data/download/MIMB/
- If HTTPS fails, the import bridge then tries with HTTP.
- If a proxy is used to access internet, you must configure that proxy in the JRE (see the -j option in the Miscellaneous parameter).
- If the import bridge does not have full access to internet, that $HOME/data/download/MIMB/ directory can be copied from another server with internet access where the command $HOME/bin/MIMB.sh (or .bat) -d can be used to download all third-party libraries used by all bridges at once.

By running this import bridge, you hereby acknowledge responsibility for the license terms and any potential security vulnerabilities from these downloaded third-party software libraries.

OVERVIEW
This import bridge imports metadata from a Looker server, including database connections, LookML Models, and associated reports (Looks and Dashboards).

REQUIREMENTS
Looker API3 key is required in order to login and use the Looker Restful API.
Please use the Looker Admin console to configure an API3 key on a user account.
The API3 key consists in a public client_id and a private client_secret (OAuth2 authentication pattern).
* Select a user in the 'Users' section of the 'Admin' panel
* In the section 'API3 Keys' choose 'Edit Keys'
The 'Client ID' and 'Client Secret' values are displayed https://docs.looker.com/reference/api-and-integration/api-auth
https://docs.looker.com/admin-options/settings/users#api3_keys
You can test that the API key is configured correctly by performing a login on this page:
https://server:port/api-docs/index.html
Looker versions 3.4+ expose the Restful API on default port 19999 or 443.
Please use the Looker Admin console to check your API port.
https://docs.looker.com/reference/api-and-integration/api-troubleshooting

You may use this URL in a web browser, to check the API availability and version(s) number(s):
https://server:port/versions

FREQUENTLY ASKED QUESTIONS
n/a

LIMITATIONS
Refer to the current general known limitations at MIMB Known Limitations or bundled in Documentation/ReadMe/MIMBKnownLimitations.html
Looker models may use Derived Tables in order to cache and precompute data from the database.
The Looker API currently doesn't expose detailed DerivedTable metadata.

The Looker API has limited support for Views that are not included in Explores.

SUPPORT
Provide a troubleshooting package with:
- the debug log (can be set in the UI or in conf/conf.properties with MIR_LOG_LEVEL=6)
- the metadata backup if available (can be set in the Miscellaneous parameter with -backup option, although this common option is not implemented on all bridges for technical reasons).

Q: How do I provide metadata to the support team to reproduce an issue?
A: Configure the import bridge parameter 'Incremental import=False' and configure the import bridge 'Miscellaneous' parameter 'backup' to save metadata as files into a local directory.
Compress the resulting files in a ZIP archive and send to the support team.


Bridge Parameters

Parameter Name Description Type Values Default Scope
Server API URL Enter the Looker API URL here.
The default port for API requests may be 19999 or 443.
All Looker API endpoints require an HTTPS connection.
STRING   https://localhost:19999/ Mandatory
Login User Enter the username which the import bridge will use to log in. Be sure this user name has necessary permissions to access the objects you wish to import.
This corresponds to the Client ID for an OAuth authentication method.
STRING     Mandatory
Login password Enter the password associated with the username which the import bridge will use to log in.
This corresponds to the Client secret for an OAuth authentication method.
PASSWORD     Mandatory
Models This option is used to select looks and dashboards by their parent model.

You can specify here multiple model identifiers, separated by semicolon (;) character.
REPOSITORY_SUBSET      
Miscellaneous INTRODUCTION
Specify miscellaneous options starting with a dash and optionally followed by parameters, e.g.
-connection.cast MyDatabase1="MICROSOFT SQL SERVER"
Some options can be used multiple times if applicable, e.g.
-connection.rename NewConnection1=OldConnection1 -connection.rename NewConnection2=OldConnection2;
As the list of options can become a long string, it is possible to load it from a file which must be located in ${MODEL_BRIDGE_HOME}\data\MIMB\parameters and have the extension .txt. In such case, all options must be defined within that file as the only value of this parameter, e.g.
ETL/Miscellaneous.txt

JAVA ENVIRONMENT OPTIONS
-java.memory <Java Memory's maximum size> (previously -m)

1G by default on 64bits JRE or as set in conf/conf.properties, e.g.
-java.memory 8G
-java.memory 8000M

-java.parameters <Java Runtime Environment command line options> (previously -j)

This option must be the last one in the Miscellaneous parameter as all the text after -java.parameters is passed "as is" to the JRE, e.g.
-java.parameters -Dname=value -Xms1G
The following option must be set when a proxy is used to access internet (this is critical to access https://repo.maven.apache.org/maven2/ and exceptionally a few other tool sites) in order to download the necessary third-party software libraries.
Note: The majority of proxies are concerned with encrypting (HTTPS) the outside (of the company) traffic and trust the inside traffic that can access proxy over HTTP. In this case, an HTTPS request reaches the proxy over HTTP where the proxy HTTPS-encrypts it.
-java.parameters -java.parameters -Dhttp.proxyHost=127.0.0.1 -Dhttp.proxyPort=3128 -Dhttp.proxyUser=user -Dhttp.proxyPassword=pass

MODEL IMPORT OPTIONS
-model.name <model name>

Override the model name, e.g.
-model.name "My Model Name"

-prescript <script name>

This option allows running a script before the bridge execution.
The script must be located in the bin directory (or as specified with M_SCRIPT_PATH in conf/conf.properties), and have .bat or .sh extension.
The script path must not include any parent directory symbol (..).
The script should return exit code 0 to indicate success, or another value to indicate failure.
For example:
-prescript "script.bat arg1 arg2"

-postscript <script name>

This option allows running a script after successful execution of the bridge.
The script must be located in the bin directory (or as specified with M_SCRIPT_PATH in conf/conf.properties), and have .bat or .sh extension.
The script path must not include any parent directory symbol (..).
The script should return exit code 0 to indicate success, or another value to indicate failure.
For example:
-postscript "script.bat arg1 arg2"

-cache.clear

Clears the cache before the import, and therefore will run a full import without incremental harvesting.

If the model was not changed and the -cache.clear parameter is not used (incremental harvesting), then a new version will not be created.
If the model was not changed and the -cache.clear parameter is set (full source import instead of incremental), then a new version will be created.

-backup <directory>

This option allows to save the bridge input metadata for further troubleshooting. The provided <directory> must be empty.

The primary use of this option is for data store import bridges, in particular JDBC based database import bridges.

Note that this option is not operational on some bridges including:
- File based import bridges (as such input files can be used instead)
- DI/BI repository import bridges (as the tool's repository native backup can be used instead)
- Some API based import bridges (e.g. COM based) for technical reasons.

DATA CONNECTION OPTIONS
Data Connections are produced by the import bridges typically from ETL/DI and BI tools to refer to the source and target data stores they use. These data connections are then used by metadata management tools to connect them (metadata stitching) to their actual data stores (e.g. databases, file system, etc.) in order to produce the full end to end data flow lineage and impact analysis. The name of each data connection is unique by import model. The data connection names used within DI/BI design tools are used when possible, otherwise connection names are generated to be short but meaningful such as the database / schema name, the file system path, or Uniform Resource Identifier (URI). The following option allows to manipulate connections. These options replaces the legacy options -c, -cd, and -cs.

-connection.cast ConnectionName=ConnectionType

Casts a generic database connection (e.g. ODBC/JDBC) to a precise database type (e.g. ORACLE) for SQL Parsing, e.g.
-connection.cast "My Database"="MICROSOFT SQL SERVER".
The list of supported data store connection types includes:
ACCESS
APACHE CASSANDRA
DB2/UDB
DENODO
GOOGLE BIGQUERY
HIVE
MYSQL
NETEZZA
ORACLE
POSTGRESQL
PRESTO
REDSHIFT
SALESFORCE
SAP HANA
SNOWFLAKE
MICROSOFT SQL AZURE
MICROSOFT SQL SERVER
SYBASE SQL SERVER
SYBASE AS ENTERPRISE
TERADATA
VECTORWISE
HP VERTICA

-connection.rename OldConnection=NewConnection

Renames an existing connection to a new name, e.g.
-connection.rename OldConnectionName=NewConnectionName
Multiple existing database connections can be renamed and merged into one new database connection, e.g.
-connection.rename MySchema1=MyDatabase -connection.rename MySchema2=MyDatabase

-connection.split oldConnection.Schema1=newConnection

Splits a database connection into one or multiple database connections.
A single database connection can be split into one connection per schema, e.g.
-connection.split MyDatabase
All database connections can be split into one connection per schema, e.g.
-connection.split *
A database connection can be explicitly split creating a new database connection by appending a schema name to a database, e.g.
-connection.split MyDatabase.schema1=MySchema1

-connection.map SourcePath=DestinationPath

Maps a source path to destination path. This is useful for file system connections when different paths points to the same object (directory or file).
On Hadoop, a process can write into a CSV file specified with the HDFS full path, but another process reads from a Hive table implemented (external) by the same file specified using a relative path with default file name and extension, e.g.
-connection.map /user1/folder=hdfs://host:8020/users/user1/folder/file.csv
On Linux, a given directory (or file) like /data can be referred to by multiple symbolic links like /users/john and /users/paul, e.g.
-connection.map /data=/users/John -connection.map /data=/users/paul
On Windows, a given directory like C:\data can be referred to by multiple network drives like M: and N:, e.g.
-connection.map C:\data=M:\ -connection.map C:\data=N:\

-connection.casesensitive ConnectionName

Overrides the default case insensitive matching rules for the object identifiers inside the specified connection, provided the detected type of the data store by itself supports this configuration (e.g. Microsoft SQL Server, MySql etc.), e.g.
-connection.casesensitive "My Database"

-connection.level AggregationLevel

Specifies the aggregation level for the external connections, e.g.-connection.level catalog
The list of the supported values:
server
catalog
schema (default)

LOOKER OPTIONS
-api.version <MajorInt>.<MinorInt>

Specify the API version to use, such as 3.1 or 4.0
Version 4.0 is used by default.
STRING      

 

Bridge Mapping

Mapping information is not available

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