=encoding UTF-8

=head1 Name

sqitch-environment - Environment variables recognized by Sqitch

=head1 Description

Sqitch supports a number of environment variables that affect its
functionality. This document lists them all, along with brief descriptions of
their purposes and pointers to relevant documentation.

=head2 Sqitch Environment

=over

=item C<SQITCH_CONFIG>

Path to the project configuration file. Overrides the default, which is
F<./sqitch.conf>. See L<sqitch-config> for details.

=item C<SQITCH_USER_CONFIG>

Path to the user's configuration file. Overrides the default, which is
F<./.sqitch/sqitch.conf>. See L<sqitch-config> for details.

=item C<SQITCH_SYSTEM_CONFIG>

Path to the system's configuration file. Overrides the default, which is a
file named C<sqitch.conf> in the directory identified by C<sqitch --etc>. See
L<sqitch-config> for details.

=item C<SQITCH_TARGET>

The name or URI of the database target to connect to. Overrides values stored
in the configuration, but not command-line options or arguments.

=item C<SQITCH_USERNAME>

Username to use when connecting to a database, for those database engines that
support authentication. Overrides values stored in a target URI or the
configuration. See L<sqitch-authentication> for details.

=item C<SQITCH_PASSWORD>

Password to use when connecting to a database, for those database engines that
support authentication. Overrides values stored in a target URI or the
configuration. See L<sqitch-authentication> for details.

=item C<SQITCH_FULLNAME>

Full name of the current user. Used to identify the user adding a change to a
plan file or deploying a change. Supersedes the <user.name> L<sqitch-config>
variable.

=item C<SQITCH_EMAIL>

Email address of the current user. Used to identify the user adding a change to
a plan file or deploying a change. Supersedes the C<user.email> L<sqitch-config>
variable.

=item C<SQITCH_ORIG_SYSUSER>

Username from the original system. Intended for use by scripts that run Sqitch
from another host, where the originating host username should be passed to the
execution host, such as
L<this Docker script|https://github.com/sqitchers/docker-sqitch/blob/master/docker-sqitch.sh>.

=item C<SQITCH_ORIG_FULLNAME>

Full name of the original system user. Intended for use by scripts that run
Sqitch from another host, where the originating host user's identity should be
passed to the execution host, such as
L<this Docker script|https://github.com/sqitchers/docker-sqitch/blob/master/docker-sqitch.sh>.
This value will be used only when neither the C<$SQITCH_FULLNAME> nor the
C<user.name> L<sqitch-config> variable is set.

=item C<SQITCH_ORIG_EMAIL>

Email address of the original user. Intended for use by scripts that run
Sqitch on a separate host, where the originating host user's identity should
be passed to the execution host, such as
L<this Docker script|https://github.com/sqitchers/docker-sqitch/blob/master/docker-sqitch.sh>.
This value will be used only when neither the C<$SQITCH_EMAIL> nor the
C<user.email> L<sqitch-config> variable is set.

=item C<SQITCH_EDITOR>

The editor that Sqitch will launch when the user needs to edit some text (a
change note, for example). If unset, the C<core.editor> configuration variable
will be used. If it's not set, C<$VISUAL> or C<$EDITOR> will be consulted (in
that order).  Finally, if none of these are set, Sqitch will invoke
C<notepad.exe> on Windows and C<vi> elsewhere.

=item C<SQITCH_PAGER>

The pager program that Sqitch will use when a command (like C<sqitch log>)
produces multi-page output. If unset, the C<core.pager> configuration
variable will be used. If this is also not set, the C<PAGER> environment
variable will be used. Finally, if none of these are set, Sqitch will attempt
to find and use one of the commonly used pager programs like C<less> and
C<more>.

=back

=head2 Engine Environments

In addition to Sqitch's environment variables, some of the database engines
support environment variables of their own. These are not comprehensive for
all variables supported by a database engine, but document those supported by
Sqitch's implementation for each engine.

=head3 PostgreSQL

All the usual
L<PostgreSQL environment variables|https://www.postgresql.org/docs/current/static/libpq-envars.html>
should be implicitly used. However, the following variables are explicitly
recognized by Sqitch:

=over

=item C<PGUSER>

The username to use to connect to the server. Superseded by
C<$SQITCH_USERNAME> and the target URI username.

=item C<PGPASSWORD>

The password to use to connect to the server. Superseded by
C<$SQITCH_PASSWORD> and the target URI password.

=item C<PGHOST>

The PostgreSQL server host to connect to. Superseded by the target URI host
name.

=item C<PGPORT>

The PostgreSQL server port to connect to. Superseded by the target URI port.

=item C<PGDATABASE>

The name of the database to connect to. Superseded by the target URI database
name.

=back

=head3 SQLite

SQLite provides no environment variable support.

=head3 MySQL

Sqitch recognizes and takes advantage of the following
L<MySQL environment variables|https://dev.mysql.com/doc/refman/5.7/en/environment-variables.html>:

=over

=item C<MYSQL_PWD>

The password to use to connect to the server. Superseded by
C<$SQITCH_PASSWORD> and the target URI password.

=item C<MYSQL_HOST>

The MySQL server host to connect to. Superseded by the target URI host
name.

=item C<MYSQL_TCP_PORT>

The MySQL server port to connect to. Superseded by the target URI port.

=back

=head3 Oracle

Sqitch's Oracle engine supports a few environment variables:

=over

=item C<ORACLE_HOME>

Required to point to the Oracle home directory, and contain both the SQL*Plus
client and the shared libraries with which the Perl Oracle driver was
compiled.

=item C<TNS_ADMIN>

The directory in which the Oracle networking interface will find its configuration
files, notably F<tnsnames.ora>. Defaults to C<$ORACLE HOME/network/admin> if not
set.

=item C<TWO_TASK>

The name of the Oracle database to connect to. Superseded by the target URI.

=item C<LOCAL>

The name of the Oracle database to connect to. Windows only. Superseded by the
target URI.

=item C<ORACLE_SID>

The System Identifier (SID) representing the Oracle database to connect to.
Superseded by the target URI, C<TWO_TASK> and C<LOCAL> on Windows.

=back

In addition, the Oracle engine in Sqitch explicitly overrides the C<NLS_LANG>
and C<SQLPATH> environment variables. The former is set to
C<AMERICAN_AMERICA.AL32UTF8> to ensure that all database connections use the
UTF-8 encoding. The latter is set to an empty string, to prevent SQL*Plus
executing SQL scripts unexpectedly.

=head3 Firebird

The Sqitch Firebird engine supports the following environment variables:

=over

=item C<ISC_USER>

The username to use to connect to Firebird. Superseded by
C<$SQITCH_USERNAME> and the target URI username.

=item C<ISC_PASSWORD>

The password to use to connect to Firebird. Superseded by C<$SQITCH_PASSWORD>
and the target URI password.

=back

=head3 Vertica

Sqitch provides explicit support for the following
L<Vertica environment variables|https://www.vertica.com/docs/8.1.x/HTML/index.htm#Authoring/ConnectingToVertica/vsql/vsqlEnvironmentVariables.htm>:

=over

=item C<VSQL_USER>

The username to use to connect to the server. Superseded by
C<$SQITCH_USERNAME> and the target URI username.

=item C<VSQL_PASSWORD>

The password to use to connect to the server. Superseded by
C<$SQITCH_PASSWORD> and the target URI password.

=item C<VSQL_HOST>

The PostgreSQL server host to connect to. Superseded by the target URI host
name.

=item C<VSQL_PORT>

The PostgreSQL server port to connect to. Superseded by the target URI port.

=item C<VSQL_DATABASE>

The name of the database to connect to. Superseded by the target URI database
name.

=back

=head3 Exasol

The Sqitch Exasol engine supports no special environment variables. It does,
however, override THE C<SQLPATH> environment variable, to prevent EXAplus
executing SQL scripts unexpectedly.

=head3 Snowflake

Sqitch provides explicit support for the following
L<Snowflake environment variables|https://docs.snowflake.net/manuals/user-guide/snowsql-start.html#connection-syntax>:

=over

=item C<SNOWSQL_ACCOUNT>

The name assigned to the snowflake account. Superseded by the target URI host
name.

=item C<SNOWSQL_USER>

The username to use to connect to the server. Superseded by
C<$SQITCH_USERNAME> and the target URI username.

=item C<SNOWSQL_PWD>

The password to use to connect to the server. Superseded by
C<$SQITCH_PASSWORD> and the target URI password.

=item C<SNOWSQL_ROLE>

The role to use when connecting to the server. Superseded by the target URI
database C<role> query parameter.

=item C<SNOWSQL_HOST>

The PostgreSQL server host to connect to. Superseded by the target URI host
name.

=item C<SNOWSQL_PORT>

The PostgreSQL server port to connect to. Superseded by the target URI port.

=item C<SNOWSQL_DATABASE>

The name of the database to connect to. Superseded by the target URI database
name.

=item C<SNOWSQL_REGION>

The snowflake region. Superseded by the target URI host name.

=item C<SNOWSQL_WAREHOUSE>

The warehouse to use. Superseded by the target URI database C<warehouse> query
parameter.

=back

=head1 See Also

=over

=item * L<sqitch-configuration>

=item * L<sqitch-config>

=item * L<sqitch-authentication>

=back

=head1 Sqitch

Part of the L<sqitch> suite.
