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Remove largely obsolete documentation pages.
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@@ -11,12 +11,10 @@ Contents:
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.. toctree::
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:maxdepth: 2
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welcome
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new-feature-tutorial
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code-style
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directory-structure
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testing
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schema-changes
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Indices and tables
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==================
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@@ -1,131 +0,0 @@
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==============
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Schema changes
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==============
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If you are making a change that requires a database schema upgrade,
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there are a few extra things you need to keep in mind.
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Using South for migrations
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--------------------------
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1. Discuss the change informally with your team.
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#. Edit ``zerver/models.py`` for your particular class.
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* See notes below about keep\_default.
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#. Run ``./manage.py schemamigration zerver --auto``
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* This will create the ``000#_***.py`` schema migration file in
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``zerver/migrations``.
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#. Read `Notes and Cautions`_ section below, as you may need to edit
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the migration. A common step here is setting keep\_default to True.
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#. Do ``git add`` with your new migration.
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#. Run ``./manage.py migrate zerver``.
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#. Write supporting code or otherwise validate the DB change locally.
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TODO: Advice on testing schema changes?
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#. Commit your changes:
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a. The migration must be in the same commit as the models.py changes.
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#. Include [schema] in the commit message.
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#. Include [manual] in the commit message if additional steps are
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required.
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#. Before deploying your code fix, read the notes on `Deploying to
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staging`_.
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Deploying to staging
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--------------------
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Always follow this process.
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1. Schedule the migration for after hours.
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#. For long-running migrations, double check that you use appropriate
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library helpers in ``migrate.py`` to ensure that changes happen in small
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batches that are committed frequently.
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#. Announce that you are doing the migration to your team, to avoid
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simultaneous migrations and other outcomes of poor communication.
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#. Do any administrative steps, such as increasing
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checkpoint\_segments.
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#. Apply the migration in advance from staging, using commands similar
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to the following, where ``[your commit]`` is the commit that has your
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migration::
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cd ~/zulip
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git fetch
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cd /tmp
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git clone ~/zulip
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cd zulip
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git checkout [your commit]
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./manage.py migrate zerver
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cd /tmp
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rm -Rf zulip
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#. Undo any temporary administrative changes, such as increasing
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checkpoint\_segments.
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Because staging and prod share a database, for most migrations, nothing
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special needs to be done when deploying to prod since the shared
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database schema will have already been updated, but in some cases some
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code to properly initialize data structures may need to be run.
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Migrating to a new schema
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-------------------------
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When doing a git pull and noticing a [schema] commit, you must manually
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perform a schema upgrade: ``./manage.py migrate zerver``.
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``generate-fixtures`` should automatically detect whether
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the schema has changed and update things accordingly.
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Notes and Cautions
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------------------
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**Large tables**
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For large tables like Message and UserMessage, you
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want to take precautions when adding columns to the table, performing
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data backfills, or building indexes. We have a ``migrate.py`` library to
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help with adding columns and backfilling data. For building indexes,
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we should do this outside of South using postgres's CONCURRENTLY
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keyword.
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**Numbering conflicts across branches**
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If you've done your schema change in a branch, and meanwhile another
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schema change has taken place, South will now have two migrations with
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the same number. To fix this, delete the migration file that South
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generated, and re-run ``./manage.py schemamigration zerver --auto``.
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**Avoid nullables**
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You generally no longer need a Nullable column
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to avoid problems with staging and prod not having the same models.
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See the next point about setting ``keep_default=True``.
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**Use keep\_default**
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When adding a new column to an existing table,
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you almost always will want to set ``keep_default=True`` in the South
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migration ``db.add_column`` call. If you don't, everything will
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appear to work fine in testing and on staging, but once the schema
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migration is done, the pre-migration code running on prod will be
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unable to save new rows for that table (so e.g. if you were adding a
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new field to UserProfile, we'd be unable to create new users). The
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exception to this rule is when your field default is not a constant
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value. In this case, you'll need to do something special to either
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set a database-level default or use a Nullable field and a multi-step
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schema deploy process.
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**Rebase pain**
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If you ever need to rebase a schema change past
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other schema changes made on other branches, in addition to
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renumbering your schema change, youalso need to be sure to regenerate
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at least the bottom part of your migration (which shows the current
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state of all the models) after rebasing; if you don't, then the next
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migration made after your migration is merged will incorrectly
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attempt to re-apply all the schema changes made in the migration you
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skipped. This can be potentially dangerous.
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**Upstreaming**
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We recommend upstreaming schema changes as soon as possible to
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avoid schema numbering conflicts (see above).
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@@ -1,39 +0,0 @@
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========
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Welcome!
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========
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This document will guide you through getting started on Zulip development.
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Installation
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============
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You should clone the Zulip git repository onto a Linux or OS X machine.
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Then follow the instructions in README.dev.
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Running the development server
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==============================
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After installing, you will have a virtual machine serving a development Zulip instance.
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To start it, simply run `vagrant up` and navigate to `http://localhost:9991/`__ in
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your browser. Behind the scenes, this is running `run-dev.py` via `supervisor`.
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Viewing the server log
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----------------------
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Sometimes things go wrong when you change backend code. The server logs are stored
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in `/var/logs/supervisor/zulip-dev-stdout---supervisor-******.log`.
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Restarting run-dev.py
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---------------------
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Most of the time, the server will refresh when you change underlying python
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files or style sheets, but sometimes you might need to restart the server
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(for example, if you have a syntax error or need to change the database schema).
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To do so, use `sudo supervisorctl restart zulip-dev`.
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Making changes
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==============
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.. attention::
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We need to determine our final development workflow
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Reference in New Issue
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