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Location: kallithea/scripts/dbmigrate-test

mads
mysql: create database with explicit UTF-8 character set and collation

A spin-off from Issue #378.

In MySQL, the character sets for server, database, tables, and connection are
set independently. Ideally, they should all use UTF-8, but systems tend to use
latin1 as default encoding, for example:

character_set_server = latin1
collation_server = latin1_swedish_ci

Databases would thus by default be created as:

character_set_database = latin1
collation_database = latin1_swedish_ci

To make things work consistently anyway, we have so far specified the utf8mb4
charset explicitly when creating tables, but there is no corresponding simple
option for specifying the collation for tables. We need a better solution.

If necessary and possible, the system charset and collation should be set to
UTF-8. Some systems already have these defaults default - see
https://mariadb.com/kb/en/differences-in-mariadb-in-debian-and-ubuntu/ .
The defaults can be changed as described on
https://mariadb.com/kb/en/setting-character-sets-and-collations/#example-changing-the-default-character-set-to-utf-8
to give something like:

character_set_server = utf8mb4
collation_server = utf8mb4_unicode_ci

Databases will then by default be created as:

character_set_database = utf8mb4
collation_database = utf8mb4_unicode_ci

and there is thus no longer any need for specifying the charset when creating
tables.

To be reasonably resilient across all systems without relying on system
defaults, we will now start specifying the charset and collation when creating
the database, but drop the specification of charset when creating tables.

For existing databases, it is recommended to change encoding (and collation) by
altering the database and each of the tables inside it as described on
https://stackoverflow.com/questions/6115612/how-to-convert-an-entire-mysql-database-characterset-and-collation-to-utf-8 .

Note the use of utf8mb4_unicode_ci instead of utf8mb4_general_ci - see
https://stackoverflow.com/questions/766809/whats-the-difference-between-utf8-general-ci-and-utf8-unicode-ci .

For investigation of these issues, consider the output from:
show variables like '%char%';
show variables like '%collation%';
show create database `KALLITHEA_DB_NAME`;
SELECT * FROM information_schema.SCHEMATA WHERE schema_name = "KALLITHEA_DB_NAME";
SELECT * FROM information_schema.TABLES T, information_schema.COLLATION_CHARACTER_SET_APPLICABILITY CCSA WHERE CCSA.collation_name = T.table_collation AND T.table_schema = "KALLITHEA_DB_NAME";
#!/bin/sh -e

if [ $# -lt 2 ] || [ $# -gt 3 ]; then
    cat >&2 <<EOD
usage: $0 CONFIG_FILE FROM_REV [TO_REV]

Runs a database migration from FROM_REV to TO_REV (default: current
working directory parent), using the specified CONFIG_FILE (.ini file).

Test is run using a clean Kallithea install, in a temporary virtual
environment. FROM_REV and (optional) TO_REV should be Mercurial revision
identifiers (e.g. changeset hash or a version number tag). The working
directory is not touched, but the database referenced in the config file
will be (re)created.

Only SQLite is available out of the box; for MySQL or PostgreSQL, set
the EXTRA environment variable to the required package(s), and it'll
be installed in the virtual environment. (E.g. EXTRA=MySQL-python or
EXTRA=psycopg2.)

The temporary directory is not removed, allowing follow-up examination
of the upgrade results. It is, however, created in /tmp by default,
which many Linux distributions automatically clean at regular intervals.
EOD
    exit 1
fi

config_file=$(readlink -f "$1")
from_rev=$2
to_rev=$3
source_repo=$(dirname "$(dirname "$(readlink -f "$0")")")

announce() {
    echo
    echo "$1"
    echo
}

quiet_if_ok() (
    local output
    local st
    set +e
    output=$("$@" < /dev/null 2>&1)
    st=$?
    if [ $st -ne 0 ]; then
        echo "$output" >&2
        echo "Command $@ returned exit status $st." >&2
        exit 1
    fi
)

HG() {
    "${HG:-hg}" --repository "$source_repo" "$@"
}

# If upgrading to "current revision", warn if working directory is dirty.
if [ ! "$to_rev" ] && [ "$(HG status -mard)" ]; then
    announce "Warning: Uncommitted changes in working directory will be ignored!"
fi

from_rev_hash=$(HG id --id --rev "${from_rev:-.}")
to_rev_hash=$(HG id --id --rev "${to_rev:-.}")
temp=$(readlink -f "$(mktemp --tmpdir -d 'dbmigrate-test.XXXXXX')")

cat <<EOD
Config file:    $config_file
EOD
sed -n -e 's/^sqlalchemy\.url *= */Database URL:   /p' "$config_file"
cat <<EOD
Working dir:    $temp
Repository:     $source_repo
Upgrade from:   $from_rev_hash (${from_rev:-current})
Upgrade to:     $to_rev_hash (${to_rev:-current})
Extra packages: ${EXTRA:-(none)}
EOD

mkdir "$temp/repos" # empty

# Enable caching for old pip versions (this will cache the pip upgrade)
# Newer pip versions cache automatically, and don't use this variable.
if [ ! "$PIP_DOWNLOAD_CACHE" ]; then
    export PIP_DOWNLOAD_CACHE=$HOME/.cache/pip/legacy
fi

install_kallithea() {
    local prefix=$1
    local rev=$2

    announce "Installing Kallithea $rev in $prefix..."

    "${VIRTUALENV:-virtualenv}" --quiet "$prefix-env"
    HG archive --rev "$rev" "$prefix"

    (
        cd "$prefix"
        . "$prefix-env/bin/activate"
        pip install --quiet --upgrade pip setuptools mercurial $EXTRA
        pip install --quiet -e .
    )
}

install_kallithea "$temp/from" "$from_rev_hash"
(
    cd "$temp/from"
    . "$temp/from-env/bin/activate"
    announce "Initializing database..."
    quiet_if_ok kallithea-cli db-create -c "$config_file" --repos="$temp/repos" --user=doe --email=doe@example.com --password=123456 --no-public-access --force-yes
    alembic -c "$config_file" current -v
)

install_kallithea "$temp/to" "$to_rev_hash"
(
    cd "$temp/to"
    . "$temp/to-env/bin/activate"

    announce "Commencing database upgrade from shown Alembic revision to head..."
    alembic -c "$config_file" current -v
    alembic -c "$config_file" upgrade head
    announce "Upgrade complete, now at the shown Alembic revision:"
    alembic -c "$config_file" current -v
)