fabfile.py

"""
Fabric deployment script for EHRI backend webapp.
"""

import os
import sys
from datetime import datetime

from fabric import task
from invoke import run as local


deploys_dir = "/opt/neo4j/ehri-rest/deploys"
target_link = "/opt/neo4j/plugins/ehri-data.jar"
neo4j_install = "/opt/neo4j/current"

@task
def deploy(ctx, clean=False):
    """Build (optionally with clean) and deploy the distribution"""
    local("mvn package -DskipTests" if not clean else "mvn clean package -DskipTests")

    artifact_version = get_artifact_version(ctx)
    version = get_version_stamp(ctx)

    src = f"build/target/ehri-data-{artifact_version}.jar"
    dst = f"{deploys_dir}/ehri-data-{version}.jar"

    ctx.put(src, remote=dst)
    symlink_target(ctx, dst, target_link)
    restart(ctx)


@task
def rollback(ctx):
    """Set the current version to the previous version directory"""
    output = ctx.run(f"ls -1rt {deploys_dir} | tail -n 2 | head -n 1").stdout.strip()
    if output == "":
        raise Exception("Unable to get previous version for rollback!")
    symlink_target(ctx, f"{deploys_dir}/{output}", target_link)
    restart(ctx)


@task
def latest(ctx):
    """Set the current version to the latest version directory"""
    output = ctx.run(f"ls -1rt {deploys_dir} | tail -n 1").stdout.strip()
    if output == "":
        raise Exception("Unable to get previous version for rollback!")
    symlink_target(ctx, f"{deploys_dir}/{output}", target_link)
    restart(ctx)


@task
def get_artifact_version(ctx):
    """Get the current artifact version from Maven"""
    return local(
        "mvn org.apache.maven.plugins:maven-help-plugin:2.1.1:evaluate" +
        " -Dexpression=project.version|grep -Ev '(^\\[|Download\\w+:)'").stdout.strip()


@task
def symlink_target(ctx, source, target):
    """Symlink a version directory"""
    ctx.run(f"ln --force --no-dereference --symbolic {source} {target}")
    ctx.run(f"chgrp -R webadm {target_link}")


@task
def restart(ctx):
    """Restart the Neo4j process"""
    if input("Restart Neo4j (y/n)\n").lower() == "y":
        ctx.run("sudo service neo4j restart")


@task
def get_version_stamp(ctx):
    """Get the tag for a version, consisting of the current time and git revision"""
    res = local("git rev-parse --short HEAD").stdout.strip()
    timestamp = datetime.now().strftime("%Y%m%d%H%M%S")
    return f"{timestamp}_{res}"


@task
def online_backup(ctx, dir, tar = True):
    """Create an online backup to directory `dir`"""
    if check_file_exists(ctx, dir):
        print(f"Remote directory '{dir}' already exists!")
        sys.exit(1)
    tar_name = dir + ".tgz"
    dirname = os.path.dirname(dir)
    basename = os.path.basename(dir)
    ctx.run(f"{neo4j_install}/bin/neo4j-admin backup --from localhost:6362 --name={basename} --backup-dir {dirname}")
    if tar:
        ctx.run(f"tar --create --gzip --file {tar_name} -C {dir} .")
        ctx.run(f"rm -rf {dir}")


@task
def online_clone_db(ctx, dir):
    """Create an online backup of the database and download to local dir `dir`"""
    timestamp = get_timestamp()
    tmpdst = "/tmp/" + timestamp
    online_backup(ctx, tmpdst, tar = False)
    ctx.run(f"tar --create --gzip --file {tmpdst}.tgz -C {tmpdst} .")
    ctx.get(f"{tmpdst}.tgz", f"{tmpdst}.tgz")
    ctx.run(f"rm -rf {tmpdst} {tmpdst}.tgz")
    local(f"mkdir -p {dir}")
    local(f"tar xf {tmpdst}.tgz -C {dir}")
    local(f"rm {tmpdst}.tgz")


def get_timestamp():
    return datetime.now().strftime("%Y%m%d%H%M%S")


def check_file_exists(ctx, remote_path):
    """
    Check if a file or directory exists on the remote server.
    """
    try:
        result = ctx.run(f'test -e {remote_path} && echo "EXISTS" || echo "NOT_FOUND"', hide=True)
        return result.stdout.strip() == "EXISTS"
    except Exception as e:
        return False