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Manual development setup

docs/published/handbook/engineering/manual-dev-setup.md

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Manual setup

This documentation is deprecated, and likely not up to date. Please use the Flox-based instant setup instead.

1. Spin up external services

In this step we will start all the external services needed by PostHog to work.

First, append line 127.0.0.1 kafka clickhouse clickhouse-coordinator objectstorage and line ::1 kafka clickhouse clickhouse-coordinator objectstorage to /etc/hosts. Our ClickHouse and Kafka data services won't be able to talk to each other without these mapped hosts. You can do this with:

bash
echo '127.0.0.1 kafka clickhouse clickhouse-coordinator objectstorage' | sudo tee -a /etc/hosts
echo '::1 kafka clickhouse clickhouse-coordinator objectstorage' | sudo tee -a /etc/hosts

If you are using a newer (>=4.1) version of Podman instead of Docker, the host machine's /etc/hosts is used as the base hosts file for containers by default, instead of container's /etc/hosts like in Docker. This can make hostname resolution fail in the ClickHouse container, and can be mended by setting base_hosts_file="none" in containers.conf.

Now, start the Docker Compose stack:

bash
docker compose -f docker-compose.dev.yml up

Friendly tip 1: If you see Error while fetching server API version: 500 Server Error for http+docker://localhost/version:, it's likely that Docker Engine isn't running.

Friendly tip 2: If you see "Exit Code 137" anywhere, it means that the container has run out of memory. In this case you need to allocate more RAM in OrbStack settings.

Friendly tip 3: On Linux, you might need sudo – see Docker docs on managing Docker as a non-root user. Or look into Podman as an alternative that supports rootless containers.

Friendly tip 4: If you see Error: (HTTP code 500) server error - Ports are not available: exposing port TCP 0.0.0.0:5432 -> 0.0.0.0:0: listen tcp 0.0.0.0:5432: bind: address already in use, you have Postgres already running somewhere. Try docker compose -f docker-compose.dev.yml first, alternatively run lsof -i :5432 to see what process is using this port.

bash
sudo service postgresql stop

Second, verify via docker ps and docker logs (or via the OrbStack dashboard) that all these services are up and running. They should display something like this in their logs:

shell
# docker ps                                                                                     NAMES
CONTAINER ID   IMAGE                                      COMMAND                  CREATED          STATUS                    PORTS                                                                                            NAMES
5a38d4e55447   temporalio/ui:2.10.3                       "./start-ui-server.sh"   51 seconds ago   Up 44 seconds             0.0.0.0:8081->8080/tcp                                                                           posthog-temporal-ui-1
89b969801426   temporalio/admin-tools:1.20.0              "tail -f /dev/null"      51 seconds ago   Up 44 seconds                                                                                                              posthog-temporal-admin-tools-1
81fd1b6d7b1b   clickhouse/clickhouse-server:23.6.1.1524   "/entrypoint.sh"         51 seconds ago   Up 50 seconds             0.0.0.0:8123->8123/tcp, 0.0.0.0:9000->9000/tcp, 0.0.0.0:9009->9009/tcp, 0.0.0.0:9440->9440/tcp   posthog-clickhouse-1
f876f8bff35f   bitnami/kafka:2.8.1-debian-10-r99          "/opt/bitnami/script…"   51 seconds ago   Up 50 seconds             0.0.0.0:9092->9092/tcp                                                                           posthog-kafka-1
d22559261575   temporalio/auto-setup:1.20.0               "/etc/temporal/entry…"   51 seconds ago   Up 45 seconds             6933-6935/tcp, 6939/tcp, 7234-7235/tcp, 7239/tcp, 0.0.0.0:7233->7233/tcp                         posthog-temporal-1
5313fc278a70   postgres:12-alpine                         "docker-entrypoint.s…"   51 seconds ago   Up 50 seconds (healthy)   0.0.0.0:5432->5432/tcp                                                                           posthog-db-1
c04358d8309f   zookeeper:3.7.0                            "/docker-entrypoint.…"   51 seconds ago   Up 50 seconds             2181/tcp, 2888/tcp, 3888/tcp, 8080/tcp                                                           posthog-zookeeper-1
09add699866e   maildev/maildev:2.0.5                      "bin/maildev"            51 seconds ago   Up 50 seconds (healthy)   0.0.0.0:1025->1025/tcp, 0.0.0.0:1080->1080/tcp                                                   posthog-maildev-1
61a44c094753   elasticsearch:7.16.2                       "/bin/tini -- /usr/l…"   51 seconds ago   Up 50 seconds             9200/tcp, 9300/tcp                                                                               posthog-elasticsearch-1
a478cadf6911   minio/minio:RELEASE.2022-06-25T15-50-16Z   "sh -c 'mkdir -p /da…"   51 seconds ago   Up 50 seconds             9000/tcp, 0.0.0.0:19000-19001->19000-19001/tcp                                                   posthog-object_storage-1
91f838afe40e   redis:6.2.7-alpine                         "docker-entrypoint.s…"   51 seconds ago   Up 50 seconds             0.0.0.0:6379->6379/tcp                                                                           posthog-redis-1

# docker logs posthog-db-1 -n 1
2021-12-06 13:47:08.325 UTC [1] LOG:  database system is ready to accept connections

# docker logs posthog-redis-1 -n 1
1:M 06 Dec 2021 13:47:08.435 * Ready to accept connections

# docker logs posthog-clickhouse-1 -n 1
Saved preprocessed configuration to '/var/lib/clickhouse/preprocessed_configs/users.xml'.

# ClickHouse writes logs to `/var/log/clickhouse-server/clickhouse-server.log` and error logs to `/var/log/clickhouse-server/clickhouse-server.err.log` instead of stdout/stsderr. It can be useful to `cat` these files if there are any issues:
# docker exec posthog-clickhouse-1 cat /var/log/clickhouse-server/clickhouse-server.log
# docker exec posthog-clickhouse-1 cat /var/log/clickhouse-server/clickhouse-server.err.log

# docker logs posthog-kafka-1
[2021-12-06 13:47:23,814] INFO [KafkaServer id=1001] started (kafka.server.KafkaServer)

# docker logs posthog-zookeeper-1
# Because ClickHouse and Kafka connect to Zookeeper, there will be a lot of noise here. That's good.

Friendly tip 1: Kafka is currently the only x86 container used, and might segfault randomly when running on ARM. Restart it when that happens.

Friendly tip 2: Checking the last Clickhouse log could show a get_mempolicy: Operation not permitted message. However, it shouldn't affect the app startup - checking the whole log should clarify that Clickhouse started properly. To double-check you can get into the container and run a basic query.

bash
# docker logs posthog-clickhouse-1
# docker exec -it posthog-clickhouse-1 bash
# clickhouse-client --query "SELECT 1"

Finally, install Postgres locally. Even if you are planning to run Postgres inside Docker, we need a local copy of Postgres (version 11+) for its CLI tools and development libraries/headers. These are required by pip to install psycopg2.

  • On macOS:

    bash
    brew install postgresql

This installs both the Postgres server and its tools. DO NOT start the server after running this.

  • On Debian-based Linux:

    bash
    sudo apt install -y postgresql-client postgresql-contrib libpq-dev

This intentionally only installs the Postgres client and drivers, and not the server. If you wish to install the server, or have it installed already, you will want to stop it, because the TCP port it uses conflicts with the one used by the Postgres Docker container.

On Linux, it's recommended to disable Postgres service by default, to ensure no port conflict arises. If postgres is already running on the port 5432, you can confirm it by checking the port, and then kill it manually.

bash
sudo systemctl disable postgresql.service
sudo lsof -i :5432
sudo kill -9 `sudo lsof -t -i :5432`

On Linux you often have separate packages: postgres for the tools, postgres-server for the server, and libpostgres-dev for the psycopg2 dependencies. Consult your distro's list for an up-to-date list of packages.

2. Prepare the frontend

  1. Install nvm, with brew install nvm or by following the instructions at https://github.com/nvm-sh/nvm. If using fish, you may instead prefer https://github.com/jorgebucaran/nvm.fish.
<blockquote class="warning-note"> After installation, make sure to follow the instructions printed in your terminal to add NVM to your{' '} <code>$PATH</code>. Otherwise the command line will use your system Node.js version instead. </blockquote>

  1. Install the latest Node.js 22 (the version used by PostHog in production) with nvm install 22. You can start using it in the current shell with nvm use 22.

  2. Install pnpm by running corepack enable and then running corepack prepare pnpm@10 --activate. Validate the installation with pnpm --version.

  3. Install Node packages by running pnpm i.

  4. Run pnpm --filter=@posthog/frontend typegen:write to generate types for Kea state management logics used all over the frontend.

The first time you run typegen, it may get stuck in a loop. If so, cancel the process (Ctrl+C), discard all changes in the working directory (git reset --hard), and run pnpm typegen:write again. You may need to discard all changes once more when the second round of type generation completes.

3. Prepare nodejs services

  1. Install the brotli compression library and rust stable via rustup:

  • On macOS:

    bash
    brew install brotli rustup
rustup default stable
rustup-init
# Select 1 to proceed with default installation

  • On Debian-based Linux:

    bash
    sudo apt install -y brotli
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
# Select 1 to proceed with default installation
  1. Run pnpm --filter=@posthog/nodejs install to install all required packages. We'll actually run the nodejs services in a later step.

Note: If you face an error like ld: symbol(s) not found for architecture arm64, most probably your openssl build flags are coming from the wrong place. To fix this, run:

bash
export CPPFLAGS=-I/opt/homebrew/opt/openssl/include
export LDFLAGS=-L/opt/homebrew/opt/openssl/lib
pnpm --filter=@posthog/nodejs install

Note: If you face an error like import gyp # noqa: E402, most probably need to install python-setuptools. To fix this, run:

bash
brew install python-setuptools

Troubleshooting nodejs services issues: If you encounter problems starting up the nodejs services, try these debugging steps:

bash
cd nodejs
pnpm rebuild
pnpm i

4. Prepare the Django server

  1. Install a few dependencies for SAML to work. If you're on macOS, run the command below, otherwise check the official xmlsec repo for more details.

    • On macOS:

      bash
      brew install libxml2 libxmlsec1 pkg-config

      If installing xmlsec doesn't work, try updating macOS to the latest version (Sonoma).

    • On Debian-based Linux:

      bash
      sudo apt install -y libxml2 libxmlsec1-dev libffi-dev pkg-config

  2. Install Python 3.12.

    • On macOS, you can do so with Homebrew: brew install [email protected].

    • On Debian-based Linux:

      bash
      sudo add-apt-repository ppa:deadsnakes/ppa -y
sudo apt update
sudo apt install python3.12 python3.12-venv python3.12-dev -y

Make sure when outside the venv to always use python3 instead of python, as the latter may point to Python 2.x on some systems. If installing multiple versions of Python 3, such as by using the deadsnakes PPA, use python3.12 instead of python3.

You can also use pyenv if you wish to manage multiple versions of Python 3 on the same machine.

  1. Install uv

uv is a very fast tool you can use for python virtual env and dependency management. See https://docs.astral.sh/uv/. Once installed you can prefix any pip command with uv to get the speed boost.

  1. Create the virtual environment with the right Python version, and install dependencies - all in one with this command:

    bash
    uv sync

    Friendly tip: Creating an env could raise a Failed to parse warning related to pyproject.toml. However, you should still see the Activate with: line at the very end, which means that your env was created successfully.

  2. Activate the virtual environment:

    bash
    # For bash/zsh/etc.
source .venv/bin/activate

# For fish
source .venv/bin/activate.fish

  3. Install requirements with uv

    If your workstation is an Apple Silicon Mac, the first time you install Python packages, you must set custom OpenSSL headers:

    bash
    brew install openssl
CFLAGS="-I /opt/homebrew/opt/openssl/include $(python3.12-config --includes)" LDFLAGS="-L /opt/homebrew/opt/openssl/lib" GRPC_PYTHON_BUILD_SYSTEM_OPENSSL=1 GRPC_PYTHON_BUILD_SYSTEM_ZLIB=1 uv sync

    Friendly tip: If you see ERROR: Could not build wheels for xmlsec, refer to this issue.

    These will be used when installing grpcio and psycopg2. After doing this once, and assuming nothing changed with these two packages, next time simply run:

    bash
    uv sync

5. Prepare databases

We now have the backend ready, and Postgres and ClickHouse running – these databases are blank slates at the moment however, so we need to run migrations to e.g. create all the tables:

bash
cargo install sqlx-cli # If you haven't already
DEBUG=1 ./bin/migrate

Friendly tip 1: The error fe_sendauth: no password supplied connecting to Postgres happens when the database is set up with a password and the user:pass isn't specified in DATABASE_URL. Try export DATABASE_URL=postgres://posthog:posthog@localhost:5432/posthog.

Friendly tip 2: You may run into psycopg2 errors while migrating on an ARM machine. Try out the steps in this comment to resolve this.

Friendly tip 3: When migrating, make sure the containers are running (detached or in a separate terminal tab).

6. Start PostHog

Now start all of PostHog (backend, worker, nodejs services, and frontend – simultaneously):

bash
hogli start

To customize which services to run, use hogli dev:setup to configure your dev environment interactively. This creates a profile that hogli start will use automatically.

Note: This command uses mprocs to run all development processes in a single terminal window. It will be installed automatically for macOS, while for Linux you can install it manually (cargo or npm) using the official repo guide.

Friendly tip: If you get the error Configuration property "enable.ssl.certificate.verification" not supported in this build: OpenSSL not available at build time, make sure your environment is using the right openssl version by setting those environment variables, and then run hogli start again.

Open http://localhost:8010 to see the app.

Note: The first time you run this command you might get an error that says "layout.html is not defined". Make sure you wait until the frontend is finished compiling and try again.

To get some practical test data into your brand-new instance of PostHog, run DEBUG=1 ./manage.py generate_demo_data. For a list of useful arguments of the command, run DEBUG=1 ./manage.py generate_demo_data --help.

Friendly Tip The first time you run the app, you can log in with a test account: user:[email protected] pwd:12345678.

7. Develop

This is it – you should be seeing the PostHog app at <a href="http://localhost:8010" target="_blank">http://localhost:8010</a>.

You can now change PostHog in any way you want. See Project structure for an intro to the repository's contents. To commit changes, create a new branch based on master for your intended change, and develop away.