Rebased PR: add docker compose for installing a chatmail relay

.dockerignore

@@ -0,0 +1,7 @@
+.git
+data/
+venv/
+__pycache__
+*.pyc
+*.orig
+.pytest_cache

.gitignore

@@ -164,3 +164,8 @@ cython_debug/
 #.idea/
 
 chatmail.zone
+
+# docker
+/data/
+/custom/
+.env

CHANGELOG.md

@@ -121,6 +121,13 @@
   Provide an "fsreport" CLI for more fine grained analysis of message files. 
   ([#637](https://github.com/chatmail/relay/pull/637))
 
+- Add installation via docker compose (MVP 1). The instructions, known issues and limitations are located in `/docs` 
+  ([#614](https://github.com/chatmail/relay/pull/614))
+
+- Add configuration parameters
+  ([#614](https://github.com/chatmail/relay/pull/614)):
+  - `change_kernel_settings` - Whether to change kernel parameters during installation (default: `True`)
+  - `fs_inotify_max_user_instances_and_watchers` - Value for kernel parameters `fs.inotify.max_user_instances` and `fs.inotify.max_user_watches` (default: `65535`)
 
 ## 1.7.0 2025-09-11
 

chatmaild/src/chatmaild/config.py

@@ -47,6 +47,12 @@ def __init__(self, inipath, params):
         self.addr_v4 = os.environ.get("CHATMAIL_ADDR_V4", "")
         self.addr_v6 = os.environ.get("CHATMAIL_ADDR_V6", "")
         self.acme_email = params.get("acme_email", "")
+        self.change_kernel_settings = (
+            params.get("change_kernel_settings", "true").lower() == "true"
+        )
+        self.fs_inotify_max_user_instances_and_watchers = int(
+            params["fs_inotify_max_user_instances_and_watchers"]
+        )
         self.imap_rawlog = params.get("imap_rawlog", "false").lower() == "true"
         self.imap_compress = params.get("imap_compress", "false").lower() == "true"
         if "iroh_relay" not in params:

chatmaild/src/chatmaild/ini/chatmail.ini.f

@@ -69,6 +69,16 @@
 # Your email adress, which will be used in acmetool to manage Let's Encrypt SSL certificates
 acme_email = 
 
+#
+# Kernel settings
+#
+
+# if you set "True", the kernel settings will be configured according to the values below
+change_kernel_settings  = True
+
+# change fs.inotify.max_user_instances and fs.inotify.max_user_watches kernel settings
+fs_inotify_max_user_instances_and_watchers = 65535
+
 # Defaults to https://iroh.{{mail_domain}} and running `iroh-relay` on the chatmail
 # service.
 # If you set it to anything else, the service will be disabled

cmdeploy/src/cmdeploy/basedeploy.py

@@ -5,6 +5,11 @@
 from pyinfra.operations import files, server, systemd
 
 
+def has_systemd():
+    """Returns False during Docker image builds or any other non-systemd environment."""
+    return os.path.isdir("/run/systemd/system")
+
+
 def get_resource(arg, pkg=__package__):
     return importlib.resources.files(pkg).joinpath(arg)
 

cmdeploy/src/cmdeploy/cmdeploy.py

@@ -109,6 +109,8 @@ def run_cmd(args, out):
 
     cmd = f"{pyinf} --ssh-user root {ssh_host} {deploy_path} -y"
     if ssh_host in ["localhost", "@docker"]:
+        if ssh_host == "@docker":
+            env["CHATMAIL_DOCKER"] = "True"
         cmd = f"{pyinf} @local {deploy_path} -y"
 
     if version.parse(pyinfra.__version__) < version.parse("3"):

cmdeploy/src/cmdeploy/deployers.py

@@ -25,6 +25,7 @@
     activate_remote_units,
     configure_remote_units,
     get_resource,
+    has_systemd,
 )
 from .dovecot.deployer import DovecotDeployer
 from .filtermail.deployer import FiltermailDeployer
@@ -65,6 +66,8 @@ def _build_chatmaild(dist_dir) -> None:
 
 
 def remove_legacy_artifacts():
+    if not has_systemd():
+        return
     # disable legacy doveauth-dictproxy.service
     if host.get_fact(SystemdEnabled).get("doveauth-dictproxy.service"):
         systemd.service(
@@ -299,7 +302,7 @@ def install(self):
             present=False,
         )
         # remove echobot if it is still running
-        if host.get_fact(SystemdEnabled).get("echobot.service"):
+        if has_systemd() and host.get_fact(SystemdEnabled).get("echobot.service"):
             systemd.service(
                 name="Disable echobot.service",
                 service="echobot.service",
@@ -535,12 +538,13 @@ def activate(self):
         )
 
 
-def deploy_chatmail(config_path: Path, disable_mail: bool, website_only: bool) -> None:
+def deploy_chatmail(config_path: Path, disable_mail: bool, website_only: bool, docker: bool) -> None:
     """Deploy a chat-mail instance.
 
     :param config_path: path to chatmail.ini
     :param disable_mail: whether to disable postfix & dovecot
     :param website_only: if True, only deploy the website
+    :param docker: whether it is running in a docker container
     """
     config = read_config(config_path)
     check_config(config)
@@ -566,34 +570,35 @@ def deploy_chatmail(config_path: Path, disable_mail: bool, website_only: bool) -
             Out().red(f"Deploy failed: mtail_address {config.mtail_address} is not available (VPN up?).\n")
             exit(1)
 
-    port_services = [
-        (["master", "smtpd"], 25),
-        ("unbound", 53),
-        ("acmetool", 80),
-        (["imap-login", "dovecot"], 143),
-        ("nginx", 443),
-        (["master", "smtpd"], 465),
-        (["master", "smtpd"], 587),
-        (["imap-login", "dovecot"], 993),
-        ("iroh-relay", 3340),
-        ("mtail", 3903),
-        ("stats", 3904),
-        ("nginx", 8443),
-        (["master", "smtpd"], config.postfix_reinject_port),
-        (["master", "smtpd"], config.postfix_reinject_port_incoming),
-        ("filtermail", config.filtermail_smtp_port),
-        ("filtermail", config.filtermail_smtp_port_incoming),
-    ]
-    for service, port in port_services:
-        print(f"Checking if port {port} is available for {service}...")
-        running_service = host.get_fact(Port, port=port)
-        services = [service] if isinstance(service, str) else service
-        if running_service:
-            if running_service not in services:
-                Out().red(
-                    f"Deploy failed: port {port} is occupied by: {running_service}"
-                )
-                exit(1)
+    if not docker:
+        port_services = [
+            (["master", "smtpd"], 25),
+            ("unbound", 53),
+            ("acmetool", 80),
+            (["imap-login", "dovecot"], 143),
+            ("nginx", 443),
+            (["master", "smtpd"], 465),
+            (["master", "smtpd"], 587),
+            (["imap-login", "dovecot"], 993),
+            ("iroh-relay", 3340),
+            ("mtail", 3903),
+            ("stats", 3904),
+            ("nginx", 8443),
+            (["master", "smtpd"], config.postfix_reinject_port),
+            (["master", "smtpd"], config.postfix_reinject_port_incoming),
+            ("filtermail", config.filtermail_smtp_port),
+            ("filtermail", config.filtermail_smtp_port_incoming),
+        ]
+        for service, port in port_services:
+            print(f"Checking if port {port} is available for {service}...")
+            running_service = host.get_fact(Port, port=port)
+            services = [service] if isinstance(service, str) else service
+            if running_service:
+                if running_service not in services:
+                    Out().red(
+                        f"Deploy failed: port {port} is occupied by: {running_service}"
+                    )
+                    exit(1)
 
     tls_domains = [mail_domain, f"mta-sts.{mail_domain}", f"www.{mail_domain}"]
 

cmdeploy/src/cmdeploy/dovecot/deployer.py

@@ -9,6 +9,7 @@
     activate_remote_units,
     configure_remote_units,
     get_resource,
+    has_systemd,
 )
 
 
@@ -22,10 +23,11 @@ def __init__(self, config, disable_mail):
 
     def install(self):
         arch = host.get_fact(Arch)
-        if not "dovecot.service" in host.get_fact(SystemdEnabled):
-            _install_dovecot_package("core", arch)
-            _install_dovecot_package("imapd", arch)
-            _install_dovecot_package("lmtpd", arch)
+        if has_systemd() and "dovecot.service" in host.get_fact(SystemdEnabled):
+            return  # already installed and running
+        _install_dovecot_package("core", arch)
+        _install_dovecot_package("imapd", arch)
+        _install_dovecot_package("lmtpd", arch)
 
     def configure(self):
         configure_remote_units(self.config.mail_domain, self.units)
@@ -116,18 +118,19 @@ def _configure_dovecot(config: Config, debug: bool = False) -> (bool, bool):
 
     # as per https://doc.dovecot.org/2.3/configuration_manual/os/
     # it is recommended to set the following inotify limits
-    for name in ("max_user_instances", "max_user_watches"):
-        key = f"fs.inotify.{name}"
-        if host.get_fact(Sysctl)[key] > 65535:
-            # Skip updating limits if already sufficient
-            # (enables running in incus containers where sysctl readonly)
-            continue
-        server.sysctl(
-            name=f"Change {key}",
-            key=key,
-            value=65535,
-            persist=True,
-        )
+    if config.change_kernel_settings:
+        for name in ("max_user_instances", "max_user_watches"):
+            key = f"fs.inotify.{name}"
+            if host.get_fact(Sysctl)[key] > 65535:
+                # Skip updating limits if already sufficient
+                # (enables running in incus containers where sysctl readonly)
+                continue
+            server.sysctl(
+                name=f"Change {key}",
+                key=key,
+                value=65535,
+                persist=True,
+            )
 
     timezone_env = files.line(
         name="Set TZ environment variable",

cmdeploy/src/cmdeploy/run.py

@@ -15,8 +15,9 @@ def main():
     )
     disable_mail = bool(os.environ.get("CHATMAIL_DISABLE_MAIL"))
     website_only = bool(os.environ.get("CHATMAIL_WEBSITE_ONLY"))
+    docker = bool(os.environ.get("CHATMAIL_DOCKER"))
 
-    deploy_chatmail(config_path, disable_mail, website_only)
+    deploy_chatmail(config_path, disable_mail, website_only, docker)
 
 
 if pyinfra.is_cli:

doc/source/getting_started.rst

@@ -80,6 +80,13 @@ steps. Please substitute it with your own domain.
    configure at your DNS provider (it can take some time until they are
    public).
 
+Docker installation
+-------------------
+
+We have experimental support for `docker compose <https://github.com/chatmail/relay/blob/docker-rebase/docs/DOCKER_INSTALLATION_EN.md>`_,
+but it is not covered by automated tests yet,
+so don't expect everything to work.
+
 Other helpful commands
 ----------------------
 

docker-compose.yaml

@@ -0,0 +1,52 @@
+services:
+  chatmail:
+    build:
+      context: ./
+      dockerfile: docker/chatmail_relay.dockerfile
+      tags:
+        - chatmail-relay:latest
+    image: chatmail-relay:latest
+    restart: unless-stopped
+    container_name: chatmail
+    cgroup: host # required for systemd
+    tty: true # required for logs
+    tmpfs: # required for systemd
+      - /tmp
+      - /run
+      - /run/lock
+    logging:
+      driver: json-file
+      options:
+        max-size: "10m"
+        max-file: "3"
+    environment:
+      CHANGE_KERNEL_SETTINGS: "False"
+      MAIL_DOMAIN: $MAIL_DOMAIN
+      ACME_EMAIL: $ACME_EMAIL
+      RECREATE_VENV: $RECREATE_VENV
+      MAX_MESSAGE_SIZE: $MAX_MESSAGE_SIZE
+      DEBUG_COMMANDS_ENABLED: $DEBUG_COMMANDS_ENABLED
+      FORCE_REINIT_INI_FILE: $FORCE_REINIT_INI_FILE
+      USE_FOREIGN_CERT_MANAGER: $USE_FOREIGN_CERT_MANAGER
+      ENABLE_CERTS_MONITORING: $ENABLE_CERTS_MONITORING
+      CERTS_MONITORING_TIMEOUT: $CERTS_MONITORING_TIMEOUT
+      IS_DEVELOPMENT_INSTANCE: $IS_DEVELOPMENT_INSTANCE
+      CMDEPLOY_STAGES: ${CMDEPLOY_STAGES:-}
+    network_mode: "host"
+    volumes:
+      ## system
+      - /sys/fs/cgroup:/sys/fs/cgroup:rw # required for systemd
+      - ./:/opt/chatmail
+
+      ## data
+      - ./data/chatmail:/home
+      - ./data/chatmail-dkimkeys:/etc/dkimkeys
+      - ./data/chatmail-acme:/var/lib/acme
+
+      ## custom resources
+      # - ./custom/www/src/index.md:/opt/chatmail/www/src/index.md
+
+      ## debug
+      # - ./docker/files/setup_chatmail_docker.sh:/setup_chatmail_docker.sh
+      # - ./docker/files/entrypoint.sh:/entrypoint.sh
+      # - ./docker/files/update_ini.sh:/update_ini.sh