refactor: deployer improvements (VM detection, mailboxes dir ensured to be there, proper unbound on ipv4)

Author: hpk42

cmdeploy/src/cmdeploy/cmdeploy.py

@@ -111,7 +111,6 @@ def run_cmd(args, out):
     if ssh_host in ["localhost", "@docker"]:
         if ssh_host == "@docker":
             env["CHATMAIL_NOPORTCHECK"] = "True"
-            env["CHATMAIL_NOSYSCTL"] = "True"
         cmd = f"{pyinf} @local {deploy_path} -y"
 
     if version.parse(pyinfra.__version__) < version.parse("3"):

cmdeploy/src/cmdeploy/deployers.py

@@ -24,6 +24,7 @@
     Deployer,
     Deployment,
     activate_remote_units,
+    blocked_service_startup,
     configure_remote_units,
     get_resource,
     has_systemd,
@@ -149,33 +150,16 @@ def __init__(self, config):
         self.need_restart = False
 
     def install(self):
-        # Run local DNS resolver `unbound`.
-        # `resolvconf` takes care of setting up /etc/resolv.conf
-        # to use 127.0.0.1 as the resolver.
-
-        #
-        # On an IPv4-only system, if unbound is started but not
-        # configured, it causes subsequent steps to fail to resolve hosts.
-        # Here, we use policy-rc.d to prevent unbound from starting up
-        # on initial install.  Later, we will configure it and start it.
-        #
-        # For documentation about policy-rc.d, see:
-        # https://people.debian.org/~hmh/invokerc.d-policyrc.d-specification.txt
-        #
-        files.put(
-            src=get_resource("policy-rc.d"),
-            dest="/usr/sbin/policy-rc.d",
-            user="root",
-            group="root",
-            mode="755",
-        )
-
-        apt.packages(
-            name="Install unbound",
-            packages=["unbound", "unbound-anchor", "dnsutils"],
-        )
-
-        files.file("/usr/sbin/policy-rc.d", present=False)
+        # Run local DNS resolver `unbound`. `resolvconf` takes care of
+        # setting up /etc/resolv.conf to use 127.0.0.1 as the resolver.
+
+        # On an IPv4-only system, if unbound is started but not configured,
+        # it causes subsequent steps to fail to resolve hosts.
+        with blocked_service_startup():
+            apt.packages(
+                name="Install unbound",
+                packages=["unbound", "unbound-anchor", "dnsutils"],
+            )
 
     def configure(self):
         server.shell(
@@ -474,8 +458,9 @@ class ChatmailDeployer(Deployer):
         ("iroh", None, None),
     ]
 
-    def __init__(self, mail_domain):
-        self.mail_domain = mail_domain
+    def __init__(self, config):
+        self.config = config
+        self.mail_domain = config.mail_domain
 
     def install(self):
         files.put(
@@ -500,6 +485,16 @@ def install(self):
         )
 
     def configure(self):
+        # metadata crashes if the mailboxes dir does not exist
+        files.directory(
+            name="Ensure vmail mailbox directory exists",
+            path=str(self.config.mailboxes_dir),
+            user="vmail",
+            group="vmail",
+            mode="700",
+            present=True,
+        )
+
         # This file is used by auth proxy.
         # https://wiki.debian.org/EtcMailName
         server.shell(
@@ -629,7 +624,7 @@ def deploy_chatmail(config_path: Path, disable_mail: bool, website_only: bool) -
     tls_deployer = get_tls_deployer(config, mail_domain)
 
     all_deployers = [
-        ChatmailDeployer(mail_domain),
+        ChatmailDeployer(config),
         LegacyRemoveDeployer(),
         FiltermailDeployer(),
         JournaldDeployer(),

cmdeploy/src/cmdeploy/dovecot/deployer.py

@@ -1,11 +1,10 @@
 import io
-import os
 import urllib.request
 
 from chatmaild.config import Config
 from pyinfra import host
 from pyinfra.facts.deb import DebPackages
-from pyinfra.facts.server import Arch, Sysctl
+from pyinfra.facts.server import Arch, Command, Sysctl
 from pyinfra.operations import apt, files, server, systemd
 
 from cmdeploy.basedeploy import (
@@ -128,7 +127,18 @@ def _download_dovecot_package(package: str, arch: str):
     return deb_filename
 
 
-def _configure_dovecot(config: Config, debug: bool = False) -> (bool, bool):
+def _can_set_inotify_limits() -> bool:
+    is_container = (
+        host.get_fact(
+            Command,
+            "systemd-detect-virt --container --quiet 2>/dev/null && echo yes || true",
+        )
+        == "yes"
+    )
+    return not is_container
+
+
+def _configure_dovecot(config: Config, debug: bool = False) -> tuple[bool, bool]:
     """Configures Dovecot IMAP server."""
     need_restart = False
     daemon_reload = False
@@ -163,19 +173,25 @@ 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
-    if not os.environ.get("CHATMAIL_NOSYSCTL"):
-        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,
+    can_modify = _can_set_inotify_limits()
+    for name in ("max_user_instances", "max_user_watches"):
+        key = f"fs.inotify.{name}"
+        value = host.get_fact(Sysctl)[key]
+        if value > 65534:
+            continue
+        if not can_modify:
+            print(
+                "\n!!!! refusing to attempt sysctl setting in containers\n"
+                f"!!!! dovecot: sysctl {key!r}={value}, should be >65534 for production setups\n"
+                "!!!!"
             )
+            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/selfsigned/deployer.py

@@ -18,6 +18,8 @@ def openssl_selfsigned_args(domain, cert_path, key_path, days=36500):
         "-keyout", str(key_path),
         "-out", str(cert_path),
         "-subj", f"/CN={domain}",
+        # Mark as end-entity cert so it cannot be used as a CA to sign others.
+        "-addext", "basicConstraints=critical,CA:FALSE",
         "-addext", "extendedKeyUsage=serverAuth,clientAuth",
         "-addext",
         f"subjectAltName=DNS:{domain},DNS:www.{domain},DNS:mta-sts.{domain}",