[Pkg-matrix-maintainers] Bug#960276: matrix-synapse: init.d script is unable to generate missing keys

[Mikko Rasa]

Package: matrix-synapse
Version: 1.12.4-1
Severity: normal

I was trying to set up synapse and kept getting the error:

Starting matrix-synapse: matrix-synapseTLS certificate file not found ... failed!

Turns out the synapse.config does not like certain files being missing, or
an invalid database configuration:

/usr/bin/python3 -m synapse.config read tls_certificate_file --config-path ...

Unsupported database type 'psycopg3'

This was my own fault for making a typo in the configuration.  However, after
fixing that I got this:

Error accessing file '/etc/matrix-synapse/homeserver.signing.key' (config for
signing_key): No such file or directory

The init.d script redirects the output of the config command to /dev/null and
only uses the return value, so it will complain about missing TLS certificates
and the user will never see the actual error.

The latter error seems to be a catch 22 in the synapse.config module.  If the
signing key does not exist, you can't retrieve its path to check if it exists
and create it if it doesn't.

-- System Information:
Debian Release: bullseye/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (500, 'testing'), (500, 'stable'), (500, 'oldstable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.4.35-core2-server (SMP w/8 CPU cores)
Kernel taint flags: TAINT_OOT_MODULE
Locale: LANG=en_US.utf8, LC_CTYPE=en_US.utf8 (charmap=UTF-8), LANGUAGE=en_US.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: sysvinit (via /sbin/init)

Versions of packages matrix-synapse depends on:
ii  adduser                    3.118
ii  debconf [debconf-2.0]      1.5.74
ii  libjs-jquery               3.5.1+dfsg-3
ii  libpython3-stdlib          3.8.2-3
ii  lsb-base                   11.1.0
ii  python3                    3.8.2-3
ii  python3-attr               19.3.0-4
ii  python3-bcrypt             3.1.7-3
ii  python3-bleach             3.1.5-2
ii  python3-canonicaljson      1.1.4-3
ii  python3-daemonize          2.4.7-4
ii  python3-distutils          3.8.2-2
ii  python3-frozendict         1.2-2
ii  python3-idna               2.9-1
ii  python3-jinja2             2.11.1-1
ii  python3-jsonschema         3.2.0-3
ii  python3-lxml               4.5.0-1.1
ii  python3-msgpack            0.6.2-1+b1
ii  python3-nacl               1.3.0-5
ii  python3-netaddr            0.7.19-4
ii  python3-openssl            19.1.0-2
ii  python3-phonenumbers       8.12.1-1
ii  python3-pil                7.0.0-4+b1
ii  python3-prometheus-client  0.7.1-1.1
ii  python3-pyasn1             0.4.2-4
ii  python3-pyasn1-modules     0.2.1-1
ii  python3-pymacaroons        0.13.0-3
ii  python3-service-identity   18.1.0-6
ii  python3-signedjson         1.1.0-1
ii  python3-six                1.14.0-3
ii  python3-sortedcontainers   2.1.0-2
ii  python3-systemd            234-3+b2
ii  python3-treq               18.6.0-0.2
ii  python3-twisted            18.9.0-11
ii  python3-typing-extensions  3.7.4.2-1
ii  python3-unpaddedbase64     1.1.0-5
ii  python3-yaml               5.3.1-2

Versions of packages matrix-synapse recommends:
ii  python3-psycopg2  2.8.5-1

Versions of packages matrix-synapse suggests:
pn  python3-txacme  <none>

-- Configuration Files:
/etc/matrix-synapse/homeserver.yaml [Errno 13] Permission denied: '/etc/matrix-synapse/homeserver.yaml'

-- debconf information excluded