How to set up MSDTC with Dockerized SQL Server for Linux

I am trying to use Docker Compose to set up MSDTC in a SQL Server container as described here:

https://learn.microsoft.com/en-us/sql/linux/sql-server-linux-configure-msdtc-docker?view=sql-server-ver15

My compose file looks like this, mirroring the command-line arguments referenced in the above document:

services:
  pte_mssql:
    build:
      context: ./mssql/docker
    environment:
      ACCEPT_EULA: 'Y'
      MSSQL_SA_PASSWORD: '${startupSaPassword}'
      MSSQL_RPC_PORT: 135
      MSSQL_DTC_TCP_PORT: 51000
    ports:
      - 1433:1433
      - 135:135
      - 51000:51000

However, the DTC service does not appear to start. I see this repeated in the output (other ports seem to be OK):

Waiting for TCP socket on 172.24.0.1:51000 of 'pte_mssql_1' (Connection refused (Connection refused))
Will use 172.24.0.1 (network vestmarkone_default) as host of pte_mssql
More forwarded TCP ports for service 'pte_mssql:135 [[HostIp:0.0.0.0, HostPort:135], [HostIp:::, HostPort:135]]'. Will use the first one.
More forwarded TCP ports for service 'pte_mssql:1433 [[HostIp:0.0.0.0, HostPort:1433], [HostIp:::, HostPort:1433]]'. Will use the first one.
More forwarded TCP ports for service 'pte_mssql:51000 [[HostIp:0.0.0.0, HostPort:51000], [HostIp:::, HostPort:51000]]'. Will use the first one.

I used the following command to confirm that nothing is running on port 51000:

root@906e7184f6bc:/var/opt/mssql/log# lsof -i -P -n | grep LISTEN
sqlservr   9 root   49u  IPv4 1613252      0t0  TCP *:135 (LISTEN)
sqlservr   9 root   51u  IPv6 1613254      0t0  TCP *:135 (LISTEN)
sqlservr   9 root   64u  IPv6 1617097      0t0  TCP *:1433 (LISTEN)
sqlservr   9 root  100u  IPv4 1617098      0t0  TCP *:1433 (LISTEN)
sqlservr   9 root  106u  IPv4 1629465      0t0  TCP 127.0.0.1:1434 (LISTEN)
sqlservr   9 root  110u  IPv4 1617101      0t0  TCP 127.0.0.1:1431 (LISTEN)

I also tried adding the following to my Dockerfile instead of setting the MSSQL_DTC_TCP_PORT environment variable:

RUN /opt/mssql/bin/mssql-conf set distributedtransaction.servertcpport 51000

This did not resolve the problem.

FWIW, creating the container from the command line (as shown in the article) rather than via Docker Compose produces the same results. Note that I started the container as root so I could run lsof to troubleshoot. I also used "2019-latest" rather than "2019-GA-ubuntu-20.04" since the latter no longer appears to exist:

docker run \
   -u root \
   -e 'ACCEPT_EULA=Y' -e 'MSSQL_SA_PASSWORD=pass@1234' \
   -e 'MSSQL_RPC_PORT=135' -e 'MSSQL_DTC_TCP_PORT=51000' \
   -p 1433:1433 -p 135:135 -p 51000:51000  \
   -d mcr.microsoft.com/mssql/server:2019-latest

Does anyone have any suggestions for how to enable the DTC service, or how to troubleshoot further?

According to Microsoft's documentation, the DTC server will not start listening until a distributed transaction has begun. Once that occurs, you should see it listening on port 51000.