diff --git a/reproman/resource/docker_container.py b/reproman/resource/docker_container.py
index 080d6e6..d9d0b2e 100644
--- a/reproman/resource/docker_container.py
+++ b/reproman/resource/docker_container.py
@@ -30,6 +30,16 @@ import logging
 lgr = logging.getLogger('reproman.resource.docker_container')
 
 
+def _image_latest_default(image):
+    # Given the restricted character set for names, the presence of ":" or "@"
+    # should be a reliable indication of a tag or digest, respectively. See
+    # - https://docs.docker.com/engine/reference/commandline/tag/#extended-description
+    # - vendor/github.com/docker/distribution/reference/regexp.go
+    if ":" not in image and "@" not in image:
+        image += ":latest"
+    return image
+
+
 @attr.s
 class DockerContainer(Resource):
     """
@@ -43,8 +53,10 @@ class DockerContainer(Resource):
     id = attrib()
     type = attrib(default='docker-container')
 
-    image = attrib(default='ubuntu:latest',
-        doc="Docker base image ID from which to create the running instance")
+    image = attrib(
+        default='ubuntu:latest',
+        doc="Docker base image ID from which to create the running instance",
+        converter=_image_latest_default)
     engine_url = attrib(default='unix:///var/run/docker.sock',
         doc="Docker server URL where engine is listening for connections")
     seccomp_unconfined = attrib(default=False,

create: Default to :latest tag when pulling Docker image
`reproman create` callers that are familiar with the command-line interface to `docker pull` would reasonably expect that, if they omit a tag, the default `:latest` will be used.  Instead we download all tags:

```
$ docker images busybox
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE

$ reproman create bb -t docker-container -b image=busybox >notag-out 2>&1

$ wc -l notag-out                      
84 notag-out                                    

$ grep -c "Download complete" notag-out
7                                               

$ tail -n3 notag-out                   
2019-11-05 15:14:27,259 [INFO] Downloading [====================>                              ]  924.4kB/2.202MB 
ERROR: 
Interrupted by user while doing magic

$ docker images busybox
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
busybox             1-musl              ff773d70e0ec        5 days ago          1.44MB
busybox             1-glibc             7636bfb4b772        5 days ago          5.2MB
busybox             1-uclibc            020584afccce        5 days ago          1.22MB
busybox             1-ubuntu            d34ea343a882        3 years ago         4.35MB
busybox             1.21-ubuntu         d34ea343a882        3 years ago         4.35MB
busybox             1.21.0-ubuntu       d34ea343a882        3 years ago         4.35MB
busybox             1.23                a84c36ecc374        4 years ago         1.1MB
```
diff --git a/reproman/resource/tests/test_docker_container.py b/reproman/resource/tests/test_docker_container.py
index 1a9b5a7..3e7238b 100644
--- a/reproman/resource/tests/test_docker_container.py
+++ b/reproman/resource/tests/test_docker_container.py
@@ -175,3 +175,12 @@ def test_container_exists(setup_ubuntu):
     from ..docker_container import DockerContainer
     assert DockerContainer.is_container_running(setup_ubuntu['name'])
     assert not DockerContainer.is_container_running('foo')
+
+
+@mark.skipif_no_docker_dependencies
+def test_image_name_latest_default():
+    from ..docker_container import DockerContainer
+    for img, expected in [("debian:buster", "debian:buster"),
+                          ("busybox@ddeeaa", "busybox@ddeeaa"),
+                          ("busybox", "busybox:latest")]:
+        assert DockerContainer(name="cname", image=img).image == expected

pip install -e .[devel]
parse_log_pytest
requirements.txt
pytest pytest-cov pytest-xdist pytest-mock pytest-asyncio
apt-get update apt-get install -y gcc
3.9
requirements-devel.txt
pytest --no-header -rA --tb=line --color=no -p no:cacheprovider -W ignore::DeprecationWarning
alabaster==0.7.16
appdirs==1.4.4
attrs==25.3.0
babel==2.17.0
bcrypt==4.3.0
boto3==1.37.23
botocore==1.37.23
certifi==2025.1.31
cffi==1.17.1
chardet==5.2.0
charset-normalizer==3.4.1
coverage==7.8.0
cryptography==44.0.2
decorator==5.2.1
Deprecated==1.2.18
distro==1.9.0
docker==7.1.0
dockerpty==0.4.1
docutils==0.21.2
exceptiongroup==1.2.2
execnet==2.1.1
fabric==3.2.2
humanize==4.12.2
idna==3.10
imagesize==1.4.1
importlib_metadata==8.6.1
importlib_resources==6.5.2
iniconfig==2.1.0
invoke==2.2.0
isodate==0.7.2
Jinja2==3.1.6
jmespath==1.0.1
line_profiler==4.2.0
MarkupSafe==3.0.2
nibabel==5.3.2
numpy==2.0.2
packaging==24.2
paramiko==3.5.1
pluggy==1.5.0
pycparser==2.22
pycrypto==2.6.1
Pygments==2.19.1
PyNaCl==1.5.0
pyOpenSSL==16.2.0
pyparsing==3.2.3
pytest==8.3.5
pytest-asyncio==0.26.0
pytest-cov==6.0.0
pytest-mock==3.14.0
pytest-xdist==3.6.1
python-dateutil==2.9.0.post0
python-debian==1.0.1
pytz==2025.2
PyYAML==6.0.2
rdflib==7.1.4
-e git+https://github.com/ReproNim/reproman.git@a5da59d720baf3048a30000632b78e1eae215f5f#egg=reproman
reprozip==1.3
requests==2.32.3
rpaths==1.0.0
s3transfer==0.11.4
scp==0.15.0
six==1.17.0
snowballstemmer==2.2.0
Sphinx==7.4.7
sphinx-rtd-theme==3.0.2
sphinxcontrib-applehelp==2.0.0
sphinxcontrib-devhelp==2.0.0
sphinxcontrib-htmlhelp==2.1.0
sphinxcontrib-jquery==4.1
sphinxcontrib-jsmath==1.0.1
sphinxcontrib-qthelp==2.0.0
sphinxcontrib-serializinghtml==2.0.0
tomli==2.2.1
tqdm==4.67.1
typing_extensions==4.13.0
urllib3==1.26.20
usagestats==1.0.1
wrapt==1.17.2
zipp==3.21.0

name: reproman
channels:
  - defaults
  - https://repo.anaconda.com/pkgs/main
  - https://repo.anaconda.com/pkgs/r
  - conda-forge
dependencies:
  - _libgcc_mutex=0.1=main
  - _openmp_mutex=5.1=1_gnu
  - ca-certificates=2025.2.25=h06a4308_0
  - ld_impl_linux-64=2.40=h12ee557_0
  - libffi=3.4.4=h6a678d5_1
  - libgcc-ng=11.2.0=h1234567_1
  - libgomp=11.2.0=h1234567_1
  - libstdcxx-ng=11.2.0=h1234567_1
  - ncurses=6.4=h6a678d5_0
  - openssl=3.0.16=h5eee18b_0
  - pip=25.0=py39h06a4308_0
  - python=3.9.21=he870216_1
  - readline=8.2=h5eee18b_0
  - setuptools=75.8.0=py39h06a4308_0
  - sqlite=3.45.3=h5eee18b_0
  - tk=8.6.14=h39e8969_0
  - tzdata=2025a=h04d1e81_0
  - wheel=0.45.1=py39h06a4308_0
  - xz=5.6.4=h5eee18b_1
  - zlib=1.2.13=h5eee18b_1
  - pip:
      - alabaster==0.7.16
      - appdirs==1.4.4
      - attrs==25.3.0
      - babel==2.17.0
      - bcrypt==4.3.0
      - boto3==1.37.23
      - botocore==1.37.23
      - certifi==2025.1.31
      - cffi==1.17.1
      - chardet==5.2.0
      - charset-normalizer==3.4.1
      - coverage==7.8.0
      - cryptography==44.0.2
      - decorator==5.2.1
      - deprecated==1.2.18
      - distro==1.9.0
      - docker==7.1.0
      - dockerpty==0.4.1
      - docutils==0.21.2
      - exceptiongroup==1.2.2
      - execnet==2.1.1
      - fabric==3.2.2
      - humanize==4.12.2
      - idna==3.10
      - imagesize==1.4.1
      - importlib-metadata==8.6.1
      - importlib-resources==6.5.2
      - iniconfig==2.1.0
      - invoke==2.2.0
      - isodate==0.7.2
      - jinja2==3.1.6
      - jmespath==1.0.1
      - line-profiler==4.2.0
      - markupsafe==3.0.2
      - nibabel==5.3.2
      - numpy==2.0.2
      - packaging==24.2
      - paramiko==3.5.1
      - pluggy==1.5.0
      - pycparser==2.22
      - pycrypto==2.6.1
      - pygments==2.19.1
      - pynacl==1.5.0
      - pyopenssl==16.2.0
      - pyparsing==3.2.3
      - pytest==8.3.5
      - pytest-asyncio==0.26.0
      - pytest-cov==6.0.0
      - pytest-mock==3.14.0
      - pytest-xdist==3.6.1
      - python-dateutil==2.9.0.post0
      - python-debian==1.0.1
      - pytz==2025.2
      - pyyaml==6.0.2
      - rdflib==7.1.4
      - reprozip==1.3
      - requests==2.32.3
      - rpaths==1.0.0
      - s3transfer==0.11.4
      - scp==0.15.0
      - six==1.17.0
      - snowballstemmer==2.2.0
      - sphinx==7.4.7
      - sphinx-rtd-theme==3.0.2
      - sphinxcontrib-applehelp==2.0.0
      - sphinxcontrib-devhelp==2.0.0
      - sphinxcontrib-htmlhelp==2.1.0
      - sphinxcontrib-jquery==4.1
      - sphinxcontrib-jsmath==1.0.1
      - sphinxcontrib-qthelp==2.0.0
      - sphinxcontrib-serializinghtml==2.0.0
      - tomli==2.2.1
      - tqdm==4.67.1
      - typing-extensions==4.13.0
      - urllib3==1.26.20
      - usagestats==1.0.1
      - wrapt==1.17.2
      - zipp==3.21.0
prefix: /opt/conda/envs/reproman

reproman/resource/tests/test_docker_container.py::test_image_name_latest_default
reproman/resource/tests/test_docker_container.py::test_dockercontainer_class
reproman/resource/docker_container.py
reproman/resource/docker_container.py