diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index d885e87..f727abc 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -36,7 +36,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [ '2.x', '3.x']
+        python-version: [ '3.x']
     steps:
     - name: Check out code
       uses: actions/checkout@v1
@@ -58,7 +58,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [ '2.x', '3.x']
+        python-version: [ '3.x']
     steps:
     - name: Check out code
       uses: actions/checkout@v1
@@ -74,5 +74,5 @@ jobs:
         echo "$HOME/.local/bin" >> $GITHUB_PATH
     - name: Test usage
       run: |
-        skipper make clean
+        sudo skipper make clean
 
diff --git a/.github/workflows/publish-to-pypi.yml b/.github/workflows/publish-to-pypi.yml
index bd6def3..059c3d3 100644
--- a/.github/workflows/publish-to-pypi.yml
+++ b/.github/workflows/publish-to-pypi.yml
@@ -11,10 +11,10 @@ jobs:
     steps:
     - name: Check out code
       uses: actions/checkout@v1
-    - name: Set up Python 2.7
+    - name: Set up Python 3
       uses: actions/setup-python@v1
       with:
-        python-version: 2.7.18
+        python-version: '3.x'
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
diff --git a/.pylintrc b/.pylintrc
index a05f2fa..156aeab 100644
--- a/.pylintrc
+++ b/.pylintrc
@@ -34,16 +34,6 @@ unsafe-load-any-extension=no
 # run arbitrary code
 extension-pkg-whitelist=
 
-# Allow optimization of some AST trees. This will activate a peephole AST
-# optimizer, which will apply various small optimizations. For instance, it can
-# be used to obtain the result of joining multiple strings with the addition
-# operator. Joining a lot of strings can lead to a maximum recursion error in
-# Pylint and this flag can prevent that. It has one side effect, the resulting
-# AST will be different than the one from reality. This option is deprecated
-# and it will be removed in Pylint 2.0.
-optimize-ast=no
-
-
 [MESSAGES CONTROL]
 
 # Only show warnings with the listed confidence levels. Leave empty to show
@@ -65,7 +55,7 @@ confidence=
 # --enable=similarities". If you want to run only the classes checker, but have
 # no Warning level messages displayed, use"--disable=all --enable=classes
 # --disable=W"
-disable=import-star-module-level,old-octal-literal,oct-method,print-statement,unpacking-in-except,parameter-unpacking,backtick,old-raise-syntax,old-ne-operator,long-suffix,dict-view-method,dict-iter-method,metaclass-assignment,next-method-called,raising-string,indexing-exception,raw_input-builtin,long-builtin,file-builtin,execfile-builtin,coerce-builtin,cmp-builtin,buffer-builtin,basestring-builtin,apply-builtin,filter-builtin-not-iterating,using-cmp-argument,useless-suppression,range-builtin-not-iterating,suppressed-message,no-absolute-import,old-division,cmp-method,reload-builtin,zip-builtin-not-iterating,intern-builtin,unichr-builtin,reduce-builtin,standarderror-builtin,unicode-builtin,xrange-builtin,coerce-method,delslice-method,getslice-method,setslice-method,input-builtin,round-builtin,hex-method,nonzero-method,map-builtin-not-iterating,missing-docstring,fixme,superfluous-parens,too-many-locals
+disable=useless-suppression,suppressed-message,missing-docstring,fixme,superfluous-parens,too-many-locals,unspecified-encoding,missing-timeout
 
 
 [REPORTS]
@@ -75,12 +65,6 @@ disable=import-star-module-level,old-octal-literal,oct-method,print-statement,un
 # mypackage.mymodule.MyReporterClass.
 output-format=text
 
-# Put messages in a separate file for each module / package specified on the
-# command line instead of printing them on stdout. Reports (if any) will be
-# written in a file name "pylint_global.[txt|html]". This option is deprecated
-# and it will be removed in Pylint 2.0.
-files-output=no
-
 # Tells whether to display a full report or only the messages
 reports=no
 
@@ -141,63 +125,33 @@ property-classes=abc.abstractproperty
 # Regular expression matching correct function names
 function-rgx=[a-z_][a-z0-9_]{2,30}$
 
-# Naming hint for function names
-function-name-hint=[a-z_][a-z0-9_]{2,30}$
-
 # Regular expression matching correct variable names
 variable-rgx=[a-z_][a-z0-9_]{2,30}$
 
-# Naming hint for variable names
-variable-name-hint=[a-z_][a-z0-9_]{2,30}$
-
 # Regular expression matching correct constant names
 const-rgx=(([A-Z_][A-Z0-9_]*)|(__.*__))$
 
-# Naming hint for constant names
-const-name-hint=(([A-Z_][A-Z0-9_]*)|(__.*__))$
-
 # Regular expression matching correct attribute names
 attr-rgx=[a-z_][a-z0-9_]{2,30}$
 
-# Naming hint for attribute names
-attr-name-hint=[a-z_][a-z0-9_]{2,30}$
-
 # Regular expression matching correct argument names
 argument-rgx=[a-z_][a-z0-9_]{2,30}$
 
-# Naming hint for argument names
-argument-name-hint=[a-z_][a-z0-9_]{2,30}$
-
 # Regular expression matching correct class attribute names
 class-attribute-rgx=([A-Za-z_][A-Za-z0-9_]{2,30}|(__.*__))$
 
-# Naming hint for class attribute names
-class-attribute-name-hint=([A-Za-z_][A-Za-z0-9_]{2,30}|(__.*__))$
-
 # Regular expression matching correct inline iteration names
 inlinevar-rgx=[A-Za-z_][A-Za-z0-9_]*$
 
-# Naming hint for inline iteration names
-inlinevar-name-hint=[A-Za-z_][A-Za-z0-9_]*$
-
 # Regular expression matching correct class names
 class-rgx=[A-Z_][a-zA-Z0-9]+$
 
-# Naming hint for class names
-class-name-hint=[A-Z_][a-zA-Z0-9]+$
-
 # Regular expression matching correct module names
 module-rgx=(([a-z_][a-z0-9_]*)|([A-Z][a-zA-Z0-9]+))$
 
-# Naming hint for module names
-module-name-hint=(([a-z_][a-z0-9_]*)|([A-Z][a-zA-Z0-9]+))$
-
 # Regular expression matching correct method names
 method-rgx=[a-z_][a-z0-9_]{2,30}$
 
-# Naming hint for method names
-method-name-hint=[a-z_][a-z0-9_]{2,30}$
-
 # Regular expression which should only match function or class names that do
 # not require a docstring.
 no-docstring-rgx=^_
@@ -225,12 +179,6 @@ ignore-long-lines=^\s*(# )?<?https?://\S+>?$
 # else.
 single-line-if-stmt=no
 
-# List of optional constructs for which whitespace checking is disabled. `dict-
-# separator` is used to allow tabulation in dicts, etc.: {1  : 1,\n222: 2}.
-# `trailing-comma` allows a space between comma and closing bracket: (a, ).
-# `empty-line` allows space-only lines.
-no-space-check=trailing-comma,dict-separator
-
 # Maximum number of lines in a module
 max-module-lines=1000
 
@@ -404,4 +352,4 @@ exclude-protected=_asdict,_fields,_replace,_source,_make
 
 # Exceptions that will emit a warning when being caught. Defaults to
 # "Exception"
-overgeneral-exceptions=Exception
+overgeneral-exceptions=builtins.Exception
diff --git a/Dockerfile.skipper-build b/Dockerfile.skipper-build
index ec3c42d..6fb8b36 100644
--- a/Dockerfile.skipper-build
+++ b/Dockerfile.skipper-build
@@ -1,4 +1,4 @@
-FROM python:2.7
+FROM python:3.11
 
 COPY requirements.txt /tmp/requirements.txt
 RUN pip install -r /tmp/requirements.txt
diff --git a/setup.cfg b/setup.cfg
index 1e9dab8..945107b 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -9,6 +9,7 @@ long_description = file: README.md
 long_description_content_type = text/markdown
 
 requires-dist = setuptools
+requires-python = >=3
 
 
 [files]
diff --git a/skipper/cli.py b/skipper/cli.py
index cce94c7..4a99906 100644
--- a/skipper/cli.py
+++ b/skipper/cli.py
@@ -46,12 +46,12 @@ def _validate_port(matcher, port_forwarding):
 
 def _validate_port_range(start, end):
     if start and end and end < start:
-        raise click.BadParameter("Invalid port range: {0} should be bigger than {1}".format(start, end))
+        raise click.BadParameter(f"Invalid port range: {start} should be bigger than {end}")
 
 
 def _validate_port_out_of_range(port):
     if port and not 1 <= int(port) <= 65535:
-        raise click.BadParameter("Invalid port number: port {0} is out of range".format(port))
+        raise click.BadParameter(f"Invalid port number: port {port} is out of range")
 
 
 @click.group()
@@ -102,16 +102,16 @@ def build(ctx, images_to_build, container_context, cache):
     else:
         for image in images_to_build:
             if image not in valid_images:
-                utils.logger.warning('Image %(image)s is not valid for this project! Skipping...', dict(image=image))
+                utils.logger.warning('Image %s is not valid for this project! Skipping...', image)
                 continue
             valid_images_to_build[image] = valid_images[image]
 
     tag = git.get_hash()
     for image, dockerfile in six.iteritems(valid_images_to_build):
-        utils.logger.info('Building image: %(image)s', dict(image=image))
+        utils.logger.info('Building image: %s', image)
 
         if not os.path.exists(dockerfile):
-            utils.logger.warning('Dockerfile %(dockerfile)s does not exist! Skipping...', dict(dockerfile=dockerfile))
+            utils.logger.warning('Dockerfile %s does not exist! Skipping...', dockerfile)
             continue
 
         fqdn_image = image + ':' + tag
@@ -121,7 +121,7 @@ def build(ctx, images_to_build, container_context, cache):
             build_context = ctx.obj['container_context']
         else:
             build_context = os.path.dirname(dockerfile)
-        command = ['build', '--network=host', '--build-arg', 'TAG={}'.format(tag),
+        command = ['build', '--network=host', '--build-arg', f'TAG={tag}',
                    '-f', dockerfile, '-t', fqdn_image, build_context]
         if cache:
             cache_image = utils.generate_fqdn_image(ctx.obj['registry'], namespace=None, image=image, tag=DOCKER_TAG_FOR_CACHE)
@@ -130,7 +130,7 @@ def build(ctx, images_to_build, container_context, cache):
         ret = runner.run(command)
 
         if ret != 0:
-            utils.logger.error('Failed to build image: %(image)s', dict(image=image))
+            utils.logger.error('Failed to build image: %s', image)
             return ret
 
         if cache:
@@ -158,7 +158,7 @@ def push(ctx, namespace, force, pbr, image):
     if pbr:
         # Format = pbr_version.short_hash
         # pylint: disable=protected-access
-        tag_to_push = "{}.{}".format(packaging._get_version_from_git().replace('dev', ''), tag[:8])
+        tag_to_push = f"{packaging._get_version_from_git().replace('dev', '')}.{tag[:8]}"
     image_name = image + ':' + tag
 
     ret = _push(ctx, force, image, image_name, namespace, tag_to_push)
@@ -169,11 +169,11 @@ def push(ctx, namespace, force, pbr, image):
 
 def _push(ctx, force, image, image_name, namespace, tag):
     fqdn_image = utils.generate_fqdn_image(ctx.obj['registry'], namespace, image, tag)
-    utils.logger.debug("Adding tag %(tag)s", dict(tag=fqdn_image))
+    utils.logger.debug("Adding tag %s", fqdn_image)
     command = ['tag', image_name, fqdn_image]
     ret = runner.run(command)
     if ret != 0:
-        utils.logger.error('Failed to tag image: %(tag)s as fqdn', dict(tag=image_name, fqdn=fqdn_image))
+        utils.logger.error('Failed to tag image: %s as fqdn: %s', image_name, fqdn_image)
         sys.exit(ret)
     repo_name = utils.generate_fqdn_image(None, namespace, image, tag=None)
     images_info = utils.get_remote_images_info([repo_name], ctx.obj['registry'],
@@ -181,19 +181,19 @@ def _push(ctx, force, image, image_name, namespace, tag):
     tags = [info[-1] for info in images_info]
     if tag in tags:
         if not force:
-            utils.logger.info("Image %(image)s is already in registry %(registry)s, not pushing",
-                              dict(image=fqdn_image, registry=ctx.obj['registry']))
+            utils.logger.info("Image %s is already in registry %s, not pushing",
+                              fqdn_image, ctx.obj['registry'])
         else:
-            utils.logger.warning("Image %(image)s is already in registry %(registry)s, pushing anyway",
-                                 dict(image=fqdn_image, registry=ctx.obj['registry']))
+            utils.logger.warning("Image %s is already in registry %s, pushing anyway",
+                                 fqdn_image, ctx.obj['registry'])
             _push_to_registry(ctx.obj['registry'], fqdn_image)
     else:
         _push_to_registry(ctx.obj['registry'], fqdn_image)
-    utils.logger.debug("Removing tag %(tag)s", dict(tag=fqdn_image))
+    utils.logger.debug("Removing tag %s", fqdn_image)
     command = ['rmi', fqdn_image]
     ret = runner.run(command)
     if ret != 0:
-        utils.logger.warning('Failed to remove image tag: %(tag)s', dict(tag=fqdn_image))
+        utils.logger.warning('Failed to remove image tag: %s', fqdn_image)
     return ret
 
 
@@ -208,7 +208,7 @@ def images(ctx, remote):
 
     valid_images = ctx.obj.get('containers') or utils.get_images_from_dockerfiles()
     images_names = valid_images.keys()
-    utils.logger.info("Expected images: %(images)s\n", dict(images=", ".join(images_names)))
+    utils.logger.info("Expected images: %s\n", ", ".join(images_names))
     images_info = utils.get_local_images_info(images_names)
     if remote:
         _validate_global_params(ctx, 'registry')
@@ -216,7 +216,7 @@ def images(ctx, remote):
             images_info += utils.get_remote_images_info(images_names, ctx.obj['registry'],
                                                         ctx.obj.get('username'), ctx.obj.get('password'))
         except Exception as exp:
-            raise click.exceptions.ClickException('Got unknow error from remote registry %(error)s' % dict(error=exp.message))
+            raise click.exceptions.ClickException(f'Got unknown error from remote registry {exp}')
 
     print(tabulate.tabulate(images_info, headers=['REGISTRY', 'IMAGE', 'TAG'], tablefmt='grid'))
 
@@ -240,7 +240,7 @@ def rmi(ctx, remote, image, tag):
         utils.delete_local_image(image, tag)
 
 
-@cli.command(context_settings=dict(ignore_unknown_options=True))
+@cli.command(context_settings={"ignore_unknown_options": True})
 @click.option('-i', '--interactive', help='Interactive mode', is_flag=True, default=False, envvar='SKIPPER_INTERACTIVE')
 @click.option('-n', '--name', help='Container name', default=None)
 @click.option('-e', '--env', multiple=True, help='Environment variables to pass the container')
@@ -276,7 +276,7 @@ def run(ctx, interactive, name, env, publish, cache, command):
                       env_file=ctx.obj.get('env_file'))
 
 
-@cli.command(context_settings=dict(ignore_unknown_options=True))
+@cli.command(context_settings={"ignore_unknown_options": True})
 @click.option('-i', '--interactive', help='Interactive mode', is_flag=True, default=False, envvar='SKIPPER_INTERACTIVE')
 @click.option('-n', '--name', help='Container name', default=None)
 @click.option('-e', '--env', multiple=True, help='Environment variables to pass the container')
@@ -369,11 +369,11 @@ def completion():
 
 
 def _push_to_registry(registry, fqdn_image):
-    utils.logger.debug("Pushing to registry %(registry)s", dict(registry=registry))
+    utils.logger.debug("Pushing to registry %s", registry)
     command = ['push', fqdn_image]
     ret = runner.run(command)
     if ret != 0:
-        utils.logger.error('Failed to push image: %(tag)s', dict(tag=fqdn_image))
+        utils.logger.error('Failed to push image: %s', fqdn_image)
         sys.exit(ret)
 
 
@@ -399,24 +399,23 @@ def runner_run(command):
         tagged_image_name = image + ':' + tag
 
         if utils.local_image_exist(image, tag):
-            utils.logger.info("Using build container: %(image_name)s", dict(image_name=tagged_image_name))
+            utils.logger.info("Using build container: %s", tagged_image_name)
             return tagged_image_name
 
         if utils.remote_image_exist(registry, image, tag, username, password):
             fqdn_image = utils.generate_fqdn_image(registry, None, image, tag)
-            utils.logger.info("Using build container: %(fqdn_image)s", dict(fqdn_image=fqdn_image))
+            utils.logger.info("Using build container: %s", fqdn_image)
             return fqdn_image
 
         if not git_revision:
-            raise click.exceptions.ClickException(
-                "Couldn't find build image %(image)s with tag %(tag)s" % dict(image=image, tag=tag))
+            raise click.exceptions.ClickException(f"Couldn't find build image {image} with tag {tag}")
 
     else:
         tagged_image_name = image
         utils.logger.info("No build container tag was provided")
 
     docker_file = utils.image_to_dockerfile(image)
-    utils.logger.info("Building image using docker file: %(docker_file)s", dict(docker_file=docker_file))
+    utils.logger.info("Building image using docker file: %s", docker_file)
     if container_context is not None:
         build_context = container_context
     else:
@@ -433,10 +432,10 @@ def runner_run(command):
         command.extend(['--cache-from', cache_image])
 
     if runner_run(command) != 0:
-        exit('Failed to build image: %(image)s' % dict(image=image))
+        sys.exit(f'Failed to build image: {image}')
 
     if git_revision and not git.uncommitted_changes():
-        utils.logger.info("Tagging image with git revision: %(tag)s", dict(tag=tag))
+        utils.logger.info("Tagging image with git revision: %s", tag)
         runner_run(['tag', image, tagged_image_name])
 
     if use_cache:
@@ -456,7 +455,7 @@ def _validate_global_params(ctx, *params):
 def _validate_project_image(image):
     project_images = utils.get_images_from_dockerfiles()
     if image not in project_images:
-        raise click.BadParameter("'%s' is not an image of this project, try %s" % (image, project_images), param_hint='image')
+        raise click.BadParameter(f"'{image}' is not an image of this project, try {project_images}", param_hint='image')
 
 
 def _expend_env(ctx, extra_env):
@@ -466,7 +465,7 @@ def _expend_env(ctx, extra_env):
     if isinstance(env, dict):
         for key, value in six.iteritems(env):
             utils.logger.debug("Adding %s=%s to environment", key, value)
-            environment.append("{}={}".format(key, value))
+            environment.append(f"{key}={value}")
     elif isinstance(env, list):
         for item in env:
             if '=' in item:
@@ -476,8 +475,8 @@ def _expend_env(ctx, extra_env):
                 # if the items is just a name of environment variable, try to get it
                 # from the host's environment variables
                 if item in os.environ:
-                    environment.append('{}={}'.format(item, os.environ[item]))
+                    environment.append(f'{item}={os.environ[item]}')
     else:
-        raise TypeError('Type {} not supported for key env, use dict or list instead'.format(type(env)))
+        raise TypeError(f'Type {type(env)} not supported for key env, use dict or list instead')
 
     return environment + list(extra_env)
diff --git a/skipper/git.py b/skipper/git.py
index 448fd49..daa02c6 100644
--- a/skipper/git.py
+++ b/skipper/git.py
@@ -16,7 +16,7 @@ def get_hash(short=False):
     if uncommitted_changes():
         logging.warning("*** Uncommitted changes present - Build container version might be outdated ***")
 
-    return subprocess.check_output(git_command).decode().strip()
+    return subprocess.check_output(git_command).strip()
 
 
 def uncommitted_changes():
diff --git a/skipper/runner.py b/skipper/runner.py
index 5f2e03f..dc86468 100644
--- a/skipper/runner.py
+++ b/skipper/runner.py
@@ -1,3 +1,4 @@
+# pylint: disable=consider-using-with
 import getpass
 import grp
 import logging
@@ -12,7 +13,7 @@
 def get_default_net():
     # The host networking driver only works on Linux hosts, and is not supported on Docker Desktop for Mac,
     # Docker Desktop for Windows, or Docker EE for Windows Server.
-    return 'host' if sys.platform != 'darwin' and sys.platform != 'win32' else 'bridge'
+    return 'host' if sys.platform not in ('darwin', 'win32') else 'bridge'
 
 
 # pylint: disable=too-many-arguments
@@ -78,15 +79,15 @@ def _run_nested(fqdn_image, environment, command, interactive, name, net, publis
 
     user = getpass.getuser()
     user_id = os.getuid()
-    cmd += ['-e', 'SKIPPER_USERNAME=%(user)s' % dict(user=user)]
-    cmd += ['-e', 'SKIPPER_UID=%(user_id)s' % dict(user_id=user_id)]
-    cmd += ['-e', 'HOME=%(homedir)s' % dict(homedir=homedir)]
-    cmd += ['-e', 'CONTAINER_RUNTIME_COMMAND=%(runtime_command)s' % dict(runtime_command=utils.get_runtime_command())]
+    cmd += ['-e', f'SKIPPER_USERNAME={user}']
+    cmd += ['-e', f'SKIPPER_UID={user_id}']
+    cmd += ['-e', f'HOME={homedir}']
+    cmd += ['-e', f'CONTAINER_RUNTIME_COMMAND={utils.get_runtime_command()}']
 
     if utils.get_runtime_command() == "docker":
         try:
             docker_gid = grp.getgrnam('docker').gr_gid
-            cmd += ['-e', 'SKIPPER_DOCKER_GID=%(docker_gid)s' % dict(docker_gid=docker_gid)]
+            cmd += ['-e', f'SKIPPER_DOCKER_GID={docker_gid}']
         except KeyError:
             pass
 
@@ -111,7 +112,7 @@ def handle_workdir(cmd, cwd, workdir):
     if workdir:
         cmd += ['-w', workdir]
     else:
-        cmd += ['-w', '%(workdir)s' % dict(workdir=cwd)]
+        cmd += ['-w', cwd]
     return cmd
 
 
@@ -128,9 +129,9 @@ def handle_networking(cmd, publish, net):
 
 def handle_volumes_bind_mount(docker_cmd, homedir, volumes, workspace):
     volumes = volumes or []
-    volumes.extend(['%(homedir)s/.netrc:%(homedir)s/.netrc:ro' % dict(homedir=homedir),
-                    '%(homedir)s/.gitconfig:%(homedir)s/.gitconfig:ro' % dict(homedir=homedir),
-                    '%(homedir)s/.docker/config.json:%(homedir)s/.docker/config.json:ro' % dict(homedir=homedir)])
+    volumes.extend([f'{homedir}/.netrc:{homedir}/.netrc:ro',
+                    f'{homedir}/.gitconfig:{homedir}/.gitconfig:ro',
+                    f'{homedir}/.docker/config.json:{homedir}/.docker/config.json:ro'])
 
     # required for docker login (certificates)
     if os.path.exists('/etc/docker'):
@@ -138,8 +139,8 @@ def handle_volumes_bind_mount(docker_cmd, homedir, volumes, workspace):
 
     if utils.get_runtime_command() == utils.PODMAN:
         volumes.extend([
-            '%(workspace)s:%(workspace)s:rw' % dict(workspace=workspace),
-            '%s:/opt/skipper/skipper-entrypoint.sh:rw' % utils.get_extra_file("skipper-entrypoint.sh"),
+            f'{workspace}:{workspace}:rw',
+            f'{utils.get_extra_file("skipper-entrypoint.sh")}:/opt/skipper/skipper-entrypoint.sh:rw',
         ])
         if os.path.exists('/var/run/docker.sock'):
             volumes.append('/var/run/docker.sock:/var/run/docker.sock:rw')
@@ -147,9 +148,9 @@ def handle_volumes_bind_mount(docker_cmd, homedir, volumes, workspace):
             volumes.append('/var/lib/osmosis:/var/lib/osmosis:rw')
     else:
         volumes.extend([
-            '%(workspace)s:%(workspace)s:rw' % dict(workspace=workspace),
+            f'{workspace}:{workspace}:rw',
             '/var/run/docker.sock:/var/run/docker.sock:rw',
-            '%s:/opt/skipper/skipper-entrypoint.sh' % utils.get_extra_file("skipper-entrypoint.sh"),
+            f'{utils.get_extra_file("skipper-entrypoint.sh")}:/opt/skipper/skipper-entrypoint.sh',
             ])
         # Will fail on Mac
         if os.path.exists('/var/lib/osmosis'):
@@ -157,7 +158,7 @@ def handle_volumes_bind_mount(docker_cmd, homedir, volumes, workspace):
 
     for volume in volumes:
         if ":" not in volume:
-            raise ValueError("Volume entry is badly-formatted - %s" % volume)
+            raise ValueError(f"Volume entry is badly-formatted - {volume}")
 
         # For OSX, map anything in /var/lib or /etc to /private
         if sys.platform == 'darwin':
@@ -218,17 +219,17 @@ def _network(net):
 
 
 def _create_network(net):
-    logging.debug("Creating network %(net)s", dict(net=net))
+    logging.debug("Creating network %s", net)
     utils.run_container_command(['network', 'create', net])
 
 
 @retry(delay=0.1, tries=10)
 def _destroy_network(net):
-    logging.debug("Deleting network %(net)s", dict(net=net))
+    logging.debug("Deleting network %s", net)
     utils.run_container_command(['network', 'rm', net])
 
 
 def _network_exists(net):
-    cmd = ['network', 'ls', "-f", "NAME=%s" % net]
+    cmd = ['network', 'ls', "-f", f"NAME={net}"]
     result = utils.run_container_command(cmd)
     return net in result
diff --git a/skipper/utils.py b/skipper/utils.py
index f6331f9..7ebc7c6 100644
--- a/skipper/utils.py
+++ b/skipper/utils.py
@@ -4,7 +4,7 @@
 import logging
 import os
 import subprocess
-from distutils.spawn import find_executable
+from shutil import which
 from six.moves import http_client
 import requests
 from requests_bearer import HttpBearerAuth
@@ -58,7 +58,7 @@ def local_image_exist(image, tag):
 
 def remote_image_exist(registry, image, tag, username, password):
     urllib3.disable_warnings()
-    url = IMAGE_TAGS_URL % dict(registry=registry, image=image)
+    url = IMAGE_TAGS_URL % {"registry": registry, "image": image}
     headers = {"Accept": "application/vnd.docker.distribution.manifest.v2+json"}
     response = requests.get(url=url, verify=False, headers=headers, auth=HttpBearerAuth(username, password))
 
@@ -95,7 +95,7 @@ def get_remote_images_info(images, registry, username, password):
 def get_remote_image_info(image, registry, username, password):
     urllib3.disable_warnings()
     image_info = []
-    url = IMAGE_TAGS_URL % dict(registry=registry, image=image)
+    url = IMAGE_TAGS_URL % {"registry": registry, "image": image}
     response = requests.get(url=url, verify=False, auth=HttpBearerAuth(username, password))
     info = response.json()
     if response.ok:
@@ -105,14 +105,14 @@ def get_remote_image_info(image, registry, username, password):
         if info['errors'][0]['code'] in ['NAME_UNKNOWN', 'NOT_FOUND']:
             pass
         else:
-            raise Exception(info)
+            raise RuntimeError(info)
 
     return image_info
 
 
 def get_image_digest(registry, image, tag, username, password):
     urllib3.disable_warnings()
-    url = MANIFEST_URL % dict(registry=registry, image=image, reference=tag)
+    url = MANIFEST_URL % {"registry": registry, "image": image, "reference": tag}
     headers = {"Accept": "application/vnd.docker.distribution.manifest.v2+json"}
     response = requests.get(url=url, headers=headers, verify=False, auth=HttpBearerAuth(username, password))
     return response.headers['Docker-Content-Digest']
@@ -120,10 +120,9 @@ def get_image_digest(registry, image, tag, username, password):
 
 def delete_image_from_registry(registry, image, tag, username, password):
     digest = get_image_digest(registry, image, tag, username, password)
-    url = MANIFEST_URL % dict(registry=registry, image=image, reference=digest)
+    url = MANIFEST_URL % {"registry": registry, "image": image, "reference": digest}
     response = requests.delete(url=url, verify=False, auth=HttpBearerAuth(username, password))
-    if not response.ok:
-        raise Exception(response.content)
+    response.raise_for_status()
 
 
 def delete_local_image(image, tag):
@@ -152,7 +151,7 @@ def dockerfile_to_image(dockerfile):
 
 def is_tool(name):
     """Check whether `name` is on PATH and marked as executable."""
-    return find_executable(name) is not None
+    return which(name) is not None
 
 
 def get_runtime_command():
@@ -163,18 +162,18 @@ def get_runtime_command():
         elif is_tool(PODMAN):
             CONTAINER_RUNTIME_COMMAND = PODMAN
         else:
-            raise Exception("Nor %s nor %s are installed" % (PODMAN, DOCKER))
+            raise RuntimeError(f"Nor {PODMAN} nor {DOCKER} are installed")
     return CONTAINER_RUNTIME_COMMAND
 
 
 def get_extra_file(filename):
-    return pkg_resources.resource_filename("skipper", "data/%s" % filename)
+    return pkg_resources.resource_filename("skipper", f"data/{filename}")
 
 
 def run_container_command(args):
     cmd = [get_runtime_command()]
     cmd.extend(args)
-    return str(subprocess.check_output(cmd).decode().strip())
+    return str(subprocess.check_output(cmd).strip())
 
 
 def create_path_and_add_data(full_path, data, is_file):
@@ -188,7 +187,9 @@ def create_path_and_add_data(full_path, data, is_file):
 
 def set_remote_registry_login_info(registry, ctx_object):
     try:
-        docker_config = json.load(open('/'.join([os.path.expanduser('~'), '.docker/config.json'])))
+        with open('/'.join([os.path.expanduser('~'), '.docker/config.json'])) as docker_file:
+            docker_config = json.load(docker_file)
+
         auth = docker_config.get('auths', {}).get(registry, {}).get('auth')
         if auth:
             username, password = base64.b64decode(auth).decode().split(r':')
diff --git a/tests/test_cli.py b/tests/test_cli.py
index 0abcd00..ce198ab 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -5,6 +5,9 @@
 import click
 import six
 from click import testing
+from shutil import which
+from requests import HTTPError
+
 from skipper import cli
 from skipper import config, utils
 
@@ -295,7 +298,7 @@ def test_build_existing_image_with_context(self, skipper_runner_run_mock):
                                                                             return_value={
                                                                                 'image1': '/home/user/work/project/Dockerfile.image1',
                                                                                 'image2': '/home/user/work/project/Dockerfile.image2'}))
-    @mock.patch('__builtin__.open', mock.MagicMock(create=True))
+    @mock.patch('builtins.open', mock.MagicMock(create=True))
     @mock.patch('os.path.exists', mock.MagicMock(autospec=True, return_value=True))
     @mock.patch('yaml.safe_load', mock.MagicMock(autospec=True, return_value=SKIPPER_CONF_WITH_CONTEXT))
     @mock.patch('skipper.git.get_hash', mock.MagicMock(autospec=True, return_value='1234567'))
@@ -317,7 +320,7 @@ def test_build_with_context_from_config_file(self, skipper_runner_run_mock):
         ]
         skipper_runner_run_mock.assert_called_once_with(expected_command)
 
-    @mock.patch('__builtin__.open', mock.MagicMock(create=True))
+    @mock.patch('builtins.open', mock.MagicMock(create=True))
     @mock.patch('os.path.exists', mock.MagicMock(autospec=True, return_value=True))
     @mock.patch('yaml.safe_load', mock.MagicMock(autospec=True, return_value=SKIPPER_CONF_WITH_CONTEXT_NO_TAG))
     @mock.patch('skipper.git.get_hash', mock.MagicMock(autospec=True, return_value='1234567'))
@@ -461,7 +464,7 @@ def test_build_all_images(self, skipper_runner_run_mock):
                                                                             return_value={
                                                                                 'image1': '/home/user/work/project/Dockerfile.image1',
                                                                                 'image2': '/home/user/work/project/Dockerfile.image2'}))
-    @mock.patch('__builtin__.open', mock.MagicMock(create=True))
+    @mock.patch('builtins.open', mock.MagicMock(create=True))
     @mock.patch('os.path.exists', mock.MagicMock(autospec=True, return_value=True))
     @mock.patch('yaml.safe_load', mock.MagicMock(autospec=True, return_value=SKIPPER_CONF))
     @mock.patch('skipper.git.get_hash', mock.MagicMock(autospec=True, return_value='1234567'))
@@ -482,7 +485,7 @@ def test_build_with_defaults_from_config_file(self, skipper_runner_run_mock):
         ]
         skipper_runner_run_mock.assert_called_once_with(expected_command)
 
-    @mock.patch('__builtin__.open', mock.MagicMock(create=True))
+    @mock.patch('builtins.open', mock.MagicMock(create=True))
     @mock.patch('os.path.abspath',
                 mock.MagicMock(autospec=True, return_value='/home/user/work/project/app1/Dockerfile'))
     @mock.patch('os.path.exists', mock.MagicMock(autospec=True, return_value=True))
@@ -677,7 +680,7 @@ def test_push_to_namespace(self, skipper_runner_run_mock, requests_get_mock):
         ]
         skipper_runner_run_mock.assert_has_calls(expected_commands)
 
-    @mock.patch('__builtin__.open', mock.MagicMock(create=True))
+    @mock.patch('builtins.open', mock.MagicMock(create=True))
     @mock.patch('os.path.exists', mock.MagicMock(autospec=True, return_value=True))
     @mock.patch('yaml.safe_load', mock.MagicMock(autospec=True, return_value=SKIPPER_CONF))
     @mock.patch('skipper.git.get_hash', mock.MagicMock(autospec=True, return_value='1234567'))
@@ -1039,7 +1042,7 @@ def test_rmi_remote(self, requests_get_mock, requests_delete_mock, requests_bear
     @mock.patch('requests.get', autospec=True)
     def test_rmi_remote_fail(self, requests_get_mock, requests_delete_mock, requests_bearer_auth_mock):
         requests_get_mock.side_effect = [mock.Mock(headers={'Docker-Content-Digest': 'digest'})]
-        requests_delete_mock.side_effect = [mock.Mock(ok=False)]
+        requests_delete_mock.side_effect = HTTPError()
         result = self._invoke_cli(
             global_params=self.global_params,
             subcmd='rmi',
@@ -1130,7 +1133,7 @@ def test_run_with_non_existing_build_container(self, requests_get_mock):
         )
         self.assertIsInstance(ret.exception, click.exceptions.ClickException)
 
-    @mock.patch('__builtin__.open', mock.MagicMock(create=True))
+    @mock.patch('builtins.open', mock.MagicMock(create=True))
     @mock.patch('os.path.exists', mock.MagicMock(autospec=True, return_value=True))
     @mock.patch('yaml.safe_load', mock.MagicMock(autospec=True, return_value=SKIPPER_CONF))
     @mock.patch('subprocess.check_output', mock.MagicMock(autospec=True, return_value='1234567\n'))
@@ -1150,7 +1153,7 @@ def test_run_with_defaults_from_config_file(self, skipper_runner_run_mock):
                                                         workdir=None, workspace=None, use_cache=False,
                                                         env_file=())
 
-    @mock.patch('__builtin__.open', mock.MagicMock(create=True))
+    @mock.patch('builtins.open', mock.MagicMock(create=True))
     @mock.patch('os.path.exists', mock.MagicMock(autospec=True, return_value=True))
     @mock.patch('yaml.safe_load', mock.MagicMock(autospec=True, return_value=SKIPPER_CONF_WITH_ENV))
     @mock.patch('subprocess.check_output', mock.MagicMock(autospec=True, return_value='1234567\n'))
@@ -1172,7 +1175,7 @@ def test_run_with_defaults_and_env_from_config_file(self, skipper_runner_run_moc
                                                         workdir=None, workspace=None, use_cache=False,
                                                         env_file=())
 
-    @mock.patch('__builtin__.open', mock.MagicMock(create=True))
+    @mock.patch('builtins.open', mock.MagicMock(create=True))
     @mock.patch('os.path.exists',
                 mock.MagicMock(autospec=True, return_value=True))
     @mock.patch('yaml.safe_load', mock.MagicMock(
@@ -1203,7 +1206,7 @@ def test_run_with_defaults_and_env_from_env_file(
                                                         use_cache=False,
                                                         env_file=(ENV_FILE_PATH,))
 
-    @mock.patch('__builtin__.open', mock.MagicMock(create=True))
+    @mock.patch('builtins.open', mock.MagicMock(create=True))
     @mock.patch('os.path.exists',
                 mock.MagicMock(autospec=True, return_value=True))
     @mock.patch('yaml.safe_load', mock.MagicMock(
@@ -1234,7 +1237,7 @@ def test_run_with_defaults_and_env_from_multiple_env_file(
                                                         use_cache=False,
                                                         env_file=tuple(ENV_FILES))
 
-    @mock.patch('__builtin__.open', mock.MagicMock(create=True))
+    @mock.patch('builtins.open', mock.MagicMock(create=True))
     @mock.patch('os.path.exists', mock.MagicMock(autospec=True, return_value=True))
     @mock.patch('yaml.safe_load', mock.MagicMock(autospec=True, return_value=SKIPPER_CONF_WITH_ENV))
     @mock.patch('subprocess.check_output', mock.MagicMock(autospec=True, return_value='1234567\n'))
@@ -1256,7 +1259,7 @@ def test_run_with_env_overriding_config_file(self, skipper_runner_run_mock):
                                                         workdir=None, workspace=None, use_cache=False,
                                                         env_file=())
 
-    @mock.patch('__builtin__.open', mock.MagicMock(create=True))
+    @mock.patch('builtins.open', mock.MagicMock(create=True))
     @mock.patch('os.path.exists', mock.MagicMock(autospec=True, return_value=True))
     @mock.patch('os.environ', {})
     @mock.patch('yaml.safe_load', mock.MagicMock(autospec=True, return_value=SKIPPER_CONF_WITH_ENV_LIST))
@@ -1279,7 +1282,7 @@ def test_run_with_env_list(self, skipper_runner_run_mock):
                                                         workdir=None, workspace=None, use_cache=False,
                                                         env_file=())
 
-    @mock.patch('__builtin__.open', mock.MagicMock(create=True))
+    @mock.patch('builtins.open', mock.MagicMock(create=True))
     @mock.patch('os.path.exists', mock.MagicMock(autospec=True, return_value=True))
     @mock.patch('os.environ', {'key2': 'value2'})
     @mock.patch('yaml.safe_load', mock.MagicMock(autospec=True, return_value=SKIPPER_CONF_WITH_ENV_LIST))
@@ -1302,7 +1305,7 @@ def test_run_with_env_list_get_from_env(self, skipper_runner_run_mock):
                                                         workdir=None, workspace=None, use_cache=False,
                                                         env_file=())
 
-    @mock.patch('__builtin__.open', mock.MagicMock(create=True))
+    @mock.patch('builtins.open', mock.MagicMock(create=True))
     @mock.patch('os.path.exists', mock.MagicMock(autospec=True, return_value=True))
     @mock.patch('yaml.safe_load', mock.MagicMock(autospec=True, return_value=SKIPPER_CONF_WITH_ENV_WRONG_TYPE))
     @mock.patch('subprocess.check_output', mock.MagicMock(autospec=True, return_value='1234567\n'))
@@ -1582,7 +1585,7 @@ def test_run_with_publish_out_of_range_port(self):
         self.assertEqual("Invalid port number: port 121111111 is out of range", result.exception.message)
         self.assertEqual(-1, result.exit_code)
 
-    @mock.patch('__builtin__.open', mock.MagicMock(create=True))
+    @mock.patch('builtins.open', mock.MagicMock(create=True))
     @mock.patch('os.path.exists', mock.MagicMock(autospec=True, return_value=True))
     @mock.patch('yaml.safe_load', mock.MagicMock(autospec=True, return_value=SKIPPER_CONF_WITH_VOLUMES))
     @mock.patch('subprocess.check_output', mock.MagicMock(autospec=True, return_value='1234567\n'))
@@ -1601,7 +1604,7 @@ def test_run_with_defaults_from_config_file_including_volumes(self, skipper_runn
                                                         volumes=['volume1', 'volume2'], workspace=None,
                                                         workdir=None, use_cache=False, env_file=())
 
-    @mock.patch('__builtin__.open', mock.MagicMock(create=True))
+    @mock.patch('builtins.open', mock.MagicMock(create=True))
     @mock.patch('os.path.exists', mock.MagicMock(autospec=True, return_value=True))
     @mock.patch('yaml.safe_load', mock.MagicMock(autospec=True, return_value=SKIPPER_CONF_WITH_SHELL_INTERPOLATION))
     @mock.patch('subprocess.check_output', mock.MagicMock(autospec=True, return_value='1234567\n'))
@@ -1617,7 +1620,7 @@ def test_run_with_defaults_from_config_file_including_interpolated_volumes(self,
         expected_fqdn_image = 'skipper-conf-build-container-image:skipper-conf-build-container-tag'
         skipper_runner_run_mock.assert_called_once_with(command, fqdn_image=expected_fqdn_image, environment=['KEY=10'],
                                                         interactive=False, name=None, net=None, publish=(),
-                                                        volumes=['/bin/cat:/cat'], workspace=None,
+                                                        volumes=[f'{which("cat")}:/cat'], workspace=None,
                                                         workdir=None, use_cache=False, env_file=())
 
     @mock.patch('yaml.safe_load', mock.MagicMock(autospec=True, return_value=SKIPPER_CONF_WITH_INVALID_SHELL_INTERPOLATION))
@@ -1632,7 +1635,7 @@ def test_run_with_defaults_from_config_file_including_invalid_interploated_volum
                 subcmd_params=run_params
             )
 
-    @mock.patch('__builtin__.open', mock.MagicMock(create=True))
+    @mock.patch('builtins.open', mock.MagicMock(create=True))
     @mock.patch('os.path.exists', mock.MagicMock(autospec=True, return_value=True))
     @mock.patch('yaml.safe_load', mock.MagicMock(autospec=True, return_value=SKIPPER_CONF_WITH_WORKDIR))
     @mock.patch('subprocess.check_output', mock.MagicMock(autospec=True, return_value='1234567\n'))
@@ -1652,7 +1655,7 @@ def test_run_with_defaults_from_config_file_including_workdir(self, skipper_runn
                                                         workdir='test-workdir', workspace=None, use_cache=False,
                                                         env_file=())
 
-    @mock.patch('__builtin__.open', mock.MagicMock(create=True))
+    @mock.patch('builtins.open', mock.MagicMock(create=True))
     @mock.patch('os.path.exists', mock.MagicMock(autospec=True, return_value=True))
     @mock.patch('yaml.safe_load', mock.MagicMock(autospec=True, return_value=SKIPPER_CONF_WITH_WORKSPACE))
     @mock.patch('subprocess.check_output', mock.MagicMock(autospec=True, return_value='1234567\n'))
@@ -1672,7 +1675,7 @@ def test_run_with_defaults_from_config_file_including_workspace(self, skipper_ru
                                                         workdir=None, workspace="/test/workspace", use_cache=False,
                                                         env_file=())
 
-    @mock.patch('__builtin__.open', mock.MagicMock(create=True))
+    @mock.patch('builtins.open', mock.MagicMock(create=True))
     @mock.patch('os.path.exists', mock.MagicMock(autospec=True, return_value=True))
     @mock.patch('yaml.safe_load', mock.MagicMock(autospec=True, return_value=SKIPPER_CONF_WITH_GIT_REV))
     @mock.patch('subprocess.check_output', mock.MagicMock(autospec=True, return_value='1234567\n'))
@@ -1693,7 +1696,7 @@ def test_run_with_config_including_git_revision_with_uncommitted_changes(self, s
                                                         workdir=None, use_cache=False, workspace=None,
                                                         env_file=())
 
-    @mock.patch('__builtin__.open', mock.MagicMock(create=True))
+    @mock.patch('builtins.open', mock.MagicMock(create=True))
     @mock.patch('os.path.exists', mock.MagicMock(autospec=True, return_value=True))
     @mock.patch('yaml.safe_load', mock.MagicMock(autospec=True, return_value=SKIPPER_CONF_WITH_GIT_REV))
     @mock.patch('subprocess.check_output', mock.MagicMock(autospec=True, return_value='1234567\n'))
@@ -1769,7 +1772,7 @@ def test_make_with_additional_make_params(self, skipper_runner_run_mock):
                                                         workdir=None, workspace=None, use_cache=False,
                                                         env_file=())
 
-    @mock.patch('__builtin__.open', mock.MagicMock(create=True))
+    @mock.patch('builtins.open', mock.MagicMock(create=True))
     @mock.patch('os.path.exists', mock.MagicMock(autospec=True, return_value=True))
     @mock.patch('yaml.safe_load', mock.MagicMock(autospec=True, return_value=SKIPPER_CONF))
     @mock.patch('subprocess.check_output', mock.MagicMock(autospec=True, return_value='1234567\n'))
diff --git a/tests/test_utils.py b/tests/test_utils.py
index c5a078c..6c8ed6b 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -8,7 +8,7 @@
 
 class TestUtils(unittest.TestCase):
 
-    @mock.patch('skipper.utils.find_executable', autospec=False)
+    @mock.patch('skipper.utils.which', autospec=False)
     def test_get_runtime_command(self, find_executable_mock):
         utils.CONTAINER_RUNTIME_COMMAND = None
         find_executable_mock.side_effect = "done"