private static async Task RestorePythonRequirementsDocker()

in src/Cli/func/Helpers/PythonHelpers.cs [488:546]
49 lines of code
8 McCabe index (conditional complexity)

        private static async Task RestorePythonRequirementsDocker(string functionAppRoot, string packagesLocation, string additionalPackages)
        {
            // Configurable settings
            var pythonDockerImageSetting = Environment.GetEnvironmentVariable(Constants.PythonDockerImageVersionSetting);
            var dockerSkipPullFlagSetting = Environment.GetEnvironmentVariable(Constants.PythonDockerImageSkipPull);
            var dockerRunSetting = Environment.GetEnvironmentVariable(Constants.PythonDockerRunCommand);

            string dockerImage = pythonDockerImageSetting;
            if (string.IsNullOrEmpty(dockerImage))
            {
                dockerImage = await ChoosePythonBuildEnvImage();
            }

            if (string.IsNullOrEmpty(dockerSkipPullFlagSetting) ||
                !(dockerSkipPullFlagSetting.Equals("true", StringComparison.OrdinalIgnoreCase) || dockerSkipPullFlagSetting == "1"))
            {
                await DockerHelpers.DockerPull(dockerImage);
            }

            var containerId = string.Empty;
            try
            {
                if (string.IsNullOrEmpty(dockerRunSetting))
                {
                    containerId = await DockerHelpers.DockerRun(dockerImage, command: "sleep infinity");
                }
                else
                {
                    (var output, _, _) = await DockerHelpers.RunDockerCommand(dockerRunSetting);
                    containerId = output.ToString().Trim();
                }

                await DockerHelpers.CopyToContainer(containerId, Constants.RequirementsTxt, $"/{Constants.RequirementsTxt}");

                var scriptFilePath = Path.GetTempFileName();
                await FileSystemHelpers.WriteAllTextToFileAsync(scriptFilePath, (await StaticResources.PythonDockerBuildScript).Replace("\r\n", "\n"));

                if (!string.IsNullOrWhiteSpace(additionalPackages))
                {
                    // Give the container time to start up
                    await Task.Delay(TimeSpan.FromSeconds(3));
                    await DockerHelpers.ExecInContainer(containerId, $"apt-get update");
                    await DockerHelpers.ExecInContainer(containerId, $"apt-get install -y {additionalPackages}");
                }

                await DockerHelpers.CopyToContainer(containerId, scriptFilePath, Constants.StaticResourcesNames.PythonDockerBuild);
                await DockerHelpers.ExecInContainer(containerId, $"chmod +x /{Constants.StaticResourcesNames.PythonDockerBuild}");
                await DockerHelpers.ExecInContainer(containerId, $"/{Constants.StaticResourcesNames.PythonDockerBuild}");

                await DockerHelpers.CopyFromContainer(containerId, $"/{Constants.ExternalPythonPackages}/.", packagesLocation);
            }
            finally
            {
                if (!string.IsNullOrEmpty(containerId))
                {
                    await DockerHelpers.KillContainer(containerId, ignoreError: true);
                }
            }
        }