如何从 Docker 容器访问 CSV 输出?

问题描述

Python 程序生成 CSV 输出。目前,能够在主机上运行 test.py 并生成 sample_output.csv。

然而,当通过 Docker Containers 实现程序时,在定位 sample_output.csv 文件时遇到了困难。下面是 Dockerfile 和 requirements.txt 文件

numpy==1.19.4
pandas==1.2.0
python-dateutil==2.8.1
pytz==2020.5
scipy==1.5.4
six==1.15.0     // -> requirements.txt



FROM python:3

workdir /demo

copY requirements.txt ./

RUN pip install --no-cache-dir -r requirements.txt

copY . .

CMD ["python","-u","./test.py"]   // -> Dockerfile

Docker Image 可以通过运行 Docker build -t imagename 生成。但是,在运行 docker run imagename 时,并没有生成 csv 文件

希望在基于 docker 镜像运行 Docker 容器后寻找 sample_output.csv 文件的帮助。

//test.py

import pandas as pd
import numpy as np
import os 
from scipy.stats import uniform,exponweib
from scipy.special import gamma
from scipy.optimize import curve_fit


N_SUBSYS = 30
STEPS = 100
LIMIT = 101*STEPS
times = np.arange(0,LIMIT,STEPS)

if not os.path.exists('./output'):
    os.mkdir('./output')

    print("Directory")

class WeibullFailure():
    def __init__(self):
        N_TRAINS = 92
        LOWER_BETA = 0.9
        RANGE_BETA = 0.3
        LOWER_LOGSCALE = 4
        RANGE_LOGSCALE = 1.5
        LOWER_SIZE = 4
        RANGE_SIZE = 8
        gensize = N_TRAINS * int(uniform.rvs(LOWER_SIZE,RANGE_SIZE))
        genbeta = uniform.rvs(LOWER_BETA,RANGE_BETA)
        genscale = np.power(10,uniform.rvs(LOWER_LOGSCALE,RANGE_LOGSCALE))
        self.beta = genbeta
        self.eta = genscale
        self.size = gensize

    def generate_failures(self):
        return exponweib.rvs(
            a=1,loc=0,c=self.beta,scale=self.eta,size=self.size
        )

    def __repr__(self):
        string = f"Subsystem ~ ({self.size} Instances)"
        string += f" Weibull({self.eta:.2f},{self.beta:.4f})"
        return string


def get_cumulative_failures(failure_times,times):
    cumulative_failures = {
        i: np.histogram(ft,times)[0].cumsum()
        for i,ft in failure_times.items()
    }
    cumulative_failures = pd.DataFrame(cumulative_failures,index=times[1:])
    return cumulative_failures


def fit_failures(cumulative_failures,subsystems):
    fitted = {}
    for i,x in cumulative_failures.items():
        size = subsystems[i].size
        popt,_ = curve_fit(
            lambda x,a,b: np.exp(a)*np.power(x,b),x.index,x.values
        )
        fitted[i] = (np.exp(-popt[0]/popt[1])*size,popt[1])
    return fitted


def kl_divergence(p1,p2):
    em_constant = 0.57721  # Euler-Mascheroni constant
    eta1,beta1 = p1
    eta2,beta2 = p2
    e11 = np.log(beta1/np.power(eta1,beta1))
    e12 = np.log(beta2/np.power(eta2,beta2))
    e2 = (beta1 - beta2)*(np.log(eta1) - em_constant/beta1)
    e3 = np.power(eta1/eta2,beta2)*gamma(beta2/beta1 + 1) - 1
    divergence = e11 - e12 + e2 + e3
    return divergence


subsystems = {i: WeibullFailure() for i in range(N_SUBSYS)}
failure_times = {i: s.generate_failures() for i,s in subsystems.items()}

cumulative_failures = get_cumulative_failures(failure_times,times)
fitted = fit_failures(cumulative_failures,subsystems)
divergences = {
    i: kl_divergence(f,[subsystems[i].eta,subsystems[i].beta])
    for i,f in fitted.items()
}

expected_failures = {i: np.power(times[1:]/s.eta,s.beta)*s.size
                     for i,s in subsystems.items()}
expected_failures = pd.DataFrame(expected_failures,index=times[1:])

modeled_failures = {i: np.power(times[1:]/f[0],f[1])*subsystems[i].size
                    for i,f in fitted.items()}
modeled_failures = pd.DataFrame(modeled_failures,index=times[1:])

cols = ['eta','fit_eta','beta','fit_beta','kl_divergence','n_instance']
out = pd.concat([
    pd.DataFrame({i: [s.size,s.eta,s.beta] for i,s in subsystems.items()},index=['n_instance','eta','beta']).T,pd.DataFrame(fitted,index=['fit_eta','fit_beta']).T,pd.Series(divergences,name='kl_divergence')
],axis=1)[cols]
out.to_csv('./output/sample_output.csv')

if not os.path.exists('./output/sample_output.csv'):
    print("Hello")

解决方法

我建议您将输出重定向到控制台而不是像这样的文件:

from io import StringIO
output = StringIO()
out.to_csv(output)
print(output.getvalue())

而不是你的容器

docker run <container> > output.csv
,

Docker 容器根据定义与主机隔离。当你在容器中运行某些东西时,它会留在容器中。

您可以将主机目录挂载到您认为脚本输出应该出现的容器中。您可以使用 -v(音量)选项执行此操作:

docker run -v /host/path:/container/path ...

可以指定多个卷:

docker run -v /host/path:/container/path -v /another/host/path:/another/container/path ...

之后,包含所有内容的主机目录将出现在容器中,就像它在主机上一样,如果您的程序要在其中添加或替换某些内容,您将看到它。

UPD:查看您的输出文件应该在 test.py 中的 /demo/output,以便您可以在那里挂载一些主机目录,例如,您的当前目录:docker run -v $(pwd):/demo/output ...