List commands used to build a docker image
Often its useful to know what commands were used to build a docker image. docker history is a handy tool for this purpose.
Here is an example that list history of a python image:
$ docker history python
IMAGE CREATED CREATED BY SIZE COMMENT
ad01f54ca3a9 11 months ago /bin/sh -c #(nop) CMD ["python3"] 0B
<missing> 11 months ago /bin/sh -c set -ex; wget -O get-pip.py 'ht… 5.93MB
<missing> 11 months ago /bin/sh -c #(nop) ENV PYTHON_PIP_VERSION=18… 0B
<missing> 11 months ago /bin/sh -c cd /usr/local/bin && ln -s idle3… 32B
<missing> 11 months ago /bin/sh -c set -ex && wget -O python.tar.x… 70.3MB
<missing> 11 months ago /bin/sh -c #(nop) ENV PYTHON_VERSION=3.7.2 0B
<missing> 12 months ago /bin/sh -c #(nop) ENV GPG_KEY=0D96DF4D4110E… 0B
<missing> 12 months ago /bin/sh -c apt-get update && apt-get install… 17MB
<missing> 12 months ago /bin/sh -c #(nop) ENV LANG=C.UTF-8 0B
<missing> 12 months ago /bin/sh -c #(nop) ENV PATH=/usr/local/bin:/… 0B
<missing> 12 months ago /bin/sh -c set -ex; apt-get update; apt-ge… 556MB
<missing> 12 months ago /bin/sh -c apt-get update && apt-get install… 142MB
<missing> 12 months ago /bin/sh -c set -ex; if ! command -v gpg > /… 7.81MB
<missing> 12 months ago /bin/sh -c apt-get update && apt-get install… 23.2MB
<missing> 12 months ago /bin/sh -c #(nop) CMD ["bash"] 0B
<missing> 12 months ago /bin/sh -c #(nop) ADD file:a61c14b18252183a4… 101MB
Note that the history is listed in reversed chronological order and some of the columns are truncated.
Futher --format flag can be used for fine tuning the outputs.
Here is the history of the same python image in chronologocal order without truncation.
Note tac command at the end.
$ docker history --no-trunc --format "{{.CreatedAt}} [{{.Size}}]: {{.CreatedBy}}" python | tac
2018-11-15T17:44:00-05:00 [101MB]: /bin/sh -c #(nop) ADD file:a61c14b18252183a4719980da97ac483044bcaa9df8a569a6d7bf0f719384b5e in /
2018-11-15T17:44:09-05:00 [0B]: /bin/sh -c #(nop) CMD ["bash"]
2018-11-16T06:15:57-05:00 [23.2MB]: /bin/sh -c apt-get update && apt-get install -y --no-install-recommends ca-certificates curl netbase wget && rm -rf /var/lib/apt/lists/*
2018-11-16T06:16:02-05:00 [7.81MB]: /bin/sh -c set -ex; if ! command -v gpg > /dev/null; then apt-get update; apt-get install -y --no-install-recommends gnupg dirmngr ; rm -rf /var/lib/apt/lists/*; fi
2018-11-16T06:17:06-05:00 [142MB]: /bin/sh -c apt-get update && apt-get install -y --no-install-recommends bzr git mercurial openssh-client subversion procps && rm -rf /var/lib/apt/lists/*
2018-11-16T06:19:28-05:00 [556MB]: /bin/sh -c set -ex; apt-get update; apt-get install -y --no-install-recommends autoconf automake bzip2 dpkg-dev file g++ gcc imagemagick libbz2-dev libc6-dev libcurl4-openssl-dev libdb-dev libevent-dev libffi-dev libgdbm-dev libgeoip-dev libglib2.0-dev libjpeg-dev libkrb5-dev liblzma-dev libmagickcore-dev libmagickwand-dev libncurses5-dev libncursesw5-dev libpng-dev libpq-dev libreadline-dev libsqlite3-dev libssl-dev libtool libwebp-dev libxml2-dev libxslt-dev libyaml-dev make patch xz-utils zlib1g-dev $( if apt-cache show 'default-libmysqlclient-dev' 2>/dev/null | grep -q '^Version:'; then echo 'default-libmysqlclient-dev'; else echo 'libmysqlclient-dev'; fi ) ; rm -rf /var/lib/apt/lists/*
2018-11-16T17:23:02-05:00 [0B]: /bin/sh -c #(nop) ENV PATH=/usr/local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
2018-11-16T17:23:03-05:00 [0B]: /bin/sh -c #(nop) ENV LANG=C.UTF-8
2018-11-16T17:23:18-05:00 [17MB]: /bin/sh -c apt-get update && apt-get install -y --no-install-recommends tk-dev uuid-dev && rm -rf /var/lib/apt/lists/*
2018-11-16T17:23:18-05:00 [0B]: /bin/sh -c #(nop) ENV GPG_KEY=0D96DF4D4110E5C43FBFB17F2D347EA6AA65421D
2018-12-26T03:42:00-05:00 [0B]: /bin/sh -c #(nop) ENV PYTHON_VERSION=3.7.2
2018-12-26T03:44:29-05:00 [70.3MB]: /bin/sh -c set -ex && wget -O python.tar.xz "https://www.python.org/ftp/python/${PYTHON_VERSION%%[a-z]*}/Python-$PYTHON_VERSION.tar.xz" && wget -O python.tar.xz.asc "https://www.python.org/ftp/python/${PYTHON_VERSION%%[a-z]*}/Python-$PYTHON_VERSION.tar.xz.asc" && export GNUPGHOME="$(mktemp -d)" && gpg --batch --keyserver ha.pool.sks-keyservers.net --recv-keys "$GPG_KEY" && gpg --batch --verify python.tar.xz.asc python.tar.xz && { command -v gpgconf > /dev/null && gpgconf --kill all || :; } && rm -rf "$GNUPGHOME" python.tar.xz.asc && mkdir -p /usr/src/python && tar -xJC /usr/src/python --strip-components=1 -f python.tar.xz && rm python.tar.xz && cd /usr/src/python && gnuArch="$(dpkg-architecture --query DEB_BUILD_GNU_TYPE)" && ./configure --build="$gnuArch" --enable-loadable-sqlite-extensions --enable-shared --with-system-expat --with-system-ffi --without-ensurepip && make -j "$(nproc)" && make install && ldconfig && find /usr/local -depth \( \( -type d -a \( -name test -o -name tests \) \) -o \( -type f -a \( -name '*.pyc' -o -name '*.pyo' \) \) \) -exec rm -rf '{}' + && rm -rf /usr/src/python && python3 --version
2018-12-26T03:44:30-05:00 [32B]: /bin/sh -c cd /usr/local/bin && ln -s idle3 idle && ln -s pydoc3 pydoc && ln -s python3 python && ln -s python3-config python-config
2018-12-26T03:44:30-05:00 [0B]: /bin/sh -c #(nop) ENV PYTHON_PIP_VERSION=18.1
2018-12-26T03:44:36-05:00 [5.93MB]: /bin/sh -c set -ex; wget -O get-pip.py 'https://bootstrap.pypa.io/get-pip.py'; python get-pip.py --disable-pip-version-check --no-cache-dir "pip==$PYTHON_PIP_VERSION" ; pip --version; find /usr/local -depth \( \( -type d -a \( -name test -o -name tests \) \) -o \( -type f -a \( -name '*.pyc' -o -name '*.pyo' \) \) \) -exec rm -rf '{}' +; rm -f get-pip.py
2018-12-26T03:44:36-05:00 [0B]: /bin/sh -c #(nop) CMD ["python3"]