Use latest Pip version when building image.

The initial problem with the new PIP resolved in 20.3 version have
been successfully solved. Seems that version 21.* is much more
stable and actually works in all cases, so we are switching back
to it.

Also changed pip and wheel dependencies to ~= (compatible) version
hoping that the experience of backwards incomptible release in
major version update have been adopted by the PIP team with
21* series release.

Closes #12838

Author: potiuk

CONTRIBUTING.rst

@@ -553,17 +553,9 @@ Airflow dependencies
 
 .. note::
 
-   On November 2020, new version of PIP (20.3) has been released with a new, 2020 resolver. This resolver
-   might work with Apache Airflow as of 20.3.3, but it might lead to errors in installation. It might
-   depend on your choice of extras. In order to install Airflow you might need to either downgrade
-   pip to version 20.2.4 ``pip install --upgrade pip==20.2.4`` or, in case you use Pip 20.3,
-   you need to add option ``--use-deprecated legacy-resolver`` to your pip install command.
+   The official way of installing Airflow is with the ``pip`` tool.
 
-   While ``pip 20.3.3`` solved most of the ``teething`` problems of 20.3, this note will remain here until we
-   set ``pip 20.3`` as official version in our CI pipeline where we are testing the installation as well.
-   Due to those constraints, only ``pip`` installation is currently officially supported.
-
-   While they are some successes with using other tools like `poetry <https://python-poetry.org/>`_ or
+   While there are some successes with using other tools like `poetry <https://python-poetry.org/>`_ or
    `pip-tools <https://pypi.org/project/pip-tools/>`_, they do not share the same workflow as
    ``pip`` - especially when it comes to constraint vs. requirements management.
    Installing via ``Poetry`` or ``pip-tools`` is not currently supported.
@@ -788,17 +780,9 @@ Pinned constraint files
 
 .. note::
 
-   On November 2020, new version of PIP (20.3) has been released with a new, 2020 resolver. This resolver
-   might work with Apache Airflow as of 20.3.3, but it might lead to errors in installation. It might
-   depend on your choice of extras. In order to install Airflow you might need to either downgrade
-   pip to version 20.2.4 ``pip install --upgrade pip==20.2.4`` or, in case you use Pip 20.3,
-   you need to add option ``--use-deprecated legacy-resolver`` to your pip install command.
-
-   While ``pip 20.3.3`` solved most of the ``teething`` problems of 20.3, this note will remain here until we
-   set ``pip 20.3`` as official version in our CI pipeline where we are testing the installation as well.
-   Due to those constraints, only ``pip`` installation is currently officially supported.
+   The official way of installing Airflow is with the ``pip`` tool.
 
-   While they are some successes with using other tools like `poetry <https://python-poetry.org/>`_ or
+   While there are some successes with using other tools like `poetry <https://python-poetry.org/>`_ or
    `pip-tools <https://pypi.org/project/pip-tools/>`_, they do not share the same workflow as
    ``pip`` - especially when it comes to constraint vs. requirements management.
    Installing via ``Poetry`` or ``pip-tools`` is not currently supported.

CONTRIBUTORS_QUICK_START.rst

@@ -167,17 +167,9 @@ Setup Airflow with Breeze and PyCharm
 
 .. note::
 
-   On November 2020, new version of PIP (20.3) has been released with a new, 2020 resolver. This resolver
-   might work with Apache Airflow as of 20.3.3, but it might lead to errors in installation. It might
-   depend on your choice of extras. In order to install Airflow you might need to either downgrade
-   pip to version 20.2.4 ``pip install --upgrade pip==20.2.4`` or, in case you use Pip 20.3,
-   you need to add option ``--use-deprecated legacy-resolver`` to your pip install command.
+   The official way of installing Airflow is with the ``pip`` tool.
 
-   While ``pip 20.3.3`` solved most of the ``teething`` problems of 20.3, this note will remain here until we
-   set ``pip 20.3`` as official version in our CI pipeline where we are testing the installation as well.
-   Due to those constraints, only ``pip`` installation is currently officially supported.
-
-   While they are some successes with using other tools like `poetry <https://python-poetry.org/>`_ or
+   While there are some successes with using other tools like `poetry <https://python-poetry.org/>`_ or
    `pip-tools <https://pypi.org/project/pip-tools/>`_, they do not share the same workflow as
    ``pip`` - especially when it comes to constraint vs. requirements management.
    Installing via ``Poetry`` or ``pip-tools`` is not currently supported.

Dockerfile

@@ -46,7 +46,7 @@ ARG CASS_DRIVER_BUILD_CONCURRENCY="8"
 
 ARG PYTHON_BASE_IMAGE="python:3.6-slim-buster"
 
-ARG AIRFLOW_PIP_VERSION=20.2.4
+ARG AIRFLOW_PIP_VERSION=21.0.1
 
 # By default PIP has progress bar but you can disable it.
 ARG PIP_PROGRESS_BAR="on"

Dockerfile.ci

@@ -266,7 +266,7 @@ ENV INSTALL_FROM_DOCKER_CONTEXT_FILES=${INSTALL_FROM_DOCKER_CONTEXT_FILES}
 ARG INSTALL_FROM_PYPI="true"
 ENV INSTALL_FROM_PYPI=${INSTALL_FROM_PYPI}
 
-ARG AIRFLOW_PIP_VERSION=20.2.4
+ARG AIRFLOW_PIP_VERSION=21.0.1
 ENV AIRFLOW_PIP_VERSION=${AIRFLOW_PIP_VERSION}
 
 # In the CI image we always:

IMAGES.rst

@@ -122,17 +122,9 @@ parameter to Breeze:
 
 .. note::
 
-   On November 2020, new version of PIP (20.3) has been released with a new, 2020 resolver. This resolver
-   might work with Apache Airflow as of 20.3.3, but it might lead to errors in installation. It might
-   depend on your choice of extras. In order to install Airflow you might need to either downgrade
-   pip to version 20.2.4 ``pip install --upgrade pip==20.2.4`` or, in case you use Pip 20.3,
-   you need to add option ``--use-deprecated legacy-resolver`` to your pip install command.
+   The official way of installing Airflow is with the ``pip`` tool.
 
-   While ``pip 20.3.3`` solved most of the ``teething`` problems of 20.3, this note will remain here until we
-   set ``pip 20.3`` as official version in our CI pipeline where we are testing the installation as well.
-   Due to those constraints, only ``pip`` installation is currently officially supported.
-
-   While they are some successes with using other tools like `poetry <https://python-poetry.org/>`_ or
+   While there are some successes with using other tools like `poetry <https://python-poetry.org/>`_ or
    `pip-tools <https://pypi.org/project/pip-tools/>`_, they do not share the same workflow as
    ``pip`` - especially when it comes to constraint vs. requirements management.
    Installing via ``Poetry`` or ``pip-tools`` is not currently supported.
@@ -673,7 +665,7 @@ The following build arguments (``--build-arg`` in docker build command) can be u
 | ``ADDITIONAL_RUNTIME_APT_ENV``           |                                          | Additional env variables defined         |
 |                                          |                                          | when installing runtime deps             |
 +------------------------------------------+------------------------------------------+------------------------------------------+
-| ``AIRFLOW_PIP_VERSION``                  | ``20.2.4``                               | PIP version used.                        |
+| ``AIRFLOW_PIP_VERSION``                  | ``21.0.1``                               | PIP version used.                        |
 +------------------------------------------+------------------------------------------+------------------------------------------+
 | ``PIP_PROGRESS_BAR``                     | ``on``                                   | Progress bar for PIP installation        |
 +------------------------------------------+------------------------------------------+------------------------------------------+

INSTALL

@@ -28,14 +28,6 @@ java -jar apache-rat.jar -E ./.rat-excludes -d .
 python3 -m venv PATH_TO_YOUR_VENV
 source PATH_TO_YOUR_VENV/bin/activate
 
-NOTE!!
-
-On November 2020, new version of PIP (20.3) has been released with a new, 2020 resolver. This resolver
-does not yet work with Apache Airflow and might lead to errors in installation - depends on your choice
-of extras. In order to install Airflow you need to either downgrade pip to version 20.2.4
-``pip install --upgrade pip==20.2.4`` or, in case you use Pip 20.3, you need to add option
-``--use-deprecated legacy-resolver`` to your pip install command.
-
 # [required] building and installing by pip (preferred)
 pip install .
 

LOCAL_VIRTUALENV.rst

@@ -63,17 +63,9 @@ Extra Packages
 
 .. note::
 
-   On November 2020, new version of PIP (20.3) has been released with a new, 2020 resolver. This resolver
-   might work with Apache Airflow as of 20.3.3, but it might lead to errors in installation. It might
-   depend on your choice of extras. In order to install Airflow you might need to either downgrade
-   pip to version 20.2.4 ``pip install --upgrade pip==20.2.4`` or, in case you use Pip 20.3,
-   you need to add option ``--use-deprecated legacy-resolver`` to your pip install command.
+   The official way of installing Airflow is with the ``pip`` tool.
 
-   While ``pip 20.3.3`` solved most of the ``teething`` problems of 20.3, this note will remain here until we
-   set ``pip 20.3`` as official version in our CI pipeline where we are testing the installation as well.
-   Due to those constraints, only ``pip`` installation is currently officially supported.
-
-   While they are some successes with using other tools like `poetry <https://python-poetry.org/>`_ or
+   While there are some successes with using other tools like `poetry <https://python-poetry.org/>`_ or
    `pip-tools <https://pypi.org/project/pip-tools/>`_, they do not share the same workflow as
    ``pip`` - especially when it comes to constraint vs. requirements management.
    Installing via ``Poetry`` or ``pip-tools`` is not currently supported.
@@ -137,17 +129,9 @@ To create and initialize the local virtualenv:
 
 .. note::
 
-   On November 2020, new version of PIP (20.3) has been released with a new, 2020 resolver. This resolver
-   might work with Apache Airflow as of 20.3.3, but it might lead to errors in installation. It might
-   depend on your choice of extras. In order to install Airflow you might need to either downgrade
-   pip to version 20.2.4 ``pip install --upgrade pip==20.2.4`` or, in case you use Pip 20.3,
-   you need to add option ``--use-deprecated legacy-resolver`` to your pip install command.
-
-   While ``pip 20.3.3`` solved most of the ``teething`` problems of 20.3, this note will remain here until we
-   set ``pip 20.3`` as official version in our CI pipeline where we are testing the installation as well.
-   Due to those constraints, only ``pip`` installation is currently officially supported.
+   The official way of installing Airflow is with the ``pip`` tool.
 
-   While they are some successes with using other tools like `poetry <https://python-poetry.org/>`_ or
+   While there are some successes with using other tools like `poetry <https://python-poetry.org/>`_ or
    `pip-tools <https://pypi.org/project/pip-tools/>`_, they do not share the same workflow as
    ``pip`` - especially when it comes to constraint vs. requirements management.
    Installing via ``Poetry`` or ``pip-tools`` is not currently supported.

README.md

@@ -147,18 +147,9 @@ correct Airflow tag/version/branch and Python versions in the URL.
 
 1. Installing just Airflow:
 
-NOTE!!!
-
-On November 2020, new version of PIP (20.3) has been released with a new, 2020 resolver. This resolver
-might work with Apache Airflow as of 20.3.3, but it might lead to errors in installation. It might
-depend on your choice of extras. In order to install Airflow reliably, you might need to either downgrade
-pip to version 20.2.4 `pip install --upgrade pip==20.2.4` or, in case you use Pip 20.3,
-you might need to add option] `--use-deprecated legacy-resolver` to your pip install command.
-While `pip 20.3.3` solved most of the `teething` problems of 20.3, this note will remain here until we
-set `pip 20.3` as official version in our CI pipeline where we are testing the installation as well.
-Due to those constraints, only `pip` installation is currently officially supported.
-
-While they are some successes with using other tools like [poetry](https://python-poetry.org) or
+The official way of installing Airflow is with the `pip` tool.
+
+While there are some successes with using other tools like [poetry](https://python-poetry.org) or
 [pip-tools](https://pypi.org/project/pip-tools), they do not share the same workflow as
 `pip` - especially when it comes to constraint vs. requirements management.
 Installing via `Poetry` or `pip-tools` is not currently supported.

UPDATING.md

@@ -1762,15 +1762,6 @@ If you want to install integration for Microsoft Azure, then instead of `pip ins
 you should use `pip install apache-airflow[apache.atlas]`.
 
 
-NOTE!
-
-On November 2020, new version of PIP (20.3) has been released with a new, 2020 resolver. This resolver
-does not yet work with Apache Airflow and might lead to errors in installation - depends on your choice
-of extras. In order to install Airflow you need to either downgrade pip to version 20.2.4
-`pip install --upgrade pip==20.2.4` or, in case you use Pip 20.3, you need to add option
-`--use-deprecated legacy-resolver` to your pip install command.
-
-
 If you want to install integration for Microsoft Azure, then instead of
 
 ```

airflow/providers/apache/beam/README.md

@@ -41,14 +41,6 @@ are in `airflow.providers.apache.beam` python package.
 
 ## Installation
 
-NOTE!
-
-On November 2020, new version of PIP (20.3) has been released with a new, 2020 resolver. This resolver
-does not yet work with Apache Airflow and might lead to errors in installation - depends on your choice
-of extras. In order to install Airflow you need to either downgrade pip to version 20.2.4
-`pip install --upgrade pip==20.2.4` or, in case you use Pip 20.3, you need to add option
-`--use-deprecated legacy-resolver` to your pip install command.
-
 You can install this package on top of an existing airflow 2.* installation via
 `pip install apache-airflow-providers-apache-beam`
 

dev/provider_packages/PROVIDER_INDEX_TEMPLATE.rst.jinja2

@@ -47,15 +47,6 @@ are in ``{{FULL_PACKAGE_NAME}}`` python package.
 Installation
 ------------
 
-.. note::
-
-    On November 2020, new version of PIP (20.3) has been released with a new, 2020 resolver. This resolver
-    does not yet work with Apache Airflow and might lead to errors in installation - depends on your choice
-    of extras. In order to install Airflow you need to either downgrade pip to version 20.2.4
-    ``pip install --upgrade pip==20.2.4`` or, in case you use Pip 20.3, you need to add option
-    ``--use-deprecated legacy-resolver`` to your pip install command.
-
-
 You can install this package on top of an existing airflow 2.* installation via
 ``pip install {{PACKAGE_PIP_NAME}}``
 {%- if PIP_REQUIREMENTS %}

dev/provider_packages/PROVIDER_README_TEMPLATE.rst.jinja2

@@ -44,14 +44,6 @@ in the `documentation <https://airflow.apache.org/docs/{{ PACKAGE_PIP_NAME }}/{{
 Installation
 ============
 
-NOTE!
-
-On November 2020, new version of PIP (20.3) has been released with a new, 2020 resolver. This resolver
-does not yet work with Apache Airflow and might lead to errors in installation - depends on your choice
-of extras. In order to install Airflow you need to either downgrade pip to version 20.2.4
-``pip install --upgrade pip==20.2.4`` or, in case you use Pip 20.3, you need to add option
-``--use-deprecated legacy-resolver`` to your pip install command.
-
 You can install this package on top of an existing airflow 2.* installation via
 ``pip install {{PACKAGE_PIP_NAME}}``
 

docs/apache-airflow-providers-airbyte/index.rst

@@ -64,15 +64,6 @@ are in ``airflow.providers.airbyte`` python package.
 Installation
 ------------
 
-.. note::
-
-    On November 2020, new version of PIP (20.3) has been released with a new, 2020 resolver. This resolver
-    does not yet work with Apache Airflow and might lead to errors in installation - depends on your choice
-    of extras. In order to install Airflow you need to either downgrade pip to version 20.2.4
-    ``pip install --upgrade pip==20.2.4`` or, in case you use Pip 20.3, you need to add option
-    ``--use-deprecated legacy-resolver`` to your pip install command.
-
-
 You can install this package on top of an existing airflow 2.* installation via
 ``pip install apache-airflow-providers-airbyte``
 
@@ -147,15 +138,6 @@ are in ``airflow.providers.airbyte`` python package.
 Installation
 ------------
 
-.. note::
-
-    On November 2020, new version of PIP (20.3) has been released with a new, 2020 resolver. This resolver
-    does not yet work with Apache Airflow and might lead to errors in installation - depends on your choice
-    of extras. In order to install Airflow you need to either downgrade pip to version 20.2.4
-    ``pip install --upgrade pip==20.2.4`` or, in case you use Pip 20.3, you need to add option
-    ``--use-deprecated legacy-resolver`` to your pip install command.
-
-
 You can install this package on top of an existing airflow 2.* installation via
 ``pip install apache-airflow-providers-airbyte``
 

docs/apache-airflow-providers-amazon/index.rst

@@ -70,15 +70,6 @@ are in ``airflow.providers.amazon`` python package.
 Installation
 ------------
 
-.. note::
-
-    On November 2020, new version of PIP (20.3) has been released with a new, 2020 resolver. This resolver
-    does not yet work with Apache Airflow and might lead to errors in installation - depends on your choice
-    of extras. In order to install Airflow you need to either downgrade pip to version 20.2.4
-    ``pip install --upgrade pip==20.2.4`` or, in case you use Pip 20.3, you need to add option
-    ``--use-deprecated legacy-resolver`` to your pip install command.
-
-
 You can install this package on top of an existing airflow 2.* installation via
 ``pip install apache-airflow-providers-amazon``
 

docs/apache-airflow-providers-apache-beam/index.rst

@@ -62,14 +62,6 @@ are in ``airflow.providers.apache.beam`` python package.
 Installation
 ------------
 
-.. note::
-
-    On November 2020, new version of PIP (20.3) has been released with a new, 2020 resolver. This resolver
-    does not yet work with Apache Airflow and might lead to errors in installation - depends on your choice
-    of extras. In order to install Airflow you need to either downgrade pip to version 20.2.4
-    ``pip install --upgrade pip==20.2.4`` or, in case you use Pip 20.3, you need to add option
-    ``--use-deprecated legacy-resolver`` to your pip install command.
-
 
 You can install this package on top of an existing airflow 2.* installation via
 ``pip install apache-airflow-providers-apache-beam``

docs/apache-airflow-providers-apache-cassandra/index.rst

@@ -68,14 +68,6 @@ are in ``airflow.providers.apache.cassandra`` python package.
 Installation
 ------------
 
-.. note::
-
-    On November 2020, new version of PIP (20.3) has been released with a new, 2020 resolver. This resolver
-    does not yet work with Apache Airflow and might lead to errors in installation - depends on your choice
-    of extras. In order to install Airflow you need to either downgrade pip to version 20.2.4
-    ``pip install --upgrade pip==20.2.4`` or, in case you use Pip 20.3, you need to add option
-    ``--use-deprecated legacy-resolver`` to your pip install command.
-
 
 You can install this package on top of an existing airflow 2.* installation via
 ``pip install apache-airflow-providers-apache-cassandra``

docs/apache-airflow-providers-apache-druid/index.rst

@@ -55,14 +55,6 @@ are in ``airflow.providers.apache.druid`` python package.
 Installation
 ------------
 
-.. note::
-
-    On November 2020, new version of PIP (20.3) has been released with a new, 2020 resolver. This resolver
-    does not yet work with Apache Airflow and might lead to errors in installation - depends on your choice
-    of extras. In order to install Airflow you need to either downgrade pip to version 20.2.4
-    ``pip install --upgrade pip==20.2.4`` or, in case you use Pip 20.3, you need to add option
-    ``--use-deprecated legacy-resolver`` to your pip install command.
-
 
 You can install this package on top of an existing airflow 2.* installation via
 ``pip install apache-airflow-providers-apache-druid``

docs/apache-airflow-providers-apache-hdfs/index.rst

@@ -64,14 +64,6 @@ are in ``airflow.providers.apache.hdfs`` python package.
 Installation
 ------------
 
-.. note::
-
-    On November 2020, new version of PIP (20.3) has been released with a new, 2020 resolver. This resolver
-    does not yet work with Apache Airflow and might lead to errors in installation - depends on your choice
-    of extras. In order to install Airflow you need to either downgrade pip to version 20.2.4
-    ``pip install --upgrade pip==20.2.4`` or, in case you use Pip 20.3, you need to add option
-    ``--use-deprecated legacy-resolver`` to your pip install command.
-
 
 You can install this package on top of an existing airflow 2.* installation via
 ``pip install apache-airflow-providers-apache-hdfs``