Renew Certificate with SHA256

Posted on March 30, 2015 by erictummers

hackersJust like my renewal in 2014 I acted on receiving an email about my certificates expiring. The free certificate’s default Secure Hash Algorithm used to be of type SHA1.

Microsoft is deprecating SHA1. Also Google posted about sunsetting SHA1. Browsers will not be fully trusting the certificates starting from 2016.

Startssl.com offers the adviced SHA256 as the default for the free class 1 certificate. Just make sure to leave it to the default or select SHA2 (default) in the generate key step. When the key is imported in Synology it will show it is SHA256.

The first issue with SSL in 2016 has been resolved. Prepare for the worst and hope for the best 😉

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Week roundup

Posted on March 27, 2015 by erictummers

Last week recap and links:
Image courtesy of kanate / FreeDigitalPhotos.net

Image courtesy of kanate / FreeDigitalPhotos.net

What are your best reads this week? Leave them in the comments below.

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Excel conditional formatting calendar

Posted on March 25, 2015 by erictummers

Excel has some magic formatting options. With conditional formatting I’ve created my own little calendar with highlighted current day / month / date. Full sample for download below this post.

excel.calendar.with.highlight

The screenshot is from March 16, but you’ve already seen that 😉

Current day

In the header of the calendar I’ve set all days (1-31) The value of each column can be compared to the DAY function. With the conditional formatting of Excel I can highlight the current day.

excel.format.cell.value

Based on the cell value that is compared to the calculated current day Excel will apply special formatting to the current day.

Current month

The months are in the vertical header of the calendar. Only difference with the day is the use of abbreviated names in stead of numbers. That is where the INDEX function comes in. With the INDEX function Excel will return the contents of a certain ROW (and COLUMN) in an area.

' A3:A14 = the vertical header
' AH3 = the calculated current month
=INDEX(A3:A14;AH3)

Now apply a conditional formatting rule to the vertical header based on the cell value and the month is highlighted.

Current date

To highlight the current date in the calendar I use the CELL function. With that I can get the column and the row of each cell.

' $AH$2 = the current day
' $AH$3 = the current month
=AND($AH$2 = CELL("col";A1);$AH$3 = CELL("row";A1))

Important was the [reference] parameter of the CELL function. This is the relative location to get the information for. A1 means the current cell.

excel.format.formula

The conditional formatting is now based on a formula. Excel will evaluate the formula for each cell and highlight the cells that evaluate to TRUE.

References

Download Excel file with 2015 calendar

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SDN event March 2015

Posted on March 23, 2015 by erictummers

The SDN – Software Development Network – is a special interest group for dutch developers. Four times a year they organise an event where people present and talk about their passion.

As a member of the SDN you are aware of the latest developments. You are part of a network of professional developers who assist each other in word and deed. This means there is a technical helpdesk at your fingertips so you can book considerable time savings in solving problems.
sdn.nl with Google translate

Here are the talks I attended.

Accelerate the business with Microservices?

toolbox.vectorolieTeun talks about his experience with microservices when building a portal used by multiple labels/brands. They designed one microservice per feature.

Every microservice implements an API, frontend and events. The API gateway links all the microservices together for presentation. The composite UI is programmed with AngularJS. Discovery and monitoring is solved with Consul. Communication is done with RabbitMQ. Finally Docker is used for the deployment of the microservices.

Is microservices the new buzzword for managers? I think this is another part of an architects toolkit.

Microservices with event sourcing and CQRS on Azure

azuremobileservicesThis in-dept presentation from Sander showed the architecture choices and problems of handling smart meter readings.

The queue (azure topic) was read with Peek/Lock pattern to prevent losing events. Deduplication and sessions were applied for optimization. With sessions per meter no database locks would occur since only one worker would access those records.

Event sourcing is used to offer audittrail and point-in-time information. This also eliminates O/R mapping issues since it is insert only. With all this information about state (audittrail is your state) debugging and new feature testing is easier.

Because event sourcing is hard to query, views were created and maintained with CQRS. This proved to be quicker than caching with the data smart partitioned in Azure tables. Using gzip the data is transferred all the way to the client and unpacked in the (client) browser.

Some tips from Sander

  • use a version number in your event/message
  • gzip your event/message to overcome the 64k limit in azure table columns
  • use blob leases for leader election pattern when scaling

Nice insight in the lessons learned of this project.

How and why Achmea introduced their microservices architecture

nuget logoBas is architect at Achmea and shows their progress to microservices. Most of the work is moving Sharepoint hosted services to IIS hosted services and designing “microservices”.

The current solution uses nugets to be included in the components. So no loose services but copies of the assemblies. This solves a lot of their issues.

Building an O365 portal with Azure to manage Azure for dev and test teams

azuremobileservicesClemens piloted his OneShare talk with us. He started a project with benched people to build an Office 365 (sharepoint) portal. The portal is used to manage VM’s and reports costs of Azure. After the three slides to introduce himself Clemens talked us through the project.

They used Redis cache to share the sharepoint context in scaled azure websites. A custom serializer was written for this. More use of the cache is planned, but not yet evident.

Dogfooding their own product they evolved from VM to workerrole to websites to webjobs to schedules. Graphs made the team cost aware.

Future development is planned to handle the authentication to manage Azure with Azure Active Directory, now a certificate is used. Also making Azure Resource Manager json available in the portal next to VM images. This will be the new way to create a set of Azure resources like Website + SQL + Redis cache.

SDN logo

Looking forward to the next SDN event.

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Week roundup

Posted on March 20, 2015 by erictummers

Last week recap and links:
Image courtesy of kanate / FreeDigitalPhotos.net

Image courtesy of kanate / FreeDigitalPhotos.net

What are your best reads this week? Leave them in the comments below.

Posted in Uncategorized | Tagged , , , , , , | Leave a comment